Co-reporter:Ani Wang, Ruiqing Fan, Ping Wang, Ru Fang, Sue Hao, Xuesong Zhou, Xubin Zheng, and Yulin Yang
Inorganic Chemistry November 6, 2017 Volume 56(Issue 21) pp:12881-12881
Publication Date(Web):October 6, 2017
DOI:10.1021/acs.inorgchem.7b01687
This study investigates the mechanism of AIE in the solid state through supramolecular metal–organic frameworks and mechanoluminescent materials for the first time. Herein, four novel differently substituted Schiff base building blocks, SB1–SB4, exhibit typical AIE properties with various fluorescence emissions from yellow to green. SB1–SB4 are linked through C–H···O hydrogen bonding interactions to construct supramolecular metal–organic frameworks (SMOFs): namely, SMOFSB1–SMOFSB4. Particularly, among these SMOFs, SMOFSB3 is observed to have micropores in the 3D supramolecular structure and exhibits mechanoluminescent properties (grinding). An emission turn-on mechanism occurs with destruction of micropores by grinding and blockage of intramolecular rotations of the methyl and acetonitrile in the micropores, resulting in emission turn-on in SMOFSB3. Single-crystal X-ray structures, powder X-ray diffraction, emission spectra at room temperature, temperature-dependent emission spectra, DFT calculations, and a charge separation hypothesis well demonstrate the emission turn-on mechanism, which is consistent with the mechanism of AIE. More importantly, the molecules demonstrated potential application for press-jet printing.
Co-reporter:Yang Song, Rui-Qing Fan, Kai Xing, Xi Du, Ting Su, Ping Wang, and Yu-Lin Yang
Crystal Growth & Design May 3, 2017 Volume 17(Issue 5) pp:2549-2549
Publication Date(Web):March 20, 2017
DOI:10.1021/acs.cgd.7b00077
Under the guidance of self-assembly, a series of Cu(I)/Cu(II) metal–organic complexes (MOCs), [Cu3(TCPB)2(H2O)3]·2H2O (1), {[Cu2(TCPB) (DMA)(H2O)]·H2O}n (2), [(Cu8I8) (Cu6I6)0.5(DABCO)3·2H2O]n (3), and [(Cu4I8) (DABCO)2·6H2O]2n (4) (H3TCPB = 1,3,5-tris(4-carbonylphenyloxy)-benzene, DABCO = 1,4-diazabicyclo[2.2.2]octane) have been synthesized and characterized. Complexes 1 and 2 are driven by noncovalent interactions to assemble into supramolecular metal–organic frameworks. Considering H3TCPB ligand with different geometrical structures, 1 forms an Eiffel Tower shaped supramolecular cage based on equilateral triangle shaped trinuclear [Cu3(CO2)3] unit, which possesses effective free volume about 24.7%. Changing the solvent, 2 displays 1D chain structure based on linear bivalent copper trinuclear {Cu3(CO2)2(H2O)2}. When inducing auxiliary ligand DABCO, H3TCPB serves as additive agent and 3 consists of mixed CuI clusters (Cu6I6 and Cu8I8) and plays a 2D layer, which is a rare example. Without additive agent, 4 exhibits a 2D cuprous iodide layer, where 3 and 4 are two novel copper-iodide supramolecular isomers. Owing to large voids in the framework, 1 can serve as a host for use in dye adsorption. The experiment results show that different dyes, including “just right size” Crystal Violet (CV) can be rapidly adsorbed by 1, but smaller Indigo Blue (IB), Methylene Blue (MEB), Methyl Orange (MO), and larger Rhodamine B (RB) and Methyl Blue (MB) can hardly be adsorbed. Surprisingly, 1 also preferentially adsorbs (or separates) CV from MO and CV in their mixed aqueous solution with fast response and high sensitivity (<16.13 s) by the theoretical calculation. Moreover, absorption spectra demonstrate the band gaps of 3 and 4 are 2.37 and 1.98 eV, respectively. When increasing the dimensions of inorganic compositions in cluster–organic complexes, it could exert a remarkable influence on the band gap.
Co-reporter:Ani Wang, Ruiqing Fan, Yuwei Dong, Yang Song, Yuze Zhou, Jianzong Zheng, Xi Du, Kai Xing, and Yulin Yang
ACS Applied Materials & Interfaces May 10, 2017 Volume 9(Issue 18) pp:15744-15744
Publication Date(Web):April 18, 2017
DOI:10.1021/acsami.7b01254
The development of efficient sensors for detection of the water content in a wide detection range is highly desirable for balance in many industrial processes and products. Presented herein are six novel different substituted Schiff base Zn(II) complexes, which exhibit the remarkable capability to detect traces of water in a wide linear range (most can reach 0–94%, v/v), low detection limit of 0.2% (v/v), and rapid response time of 8 s in various organic solvents by virtue of an unusual water-activated hydrogen-bonding cross-linking AIE (WHCAIE) mechanism. As a proof-of-concept, the WHCAIE mechanism is explained well by single X-ray diffraction, absorption spectra, fluorescence spectra, dynamic light scattering, 1H NMR spectra, and theoretical calculations. In addition, the molecules demonstrated their application for the detection of humidity (42–80%). These Schiff base Zn(II) complexes become one of the most powerful water sensors known due to their extraordinary sensitivity, fast response, and wide detection range for water.Keywords: detect trace water; Schiff base; theoretical calculations; water-activated hydrogen-bonding cross-linking AIE; wide detection range;
Co-reporter:Xi Du, Ruiqing Fan, Liangsheng Qiang, Yang Song, Kai Xing, Wei Chen, Ping Wang, and Yulin Yang
Inorganic Chemistry March 20, 2017 Volume 56(Issue 6) pp:3429-3429
Publication Date(Web):March 6, 2017
DOI:10.1021/acs.inorgchem.6b02963
Humidity-induced single-crystal transformation was observed in the indium metal–organic polyhedra [In2(TCPB)2]·2H2O (In1), where H3TCPB is 1,3,5-tri(4-carboxyphenoxy)benzene. When the humidity is above 58% relative humidity (RH) at room temperature, the neutral compound In1 could be successfully converted into the positively charged compound In1-H along with the color change from yellow to deep red, which also undergoes a reversible transformation into In1 driven by thermal dehydration. Notably, the color of In1 takes only 5 min to change under 58% RH at room temperature, which is much quicker than common desiccant bluestone. As the water content is increased from 0.0% to 0.2% in acetonitrile solvent, compound In1 exhibits rapid detection of trace amounts of water through turn-off luminescence sensing mechanism with a low detection limit of 2.95 × 10–4%. Because of the formation of extensive hydrogen-bonding network between the metal–organic polyhedra (MOPs) and surrounding guest OH– ions, compound In1-H, along with isostructural Ga1-H, displays excellent proton conductivity up to 2.84 × 10–4 and 2.26 × 10–4 S cm–1 at 298 K and 98% RH, respectively. Furthermore, the activation energies are found to be 0.28 eV for In1-H and 0.34 eV for Ga1-H. This method of incorporation of OH– ions to obtain high proton conductivity MOPs with low activation energy demonstrates the advantage of OH– ion conduction in the solid-state materials.
Co-reporter:Xi Du, Ruiqing Fan, Liangsheng Qiang, Kai Xing, Haoxin Ye, Xinya Ran, Yang Song, Ping Wang, and Yulin Yang
ACS Applied Materials & Interfaces August 30, 2017 Volume 9(Issue 34) pp:28939-28939
Publication Date(Web):August 4, 2017
DOI:10.1021/acsami.7b09227
Drug delivery in target regions could make extraordinary progress in chemoselective therapies. A novel preferred coordination (PC) strategy referring to proactive interacting with open active sites to replace previous occupation by ion-exchange for controlling release of drug molecules is well-constructed. Two topological types of MOF-In1 (Schläfli symbol: (4,8)-connected of (410·615·83)(45·6)2) and MOF-In2 (Schläfli symbol: (4,4)-connected of (66)) show the specific way. Increasing node connectivity as well as the trapping of guest OH– anions, 5-fluorouracil (5-FU) is preferentially captured into the MOF-In1, which exhibits an outstanding loading capacity around 34.32 wt %. 19F NMR spectroscopy was further employed to investigate host–guest interaction and reveal the binding constant (Ka = 3.84 × 102 M–1). Meanwhile, the controlled release of 5-FU in a simulated human body with liquid phosphate-buffered saline solution by biofriendly Zn2+-triggered is realized. With an elevated Zn2+ concentration, the drug release will be enhanced. This efficient strategy for MOFs as multifunctional drug carrier opens a new avenue for biological and medical applications.Keywords: host−guest interaction; nano-MOFs; open active sites; preferred coordination strategy; Zn2+-triggered drug release;
Co-reporter:Guohua Dong, Debin Xia, Yulin YangLi Shenga, Tengling Ye, Ruiqing Fan
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 3) pp:
Publication Date(Web):January 6, 2017
DOI:10.1021/acsami.6b12938
The conventional perovskite solar cells (PSCs) with 2,2′,7,7′-tetrakis(N,N-dimethoxyphenylamine)-9,9′-spirobifluorene (spiro-OMeTAD) as a hole transporting material commonly suffer from poor stability and reproducibility mainly due to the process of placing the devices in air and illumination for oxidizing the spiro-OMeTAD. Herein, Keggin-type polyoxometalates (POMs)-phosphovanadomolybdate (H4PMo11V·nH2O, denoted as PMo11V) is for the first time employed as a p-type dopant for promoting the oxidation of spiro-OMeTAD. Thereby, without illumination and air, the conductivity and hole extraction efficiency of the PMo11V doped spiro-OMeTAD with assistance of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) and 4-tert-butylpyridine (TBP) can be dramatically enhanced. On the basis of this strategy, the corresponding PSCs exhibit substantially improved photovoltaic performance and good reproducibility. The best performing device yields a power conversion efficiency (PCE) of 14.05%. This work indicates a great potential of polyoxometalates for further applications in solar cells and other optoelectronics devices.Keywords: conductivity; hole extracting efficiency; Keggin-type PMo11V; p-type dopant; perovskite solar cells; spiro-OMeTAD;
Co-reporter:Yan Shi;Yulin Yang;Guohua Dong;Yanxia Jiang
Chemical Research in Chinese Universities 2017 Volume 33( Issue 2) pp:298-304
Publication Date(Web):14 March 2017
DOI:10.1007/s40242-017-6363-z
The low spectrum utilization and the recombination of photo-generated electrons are the main challenges for improving the performance of dye sensitized solar cells(DSSCs). In this article, a three-dimensional flower-like rutile titanium dioxide(TDF-TiO2) was successfully synthesized via a simple sol-thermal process. X-Ray diffraction patterns(XRD) and scan electron microscopy(SEM) images exhibit that the TDF-TiO2 are the rutile TiO2 microsphere composed of lots of regular cuboid nanorods. Applying this TDF-TiO2 as light scattering layer on the photoanode of DSSCs, the devices present an excellent photovoltage performance, yielding a power conversion efficiency(PCE) of 7.69%, which can be mainly attributed to the enhanced light utilization and the reduced recombination of pho-to-generated electrons upon a combined analysis of electrochemical impedance spectroscopy(EIS), open-circuit vol-tage decay(OCVD), and intensity-modulated photocurrent spectroscopy and intensity-modulated photovoltage spec-troscopy(IMPS/IMVS), etc. As a conclusion, TDF-TiO2 is a potential material as light scattering layer and optical transition medium to improve the performance of DSSCs, and this work further demonstrated that regulating the morphology and particle size of TiO2 is an efficient approach for enhancing the performance of DSSCs by optimizing the utilization of light and the transporting behaviors of photo-generated electrons.
Co-reporter:Liguo Wei, Ping Wang, Yulin Yang, Yongli Dong, Ruiqing Fan, Weina Song, Yonglian Qiu, Yuze Yang, Tianzhu Luan
Thin Solid Films 2017 Volume 639(Volume 639) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.tsf.2017.08.011
•Reduced graphene oxide (RGO)/TiO2 blocking layer was introduced into photoanode.•The blocking layer prevented direct contact between FTO glass and electrolyte.•The electron recombination was inhibited by RGO/TiO2 blocking layer.•A 30% higher efficiency was obtained by using RGO/TiO2 blocking layer.•RGO content in blocking layer is an important factor to affect DSSCs performance.A reduced graphene oxide/TiO2 (RGO/TiO2) blocking layer in the photoanode of a dye sensitized solar cell (DSSC) was fabricated in a simple way by depositing a RGO/TiO2 paste onto a FTO substrate through screen printing method. The RGO content in the RGO/TiO2 blocking layer was optimized for better DSSC performance. The effect of the RGO/TiO2 blocking layer on the performance of the DSSC was examined based on the electrochemical impedance spectral analysis, the photocurrent-voltage measurement, and the open-circuit voltage decay technology. After the introduction of RGO/TiO2 blocking layer in the photoanode, direct contact between the electrolyte and the FTO glass surface was prevented. The electron transfer from the TiO2 film to the FTO glass substrate was thus improved, the charge recombination rate suppressed, the electron transport rate enhanced, and the electron collection efficiency increased, resulting in higher current density. At the best level of RGO in the composite blocking layer, the DSSC has an energy conversion efficiency (η) of 7.48% with a Jsc of 15.29 mA cm− 2, a Voc of 0.74 V and a FF of 0.66, indicating a 29% and a 30% increase in Jsc and η, respectively, compared to that of a DSSC based on pure TiO2 photoanode, which exhibits a η value of 5.76% with a Jsc of 11.85 mA cm− 2, a Voc of 0.74 V, and a FF of 0.66. The introduction of the RGO/TiO2 blocking layer in the photoanode could really enhance the efficiency of DSSC by preventing the direct contact between the electrolyte and the FTO glass surface.
Co-reporter:Liguo Wei;Ping Wang;Yulin Yang;Ruiqing Fan;Yuze Yang;Yonglian Qiu
Sustainable Energy & Fuels (2017-Present) 2017 vol. 1(Issue 5) pp:1112-1122
Publication Date(Web):2017/06/27
DOI:10.1039/C7SE00192D
Graphene has attracted a lot of attention because of its unique optical, thermal, mechanical and electrical properties. In this study, the effect of graphene on the performance of dye sensitized solar cells (DSSCs) was investigated by constructing TiO2 photoanodes with a gradient graphene content. After the construction of photoanodes with a gradient graphene content, the DSSCs displayed a higher dye loading amount, lower internal resistances, lower electron recombination rate and faster electron transport rate, which resulted in high open circuit voltage and current density. Under the optimum conditions, the DSSC exhibited a Voc of 0.72 V, a Jsc of 17.11 mA cm−2, a FF of 0.63, and an energy conversion efficiency (η) of 7.71%, indicating a 41% increase in η than that of the DSSC based on a pure TiO2 photoanode, which gives a Voc of 0.69 V, a Jsc of 12.63 mA cm−2, a FF of 0.62, and an η value of 5.45%. The construction of TiO2 photoanodes with a gradient graphene content could really enhance the efficiency of DSSCs by improving the dye loading amount and enhancing the electron bridge effect of graphene from TiO2 to the FTO, which lowered the electron recombination rate and accelerated the electron transport rate.
Co-reporter:Wei Chen;Ruiqing Fan;Huijie Zhang;Yuwei Dong;Ping Wang;Yulin Yang
Dalton Transactions 2017 vol. 46(Issue 13) pp:4265-4277
Publication Date(Web):2017/03/27
DOI:10.1039/C7DT00218A
A series of lanthanide coordination polymers(LnCPs) containing both light and heavy rare-earth elements, namely {[Eu2(pydc)3(H2O)]·2H2O}n (1-Eu, H2pydc = pyridine-2,3-dicarboxylic acid), [Ln(pyc)2(Hpyc)(NO3)]n (Ln = Nd (2-Nd), Sm (3-Sm), Eu (4-Eu), Gd (5-Gd), Tb (6-Tb), Ho (7-Ho), and Er (8-Er), Hpyc = pyridine-3-carboxylic acid), has been synthesized under hydro(solvo)thermal conditions and fully characterized. The crystal structure analysis indicates that in situ decarboxylation of H2pydc occurred in the synthesis process of 2-Nd–8-Er. Coordination polymer 1-Eu displays a 3-D pcu network with central-symmetric quad-core structural units [Eu4(COO)6] linked by 1-D chains. 2-Nd–8-Er are of triple helical chain enantiomeric pair 61/65 axis, and can be further linked through two separate kinds of H⋯bonding interaction to form a mirror symmetrical 3-D framework; the final topological symbol of the jointly connected network is rare {47·68}. Solid-state luminescence studies show that the emission spectra of these LnCPs cover both the visible and near-infrared luminescence region. 2-Nd exhibits characteristic 4F3/2 → 4IJ/2 (J = 9, 11, 13) transition NIR emission. 1-Eu and 4-Eu provide characteristic 5D0 → 7FJ intense and bright red luminescence, while 4-Eu exhibits better luminescence performance because of the presence of the O–H oscillators within 1-Eu. 6-Tb exhibits characteristic 5D4 → 7FJ intense and bright green luminescence. Furthermore, through doping with PMMA polymer, the luminescence properties of 4-Eu and 6-Tb are all improved. The results show the best doping concentration is 4%. The thermal stabilities of 4-Eu-PMMA and 6-Tb-PMMA increased from 270 to 315 °C when compared with single coordination polymers 4-Eu and 6-Tb. The co-doping of 4-Eu, 5-Gd, and 6-Tb (0.92/0.04/0.04) with PMMA at a total concentration of 4% resulted in a tunable luminescence material W(4-Eu,5-Gd,6-Tb)-PMMA film. When excited at 285 nm, W(4-Eu,5-Gd,6-Tb)-PMMA shows white-light emission with the CIE chromaticity coordinates of (0.33, 0.35). The lifetime of Eu3+ ions in W(4-Eu,5-Gd,6-Tb)-PMMA increased from 1032.24 μs to 1272.26 μs when compared with 4-Eu-PMMA, and the efficiency of energy transfer (ηET) from Tb3+ to Eu3+ within the co-doping PMMA film could be estimated to be 29.9%.
Co-reporter:Yuwei Dong;Ruiqing Fan;Wei Chen;Ping Wang;Yulin Yang
Dalton Transactions 2017 vol. 46(Issue 20) pp:6769-6775
Publication Date(Web):2017/05/23
DOI:10.1039/C7DT00956A
A new simple ‘dual’ chemosensor MQA ((E)-2-methoxy-N-((quinolin-2-yl)methylene)aniline) for distinguishing Zn2+ and Hg2+ has been designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn2+/Hg2+ over other commonly coexisting cations (such as Na+, Mg2+, Al3+, K+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Ga3+, Cd2+, In3+ and Pb2+) in DMSO–H2O solution (1/99 v/v), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit for Zn2+/Hg2+ by MQA both reached the 10−8 M level. The 1 : 1 ligand-to-metal coordination patterns of the MQA-Zn2+ and MQA-Hg2+ were calculated through a Job's plot and ESI-MS spectra, and were further confirmed by X-ray crystal structures of complexes MQA-Zn2+ and MQA-Hg2+. This chemosensor can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions. DFT calculations have revealed that the energy gap between the HOMO and LUMO of MQA has decreased upon coordination with Zn(II)/Hg(II).
Co-reporter:Xubin Zheng;Ruiqing Fan;Yang Song;Ani Wang;Kai Xing;Xi Du;Ping Wang;Yulin Yang
Journal of Materials Chemistry C 2017 vol. 5(Issue 38) pp:9943-9951
Publication Date(Web):2017/10/05
DOI:10.1039/C7TC02430D
The fabrication of luminescent materials with lanthanide cations encapsulated within MOF pores is currently of interest because luminescent materials are used in numerous applications. In this study, a distinctive strategy via postsynthetic modification (PSM) of a novel metal–organic framework [Cu(HCPOC)2]n (Cu1) (H2CPOC = 5-(4′-carboxyphenoxy)nicotinic acid) and terbium ions (Tb3+) for sensing hydrogen sulfide (H2S) is reported. The obtained composite Tb3+@Cu1 emits a weak typical Tb3+ ion emission and strong ligand-centred emission. Interestingly, H2S, as a strong electron donor, can strongly enhance the luminescence of Tb3+ through its superior affinity for Cu2+ ions. The composite Tb3+@Cu1 was designed as a luminescent turn-on ratiometric probe for H2S detection, showing high sensitivity and selectivity. The detection limit of Tb3+@Cu1 (1.20 μM) is far below that of Cu1 (13.25 μM). Moreover, a similar ligand, 5-(4′-carboxyphenyl)nicotinic acid (H2CPC), was used to synthesize a fascinating structure, [Cu5(CPC)2(HCPC)2(OH−)4]n (Cu2), which was quite similar to that of the famous semiconductor MoS2, with the advantageous support of an organic linker between layers, and it showed a band gap of 2.45 eV.
Co-reporter:Ani Wang;Ruiqing Fan;Yuwei Dong;Wei Chen;Yang Song;Ping Wang;Sue Hao;Zhigang Liu;Yulin Yang
Dalton Transactions 2017 vol. 46(Issue 1) pp:71-85
Publication Date(Web):2016/12/19
DOI:10.1039/C6DT03853K
Judicious structural design employing 2-quinolinecarboxaldehyde and 4-methylaniline was used to generate the Schiff base ligand (E)-4-methyl-N-((quinolin-2-yl)ethylidene)aniline (L). Five IIB complexes, namely, [ZnLCl2] (1), [ZnL(NO3)2] (2), [ZnL(OAc)2]3 (3), [CdL(OAc)2]3 (4), and [HgLCl2] (5) have been synthesized based on L. Single-crystal X-ray diffraction analysis indicates that complexes 1, 3 and 4 exhibit 3D networks, whereas 2 and 5 form 2D layers and 1D chains, respectively. TD-DFT calculations show a good correlation with the UV-vis absorption assigned to π → π* intraligand transitions. Furthermore, complexes 1–5 displayed strong greenish luminescent emissions (518–524 nm) in the aggregate state but weak emissions in solution (aggregation-induced emission enhancement), which may be due to the existence of C–H⋯Cl/O hydrogen bonding and π⋯π stacking interactions, resulting in restriction of intramolecular rotation (RIR). Variable-concentration 1H NMR studies suggested that the aggregates undergo intramolecular changes in conformation due to intermolecular interactions. Moreover, the emission intensity and lifetime exhibited obvious increases induced by mechanical grinding and temperature reduction, which were also attributed to AIEE properties. Subsequently, complex 1 was incorporated into poly(methyl methacrylate) (PMMA), whereby 1-PMMA exhibited enhanced emission intensity (20-fold increase in comparison with that of 1), which offers opportunities for use in plastic greenhouses to increase leaf photosynthesis.
Co-reporter:Yu-Wei Dong;Rui-Qing Fan;Wei Chen;Hui-Jie Zhang;Yang Song;Xi Du;Ping Wang;Li-Guo Wei
Dalton Transactions 2017 vol. 46(Issue 4) pp:1266-1276
Publication Date(Web):2017/01/24
DOI:10.1039/C6DT04159K
A series of Zn(II) complexes with different conjugated systems, [ZnL1Cl2]2 (Zn1), [ZnL2Cl2] (Zn2), [Zn(L3)2]·(ClO4)2 (Zn3), [Zn2L4Cl4] (Zn4), and [ZnL5Cl2] (Zn5), were synthesized and subsequently characterized via single crystal X-ray diffraction, 1H and 13C NMR, FT-IR, elemental analyses, melting point, and PXRD. The X-ray diffraction analyses revealed that the supramolecular frameworks of complexes Zn1–Zn5 are constructed by C–H⋯O/Cl hydrogen bonds and π⋯π interactions. Complexes Zn1–Zn3 feature 3D 6-connected {412·63} topological structures, whereas complex Zn4 exhibits a 3D 7-connected supramolecular framework with a {417·64} topological structure. However, complex Zn5 shows one-dimensional “wave-like” chains. Based on these varied structures, the emission maximum wavelengths of complexes Zn1–Zn5 can be tuned in a wide range of 461–592 nm due to the red shift direction of λem caused by different conjugated systems and their electron donating abilities. Complex Zn3 shows a strong luminescence in the solid state and in the acetonitrile solution. Therefore, a series of Zn3-poly(methylmethacrylate) (Zn3-PMMA) hybrid materials were obtained by controlling the concentration of complex Zn3 in poly(methylmethacrylate) (PMMA). At an optimal concentration of 4%, the doped polymer film of Zn3-PMMA displays strong green luminescence emissions that are 19-fold in the luminescence intensities and 98 °C higher in the thermal stability temperature compared to the Zn3 film.
Co-reporter:Jia Yu, Yulin Yang, Ruiqing Fan, Ping Wang and Yuwei Dong
Nanoscale 2016 vol. 8(Issue 7) pp:4173-4180
Publication Date(Web):25 Jan 2016
DOI:10.1039/C5NR08319B
New up-conversion YbF3-Ho/TiO2 (UC/TiO2) nanoheterostructures are designed and explored as an efficient photoelectrode material to yield dye-sensitized solar cells (DSSCs) with enhanced performance. In this study, we analyze the photogenerated charge transfer properties of the UC/TiO2 nanoheterostructures via surface photovoltage (SPV) and transient photovoltage (TPV) techniques, and the interfacial dynamics of charge transfer and recombination processes in DSSCs using electrochemical impedance spectroscopy (EIS) and open circuit photovoltage decay (OCVD) techniques. It is found that these UC/TiO2 nanoheterostructures combine the upconversion function of YbF3-Ho and the semiconductive merits from TiO2. More importantly, the hetero-junction interface in the UC/TiO2 nanoheterostructures not only induces direct electron-injection from YbF3-Ho to TiO2 by utilizing near-infrared light, but also further improves the existing merits of TiO2 through facilitating the interfacial photoinduced charge separation, suppressing the photoinduced charge recombination and prolonging the lifetimes of excited electrons, which can give further improvement of the photovoltaic performances. When integrating the UC/TiO2 nanoheterostructures into DSSCs, an overall energy conversion efficiency of 8.0% is achieved. There is a 23% enhancement in the overall conversion efficiency and a 19% improvement in the photocurrent, compared to the pristine devices.
Co-reporter:Yanxia Jiang, Yulin Yang, Liangsheng Qiang, Tengling Ye, Liang Li, Ting Su, Ruiqing Fan
Journal of Power Sources 2016 Volume 327() pp:465-473
Publication Date(Web):30 September 2016
DOI:10.1016/j.jpowsour.2016.07.086
•SiW11Cu/Pt shows higher catalytic activity for I3− compared to Pt.•SiW11Cu/TiO2 reduces the pohotogenerated charge recombination effectively.•The modified photoelectrodes give conversion efficiency of 7.62% in DSSCs.The device of polyoxometalate (POM) modified photoelectrodes is designed and successfully constructed. K6SiW11O39Cu(H2O)·xH2O (SiW11Cu) has been synthesized and explored as an efficient photoanode and counter electrode material to develop dye-sensitized solar cells (DSSCs) with enhanced performance. The SiW11Cu modified TiO2 (SiW11Cu/TiO2) powders is mixed with commercial P25 in a ratio of 1:9 as a photoanode. The modified TiO2 is used as an efficient material by improving the electronic injection ability and reducing the pohotogenerated charge recombination. The counter electrode is consisted of one layer SiW11Cu and two layers conventional Pt nanoparticles, denoted as (Cu/Pt). The DSSC based on SiW11Cu modified photoelectrodes has an improved power conversion efficiency of 7.62%, which is 16% higher than that of traditional DSSC based on P25-Pt. Under standard AM 1.5G, Jsc reaches 17.91 mA cm−2, which results in a much better power conversion efficiency. This can be attributed to the good catalytic activity of the new counter electrode. This result is analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Tafel-polarization curves, the incident photon to current conversion efficiency (IPCE) and UV–vis spectra techniques.
Co-reporter:Song Gao, Ruiqing Fan, Bingjiang Li, Liangsheng Qiang, Yulin Yang
Electrochimica Acta 2016 Volume 215() pp:171-178
Publication Date(Web):10 October 2016
DOI:10.1016/j.electacta.2016.08.069
•Novel ZnO@porous carbon matrix nanocomposites are constructed by pyrolysis of Zn-based MOFs.•The nanocomposites constructed with Zn-based MOFs show low carbon content.•The constructed nanocomposites exhibit high energy density, super-high rate capability and long cycling life.Single-C formic acid-based metal-organic frameworks (MOFs) are used to construct novel ZnO@porous carbon matrix nanocomposites by controlled pyrolysis. In the constructed nanocomposites, the porous carbon matrices act as a confined support to prevent agglomeration of the ZnO nanoparticles and create a rapid electron conductive network. Meanwhile, the well-defined, continuous porous structured MOFs provide a large specific surface area, which increases the contact of electrolyte-electrode and improves the penetration of electrolyte. Especially, the reasonable choice of formic acid-based MOFs construct the low carbon content composite, which contribute to the high energy density and long cycle life. The constructed nanocomposites show stable, ultrahigh rate lithium ion storage properties of 650 mAh g−1 at charge/discharge rate of 1 C even after 200 cycles.The nanocomposites constructed from Zn-based MOFs exhibit low carbon content with super-high rate capability and long cycling life.
Co-reporter:Huijie Zhang, Ruiqing Fan, Wei Chen, Jizhuang Fan, Yuwei Dong, Yang Song, Xi Du, Ping Wang, and Yulin Yang
Crystal Growth & Design 2016 Volume 16(Issue 9) pp:5429-5440
Publication Date(Web):August 17, 2016
DOI:10.1021/acs.cgd.6b00903
Five novel three-dimensional lanthanide metal–organic frameworks (Ln–MOFs) constructed by 4-(3′,5′-dicarboxylphenoxy) phthalic acid (H4dcppa), namely, {[Eu(Hdcppa)(H2O)2]·H2O}n (Eu-1), [Eu1.5(dcppa) (HCOO)0.5(H2O)2]n (Eu-2), {[Ln2K2(dcppa)2(H2O)6]·mH2O}n (Ln = Eu-3, Tb-4, Gd-5, m = 5 for Eu-3 and Tb-4; m = 4 for Gd-5) (HCOOH = formic acid) have been prepared by hydro(solvo)thermal method and fully characterized. Structural analyses indicated that H4dcppa ligand took four different coordination fashions in 1–5 and, thus, resulted in diversity of the targeted Ln–MOFs: Eu-1 displays the rare 3D (5,5)-connected vbk net, containing one-dimensional left- and right-handed helical chains; Eu-2 possesses a 3D (3,8)-connected tfz-d topology constructed by trinuclear paddlewheel [Eu3(CO2)6] SBUs; 3–5 are isostructural and show 3D (Ln-dcppa4–) + 2D (K-dcppa4–) → 3D (LnK-dcppa4–) structure. Eu-3, with regular 1D channels and open Lewis basic oxygen atoms on the pore surface was utilized for specific sensing and binding of metal ions through Lewis base interactions, shows high selectivity, fast response time (8 min), and high sensitivity (KSV = 4.3/5.2 × 104 L/mol) for Fe3+ and Cu2+ ions with luminescent quenching. Furthermore, the detection limit of the sensor is in the 10–6 M level. The triplet state (T1 = 23364 cm–1) of H4dcppa studied by the Gd(III)–MOF and Gd-5 demonstrates that the ligand ideally populates Eu(III)/Tb(III) emission with luminescent quantum yields (Φoverall) of 11.2% for Eu-1, 27.6% for Eu-2, 18.5% for Eu-3, and 62% for Tb-4, respectively.
Co-reporter:Kai Xing, Ruiqing Fan, Jizhuang Fan, Xi Du, Yang Song, Song Gao, Ping Wang, and Yulin Yang
Crystal Growth & Design 2016 Volume 16(Issue 8) pp:4727-4735
Publication Date(Web):July 5, 2016
DOI:10.1021/acs.cgd.6b00791
Two three-dimensional supramolecular organic frameworks, [(H2bpdc)0.5(bipy)0.5] (1) and [(H3dpob)(bipy)·3H2O] (2), have been successfully constructed and structurally characterized (H2bpdc = 2,2′-biphenyldicarboxylic acid; H3dpob = 3-(2′,3′-dicarboxylphenoxy)benzonic acid; bipy = 4,4′-bipydine). 1 is driven by C–H···π hydrogen-bonded packing to three dimension. 2 origins form parallel-packed wavy chains and show π–π stacking-directed structure. After the SOFs are formed via weak noncovalent interaction, 1 and 2 show an enhancement in thermostability. The different conformations of bipy induced by weak noncovalent interactions are responsible for the huge dissimilarity of structural and luminescence behavior between them. Under the excitation of 365 nm ultraviolet light, 1 and 2 show stronger blue-white and green-white luminescent emissions in the solid state, respectively. In comparison with 2, supramolecular organic framework 1 shows superior performance in aggregation-induced emission (AIE) activity, which is explained and elaborated via the simple model from the viewpoint of planarity (Ψr) and rotatability (θr). Moreover, stimuli-responses behaviors to mechanical force were evaluated to explore stability of AIE materials, luminescent shift (Δλem ≈ 36 nm) was observed in 2, whereas almost no change of 1 was found. Subsequently, 1 doped poly(methyl methacrylate) film demonstrates the comparable intensity with the solid state at concentrations of 2.0%, accompanied by the improvement of thermal stability.
Co-reporter:Yang Song, Ruiqing Fan, Xi Du, Kai Xing, Ping Wang, Yuwei Dong and Yulin Yang
CrystEngComm 2016 vol. 18(Issue 34) pp:6411-6424
Publication Date(Web):04 Jul 2016
DOI:10.1039/C6CE01106C
Four novel luminescent materials, namely, [Ag3(3,2′,3′-dpob)(bpy)]n (1·Ag), [Ag(3,3′,4′-H2dpob)(bpy)]n (2·Ag), [Ag3(3,2′,3′-Hdpob)(3,2′,3′-H2dpob)(bib)3·2H2O]n (3·Ag), and [Cu(3,2′,3′-Hdpob)(bib)·2H2O]n (4·Cu) [3,2′,3′-H3dpob = 3-(2′,3′-dicarboxylphenoxy)benzonic acid; 3,3′,4′-H3dpob = 3-(3′,4′-dicarboxylphenoxy)benzonic acid; bpy = 4,4′-bipyridine; bib = 1,4-bis(1-imidazoly)benzene] have been hydrothermally synthesized by mixed ligands and characterized using single crystal X-ray diffraction, infrared (IR), elemental analysis and thermogravimetric analysis (TGA). The crystal structures of four compounds indicate that the hydrogen bonding (O–H⋯O, C–H⋯O and C–H⋯π) and π⋯π stacking interactions play critical roles in the formation of the extended supramolecular array. 1·Ag displays a rare 3D compact structure with a 1D right-handed helical chain [–Ag1–CO2–Ag3–CO2–Ag1–]. 2·Ag and 3·Ag exhibit a 3D supramolecular architecture linked by intermolecular hydrogen bonds based on a 1D double-chain and 1D triple-chain, respectively. 4·Cu shows a 1D + 1D → 2D sheet, which is propagated to form an extended 3D structure with pcu (primitive cubic) topology via π⋯π stacking. The four compounds display remarkable narrow band emission with smaller full width at half-maximum (FWHM) (77 K, 97.91, 92.27, 72.98 and 77.96 nm; 298 K, 169.41, 241.98, 293.66 and 148.50 nm) in the solid state. The combination of such narrow FWHM and the red-shift from 298 K to 77 K endow them with a prominent thermochromic effect. It is worth noting that 2·Ag and 3·Ag display good aggregation-induced emission (AIE) properties. Both of them show very weak luminescence in dimethyl sulfoxide (DMSO, good solvent) while their intensities increased enormously with the addition of water (H2O, poor solvent) due to aggregation. In addition, adsorption spectra reveal their semiconductive nature (2.35 eV for 1·Ag and 2.91 eV for 3·Ag) and the role of Ag⋯Ag interactions in controlling the performance of semiconductive properties is highlighted.
Co-reporter:Yang Song, Rui-Qing Fan, Xin-Ming Wang, Song Gao, Xi Du, Ping Wang and Yu-Lin Yang
CrystEngComm 2016 vol. 18(Issue 11) pp:1878-1882
Publication Date(Web):05 Feb 2016
DOI:10.1039/C6CE00132G
With the help of ascorbic acid as reductant, an exceedingly rare example of a visible single-crystal-to-single-crystal transformation from a CuII-framework to a CuI-chain under mild conditions has been observed, which involves the metal valence tautomerism and restructuring of bonds. The two compounds exhibit the properties of solvatochromism and luminescence aggregation-induced-emission towards CH3OH, respectively.
Co-reporter:Huijie Zhang, Ruiqing Fan, Yuwei Dong, Wei Chen, Xi Du, Ping Wang and Yulin Yang
CrystEngComm 2016 vol. 18(Issue 20) pp:3711-3724
Publication Date(Web):12 Apr 2016
DOI:10.1039/C6CE00483K
By reacting an asymmetric semi-rigid V-shaped linker H3dpob (H3dpob = 3-(2′3′-dicarboxylphenoxy)benzoic acid) and Ln(NO3)3·6H2O, nine novel Ln-based luminescent materials, from 1D to 3D, namely {[Eu(dpob)(phen)]·H2O}n (1), {[Ln(Hdpob)(ox)0.5(H2O)2]}n (Ln = Eu(2), Sm(3), Gd(4), Tb(5)), {[Eu(dpob)(H2O)2]·0.5H2O}n (6), and {[Ln(dpob)(H2O)2]·mH2O}n (Ln = Eu(7), Gd(8), Tb(9), m = 0.5 for 7 and 9; m = 1 for 8) (phen = 1,10-phenanthroline; H2ox = oxalic acid) have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, infrared (IR) spectroscopy, elemental analysis, and PXRD. The crystal structures of 1–9 indicate that the coordination modes and coordination configuration of the H3dpob ligand play critical roles in the formation of the lanthanide architectures. Complexes 1–5 display multiple structures from double-stranded 1D chains to 4-connected 2D layers, through [Eu2(CO2)4] or [Eu2(CO2)2] dinuclear units with different auxiliary ligands. Complexes 6 and 7 are genuine supramolecular isomers which are induced by the concentration effect. 6 possesses a 2D kgd network with a Schläfli symbol of (43)2(46·66·83) built from 6-connected [Eu2(CO2)2] units and 3-connected H3dpob, which further connects to a (3,8)-connected tfz-d topology through O–H⋯O hydrogen bonds. 7 displays a 3D (3,6)-connected rtl network with the Schläfli symbol (4·62)2(42·610·83). Eu complexes 1, 2, 6, and 7 as well as Tb complexes 5 and 9 could provide intense and bright characteristic 5D0 → 7FJ/5D4 → 7FJ red/green luminescence under UV excitation in the solid state at 298 K and 77 K. The calculated singlet and triplet energies of H3dpob as well as phen and H2ox ligands indicate that these ligands act as antenna chromophores that are able to efficiently absorb and transfer energy to Ln(III) ions. In complexes 1, 2 and 5, ligand-to-metal energy transfer processes could occur in mixed ligands. However, these processes occurred in a single H3dpob ligand in complexes 6 and 7. With careful adjustment of the relative concentration of the lanthanide ions and by varying the excitation wavelengths of {[Gd0.92Eu0.04Tb0.04(dpob)(H2O)2]·0.5H2O}n (10), tunable yellow (CIE coordinate: 0.51, 0.40) to white-light (CIE coordinate: 0.33, 0.34) emission has been obtained.
Co-reporter:Song Gao, Rui Qing Fan, Xin Ming Wang, Li Guo Wei, Yang Song, Xi Du, Kai Xing, Ping Wang and Yu Lin Yang
Physical Chemistry Chemical Physics 2016 vol. 18(Issue 28) pp:19001-19010
Publication Date(Web):22 Jun 2016
DOI:10.1039/C6CP02530G
In this work, a rare 2D → 3D single-crystal-to-single-crystal transformation (SCSC) is observed in metal–organic coordination complexes, which is triggered by thermal treatment. The 2D two-fold interpenetrating square lattice layer [Cd(IBA)2]n (1) is irreversibly converted into a 3D four-fold interpenetrating diamond framework {[Cd(IBA)2(H2O)]·2.5H2O}n (2) (HIBA = 4-(1H-imidazol-1-yl)benzoic acid). Consideration is given to these two complexes with different interpenetrating structures and dimensionality, and their influence on photovoltaic properties are studied. Encouraged by the UV-visible absorption and HOMO–LUMO energy states matched for sensitizing TiO2, the two complexes are employed in combination with N719 in dye-sensitized solar cells (DSSCs) to compensate absorption in the ultraviolet and blue-violet region, offset competitive visible light absorption of I3− and reducing charge the recombination of injected electrons. After co-sensitization with 1 and 2, the device co-sensitized by 1/N719 and 2/N719 to yield overall efficiencies of 7.82% and 8.39%, which are 19.94% and 28.68% higher than that of the device sensitized only by N719 (6.52%). Consequently, high dimensional interpenetrating complexes could serve as excellent co-sensitizers and have application in DSSCs.
Co-reporter:Xi Du, Ruiqing Fan, Xinming Wang, Guangzhi Yu, Liangsheng Qiang, Ping Wang, Song Gao, and Yulin Yang
Crystal Growth & Design 2016 Volume 16(Issue 3) pp:1737-1745
Publication Date(Web):January 28, 2016
DOI:10.1021/acs.cgd.5b01825
In this work, the coexistence of In(III) and K(I) induces a rapid crystal growth of single crystals of heterometallic metal–organic frameworks (MOFs), [In0.5K(3-qlc)Cl1.5(H2O)0.5]2n (1) and [InK(ox)2(H2O)4]n (2) (3-Hqlc = quinoline-3-carboxylic acid; H2ox = oxalic acid). Remarkably, with the help of achiral 3-Hqlc, compound 1 represents the chiral interpenetrating p-block heterometallic MOFs with helical chain along the 43 screw axis, while compound 2 possesses a highly symmetric (4,4,4)-connected topology network with a Schläfli symbol of (42·83·10)(42·84). Consideration of two different organic ligands viz. 3-Hqlc and H2ox constructed heterometallic MOFs with different geometrical dimensions of unit cells, their influences on luminescence and photovoltaic properties are studied. Compounds 1 and 2 show tunable luminescence from blue to yellow and white by varying the temperature in the solid state. Encouraged by the UV–visible absorption and HOMO–LUMO energy states matched for sensitizing TiO2, the two compounds are employed in combination with N719 in dye-sensitized solar cells (DSSCs) to compensate for absorption in the region of ultraviolet and blue-violet. Under optimized conditions, the DSSCs devices using cosensitizers of 1/N719 and 2/N719 display an overall conversion efficiency of 8.07% and 7.42%, which is 22.09% and 12.25% higher than that of a device solely sensitized by N719 (6.61%). Consequently, both of the two compounds could serve as excellent photosensitizers and application in luminescence sensors and DSSCs.
Co-reporter:Yu-Wei Dong, Rui-Qing Fan, Xin-Ming Wang, Ping Wang, Hui-Jie Zhang, Li-Guo Wei, Wei Chen, and Yu-Lin Yang
Crystal Growth & Design 2016 Volume 16(Issue 6) pp:3366-3378
Publication Date(Web):May 9, 2016
DOI:10.1021/acs.cgd.6b00347
Using five Schiff base ligands (E)-N-(pyridine-2-yl) (CH═NPhR) (where R = 4–CH3, L1; 2,6-(CH3)2, L2; 2,4,6-(CH3)3, L3; 2,6-(C2H5)2, L4; 2,6-(i-C3H7)2, L5), nine Zn(II)/Cd(II) complexes, namely, Zn1–Zn3, Cd1, Cd2, Cd3a, Cd3b, Cd4, and Cd5, have been successfully synthesized. The structures of the Zn(II)/Cd(II) complexes have been established by single crystal X-ray diffraction and further physically characterized by 1H NMR, FT–IR, and elemental analysis. The crystal structures of these complexes indicate that the structures of ligand and anions can directly influence the formation of 1D → 3D supramolecular metal–organic frameworks (SMOFs) via C–H···O/C–H···Cl hydrogen bonds and π···π interactions. Upon irradiation with UV light, the nine Zn(II)/Cd(II) complexes display deep blue emissions of 401–436 nm in acetonitrile solution and light blue or bluish green emissions of 485–575 nm in the solid state, respectively. The photoluminescence properties of nine Zn(II)/Cd(II) complexes can be finely and predictably tuned over a wide range of wavelengths by small and easily implemented changes to ligand structure. It is worth noting that Zn1 and Cd1 exhibit obvious aggregation-induced emission enhancement (AIEE) properties in the CH3CN–H2O mixture solutions.
Co-reporter:Kai Xing, Ruiqing Fan, Song Gao, Xinming Wang, Xi Du, Ping Wang, Ru Fang and Yulin Yang
Dalton Transactions 2016 vol. 45(Issue 11) pp:4863-4878
Publication Date(Web):01 Feb 2016
DOI:10.1039/C5DT04759E
Based on a new asymmetric semi-rigid V-shaped tricarboxylate ligand 3-(2′,3′-dicarboxylphenoxy)benzoic acid (H3dpob), a series of zinc/cadmium(II) coordination polymers, {[Cd(Hdpob)(H2O)3]·H2O}n (1), [Cd(Hdpob)(bib)]n (2), [Zn(Hdpob)(bib)0.5]n (3), {[Cd1.5(dpob)(2,2′-bipy)]·0.5H2O}2n (4) and {[Cd3(dpob)2(4,4′-bipy)2]·3H2O}n (5) [bib = 1,4-bis(1-imidazolyl)benzene; 2,2′-bipy = 2,2′-bipyridine; 4,4′-bipy = 4,4′-bipyridine], have been successfully synthesized via hydro(solvo)thermal reactions. 1 forms a three dimensional (3D) supramolecular structure linked by two types of intermolecular hydrogen bonds based on zig-zag 1D chains, whereas 2 and 3 are obtained with a similar 2D layer structure by the same ligands and further connected into a 3D structure through hydrogen bonds. 4 displays a homochiral 2D structure though two achiral ligands 2,2′-bipy and H3dpob, which contains right-handed helical infinite chains. 5 is a 3D structure containing 2D metal-pyridine layer motifs, which are further pillared by beaded dpob3− ligands to complete the structure and form a 6-connected pcu (primitive cubic) net. In DMSO solvent, 1–5 illustrate dual-emission properties but have different low-energy emission (LE) intensities relatively. Extraordinarily, the difference resulting from central metals between 2 and 3 makes the intensity of LE dramatically enhanced and quenched. In this regard, the luminescence of 2 and 3 can be tuned between blue and green regions by varying the excitation light, and the tuning tendency can be tailored with inverse directions. Comparing their tunable-sensitivity to energy quantitatively, the theoretical calculation displays that 3 (4.29%) is little higher than 2 (3.59%) in a relative lower excitation wavelength zone. Meanwhile, five coordination polymers show distinct luminescence thermochromism in the solid state. When the temperature decreases from 298 K to 77 K, the red-shift from blue/green to the pure yellow light region is highlighted. The fantastic and unique luminescence phenomenon not only brings an insight into the synthesis of dual-emissive materials, but helps us to understand the luminescence behavior deeply as well.
Co-reporter:Yuwei Dong, Liguo Wei, Ruiqing Fan, Yulin Yang and Ping Wang
RSC Advances 2016 vol. 6(Issue 46) pp:39972-39981
Publication Date(Web):15 Apr 2016
DOI:10.1039/C6RA06017J
Unsymmetrical (N-(2-pyridinecarboxaldimine)-1-aminonaphthalene, USP) and symmetrical (N,N′-bis-(2-pyridinecarboxaldimine)-1,8-diaminonaphthalene, SDP) pyridine-anchor co-adsorbents with different numbers of anchoring groups are synthesized and employed in combination with a ruthenium complex N719 in dye sensitized solar cells (DSSCs). Both the prepared co-adsorbents can overcome the deficiency of N719 absorption in the low wavelength region of the visible spectrum, offset competitive visible light absorption of I3−, suppress the charge recombination and prolong the electron lifetime. The SDP co-adsorbent containing double anchoring groups shows better electronic coupling with TiO2 than the USP co-adsorbent with a single anchoring group. This enhanced electronic coupling leads SDP to exhibit better performance for DSSCs. A short circuit current density of 13.19 mA cm−2, an open circuit voltage of 0.75 V and a fill factor of 0.66 corresponding to an overall conversion efficiency of 6.51% under AM 1.5G solar irradiation are achieved when SDP is used as a co-adsorbent, which is much higher than that for DSSCs only sensitized by N719 (5.28%) under the same conditions.
Co-reporter:Yu-Wei Dong;Rui-Qing Fan;Xin-Ming Wang;Ping Wang;Hui-Jie Zhang;Li-Guo Wei;Yang Song;Xi Du;Wei Chen
European Journal of Inorganic Chemistry 2016 Volume 2016( Issue 22) pp:3598-3610
Publication Date(Web):
DOI:10.1002/ejic.201600231
From two series of Schiff base ligands, (E)-N-(pyridine-2-yl)(CMe=NPhR) and (E)-N-(pyridine-2-yl)(CH=NPhR) [R = H, L1a, L1b; 2-CH3, L2a, L2b; 4-CH3, L3a, L3b; 2,6-(CH3)2, L4a, L4b; 2,6-(C2H5)2, L5a, L5b; 2,6-(i-C3H7)2, L6a, L6b; 2,4,6-(CH3)3, L7a, L7b], fourteen mercury(II) complexes, namely, Hg1a–Hg7a and Hg1b–Hg7b were synthesized. Their structures were established by single-crystal X-ray diffraction, and they were physically characterized by 1H and 13C NMR spectroscopy, ESI-MS, FTIR spectroscopy, elemental analysis (EA), and powder XRD (PXRD). The crystal structures indicate that the position and type of substituent can directly influence the formation of 1D 3D supramolecular metal–organic frameworks through C–H···Cl and π–π interactions. Complexes Hg1a–Hg7a and Hg1b–Hg7b display deep blue emissions at λ = 401–428 nm in acetonitrile solution and light blue emissions at λ = 443–494 nm in the solid state. It is worth noting that Hg1a, Hg3a, Hg1b, and Hg3b exhibit good aggregation-induced emission (AIE) properties in CH3CN/H2O solutions.
Co-reporter:Guohua Dong, Yulin Yang, Li Sheng, Debin Xia, Ting Su, Ruiqing Fan, Yan Shi and Junhai Wang
RSC Advances 2016 vol. 6(Issue 50) pp:44034-44040
Publication Date(Web):19 Apr 2016
DOI:10.1039/C6RA07497A
Thermal annealing (TA) plays a vital role in obtaining pinhole-free CH3NH3PbI3 perovskite films with high crystallinity and morphology, which is crucial for achieving high performance for perovskite solar cells (PSCs). In this study, a novel approach named as inverted thermal annealing (ITA) was adopted to dispose the perovskite films. We studied and compared the morphology, surface roughness, and optical and electrical properties of the perovskite films treated by routine TA and ITA, respectively. The perovskite films treated by ITA exhibited higher crystallinity and more favorable morphology and showed stronger of UV light absorption and photoluminescence emission. Therefore, the corresponding PSCs also showed higher average power conversation efficiency (PCE) of 13.49% ± 0.61% than the devices treated by TA (11.37% ± 1.15%), and the PCE of the best performing PSCs is as high as 14.10% with an ITA treatment at 100 °C. These findings suggest that the ITA treatment is an effective and facile method for preparing high-quality perovskite films and can be used widely for obtaining high performance PSCs.
Co-reporter:Yang Xu, Liang-Sheng Qiang, Yu-Lin Yang, Li-Guo Wei, Ping Wang, Rui-Qing Fan
Chinese Chemical Letters 2016 Volume 27(Issue 1) pp:127-134
Publication Date(Web):January 2016
DOI:10.1016/j.cclet.2015.06.010
A pyridine-anchor co-adsorbent of N,N’-bis((pyridin-2-yl)(methyl) methylene)-o-phenylenediamine (named BPPI) is prepared and employed as co-adsorbent in dye-sensitized solar cells (DSSCs). The prepared co-adsorbent could overcome the deficiency of N719 absorption in the low wavelength region of visible spectrum, offset competitive visible light absorption of I3−, enhance the spectral responses of the co-adsorbed TiO2 film in region from 300 nm to 750 nm, suppress charge recombination, prolong electron lifetime, and decrease the total resistance of DSSCs. The optimized cell device co-sensitized by BPPI/N719 dye gives a short circuit current density of 12.98 mA cm−2, an open circuit voltage of 0.73 V, and a fill factor of 0.66 corresponding to an overall conversion efficiency of 6.22% under standard global AM 1.5 solar irradiation, which is much higher than that of device solely sensitized by N719 (5.29%) under the same conditions. Mechanistic investigations are carried out by various spectral and electrochemical characterizations.Prepared organic co-adsorbent could notably enhance the overall conversion efficiency of N719 sensitized DSSCs under AM 1.5G solar irradiation.
Co-reporter:Li Zhou, Liguo Wei, Yulin Yang, Xue Xia, Ping Wang, Jia Yu, Tianzhu Luan
Chemical Physics 2016 Volume 475() pp:1-8
Publication Date(Web):22 August 2016
DOI:10.1016/j.chemphys.2016.05.018
Highlights
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Cu-doped TiO2 semiconductors were prepared and applied in DSSCs.
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Band edge movement of Cu-doped TiO2 was investigated by spectroelectrochemical.
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The DSSC based on 1.0 at.% Cu–TiO2 exhibited higher Jsc and η.
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Doping TiO2 with Cu is a promising way to achieve improvements in DSSCs performance.
Co-reporter:Yan-Bing Yin, Hui-Song Wang, Yu-Lin Yang, Rui-Qing Fan, Guo-Hua Dong, Li-Guo Wei
Chinese Chemical Letters 2016 Volume 27(Issue 4) pp:613-618
Publication Date(Web):April 2016
DOI:10.1016/j.cclet.2016.02.002
In this work, a series of molybdovanadophosphoric heteropoly acid quaternary ammonium salts (H3 + xPMo12 − xVxO40-T) were synthesized and employed as a reaction inhibitor in the self-polymerization of methyl methacrylate (MMA). The polymerization inhibition effect of H3 + xPMo12 − xVxO40-T with different number of vanadium atoms and reaction dosages was investigated using differential scanning calorimetry (DSC). It shows that the inhibitory effect was improved with the increasing dosages of H3 + xPMo12 − xVxO40-T, and the polymerization inhibition was also affected by the number of vanadium atoms in the H3 + xPMo12 − xVxO40-T. Furthermore, cyclic voltammograms (CV) was used to probe the mechanism of the inhibition reaction with H3 + xPMo12xVxO40-T. The result of CV indicates that the inhibition reaction is an oxidation–reduction reaction. H3 + xPMo12 − xVxO40-T can react directly with the MMA monomer radicals, which eliminated the MMA monomers, and therefore the self-polymerization of the MMA can be effectively inhibited by H3 + xPMo12 − xVxO40-T.H3 + xPMo12 − xVxO40-T (x = 1,2,3,4) is a satisfied self-polymerization inhibitor for MMA.
Co-reporter:Yang Song, Ruiqing Fan, Ping Wang, Xinming Wang, Song Gao, Xi Du, Yulin Yang and Tianzhu Luan
Journal of Materials Chemistry A 2015 vol. 3(Issue 24) pp:6249-6259
Publication Date(Web):20 May 2015
DOI:10.1039/C5TC01273B
Poly(methyl methacrylate) (PMMA) films doped with Cu(I)-based imidazole derivative coordination polymers [Cu3I3(bib)1.5]n (1) and [Cu4I4(bix)2]n (2) [bib = 1,4-bis(1-imidazolyl)benzene and bix = 1,4-bis(imidazol-1-ylmethyl)benzene] were synthesized and their photophysical properties were studied. 1 and 2 were prepared by a solvothermal method and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy, 1H NMR, PXRD and thermal gravimetric analyses. Molecular structural analysis reveals that 1 exhibits a unique one-dimensional (1D) infinite triplex chain and 2 is built from a [Cu4I4]n cluster which possesses an interesting two-dimensional (2D) (4,4)-connected sql (square lattice) network. Detailed structural characterization of the supramolecular organization of 1 and 2 revealed overall three-dimensional (3D) interlinked networks driven by extensive π⋯π stacking interactions. Both 1 and 2 display remarkable narrow band emission with a smaller full width at half-maximum (FWHM) (77 K, 34.63 and 60.07 nm; 298 K, 121.95 and 126.83 nm) in the solid state at 77 K, which leads to excellent monochromaticity. The combination of such a narrow FWHM and the large red-shift of 62 nm from 298 K to 77 K endows 2 with a more prominent thermochromism effect than 1, with emissions strongly depending on temperature and tunable from yellow to red by changing the temperature from 298 K to 77 K. Here, the role of the [Cu4I4]n cluster in controlling the performance of thermochromic luminescence is highlighted. Meanwhile, 1 and 2 demonstrate stronger and longer lifetime yellow luminescence emissions at concentrations of 0.8% (τ = 156.62 μs) and 1.0% (τ = 92.28 μs) in poly(methyl methacrylate) (PMMA). Furthermore, development of easy-to-prepare hybrid materials 1–PMMA and 2–PMMA leads to bright yellow luminescence polymer film materials with outstanding thermal stability in daily applications (321 °C and 500 °C).
Co-reporter:Song Gao, Rui Qing Fan, Xin Ming Wang, Liang Sheng Qiang, Li Guo Wei, Ping Wang, Hui Jie Zhang, Yu Lin Yang and Yu Lei Wang
Journal of Materials Chemistry A 2015 vol. 3(Issue 11) pp:6053-6063
Publication Date(Web):30 Jan 2015
DOI:10.1039/C4TA06671E
Based on a new design of 4-cyanobenzyl-based 1,2,4-triazole ligand 4-(1,2,4-triazolylmethyl) cyanobenzene (TMCB), a series of cadmium complexes 1–5′ from a mononuclear to three-dimensional (3D) structure have been synthesized through hydro(solvo)thermal reactions; they were generally formulated as [Cd(TMCBA)2]n (1), [Cd(TMCB)(1,4-bda)(H2O)]n (2), {[Cd2(TMCB)4(1,4-bda)2(H2O)2]n·3H2O}n (3), {[Cd(TMCB)4(H2O)2]·(NO3)2·(H2O)2}n (4), [Cd1.5(1,4-bda)1.5(DMF)2]2n (5) and [Cd1.5(1,4-bda)1.5(DMF)2]2n (5′) (TMCBA = 4-(1,2,4-triazolylmethyl) benzoic acid, which is formed from the hydrolysis of TMCB; 1,4-H2bda = 1,4-benzenedicarboxylic acid; the difference between two genuine supramolecular isomers of 5 and 5′ is the use of TMCB as the additive agent for the reaction). Complexes 1–5′ exhibit tunable luminescence with emission maxima containing deep blue, blue, light blue, green and deep green region at 298 K or 77 K in both different solvents (polarity: DMSO > CH3OH > CHCl3) and solid state. Interestingly, the good thermal stability accompanied by their compensated adsorption to ruthenium complex N719 in the region of low wavelength, enabled 1 and 4 to serve as co-sensitizers in combination with N719 in dye sensitized solar cells (DSSCs). After co-sensitization with N719, the overall conversion efficiency of 1 and 4 were found to be 7.68% and 6.85%, which are 40.40% and 25.23% higher than that for DSSCs only sensitized by N719 (5.47%) under the same conditions, respectively. The improvement in efficiency is attributed to the fact that complexes 1 and 4 overcome the deficiency of N719 absorption in the low wavelength region of ultraviolet and blue-violet, offset competitive visible light absorption of I3− and reduce charge recombination due to the formation of an effective cover layer of the dye molecules on the TiO2 surface. As a result, the synthesized complexes are promising candidates as co-adsorbents and co-sensitizers for highly efficient DSSCs.
Co-reporter:Ting Su, Yulin Yang, Yong Na, Ruiqing Fan, Liang Li, Liguo Wei, Bin Yang, and Wenwu Cao
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 6) pp:3754
Publication Date(Web):January 26, 2015
DOI:10.1021/am5085447
Hydrogenated titanium dioxide (H-TiO2) nanocrystals were successfully prepared via annealing TiO2 in H2/N2 mixed gas flow at elevated temperatures ranging from 300 to 600 °C. Electron paramagnetic resonance (EPR) spectra were used to determine the produced oxygen vacancy in H-TiO2. Variations in temperature were studied to investigate the concentration change of oxygen vacancy in H-TiO2. The H-TiO2 nanocrystals prepared at different temperatures were employed into photoanodes sensitized by N719 dye and found to have exceptional effect on the solar-to-electric energy conversion efficiency (η). Photoanodes with H-TiO2 nanocrystals hydrogenated at 300 °C show the highest short-circuit current density (Jsc) of 18.92 mA cm–2 and photoelectrical conversion efficiency of 7.76% under standard AM 1.5 global solar irradiation, indicating a 27 and 28% enhancement in Jsc and η, respectively, in comparison to those with TiO2. The enhancement is attributed to high donor density, narrow band gap and positive shift of flat band energy (Vfb) of H-TiO2 that promote the driving force for electron injection. Intensity-modulated photocurrent spectroscopy (IMPS) accompanied by intensity-modulated photovoltage spectroscopy (IMVS) and other analyses were applied to shed more light on the fundamental mechanisms inside the charge transfer and transport in these systems.Keywords: DSSCs; hydrogenation temperature; oxygen vacancy; photoanode; TiO2 nanocrystals
Co-reporter:Yu-Wei Dong; Rui-Qing Fan; Ping Wang; Li-Guo Wei; Xin-Ming Wang; Song Gao; Hui-Jie Zhang; Yu-Lin Yang;Yu-Lei Wang
Inorganic Chemistry 2015 Volume 54(Issue 16) pp:7742-7752
Publication Date(Web):July 24, 2015
DOI:10.1021/acs.inorgchem.5b00661
Using Schiff-base ligands (E)-N-(6-methoxypyridin-2-yl)(CH═NAr) (where Ar = C6H5, L1; 2-MeC6H4, L2; 2,4,6-Me3C6H2, L3), six Zn(II)/Hg(II) complexes, namely, [ZnL1Cl2] (Zn1), [HgL1Cl2] (Hg1), [ZnL2Cl2] (Zn2), [HgL2Cl2] (Hg2), [ZnL3Cl2] (Zn3), and [HgL3Cl2] (Hg3) have been synthesized under solvothermal conditions. The structures of six complexes have been established by X-ray single-crystal analysis and further physically characterized by EA, FT-IR, 1H NMR, and ESI-MS. The crystal structures of these complexes indicate that noncovalent interactions, such as hydrogen bonds, C–H···Cl, and π···π stacking, play essential roles in constructing the resulting supramolecular structures (1D for Hg3; 2D for Zn2, Hg2; 3D for Zn1, Hg1, and Zn3). Upon irradiation with UV light, the emission of complexes Zn1–Zn3 and Hg1–Hg3 could be finely tuned from green (480–540 nm) in the solid state to blue (402–425 nm) in acetonitrile solution. It showed that the ligand and metal cation can influence the structures and luminescence properties of complexes such as emission intensities and maximum wavelengths. Since these ligands and complexes could compensate for the absorption of N719 in the low-wavelength region of the visible spectrum and reduce charge recombination of the injected electron, the ligands L1–L3 and complexes Zn3/Hg3 were employed to prepare cosensitized dye-sensitized solar cells devices for investigating the influences of the electron-donating group and coordination on the DSSCs performance. Compared to DSSCs only being sensitized by N719, these prepared ligands and complexes chosen to cosensitize N719 in solar cell do enhanced its performance by 11–41%. In particular, a DSSC using L3 as cosensitizer displays better photovoltaic performance with a short circuit current density of 18.18 mA cm–2, corresponding to a conversion efficiency of 7.25%. It is much higher than that for DSSCs only sensitized by N719 (5.14%).
Co-reporter:Xin-Ming Wang, Ping Wang, Rui-Qing Fan, Meng-Ying Xu, Liang-Sheng Qiang, Li-Guo Wei, Yu-Lin Yang and Yu-Lei Wang
Dalton Transactions 2015 vol. 44(Issue 11) pp:5179-5190
Publication Date(Web):03 Feb 2015
DOI:10.1039/C4DT03856H
A novel polydentate Schiff base ligand N1,N3-bis[(6-methoxypyridin-2-yl)methylene]benzene-1,3-diamine (L) and its two dinuclear sandwich-like complexes {[CdL(NO3)(H2O)]·NO3}2 (1) and {[CdL(CH3CN)(H2O)]·(ClO4)2·(CH3CN)2}2 (2) were synthesized. Both C–H⋯O, C–H⋯N and π–π non-covalent interactions had essential roles in constructing the resulting three-dimensional supramolecular networks. L emits a more intense blue-green fluorescence emission around 493 nm than in dilute solution, exhibiting stacking-induced emission properties. Complexes 1 and 2 exhibited the dual properties of exceptional solvatochromism and fluorescence quenching towards CH3OH molecules. As these compounds could overcome the absent absorption of ruthenium complex N719 in the low wavelength region of the visible spectrum, offset the competitive visible light absorption of I3− and reduce the charge recombination of injected electrons, the Schiff base ligand L and complexes 1 and 2 were used as co-sensitizers in combination with N719 to investigate their effect on enhancing the performance of dye-sensitized solar cells. A short circuit current density of 14.37 mA cm−2, an open-circuit voltage of 0.71 V and a fill factor of 0.61 corresponding to an overall conversion efficiency of 6.17% under AM 1.5 G solar irradiation were achieved when 1 was used as a co-sensitizer, which are much higher than the results obtained for dye-sensitized solar cells sensitized by N719 alone (5.06%).
Co-reporter:Xi Du, Ruiqing Fan, Xinming Wang, Liangsheng Qiang, Ping Wang, Song Gao, Huijie Zhang, Yulin Yang, and Yulei Wang
Crystal Growth & Design 2015 Volume 15(Issue 5) pp:2402-2412
Publication Date(Web):April 13, 2015
DOI:10.1021/acs.cgd.5b00198
Six novel luminescent materials In(III)-2,3-H2qldc/phen metal–organic assemblies (MOAs), namely, [In2(phen)3Cl6]·CH3CN (In1), [In2(phen)3Cl6]·CH3CN·2H2O (In2), [In2(phen)2Cl6] (In3), [In(3-qlc)2(phen)Cl] (In4), [In(3-qlc)2(2,2′-bipy)Cl]·2H2O (In5) and [In(3-qlc)3(phen)]·H2O (In6) (2,3-H2qldc = quinoline-2,3-dicarboxylic acid; 3-Hqlc = quinoline-3-carboxylic acid, which is formed from the decarboxylation reaction of 2,3-H2qldc; phen = 1,10-phenanthrolin; 2,2′-bipy = 2,2′-bipyridine) have been hydro(solvo)thermally synthesized and characterized by single-crystal X-ray diffraction, infrared (IR), elemental analysis, 1H NMR spectra, and thermogravimetric analysis (TGA). The crystal structures of In1–In6 indicate that the hydrogen bonding and π···π stacking interactions play critical roles in the formation of the extended supramolecular array. In1 displays the rare hexatomic ring 3D (4,5)-connected supramolecular architecture through twofold interpenetrating of 2D cell membrane-like structures. In2 exhibits a 3D 4-connected sra supramolecular architecture. In3 is built from binuclear [In2Cl2] clusters and possesses an interesting 2D (4,4)-connected sql supramolecular network. Due to existing hydrogen bonds forming coplanar dimers, In4 and In5 show more extended π-conjugated system and appear as 3D diamond-like supramolecular architectures with point symbol 66. In6 is coordinated with four almost vertical ligands and further form a 3D diamond-like supramolecular architecture via hydrogen bonding and π···π stacking interactions. Complexes In1–In6 exhibit tunable luminescence with emission maxima containing deep blue, blue, light blue, green, and yellow green at 298 and 77 K both in DMSO solvent and in the solid state. It is worth noting that In4 and In5 exhibit good aggregation-induced emission (AIE) properties in the solid state. Both of them show very weak luminescence in dimethyl sulfoxide (DMSO, good solvent) while their intensity increased enormously by the addition of water (H2O, poor solvent) due to aggregation.
Co-reporter:Yanxia Jiang, Yulin Yang, Liangsheng Qiang, Ruiqing Fan, Liang Li, Tengling Ye, Yong Na, Yan Shi and Tianzhu Luan
Physical Chemistry Chemical Physics 2015 vol. 17(Issue 10) pp:6778-6785
Publication Date(Web):04 Feb 2015
DOI:10.1039/C4CP05795C
A novel heteropolyacid (HPA) K6SiW11O39Ni(H2O)·xH2O (SiW11Ni) modified TiO2 has been successfully synthesized and introduced into the photoanode of dye-sensitized solar cells (DSSCs). The performance of the cell with the HPA-modified photoanode (SiW11Ni/TiO2), mixed with P25 powder in the ratio of 2:8, is better than the cell with a pristine P25 photoanode. An increase of 31% in the photocurrent and 22% improvement in the conversion efficiency are obtained. The effect of the heteropolyacid was well studied by UV-vis spectroscopy, spectro-electrochemical spectroscopy, dark current, intensity-modulated photocurrent spectroscopy and intensity-modulated photovoltage spectroscopy, open-circuit voltage decay and electrochemical impedance spectroscopy. The results show that the interfacial layer modified by SiW11Ni can enhance the injection and transport of electrons, and then retard the recombination of electrons, which results in a longer electron lifetime. What's more, the introduction of SiW11Ni can simultaneously broaden the absorption in the visible region, eventually leading to an efficient increase in energy conversion efficiency.
Co-reporter:Liguo Wei, Yong Na, Yulin Yang, Ruiqing Fan, Ping Wang and Liang Li
Physical Chemistry Chemical Physics 2015 vol. 17(Issue 2) pp:1273-1280
Publication Date(Web):25 Nov 2014
DOI:10.1039/C4CP04240A
2,6-Bis[1-(phenylimino)ethyl]pyridine (M0) and its derivatives containing methyl groups on their phenyl rings (M1o, M1p and M2) are employed as co-sensitizers in dye-sensitized solar cells (DSSCs). The prepared co-sensitizers could alleviate the aggregation of ruthenium dye N719 on the TiO2 film, enhance the spectral responses of the co-sensitized TiO2 film in the region from 400 to 750 nm, suppress the electron recombination, prolong the electron lifetime and decrease the total resistance of DSSCs. The number and position of the methyl groups are two key factors that play important roles in the performances of DSSCs. The optimized cell device co-sensitized by the M1p/N719 dye gives a short circuit current density of 16.48 mA cm−2, an open circuit voltage of 0.72 V and a fill factor of 0.62 corresponding to an overall conversion efficiency of 7.32% under standard global AM 1.5 solar irradiation, which is 35% higher than that of a device solely sensitized by N719 under the same conditions.
Co-reporter:Song Gao, Rui Qing Fan, Xin Ming Wang, Liang Sheng Qiang, Li Guo Wei, Ping Wang, Yu Lin Yang and Yu Lei Wang
Dalton Transactions 2015 vol. 44(Issue 41) pp:18187-18195
Publication Date(Web):22 Sep 2015
DOI:10.1039/C5DT02951A
This work reports on two new complexes with the general formula [Cd3(IBA)3(Cl)2(HCOO)(H2O)]n (1) and {[Cd1.5(IBA)3(H2O)6]·3.5H2O}n (2), which can be synthesized by the reaction of CdII with rigid linear ligand 4-HIBA containing imidazolyl and carboxylate functional groups [4-HIBA = 4-(1H-imidazol-1-yl)benzoic acid]. Single-crystal X-ray diffraction analyses indicate that complex 1 is a 2D “wave-like” layer structure constructed from trinuclear units and complex 2 is just a mononuclear structure. Surprisingly, both complexes 1 and 2 appear as a 3D supramolecular network via intermolecular hydrogen bonding interactions. What's more, due to their strong UV-visible absorption, 1 and 2 can be employed as co-sensitizers in combination with N719 to enhance dye-sensitized solar cell (DSSC) performance. Both of them could overcome the deficiency of the ruthenium complex N719 absorption in the region of ultraviolet and blue-violet, and the charge collection efficiency is also improved when 1 and 2 are used as co-sensitizers, which are all in favor of enhancing the performance. The DSSC devices using co-sensitizers of 1/N719 and 2/N719 show an overall conversion efficiency of 8.27% and 7.73% with a short circuit current density of 17.48 mA cm−2 and 17.39 mA cm−2, and an open circuit voltage of 0.75 V and 0.74 V, respectively. The overall conversion efficiency is 27.23% and 18.92% higher than that of a device solely sensitized by N719 (6.50%). Consequently, the prepared complexes are high efficiency co-sensitizers for enhancing the performance of N719 sensitized solar cells.
Co-reporter:Xin-Ming Wang, Shuo Chen, Rui-Qing Fan, Fu-Qiang Zhang and Yu-Lin Yang
Dalton Transactions 2015 vol. 44(Issue 17) pp:8107-8125
Publication Date(Web):23 Mar 2015
DOI:10.1039/C5DT00057B
The photophysical properties of ZnII/HgII Schiff base complexes could be fine and predictably tuned over a wide range of wavelengths by changing the ligand structures. A new series of polydentate Schiff base-type ligands, N,N′-bis(2-pyridinylethylidene)R3-1,2-diamine (L1–L6), which contain a flexible, semi-rigid or rigid group (R3 = butyl, cyclohexane, tolyl and phenylene), has been designed and employed for synthetizing new mononuclear or binuclear trans ZnII/HgII complexes with a general formula of [M(L1)Cl2] (L1 = N,N′-bis(2-pyridinylethylidene)phenylene-1,2-diamine, M = Zn, 1a; M = Hg, 1b), [M(L2)Cl2] (L2 = N,N′-bis(2-pyridinylethylidene)toluene-3,4-diamine, M = Zn, 2a; M = Hg, 2b), [M2(L3)Cl4]·nCH2Cl2 (L3 = N,N′-bis(2-pyridinylmethylene)cyclohexane-1,2-diamine, M = Zn, n = 0, 3a; M = Hg, n = 1, 3b), [M2(L4)Cl4]·nCH3OH (L4 = N,N′-bis(2-pyridinylethylidene)cyclohexane-1,2-diamine, M = Zn, n = 1, 4a; M = Hg, n = 0, 4b), [M2(L5)Cl4] (L5 = N,N′-bis(3-methoxy-2-pyridinylmethylene)-cyclohexane-1,2-diamine, M = Zn, 5a; M = Hg, 5b), [M2(L6)Cl4]·nCH3CN (L6 = N,N′-bis(3-methoxy-2-pyridinylmethylene)butane-1,4-diamine, M = Zn, n = 4, 6a; M = Hg, n = 0, 6b). All the ligands and complexes have been characterized by elemental analyses, IR spectra, and 1H NMR spectra. Twelve structures of L5, L6, 1a–6a, 1b, 3b, 5b and 6b crystallized in three different conditions are further determined by single-crystal X-ray diffraction analyses. Their properties are fully characterized by UV-vis and fluorescence spectra both in solution and the solid state at room temperature. The luminescence color of these ZnII/HgII Schiff base complexes could be tuned from blue to green to red (429–639 nm for 6a–1a, 434–627 nm for 6b–1b) in solution by changing the ligand conjugated systems from flexibile (L6) to semi-rigid (L3–L5) to rigid (L1–L2). The spectra of the free Schiff bases L6–L1 are centered around 402–571 nm, which are perturbed upon the coordination to the ZnII/HgII ion. Both the electrochemical data and TD-DFT calculations show that the HOMO–LUMO band gap from the ligand to the complex is reduced by complexation. Meanwhile, the emission efficiencies of ZnII-complexes are found to be strongly dependent on the Schiff-base ligands with quantum yields ranging from 14% to 25% for 1a–6a. However, the emission efficiencies dramatically decline in HgII-complexes with quantum yields ranging from 4% to 19%, due to the heavy atom effect.
Co-reporter:Yu-Wei Dong, Rui-Qing Fan, Ping Wang, Li-Guo Wei, Xin-Ming Wang, Hui-Jie Zhang, Song Gao, Yu-Lin Yang and Yu-Lei Wang
Dalton Transactions 2015 vol. 44(Issue 12) pp:5306-5322
Publication Date(Web):24 Dec 2014
DOI:10.1039/C4DT03602F
Nine IIB group complexes, [ZnL1Cl2] (Zn1), [CdL1Cl2]2 (Cd1), [HgL1Cl2] (Hg1), [ZnL2Cl2] (Zn2), [CdL2Cl2] (Cd2), [HgL2Cl2] (Hg2), [ZnL3Cl2] (Zn3), [CdL3Cl2] (Cd3) and [HgL3Cl2] (Hg3), have been synthesized from the corresponding ortho-(6-methoxy-pyridyl)(CHNAr) (where Ar = 2,6–iPr2C6H3, L1; 4–MeC6H4, L2; 2–OMeC6H4, L3) Schiff base and structurally characterized by elemental analysis, FT-IR, 1H NMR and X-ray single-crystal analysis. Crystallographic studies reveal that the center metal of the complexes adopts a distorted tetrahedron geometry (except for Cd1 and Cd3, which display square pyramidal geometry) and C–H⋯Cl hydrogen bonds and π⋯π stacking interactions contribute to three-dimensional supramolecular structures. The series of complexes exhibit tunable luminescence from blue, through green, to light yellow by varying the temperature (298 K and 77 K), both in solution and in the solid state. Moreover, the quantum yields range from 0.027 to 0.422, and decrease according to the order of the periodic table (Zn > Cd > Hg). These results indicate that the center atom of the complexes leads to the geometry differences and hence to the tunable luminescence properties. Because Zn1–Zn3 exhibited higher molar extinction coefficients and a distinct absorption region, they were employed as co-sensitizers in ruthenium dye N719-sensitized photoanodes to deliver light-electricity efficiency enhancement, being assembled with counter-electrodes and electrolyte to prepare ZnX/N719 (where ZnX = Zn1, Zn2 and Zn3) co-sensitized dye sensitized solar cell (DSSC) devices. The prepared co-absorbent could overcome the deficiency of N719 absorption in the low-wavelength region of the visible spectrum, and offset competitive visible-light absorption of I3−. Application of these prepared complexes in N719-sensitized solar cells enhanced their performance by 10–36%, which indicated a potential application of these types of complexes in DSSCs.
Co-reporter:Hui-Jie Zhang, Rui-Qing Fan, Xin-Ming Wang, Ping Wang, Yu-Lei Wang and Yu-Lin Yang
Dalton Transactions 2015 vol. 44(Issue 6) pp:2871-2879
Publication Date(Web):11 Dec 2014
DOI:10.1039/C4DT03348E
Poly(methylmethacrylate) (PMMA) doped with Tb-based imidazole derivative coordination polymer {[Tb3(L)(μ3-OH)7]·H2O}n (1) (L = N,N′-bis(acetoxy)biimidazole) was synthesized and its photophysical properties were studied. The L′ (L′ = N,N′-bis(ethylacetate)biimidazole) ligand was synthesized by an N-alkylation reaction process followed by ester hydrolysis to produce ligand L. Polymer 1 and ligand L′ have been characterized by 1H NMR and IR spectroscopy, elemental analysis, PXRD and X-ray single-crystal diffraction. Coordination polymer 1 is the first observation of a CdCl2 structure constructed with hydroxy groups and decorated by ligand L in lanthanide N-heterocyclic coordination polymers. In the 2D layered structure of 1, each Tb3 metal center is connected with three Tb1 and three Tb2 metal centers by seven hydroxyl groups in different directions, resulting in a six-membered ring. After doping, not only the luminescence intensity and lifetime enhanced, but also their thermal stability was increased in comparison with 1. When 1 was doped into poly(methylmethacrylate) (1@PMMA), polymer film materials were formed with the PMMA polymer matrix (w/w = 2.5%–12.5%) acting as a co-sensitizer for Tb3+ ions. The luminescence intensity of the Tb3+ emission at 544 nm increases when the content of Tb3+ was 10%. The lifetime of 1@PMMA (914.88 μs) is more than four times longer than that of 1 (196.24 μs). All τ values for the doped polymer systems are higher than coordination polymer 1, indicating that radiative processes are operative in all the doped polymer films. This is because PMMA coupling with the O–H oscillators from {[Tb3(L)(μ3-OH)7]·H2O}n can suppress multiphonon relaxation. According to the variable-temperature luminescence (VT-luminescence) investigation, 1@PMMA was confirmed to be a stable green luminescent polymer film material.
Co-reporter:Liguo Wei, Yulin Yang, Zhaoyang Zhu, Ruiqing Fan, Ping Wang, Yuwei Dong and Shuo Chen
RSC Advances 2015 vol. 5(Issue 117) pp:96934-96944
Publication Date(Web):06 Nov 2015
DOI:10.1039/C5RA19417B
Three bis(6-methoxylpyridin-2-yl) substituted pyridine-anchor co-sensitizers with different donor groups are synthesized by 1,2-diaminobenzene (named L4), 1,2-diaminocyclohexane (named L5) and 1,4-butanediamine (named L6) with the aim to obtain rigid, semi-rigid and flexible co-sensitizer molecules, respectively. Their adaptability in N719 sensitized solar cells as co-sensitizers and the effects of their molecular rigidity, conjugation and co-planarity on the performance of DSSCs are studied. The results show that these three co-sensitizers are suitable to use in N719 sensitized solar cells. However, due to the different donor groups in the molecular structure, the co-sensitization performance of the rigid co-sensitizer with a large conjugate system is better than that of semi-rigid and flexible co-sensitizers. A short circuit current density of 13.27 mA cm−2, an open circuit voltage of 0.73 V and a fill factor of 0.63 corresponding to an overall conversion efficiency of 6.16% under AM 1.5G solar irradiation were achieved when rigid L4 was used as the co-sensitizer, which is 30% higher than that for DSSCs only sensitized by N719 (5.37%) under the same conditions. Mechanistic investigations are carried out by various spectral and electrochemical characterizations.
Co-reporter:Liguo Wei, Yulin Yang, Xue Xia, Ruiqing Fan, Ting Su, Yan Shi, Jia Yu, Liang Li and Yanxia Jiang
RSC Advances 2015 vol. 5(Issue 86) pp:70512-70521
Publication Date(Web):12 Aug 2015
DOI:10.1039/C5RA15815J
Pure TiO2 and 8 at% Sm-doped TiO2 nanoparticles are prepared via a novel hydrolysis followed by a hydrothermal process at 473 K for 24 h and successfully used in the photoanode of dye sensitized solar cells (DSSCs). The performance of DSSCs based on 8 at% Sm-doped TiO2 is significantly better compared to DSSCs based on undoped TiO2. The Jsc is 14.53 mA cm−2 and η is 6.78%, which is 15% and 5% higher than that of DSSCs based on undoped TiO2, respectively. The results of a variable temperature spectroelectrochemistry study show that the conduction band edge of 8 at% Sm-doped TiO2 shifts positively. The lower conduction band position enhances the driving force of electrons and improves the electron injection efficiency from the lowest unoccupied molecular orbital (LUMO) of the dye to the conduction band (CB) of TiO2, and the narrower band gap expands the response in the visible region and increases the utilization percentage of sunlight. These all contribute to enhancing the performance of cells based on an 8 at% Sm-doped TiO2 photoanode. The as prepared Sm-doped TiO2 material is proven in detail to be a better photoanode material than pure TiO2.
Co-reporter:Song Gao, Rui Qing Fan, Xin Ming Wang, Liang Sheng Qiang, Li Guo Wei, Ping Wang, Yu Lin Yang, Yu Lei Wang and Tian Zhu Luan
RSC Advances 2015 vol. 5(Issue 54) pp:43705-43716
Publication Date(Web):08 May 2015
DOI:10.1039/C5RA07160G
We design two novel d10 metal complexes [Zn(3-qlc)2]n (Zn1), [Cd(3-qlc)2]n (Cd1) (3-Hqlc = quinoline-3-carboxylic acid), which display similar 2D layer structures, and further form 3D 6-connected primitive cubic (pcu) network topology via π⋯π stacking interactions with the point symbol {412·63}. Complexes Zn1 and Cd1 exhibit tunable luminescence and photovoltaic properties as a new type of multifunctional materials. Zn1 and Cd1 show tunable luminescence from blue to green by varying the temperature in the solid state. What's more, both of them exhibit excellent aggregation-induced emission (AIE) properties in DMSO/water mixtures. Encouraged by the UV-visible absorption in an ethanol solution result, Zn1 and Cd1 can be considered as co-sensitizers in combination with N719 to investigate their effect on enhancing the dye-sensitized solar cells (DSSCs) performance. Zn1 and Cd1 could overcome the deficiency in the ruthenium complex N719 absorption in the ultraviolet and blue-violet region, offsetting competitive visible light absorption of I3− and reducing the charge recombination of injected electrons. After being co-sensitized with Zn1 and Cd1, the devices co-sensitized by Zn1/N719 and Cd1/N719 yield an overall efficiency of 7.75% and 7.70%, which are 44.59% and 43.66% higher than that of the device sensitized only by N719 (5.36%).
Co-reporter:Huijie Zhang, Ruiqing Fan, Ping Wang, Xinming Wang, Song Gao, Yuwei Dong, Yulei Wang and Yulin Yang
RSC Advances 2015 vol. 5(Issue 48) pp:38254-38263
Publication Date(Web):08 Apr 2015
DOI:10.1039/C5RA01796C
A series of lanthanide complexes with formulae {[KEu(Hqlc)(qlc)(H2O)6(OH)]2+·2Cl−}n (1·Eu), {[Eu(qlc)2(phen)(H2O)2]+·Cl−}·CH3CN (2·Eu), [Eu(qlc)2(phen)(NO3)]·H2O (3·Eu), [Ln(qlc)2(H2O)4]·(qlc)·(H2O) (Ln = Eu(4·Eu), Sm(5·Sm), Gd(6·Gd), Tb(7·Tb), Dy(8·Dy), Ho(9·Ho)) (Hqlc = quinoline-3-carboxylic acid, phen = 1,10-phenanthrolin) are synthesized under solvo(hydro)thermal conditions and characterized by single-crystal X-ray diffraction, infrared spectra, elemental analysis, and powder X-ray diffraction. Complex 1 exhibits two-dimensional (6,3)-connected hcb networks and possesses a stable structure through typical O/C–H⋯Cl intermolecular hydrogen bonds. Complexes 2–4 display three diverse dimer structures, due to the synergistic effect from coordination modes of Hqlc ligand and anion effect. Complexes 5–9 are isostructural with complex 4. Eu-complexes 1–4 could provide intense and bright characteristic 5D0 → 7FJ red luminescence under UV excitation in the solid state at 298 K and 77 K. In complexes 2 and 3, the coordinate phen ligand could play the antenna role in the energy transfer process. Therefore, the luminescence lifetimes of complexes 2 (779.62 and 792.65 μs) and 3 (947.21 and 1095.59 μs) are longer than those of complexes 1 (456.93 and 499.33 μs) and 4 (283.70 and 46469 μs) in the solid state at 298 K and 77 K. Complexes 5, 7 and 8 exhibit characteristic Sm3+, Tb3+ and Dy3+ ion luminescence. Furthermore, through controlling the concentration of complexes 3 and 4 in poly(methyl methacrylate) (PMMA), a series of 3–PMMA and 4–PMMA hybrid materials are obtained, respectively. They all display strong and characteristic red luminescence emissions at a concentration of 8%. Compared with 3 and 4, the luminescence intensities and luminescence lifetimes of 3–PMMA and 4–PMMA are increased, due to the replacement of water molecules by PMMA.
Co-reporter:Yang Song, Rui-Qing Fan, Hui-Jie Zhang, Zhi-Wei Liu, Xue-Tao Wang, Cai-Tu Tan, Yu-Lin Yang and Yu-Lei Wang
RSC Advances 2015 vol. 5(Issue 22) pp:17343-17353
Publication Date(Web):03 Feb 2015
DOI:10.1039/C4RA16863A
Three one-dimensional (1D) Ag(I)/Cu(I) coordination polymers, formulated as [Ag(2,3-Hqldc)]n (Ag1), [Ag(3-qlc)]2n (Ag2) and [CuI(3-Hqlc)]n (Cu1) based on the ligand quinoline-2,3-dicarboxylic acid (H2qldc), were synthesized through hydrothermal (solvothermal) method and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy and elemental analysis. Molecular structural analysis reveals that Ag1 was a 1D + 1D → 1D infinite chain synthesized at a relatively low temperature 80 °C, which further forms a three-dimensional (3D) structure by π–π stacking interactions. Ag2 forms a 1D dimer chain structure and via π⋯π packing interactions shows a two-dimensional (2D) supramolecular network. Both Ag1 and Ag2 display stable blue luminescent in the solid state and in organic solvents (DMSO, CH3CN and CH3OH) at 298 K and 77 K. However, Cu1 possess a 1D ladder chain structure, which further forms a 2D structure by hydrogen bonding interactions. Cu1 shows tunable luminescence at 298 K and 77 K in the solid state with a large red-shift of 70 nm and the CIE color shifts from bright yellow (0.51, 0.48) to red (0.67, 0.30), indicating thermochromic luminescence for Cu1. After doping with poly(methylmethacrylate) (PMMA), not only are the luminescence intensity and lifetimes enhanced, but the thermal stability is also increased in comparison with Cu1. After Cu1 was doped with PMMA (Cu1@PMMA), the lifetime of the polymer film material Cu1@PMMA increases and reaches a maximum at 1.0% (τ = 95.57 μs), which is more than eight times longer than that of Cu1 (τ = 13.78 μs). Cu1@PMMA is confirmed as a bright yellow luminescent polymer film material.
Co-reporter:Deyan Kong;Xinli Xiao;Xueying Qiu;Wenbo Zhang ;Yulin Yang
Chinese Journal of Chemistry 2015 Volume 33( Issue 9) pp:1024-1030
Publication Date(Web):
DOI:10.1002/cjoc.201500343
Abstract
Hydroxyapatite (HAp) nanorods possess vast potential applications in various fields, and here HAp nanorods with high aspect ratio were synthesized via a convenient two-stage precipitation-hydrolysis process at 60°C under atmospheric pressure. The precursor of CaHPO4 at precipitation stage is well crystallized as nubby morphology with CTAB as surfactant, while CaHPO4 was dissolved and CTA+ stabilized the HAp nuclei during the hydrolysis stage. OH− ions were absorbed onto the active crystal surface, where Ca2+ and PO43+ reacted with OH− to make the nuclei grow into larger crystals, and highly crystalline HAp nanorods were obtained by Ostwald ripening. The loaded drug of IBU on the HAp crystals can be 100% released in 24 h. PVP modified HAp nanorods can increase the drug-loading capacity and release drug faster than pure HAp nanorods. The results indicate that HAp nanorods modified with suitable surfactants are of great use in drug delivery system.
Co-reporter:Yong Na, Bo Hu, Qiu-Ling Yang, Jian Liu, Li Zhou, Rui-Qing Fan, Yu-Lin Yang
Chinese Chemical Letters 2015 Volume 26(Issue 1) pp:141-144
Publication Date(Web):January 2015
DOI:10.1016/j.cclet.2014.09.011
CdS sensitized NiO electrode was used as the photoactive cathode in a photoelectrochemical cell for water splitting, avoiding the use of a sacrificial electron donor. Photocurrent increment under visible light irradiation was observed after integration of [Co(dmgH)2(4-Me-py)Cl] (1) to the photocathode, suggesting 1 could accept electrons from photoexcited CdS for water reduction and NiO could move the holes in the valence band of CdS to anode for water oxidation.Cobalt catalyst 1 was integrated to CdS sensitized NiO photocathode in photoelectrochemical cell (PEC) for water splitting without sacrificial electron donors. Photocurrent increment in PEC system was demonstrated under visible light irradiation.
Co-reporter:Xin-Ming Wang, Rui-Qing Fan, Liang-Sheng Qiang, Ping Wang, Yu-Lin Yang, Yu-Lei Wang
Inorganic Chemistry Communications 2015 Volume 55() pp:73-76
Publication Date(Web):May 2015
DOI:10.1016/j.inoche.2015.03.016
•Four new indium complexes and one organic molecular were synthesized.•The strong noncovalent interactions form the 2D or 3D supermolecular structures.•1–5 display white, green and blue fluorescent in the solid state, respectively.•The fluorescence spectra of 3 and 5 almost have no change in different solvents.•The frameworks of 3 and 5 are stable up to 190 and 272 °C, respectively.Five new compounds with mixed-ligand formulated as (H4bptc)(phen) (1), [In(phen)2Cl2](H4bptc)(NO3)(H2O) (2), [In(Hbptc)(phen)(H2O)]2 (3), In(2,6-pydc)(phen)(H2O)Cl (4), and {[In(2,6-pydc)(Ox)0.5(H2O)2](H2O)}2 (5) have been synthesized under hydrothermal conditions. Compounds 1–5 display white, green and blue fluorescence at 298 K in the solid state, respectively. It is shown that 1 assumes solvent-dependent photoluminescence. By contrast, the different polarities of solvents do not alter the luminescence position of 3 and 5. The thermogravimetric curves show that binuclear compounds 3 and 5 have excellent thermal stability, whose structures are stable up to 190 and 272 °C, respectively.Five new compounds with mixed-ligand formulated as (H4bptc)(phen) (1), [In(phen)2Cl2](H4bptc)(NO3)(H2O) (2), [In(Hbptc)(phen)(H2O)]2 (3), In(2,6-pydc)(phen)(H2O)Cl (4), and {[In(2,6-pydc)(Ox)0.5(H2O)2](H2O)}2 (5) have been synthesized under hydrothermal conditions. The strong hydrogen bonding and π–π interactions play an important role in governing the crystal packing and determining the formation of 2D–3D supermolecular structures. Compounds 1–5 display white, green and blue fluorescent at 298 K in the solid state, respectively. Binuclear compounds 3 and 5 have excellent thermal stability, whose frameworks are stable up to 190 and 272 °C, respectively.
Co-reporter:Xin-Ming Wang, Rui-Qing Fan, Ping Wang, Liang-Sheng Qiang, Yu-Lin Yang, Yu-Lei Wang
Inorganic Chemistry Communications 2015 Volume 51() pp:29-35
Publication Date(Web):January 2015
DOI:10.1016/j.inoche.2014.11.002
•In1 and In2 have 3D structure constructed through C–H⋯Cl or π⋯π interaction.•In1 and In2 both display stable blue fluorescent in the solid state.•In1 possesses solvent-dependent photoluminescence.•In2 has good fluorescence stability in different solvents.•In1 and In2 are stable up to 450 and 495 °C, respectively.Two new indium coordination polymers (CPs) with mixed-ligand formulated as {[In(1,4-bda)1.5(phen)]·2H2O}n (In1) and {In(1,4-bda)(2,2′-bipy)Cl}n (In2) (1,4-H2bda = 1,4-benzenedicarboxylic acid; phen = 1,10-phenanthrolin; 2,2′-bipy = 2,2′-bipyridine) have been synthesized and characterized by single-crystal X-ray diffraction, infrared (IR), elemental analysis and thermal gravimetric analyses (TGA). In1 exhibits one-dimensional (1D) ladder chain, which further forms three-dimensional (3D) structure with π⋯π stacking interaction. Formation of 3D compact supramolecular framework in In2 is generated through C–H…Cl hydrogen bonding contacts and π⋯π stacking interaction. The photoluminescence (PL) characterizations to In1 and In2 affected by solvent and temperature are studied in detail. Thermogravimetric curves showed that In1 and In2 start to undergo phase transition until ca. 450 °C and 495 °C, respectively.Two new indium coordination polymers (CPs) with mixed-ligand formulated as {[In(1,4-bda)1.5(phen)]·2H2O}n (In1) and {In(1,4-bda)(2,2′-bipy)Cl}n (In2) (1,4-H2bda = 1,4-benzenedicarboxylic acid; phen = 1,10-phenanthrolin; 2,2′-bipy = 2,2′-bipyridine) have been synthesized under hydrothermal conditions. In1 exhibits one-dimensional (1D) ladder chain, which further forms three-dimensional (3D) structure by π⋯π stacking interaction. The 3D inserted compact supramolecular framework in In2 is generated through C–H⋯Cl hydrogen bonding contacts and π⋯π stacking interaction between neighboring 1D zigzag chains. The emission peak positions of In1 are sensitive to different polar solvents, assuming solvent-dependent PL. By contrast, the PL spectrum of In2 does not change in different solvents, and possesses better PL stability.
Co-reporter:Xin Ming Wang, Rui Qing Fan, Liang Sheng Qiang, Wei Qi Li, Ping Wang, Hui Jie Zhang and Yu Lin Yang
Chemical Communications 2014 vol. 50(Issue 39) pp:5023-5026
Publication Date(Web):25 Mar 2014
DOI:10.1039/C3CC48867E
Two rare 2D Ga/In-based coordination polymers in which one metal center coexists with three distinct aromatic ligands were synthesized. Helical channels along the 21 screw axis are exhibited to form a hcb net. The compounds exhibit tunable fluorescence from blue, green, white to yellow light by varying the temperature and solvents.
Co-reporter:Liang Li, Yulin Yang, Ruiqing Fan, Shuo Chen, Ping Wang, Bin Yang, and Wenwu Cao
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 11) pp:8223
Publication Date(Web):May 8, 2014
DOI:10.1021/am5009776
F-doped SnO2 (FTO) nanocrystals modified by Er and Yb with upconversion capability and excellent catalytic properties have been designed and fabricated as an economic replacement for Pt for use as the counter electrode (CE) in dye-sensitized solar cells. The cost of the UC-FTO counter electrode is only ∼1/20th of that for Pt. The upconverted luminescence-mediated energy transfer and the superior catalytic property for I3–/I– circulation overpowered the slight degradation caused by increased CE/electrolyte interface resistance. A 23.9% enhancement in photocurrent was achieved with little degradation in photovoltage, resulting in a 9.12% increase in solar-to-electric power conversion efficiency. Near-infrared (NIR) light-to-electricity has been directly observed by SPS and IPCE characterizations, showing the effect of the upconversion counter electrode.Keywords: conductive; counter electrode; dye-sensitized solar cells; low cost; Pt-free; upconversion;
Co-reporter:Liang Li, Yulin Yang, Ruiqing Fan, Yanxia Jiang, Liguo Wei, Yan Shi, Jia Yu, Shuo Chen, Ping Wang, Bin Yang, Wenwu Cao
Journal of Power Sources 2014 Volume 264() pp:254-261
Publication Date(Web):15 October 2014
DOI:10.1016/j.jpowsour.2014.04.100
•UC-YF3 is utilized as an attachment layer in DSSC.•UC-YF3 as light scattering layer achieve a higher power-conversion efficiency.•FRET and FRET-like process are found in the modified DSSC.•The NIR-photon to electron process is confirmed by SPS and IPCE.Upconversion (UC) Er, Yb-YF3 is introduced into dye-sensitized solar cells (DSSC) through a simple method to investigate the effect of UC particles in photoanode. The utilization of UC phosphor can significantly improve the photocurrent of the cells under both infrared irradiation and sunlight. Fluorescence resonance energy transfer (FRET) and luminescence-mediated energy transfer between UC-YF3 and N719 dye are explored as the main contribution that UC-YF3 made to DSSC. With the multi-efforts of UC-YF3, power conversion efficiency (PCE) of DSSC is improved from 5.18% to 6.22%. Besides, Electron transfer between UC-YF3 and TiO2 is found after sintered at 450 °C, and the PCE value of DSSC is improved further (5.34% → 6.76%). In addition, we explore that UC-YF3 can serve as a scattering material to increase the light absorption capability of the cells and increase the photocurrent of the cells under simulated sunlight irradiation.
Co-reporter:Jia Yu, Yulin Yang, Ruiqing Fan, Danqing Liu, Liguo Wei, Shuo Chen, Liang Li, Bin Yang, and Wenwu Cao
Inorganic Chemistry 2014 Volume 53(Issue 15) pp:8045-8053
Publication Date(Web):July 14, 2014
DOI:10.1021/ic501041h
New near-infrared (NIR)-to-green upconversion nanoparticles of Ho3+-Yb3+-F– tridoped TiO2 (UC-F-TiO2) were designed and fabricated via the hydrosol–hydrothermal method. Under 980 nm NIR excitation, UC-F-TiO2 emit strong green upconversion fluorescence with three emission bands at 543, 644, and 751 nm and convert the NIR light in situ to the dye-sensitive visible light that could effectively reduce the distance between upconversion materials and sensitizers; thus, they minimize the loss of the converted light. Our results show that this UC-F-TiO2 offers excellent opportunities for the other types of solar cells applications, such as organic solar cells, c-Si solar cells, multijunction solar cells, and so on. When integrating the UC-F-TiO2 into dye-sensitized solar cells (DSSCs), superior total energy conversion efficiency was achieved. Under AM1.5G light, open-circuit voltage reached 0.77 ± 0.01 V, short-circuit current density reached 21.00 ± 0.69 mA cm–2, which resulted in an impressive overall energy conversion efficiency of 9.91 ± 0.30%, a 37% enhancement compared to DSSCs with pristine TiO2 photoanode.
Co-reporter:Shuo Chen, Rui-Qing Fan, Xin-Ming Wang and Yu-Lin Yang
CrystEngComm 2014 vol. 16(Issue 27) pp:6114-6125
Publication Date(Web):07 Apr 2014
DOI:10.1039/C4CE00382A
Five IIB group complexes, [ZnL1Cl2] (1), {[CdL1Cl2]}2 (2), [Cd(L1)2(NO3)2]·H2O (3), [HgL1Cl2] (4), and [ZnL2Cl2] (5) [L1 = 1-[2-(6-methoxy-2-pyridylmethyl)]-2-[2-(6-methoxy-pyridyl)]benzimidazole; L2 = 2-[2-(6-methoxypyridyl)]benzimidazole] have been synthesized and structurally characterized by elemental analysis, IR spectroscopy, 1H NMR, 13C NMR and X-ray single-crystal analyses. The structural investigations testify that the ionic radius and counterions (Cl− and NO3−) cooperatively affect the coordination mode of central metal. As small and medium radii, four-coordinated Zn2+ (1 and 5) and five-coordinated Cd2+ (2) possess tetrahedron and trigonal bipyramid geometries, respectively. Though Hg2+ (4) has a larger radius, its three-coordinated geometry is trigonal planar in order to eliminate repulsive forces. Further observations illustrate that Cd2+ (3) is bound to two ligands L1 when NO3− is the counter anion, forming seven-coordinated monocapped trigonal prismatic geometry. Complexes 1–5 display bright blue luminescence with the emission maxima (λmax) ranging from 399 to 499 nm at 298 K, depending on the N,N′-chelating ligand-centered π* → π transition. Upon cooling to 77 K, the complexes show rich structured emission profiles compared to those at 298 K. The emission lifetimes of L and 1–5 are on the microsecond scale. The emission efficiency of 1–5 is shown by quantum yields ranging from 0.23 to 0.40. Complexes 1–5 offer a good insight into the opportunities in the utilization of blue materials for application and function.
Co-reporter:Song Gao, Rui-Qing Fan, Liang-Sheng Qiang, Ping Wang, Shuo Chen, Xin-Ming Wang and Yu-Lin Yang
CrystEngComm 2014 vol. 16(Issue 6) pp:1113-1125
Publication Date(Web):22 Nov 2013
DOI:10.1039/C3CE42216J
In this work, we present the synthesis of three novel 3D Cd(II) coordination polymers, {[Cd(IN)2]·H2O}n (1), [Cd2(IN)2(SO4)(DMF)2]n (2) and {[Cd3(IN)5.5]·0.5OH−}n (3) (HIN = isonicotinic acid). Coordination polymers 1 and 2 were obtained via solvothermal reactions. The synthesis of coordination polymer 3 was realized by a simple temperature induced single crystal to single crystal transition from 1. Single-crystal X-ray diffraction analyses revealed that 1–3 exhibit three different structural types: 1 displays a (6,3)-connected rtl net with the Schläfli symbol (4·62)2 (42·610·83) constructed from mononuclear [CdO4N2] clusters with the help of HIN. 2 is defined as a 6-connected pcu net with the Schläfli symbol {412·63} which is built from binuclear [Cd2(SO2)2] clusters and HIN linkers. 3 can be regarded as a 9-connected ncd net with the Schläfli symbol {36·422·58}, which consists of paddlewheel trinuclear [Cd3(O2C)5] clusters and a bridging HIN. Coordination polymers 1–3 display luminescence with emission maxima containing deep blue, blue, light blue and green at 298 K or 77 K both in solvents (polarity: DMF > CH3OH > CH2Cl2) and in the solid state. The lifetime of all the molecules is in microsecond scale.
Co-reporter:Yan Shi, Yu-Lin Yang, Rui-Qing Fan, Liang Li, Jia Yu and Shuo Li
RSC Advances 2014 vol. 4(Issue 33) pp:17245-17248
Publication Date(Web):31 Mar 2014
DOI:10.1039/C3RA42021C
β-In2S3 solid micro-spheres composed of wedge-like octahedra, and hollow micro-spheres composed of nanorods have been fabricated by a simple one-step hydrothermal treatment. The unique surface photovoltage properties of the as-prepared In2S3 samples were investigated through surface photovoltage (SPV) spectroscopy.
Co-reporter:Shuo Chen, Rui-Qing Fan, Song Gao, Xinming Wang, Yu-Lin Yang
Journal of Luminescence 2014 Volume 149() pp:75-85
Publication Date(Web):May 2014
DOI:10.1016/j.jlumin.2014.01.006
•A series of N4-donor Schiff base lanthanide complex are designed and synthesized.•The characteristic luminescence from visible to near infrared region could be revealed.•The influence of deuterated reagent and temperature on luminescent properties is described.A series of lanthanide complexes [LnL(NO3)3]·CH3CN [Ln=Ce, (1•Ce); Nd, (2•Nd); Tb, (3•Tb); Dy, (4•Dy); Ho, (5•Ho); Er, (6•Er); Tm, (7•Tm); Yb (8•Yb)] have been synthesized by the reaction of N4 chelate ligand N,N'-bis(2-pyridinylmethylene)cyclohexane-1,2-diamine (L) with lanthanide salts. Photoluminescence spectra of complexes 2•Nd, 3•Tb, 4•Dy, and 8•Yb show the strong characteristic luminescence from visible to near infrared (NIR) region. Further, the singlet state (32,467 cm−1) and the lowest triplet (23,202 cm−1) energy level of L are calculated, indicating that the energy transfer from L to Tb3+ ion is more effective than that to Dy3+ ion. An extended work is developed to discuss on the effect of deuterated reagent and temperature on luminescent properties of 3•Tb and 8•Yb.
Co-reporter:Shuo Chen, Ruiqing Fan, Xinming Wang, Yulin Yang
Inorganic Chemistry Communications 2014 Volume 44() pp:101-106
Publication Date(Web):June 2014
DOI:10.1016/j.inoche.2014.03.006
•A novel indium complex was synthesized by the tetradentate Schiff base ligand.•Complex 1 exhibits blue emitting with the millisecond lifetime.•The effect of deuterated reagent and temperature on luminescent properties is discussed.A novel indium complex {[InL(NO3)(OH)] · NO3 · CH3OH}2 (1) is isolated from the refluxing reaction of a tetradentate Schiff base ligand, N,N′-bis(2-pyridinylmethylene)cyclohexane-1,2-diamine (L), and In(III) nitrate hydrate. The room temperature (298 K) and cryogenic temperature (77 K) emission spectra of 1 are recorded in solid state and different solvents (CH3OH, CHCl3, CH3CN and DMSO). Complex 1 exhibits a pronounced bathochromic shift in emission spectra as solvent polarity increases (polarity order: DMSO > CH3CN > CHCl3), indicating a change in dipole moment of 1 upon excitation. Further bathochromic shift exists in CH3OH (467 nm) solution. An extended work is developed to discuss on maximum emission and lunminescent lifetime of 1 dispersed in the deuterated reagents (CD3OD, CDCl3, CD3CN and DMSO-d6). The results exhibit that the similar emission also exists in deuterated reagents and the longer lifetime is observed due to the scarcity of OH, NH, and CH oscillators. The quantum yield of 1 decreases with increasing polarity of solvent within the region of 7.8–15.4%. Commission Internationale de L'Eclairage (CIE) 1931 demonstrates that the color gamut of 1 is blue.One novel indium complex {[InL(NO3)(OH)] · CH3OH · NO3}2 is obtained. The emission is sensitive to the polarity of the solvent as well as specific solute–solvent interaction such as hydrogen bonding. In addition, the utilization of deuterated solvents can favor to prolong lifetime.
Co-reporter:Jia Yu ; Yulin Yang ; Ruiqing Fan ; Liang Li ;Xinyuan Li
The Journal of Physical Chemistry C 2014 Volume 118(Issue 17) pp:8795-8802
Publication Date(Web):April 9, 2014
DOI:10.1021/jp500870v
Nitrogen- and fluorine-doped flower-like anatase TiO2 (NF-TiO2) with {001} dominated facets was fabricated by a facile hydrothermal method. We investigated its electrical and optical properties, applied it in dye-sensitized solar cells as an electrode material, and achieved an improved conversion efficiency of 8.20%. There was a 52% increase in the photocurrent and 22% improvement in the conversion efficiency. Such improvements mainly arise from the positive-shift flat band, increasing the driving force of electrons and then improving the electron injection efficiency from the lowest unoccupied molecular orbital (LUMO) of the dye and the conduction band of TiO2; from the incorporation of the flower-like anatase NF-TiO2 crystals with exposed {001} facets, serving as effective light-scattering centers and improving the reactivity, both important attributes for achieving a higher light harvesting and thus an improved Jsc and conversion efficiency; and from the narrowed band gap, expanding the response in the visible region and increasing the utilization percentage of visible light. This study provides straightforward evidence for the nitrogen- and fluorine-doped {001} facets dominated anatase TiO2, and with these merits, NF-TiO2 with {001} dominated facets may find its way in various environmental and energy-related applications.
Co-reporter:Mengying Xu;Zhigang Liu;Ruiqing Fan
Chemical Research in Chinese Universities 2014 Volume 30( Issue 5) pp:720-725
Publication Date(Web):2014 October
DOI:10.1007/s40242-014-4032-z
A novel one dimension(1D) cadmium coordination polymer {[Cd(mpda)3]·2(NO3)}n(1) was synthesized via refluxing a mixture of tetradentate Schiff base ligand N,N′-bis(2-pyridinylethylidene)phenylene-1,3-diamine(L) and Cd(NO3)2 in acetonitrile, whose structure was characterized by means of single crystal X-ray diffraction, FTIR spectroscopy, elemental analysis and proton nuclear magnetic resonance(1H NMR). Center metal Cd(II) ion is six-coordinated by six nitrogen atoms from six different m-phenylenediamine(mpda), giving rise to a [CdN6] octahedral coordination environment. The two adjacent cadmium centers are linked by three mpda molecules leading to the construction of 1D chain structure. The crystal structure is stabilized by N—H…O hydrogen bonds to form three-dimension supramolecule. Compound 1 exhibits intense yellow luminescence in solid state at 298 K(λem=554 nm), which shows a blue shift at 77 K(ca. 147 nm). Additionally, fluorescence characteristics of compound 1 were investigated in different solvents(polarity: DMSO>CH3CN>CH3OH>CHCl3>toluene) at 298 and 77 K. The results show that the emission peak of compound 1 in solvent exhibits a slight bathochromic shift. However, the emission peaks of compound 1 in CH3OH and CHCl3 are red shift compared with that in CH3CN. It is revealed that the luminescence behavior of compound 1 depends on not only the polarity of solvent but also the hydrogen bonding properties between solvent and solute. In addition, the emission peak of compound 1 in solution shows a red shift obviously at 77 K than that at 298 K(ca. 144–159 nm), with the fluorescence lifetime increased at 77 K. The lifetime in DMSO at 77 K(τ=12.470 μs) was the longest one. The quantum yield of compoud 1 increases with increasing the polarity of solvent within a range of 1.8%–8.3 %.
Co-reporter:Guangpeng Zhou, Jiajun Han, Yulin Yang, Ruiqing Fan, Juan Li, Liqiu Fu, Yuan Zhang
Inorganic Chemistry Communications 2014 40() pp: 124-128
Publication Date(Web):
DOI:10.1016/j.inoche.2013.11.039
Co-reporter:Lingyun Zhang, Yulin Yang, Ruiqing Fan, Jia Yu and Liang Li
Journal of Materials Chemistry A 2013 vol. 1(Issue 39) pp:12066-12073
Publication Date(Web):25 Jul 2013
DOI:10.1039/C3TA11570D
Pr and N co-doped ZnO (Pr:N:ZnO, doping concentration: 1 mol% Pr, 0.36 mol% N) was synthesized using an annealing method under an atmosphere of NH3 gas in a custom stainless steel autoclave. Scanning electron microscopy (SEM) was used to characterize the morphology of Pr:N:ZnO. The structure and chemical composition of the material were characterized using X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS). The results demonstrated that Pr:N:ZnO maintained a hexagonal wurtzite structure, and that Pr and N atoms were successfully incorporated into the lattice of ZnO. The co-doping of Pr and N has a significant influence on the optical properties of ZnO. UV-visible absorption spectroscopy (UV-vis) showed that Pr and N co-doping led to a red shift of the absorption edge of ZnO into the visible-light region. UV-visible absorption spectroscopy and surface photovoltage spectroscopy (SPS) demonstrated that the band gap of ZnO was narrowed with the dopant atoms generating impurity sub-bands. The incident photon-to-current conversion efficiency (IPCE) spectra demonstrated that Pr and N co-doping could successfully improve the light harvesting of a DSSC. The transient photovoltage (TPV) indicated that Pr and N co-doping increased the rate of charge separation and the electron lifetime. A dye-sensitized solar cell with Pr:N:ZnO as the anode exhibited a short-circuit photocurrent density as high as 13.84 mA cm−2, an open-circuit photovoltage of 590 mV, a fill factor of 0.63, and an overall light conversion efficiency of 5.2% under standard global AM 1.5 solar irradiation conditions.
Co-reporter:Ping Wang, Rui-Qing Fan, Yu-Lin Yang, Xin-Rong Liu, Peng Xiao, Xin-Yu Li, Wuliji Hasi and Wen-Wu Cao
CrystEngComm 2013 vol. 15(Issue 22) pp:4489-4506
Publication Date(Web):28 Mar 2013
DOI:10.1039/C3CE40184G
One-dimensional to three-dimensional lanthanide coordination polymers 1–8 based on benzimidazole-5,6-dicarboxylic acid (H3BIDC) have been synthesized under hydrothermal conditions at different pH values, generally formulated as {[Pr(HBIDC)(ox)0.5(H2O)]·H2O}n (1), [Yb(HBIDC)(ox)0.5(H2O)2]n (2), and [Ln(HBIDC)(ox)0.5(H2O)3]n [Ln = Ho (3), and Tb (4)] and {[Ln(H2BIDC)(HBIDC)(H2O)3]·3H2O}n [Ln = Tb (5), Sm (6), Dy (7), and Gd (8), H2ox = oxalic acid]. All coordination polymers have been characterized by elemental analysis, infrared spectra and single-crystal X-ray diffraction. The structural diversity, luminescence and thermal properties of all coordination polymers have been investigated. Coordination polymers 1–8 exhibit four different structural types: topological analysis has given the 3-D pcu network, with the point symbol of {412·63} in coordination polymer 1. Coordination polymer 2 exhibits a 4-connected 44 topology, and coordination polymers 3–4 appear as 2-D (6,3)-connected hcb network topology. The 1-D helical infinite chain of coordination polymers 5–8 around the crystallographic 21 axis spread along the b axis direction, with different 1-D helical infinite chains forming 3-D supramolecular framework via hydrogen bonds and π–π stacking interactions. The coordination polymers 4 and 5 could be triggered to have intense characteristic lanthanide-centered green luminescence under UV excitation in the solid state at room and liquid nitrogen temperature, or dispersed in CH2Cl2 at 77 K. In coordination polymers 4 and 5, the oxalic acid introduced into coordination polymer 4 as a second ligand further sensitized the trivalent terbium ion, and resulted in longer fluorescence lifetimes of coordination polymer 4 (1058.58 μs at 298 K, 679.42 μs at 77 K in the solid-state, 867.82 μs in CH2Cl2 at 77 K) than coordination polymer 5 (595.06 μs at 298 K, 583.19 μs at 77 K in the solid-state, 584.38 μs in CH2Cl2 at 77 K). In coordination polymers 6 and 7, we not only measured emission spectra in the visible region, but also detected the infrequent NIR emission spectra in the near infrared region of samarium and dysprosium ions. The singlet excited state (30303 cm−1) and the lowest triplet state energy level (24390 cm−1) of H3BIDC ligand were calculated based on the UV-vis absorbance edges of ligand and the phosphorescence spectrum of Gd(III) coordination polymer (8) at 77 K, showing that the effective extent of energy transfer from H3BIDC ligand to lanthanide ions follows the sequence of Tb3+, Dy3+ > Sm3+. Finally, thermal behaviors of all coordination polymers were studied by thermogravimetric analysis, which exhibited high thermal stability.
Co-reporter:Ping Wang, Rui-Qing Fan, Xin-Rong Liu, Li-Yuan Wang, Yu-Lin Yang, Wen-Wu Cao, Bin Yang, WuLiJi Hasi, Qing Su and Ying Mu
CrystEngComm 2013 vol. 15(Issue 10) pp:1931-1949
Publication Date(Web):08 Jan 2013
DOI:10.1039/C3CE26684B
Three series of two-dimensional and three-dimensional lanthanide coordination polymers {[Ln(ox)1.5(H2O)3]·mH2O}n [Ln = Ce (1), m = 2 and Pr (2), m = 3, H2ox = oxalic acid], {[Ln(ox)2(H3O)]·EtOH·3H2O}n [Ln = Nd (3), Sm (4), Eu (5), Gd (6), Tb (7), Dy (8), Ho (9), Er (10) and Yb (11), EtOH = ethanol] and {[Ln2(IMDC)2(H2O)3]·mH2O}n [Ln = Sm (12), Eu (13), Gd (14), Tb (15) and Dy (16), where m = 2.25 except for 15 where m = 1.75, H3IMDC = imidazole-4,5-dicarboxylic acid] have been synthesized under hydrothermal conditions. All the coordination polymers have been characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Coordination polymers 1–11 exhibit two different structural types: the 2-D structure of coordination polymers 1–2 are a (6,3)-connected hcb network, coordination polymers 3–11 appear as a 3-D diamond structure with 66-network topology. Coordination polymers 12–16 are 3-D structures constructed from the bridged carboxyl group of IMDC3−, in which IMDC3− bridged the DNA-like double-helix line and the triple-helix line, intertwined and connected into a 1-D chain and then conformed into a 3-D structure along the ab plane. The different structures of the two dicarboxylate ligands (oxalic acid as a flexible ligand and imidazole-4,5-dicarboxylic acid as a rigid planar ligand) were described and discussed. Furthermore, the luminescent properties in the visible region and the fluorescence lifetimes of the coordination polymers exhibited the characteristic transitions of the corresponding lanthanide ions. It was noted that coordination polymers 5 and 7 have long solid-state fluorescence lifetimes of 824.84 and 733.87 μs, respectively. The NIR emission spectra of the Nd (3), Sm (4 and 12), Dy (8 and 16) and Yb (3) coordination polymers in the solid-state were measured. The singlet excited state (30842 cm−1 for oxalic acid, 32258 cm−1 for H3IMDC) and the lowest triplet state energy level (23753 cm−1 for oxalic acid and 22371 cm−1 for H3IMDC) of the H2ox and H3IMDC ligand were calculated on the basis of the UV-Vis absorbance edges of the ligand and the phosphorescence spectrum of the Gd(III) coordination polymers 6 and 14 at 77 K, respectively. The relationship between the lowest triplet state energy level of the two dicarboxylate ligands and lowest resonance energy levels of the Sm(III), Eu(III), Tb(III) and Dy(III) ions were described and discussed. The results showed that the energy transfer from the oxalic acid ligands is much more effective than H3IMDC.
Co-reporter:Liguo Wei, Yulin Yang, Ruiqing Fan, Ping Wang, Liang Li, Jia Yu, Bin Yang and Wenwu Cao
RSC Advances 2013 vol. 3(Issue 48) pp:25908-25916
Publication Date(Web):04 Oct 2013
DOI:10.1039/C3RA44194F
Three organic dyes 2,6-bis(iminoalkyl)pyridines [2,6-(2,6-R2C6H2NCMe)2]C5H3N (R = methyl, ethyl, isopropyl) (named DM, DE and DP, respectively) were synthesized and assembled onto nanocrystalline TiO2 film to prepare 2,6-bis(iminoalkyl)pyridine/N719 co-sensitized photoelectrodes for dye-sensitized solar cell (DSSCs) applications, and their photoelectrochemical performances were studied. In each of the three composite electrodes, the aggregation of N719 was alleviated and its spectra response was enhanced by the 2,6-bis(iminoalkyl)pyridines in region of 400 to 750 nm, and the total resistance of DSSCs was decreased after co-sensitizing with 2,6-bis(iminoalkyl)pyridine, all of which facilitate to improve efficiency of DSSCs. The optimized cell which was co-sensitized with DM gave a short circuit current density of 16.57 mA cm−2, an open circuit voltage of 0.72 V and a fill factor of 0.59 corresponding to an overall conversion efficiency of 7.00% under standard global AM1.5 solar irradiation conditions, which is 28.91% higher than that for DSSCs only sensitized by N719 (5.43%). The incident photo-to-current conversion efficiency, electrochemical impedance spectroscopy, surface photovoltage spectroscopy and UV-visible adsorption spectra were used to analyze their photoelectrochemical performances, and X-ray single-crystal structural analysis was used to analyze the structures of 2,6-bis(iminoalkyl)pyridines.
Co-reporter:Liang Li, Yulin Yang, Xinrong Liu, Ruiqing Fan, Yan Shi, Shuo Li, Lingyun Zhang, Xiao Fan, Pengxiao Tang, Rui Xu, Wenzhi Zhang, Yazhen Wang, Liqun Ma
Applied Surface Science 2013 Volume 265() pp:36-40
Publication Date(Web):15 January 2013
DOI:10.1016/j.apsusc.2012.10.075
Abstract
B-doped TiO2 was synthesized by a direct hydrolyzation of n-tetrabutyl titanate in a solution of boric acid, and was treated by hydro-thermal synthesis. The powder was characterized by X-ray diffraction (XRD), FT-IR, scanning and transmission electron microscopy (SEM and TEM), surface photoviolet spectra, UV–visible absorption spectra and X-ray photoelectron spectroscopy (XPS). Rhodamine B (RhB) degradation was used as a probe reaction to evaluate the photocatalytic activity of B-doped TiO2 under simulate sunlight, and excellent photocatalytic performance was achieved.
Co-reporter:Li Liang, Yang Yulin, Zhou Mi, Fan Ruiqing, Qiu LeLe, Wang Xin, Zhang Lingyun, Zhou Xuesong, He Jianglong
Journal of Solid State Chemistry 2013 Volume 198() pp:459-465
Publication Date(Web):February 2013
DOI:10.1016/j.jssc.2012.10.013
TiO2 with NIR-absorption and visible upconversion luminescence (UC-TiO2) is prepared by a sol–gel method and calcined at 700 °C for 6 h. The material broadens the response region of dye sensitized solar cells (DSSCs) from an ultraviolet–visible region to the whole region of the solar spectrum. It shifts NIR sunlight to visible light which matches the strong absorbing region of the dye (N719). DSSCs based on UC-TiO2 achieved higher conversion efficiency than that on raw TiO2. UC-TiO2 was mixed with commercial raw TiO2 as additive, and the short-circuit current density, open-circuit voltage and conversion efficiency of the DSSC reached to the optimum values 13.38 mA/cm2, 0.78 V and 6.63% (AM1.5 global), comparing with the blank values: 7.99 mA/cm2, 0.75 V and 4.07%, respectively. Also the mechanisms of upconversion by multiphoton absorption and energy transfer processes are interpreted in this paper.Graphical abstractBy introducing TiO2 with NIR-absorption and visible up-conversion luminescence into DSSC, a signal reflection was explored from ultra-violet region to visible region, and to near-IR region.Highlights► TiO2 with NIR-absorption and visible up-conversion luminescence (UC-TiO2) was prepared by a sol–gel method. ► A systematic characterization and analysis was carried out to discuss the mechanism. ► A significantly enhanced performance of DSSC was explored by using UC-TiO2 as an additive.
Co-reporter:Guang-peng Zhou;Rui-qing Fan
Chemical Research in Chinese Universities 2013 Volume 29( Issue 2) pp:201-205
Publication Date(Web):2013 April
DOI:10.1007/s40242-013-2212-x
Two new open-framework gallium phosphites formulated as (C2N2H10)0.5Ga2(OH)(H2O)(HPO3)3(1) and (C3N2H5)2(C3N2H6)Ga8(H2O)6(HPO3)14(2) were hydrothermally synthesized in the presence of ethylenediamine(en) and imidazole as structure directing agents(SDA), respectively. Structural analyses reveal that the 3D structures of compounds 1 and 2 are both built up from the linkage of GaO6, GaO5(H2O) and HPO32− units by sharing vertices. The structure of compound 2 is constructed from well-known 4.6.12-net connecting layers in the AAAA stacking sequence, which are penetrated by the 1D Ga-O-P chains to form a 3D pillared-layered structure.
Co-reporter:Lingyun Zhang, Yulin Yang, Ruiqing Fan, Ping Wang, Liang Li
Dyes and Pigments 2012 Volume 92(Issue 3) pp:1314-1319
Publication Date(Web):March 2012
DOI:10.1016/j.dyepig.2011.09.007
We designed a new type of sensitizer for dye-sensitized solar cells based on ZnO photoelectrode. Three five-coordinate transition metal complexes [2,6-(ArNCMe)2C5H3NMCl2·nCH3CN] (MZn, Cd, Hg) (named as Zn1, Cd1, Hg1), have been synthesized. In all complexes, the metal center is tridentately chelated by the ligand and further coordinated by two chlorine atoms, resulting in distorted trigonal bipyramidal geometry. The improvement in conversion efficiency of dye-sensitized solar cell was achieved by the complexes (M) and N719 co-sensitizing ZnO photoelectrode. In the tandem structure of M/N719/ZnO, the M forms a re-organization of energy level due to its single-crystal structure, which is advantageous to the electron injection and the hole recovery. The result demonstrates the M/N719 co-sensitized solar cell exhibited excellent photovoltaic performances with the short-circuit photocurrent density of 8.943 mA cm−2, the open-circuit photovoltage of 591 mV and the fill factor of 0.639 under standard global AM 1.5 solar irradiation conditions.Highlights► Three five-coordinate transition metal complexes were synthesized and designed to be a new type of sensitizer for solar cells. ► The effect of the complex on ZnO-based dye-sensitizer solar cells was investigated. ► The overall conversion efficiency of ZnO-based dye-sensitized solar cells is successfully improved by co-sensitizing.
Co-reporter:Shuo Chen, Rui-Qing Fan, Cun-Fa Sun, Ping Wang, Yu-Lin Yang, Qing Su, and Ying Mu
Crystal Growth & Design 2012 Volume 12(Issue 3) pp:1337-1346
Publication Date(Web):January 18, 2012
DOI:10.1021/cg201411b
A series of novel lanthanide coordination polymers have been successfully synthesized under hydrothermal or solvothermal conditions, namely, [Eu2(2,4′-bpdc)2(OH)(NO3)(H2O)3]n (1), [Ln(2,4′-bpdc)(1,4-bdc)0.5(DMF)-(H2O)·H2O]n [Ln = Eu (2); Ln = Pr (3); Ln = Nd (4)], [Ln(2,4′-bpdc)(DMF)2NO3]n [Ln = Eu (5); Ln = Nd (6); Ln = Gd (7)], and [Eu(2,4′-bpdc)(2,4′-Hbpdc)(H2O)]n(8), (2,4′-H2bpdc = 2,4′-biphenyldicarboxylic acid, 1,4-H2bdc = 1,4-benzenedicarboxylic acid, and DMF = N,N′-dimethylformamide). X-ray crystallographic studies reveal that 1 features a three-dimensional (3D) framework with 45 topology. 2–4, which are isostructural and synthesized by using a mixture of 2,4′-H2bpdc and 1,4-H2bdc, exhibit two-dimensional (2D) (3,4)-connected net structures. 5–7 show 2D layered structures containing double helix chains (Δ and Λ) with 44 topology. 8 possesses a 2D layered structure containing (4,6)-connected networks, which are connected by means of infinite zigzag chains linked by 2,4′-bpdc2– and 2,4′-Hbpdc– anions. Furthermore, steady-state and time-resolved spectroscopic measurements reveal that the four Eu(III) complexes, 1, 2, 5, and 8, exhibit remarkable red luminescence emissions with lifetimes at the millisecond scale. Complexes 4 and 6 display characteristic luminescent properties for Nd(III) in the near-infrared region. The singlet state and the lowest triplet level of ligand 2,4′-H2bpdc were calculated on the basis of the UV–vis absorbance edges of ligand and the phosphorescence spectrum of Gd(III) complex 7. The energy transfer mechanisms in the lanthanide polymers are described and discussed.
Co-reporter:Guangpeng Zhou, Yulin Yang, Ruiqing Fan, Wenwu Cao and Bin Yang
CrystEngComm 2012 vol. 14(Issue 1) pp:193-199
Publication Date(Web):21 Oct 2011
DOI:10.1039/C1CE05841J
Three new indium coordination polymers formulated as In(phen)(BPDA)1.5 (1), In(OH)(H2O)(BPDA) (2), and In(BPDA)2·Me2NH2·H2O (3) (phen = 1,10-phenanthroline, C12N2H8; H2BPDA = 4,4′-biphenyldicarboxylic acid, C14O4H10; Me2NH = dimethylamine, C2H7N), have been synthesized under hydro(solvo)thermal conditions and characterized by infrared (IR), thermal gravimetric analysis (TGA) and luminescence studies. In the two-dimensional (2D) trapezoid-like layer of 1, three BPDA2− anions and one phen group bind to a seven-coordinated In3+ ion with the distorted pentagonal bi-pyramid geometry. In 2, the extended –In–OH–In– chains are connected through BPDA2− to form a 3D framework. Complex 3 possesses a two-fold interpenetrating structure, which consists of two independent infinite diamond-like frameworks with point symbol 66. All three samples exhibit varied solid-state fluorescence: emissions at 468 nm (intense blue), 559 nm (greenish-yellow), and 577–645 nm (broad intense orange band with a maximum at 611 nm, λex = 257 nm) for 1, 567 nm (weak greenish-yellow, λex = 344 nm) for 2, and 480 nm (intense greenish-blue, λex = 385 nm) for 3.
Co-reporter:Xin Wang, Yu-Lin Yang, Ping Wang, Liang Li, Rui-Qing Fan, Wen-Wu Cao, Bin Yang, Hui Wang and Jing-Yao Liu
Dalton Transactions 2012 vol. 41(Issue 35) pp:10619-10625
Publication Date(Web):19 Jun 2012
DOI:10.1039/C2DT30430A
Two lanthanide complexes, Ln(HPDA)3·4EtOH (Ln = Tb, Dy) (H2PDA = pyridine-2,6-dicarboxylic acid, EtOH = ethanol), have been successfully synthesized using hydrothermal or solvothermal methods, and their crystal structures were analyzed by single crystal XRD. Both crystals have orthorhombic symmetry with space group Pbcn, exhibiting three-dimensional (3D) supramolecular architecture through hydrogen bonding interactions. The metal center was coordinated to nine atoms by three pyridine-2,6-dicarboxylic acid ligands. The nine-coordinated lanthanide metal complexes were assembled onto a nanocrystalline TiO2 film to form co-sensitized photoelectrodes with N719 for dye-sensitized solar cells, and their photoelectrochemical performance was studied. In the tandem structure of composite electrodes, the energy levels of lanthanide metal complexes are reorganized in their single-crystal form, as verified by ab initio calculations. The co-sensitized systems are far superior for electron-injection and hole-recovery compared with single N719-sensitized systems. Luminescence properties were measured and electrochemical analysis was also performed on these complexes.
Co-reporter:Guangpeng Zhou, Yulin Yang, Ruiqing Fan
Inorganic Chemistry Communications 2012 Volume 16() pp:17-20
Publication Date(Web):February 2012
DOI:10.1016/j.inoche.2011.11.018
A new 2D gallium metal–organic framework formulated as Ga(OH)(BPDA) (1) (H2BPDA = 2,4′-biphenyldicarboxylic acid, C14O4H10) has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, infrared (IR) spectroscopy, thermal gravimetric analysis (TGA) and luminescence studies. The neutral layer structure of the coordination polymer 1 is constructed from GaO4(OH)2 octahedra and organic BPDA2- linkers, with the parallelogram tunnels joined through one-dimensional OHGaOH chains. Complex 1 exhibits intense green-blue emission at 482 nm (λex = 329 nm) in the solid state at room temperature.A new 2D gallium-2,4′-biphenyldicarboxylate layer with (6,4) topological structure and parallelogram tunnels.Highlights► A new gallium layer structure with parallelogram tunnels. ► The 2D layer displays (6,4) topological structure. ► The complex exhibits intense green-blue emission at room temperature.
Co-reporter:Lingyun Zhang, Yulin Yang, Ruiqing Fan, Haiyan Chen, Ruokun Jia, Yonghui Wang, Liqun Ma, Yazhen Wang
Materials Science and Engineering: B 2012 Volume 177(Issue 12) pp:956-961
Publication Date(Web):25 July 2012
DOI:10.1016/j.mseb.2012.04.026
In this study two methods, namely the solution and annealing methods, were used to prepare nitrogen-doped ZnO. The X-ray photoelectron spectroscopy (XPS) was performed to identify the composition and chemical states of N-doped ZnO. The N doping by the solution method was found to effectively decrease the acceptor effects. Surface photovoltage measurements (SPS) revealed a redshift of the threshold wavelength for the N-doped ZnO. And the recombination of photoinduced electron–hole pairs in this semiconductor material was obviously suppressed. The N-doped ZnO (solution method) exhibits the best performances among all the materials, even superior to N-doped ZnO (annealing method). Its Jsc and η values (9.35 mA/cm2 and 2.64%) have enhanced by several times compared with un-doped ZnO (Jsc, 2.85 mA/cm2; η, 0.67%). The overall conversion efficiency of ZnO-based dye-sensitized solar cells was successfully improved by the N doping.Graphical abstractHighlights► Two methods (the solution and annealing methods) are used to prepare nitrogen-doped ZnO. ► The charge-transfer properties of N-doping ZnO are investigated. ► The overall conversion efficiency of N-doped ZnO-based dye-sensitized solar cells is successfully improved by N doping.
Co-reporter:Ping Wang;Rui-Qing Fan;Xing-Rong Liu
Journal of Inorganic and Organometallic Polymers and Materials 2012 Volume 22( Issue 4) pp:744-755
Publication Date(Web):2012 July
DOI:10.1007/s10904-011-9633-0
Four lanthanide coordination polymers, {[Ln(HPDA)(PDA)(H2O)2]·4H2O}n (Ln = Sm (1), Eu (2), Tb (3)) and {[Sm3(H2PDA)2(HPDA)2(PDA) (OH)5(H2O)3]·2dta·4H2O}n (4) (H2PDA = pyridine-2,6-dicarboxylic acid, dta = diethyl amine), have been synthesized under hydrothermal conditions and were characterized by elemental analysis, IR spectrometer, and single-crystal X-ray crystallography. In the complexes 1–3, the 1D chains are assembled into 2D layer by hydrogen bonds formed between the carboxyl groups, and were further assembled into 3D framework by hydrogen bonds and π–π stacking interactions. In complex 4, each Sm3+ ion connected to the neighboring Sm3+ ion through bridging carboxyl oxygen atoms, and then give rise to a new 2D layered open-framework structure. The 3D supramolecular structure of 4 is constructed through hydrogen-bonding and π–π stacking interactions between adjacent metal–organic polymeric coordination chains. Complexes 1–3 were dispersed in mesoporous materials SBA-15 in DMF solution (denoted as ML-SBA-15, ML = 1, 2, 3), which were characterized by XRD, IR, and fluorescence spectra. Compared to the complexes 1–3, the photoluminescence efficiency of hybrid material was improved by the energy transition between mesoporous materials and the complexes. The complexes encapsulated in mesoporous materials SBA-15 exhibited stronger luminescence intensity and longer fluorescence lifetime.
Co-reporter:Xin Wang, Yu Lin Yang, Ruiqing Fan, Yonghui Wang, Zhao Hua Jiang
Journal of Alloys and Compounds 2010 Volume 504(Issue 1) pp:32-36
Publication Date(Web):13 August 2010
DOI:10.1016/j.jallcom.2010.05.053
In this research, a simple and facile approach was reported for the synthesis of highly oriented TiOx/Ny nanowire arrays that originated from TiO2 nanoparticles. The results indicated that nanowire arrays were fabricated with controllable lengths by adjusting the amount of NH3 under medium pressures. The preferable orientation of nanowires was (1 0 3) crystal facet, which led to remarkable Voc values in comparison with TiO2 nanoparticles. An NH3-assisted vapor–liquid–solid (VLS) growth mechanism was proposed for the direct growth of nanowire arrays from TiO2 nanoparticles.
Co-reporter:Xin Wang, Yulin Yang, Ruiqing Fan and Zhaohua Jiang
New Journal of Chemistry 2010 vol. 34(Issue 11) pp:2599-2604
Publication Date(Web):16 Aug 2010
DOI:10.1039/C0NJ00361A
Three five-coordinate transition metal complexes [2,6-(PhNCMe)2C5H3NMCl2·CH3CN] (M = Zn, Cd, Hg) (named M1) have been assembled onto a nanocrystalline TiO2 film to prepare transition metal complex/N719 co-sensitized photoelectrodes for dye-sensitized solar cell applications. The metal center is chelated in a tridentate manner by the ligand and further coordinated by two chlorine atoms, resulting in distorted trigonal bipyramidal geometry. In the tandem structure of the TiO2/M1/dye electrode, the M1 undergoes a re-organization of energy levels due to its single-crystal structure, which is advantageous to electron injection and hole recovery. The co-sensitized structure is proved to have a superior ability, when compared to a single N719 dye’s influence on TiO2. Therefore, co-sensitized solar cells based on TiO2/M1/N719 electrodes yield a remarkably high photocurrent density (Jsc), open circuit voltage (Voc) and energy conversion efficiency under standard global AM1.5 solar irradiation conditions, which are relatively higher than those for DSSCs using single organic sensitizers.
Co-reporter:Guangpeng Zhou, Yulin Yang, Ruiqing Fan, Xinrong Liu, Hengwu Hong, Fuping Wang
Solid State Sciences 2010 Volume 12(Issue 7) pp:1103-1106
Publication Date(Web):July 2010
DOI:10.1016/j.solidstatesciences.2010.04.013
Using H3PO3 as a phosphorus source and oxalic acid as a reducing agent, the first three-dimensional open-framework gallium phosphate–phosphite formula as (C6N2H18)2(C6N2H17)Ga15(OH)8(PO4)2(HPO4)12(HPO3)6·2H2O (1), has been hydrothermally synthesized in the presence of N,N,N′,N′-tetramethylenediamine (TMEDA) as a structure-directing agent. Compound 1 crystallizes in trigonal system with space group P − 3, a = b = 19.046(3) Å, c = 8.3306(17) Å, γ = 120°, V = 2617.1(7) Å3, and Z = 1. Its 3-D network is based on alternated Ga-centered (GaO4 tetrahedra, GaO5 trigonal bipyramids, and GaO6 octahedra) and P-centered (PO43−, HPO42−, and HPO32−) units. Protonated organic amines and water molecules are located in the 12-membered ring channels.
Co-reporter:Guangpeng Zhou, Yulin Yang, Ruiqing Fan, Xinrong Liu, Qing Wang, Fuping Wang
Solid State Sciences 2010 Volume 12(Issue 5) pp:873-881
Publication Date(Web):May 2010
DOI:10.1016/j.solidstatesciences.2010.02.002
Three new gallium phosphite–oxalates formula as (C6N2H14)2[Ga2(OH)2(C2O4)2(HPO3)2]·2H2O (1), (C6N2H18)0.5[Ga(OH)(C2O4)0.5(HPO3)] (2), and Ga(C2O4)0.5(C3N2H4)(HPO3) (3) have been hydrothermally synthesized by controlling the pH value of the reaction system. Compound 1 possesses a one-dimensional ladder-like chain structure, in which the C2O42− anion is coordinated to one Ga center and acts as mono-bidentate ligand. In 2 and 3, the C2O42− anions serve as bis-bidentates ligands bridging between two Ga atoms to form the two-dimensional layered structures. Furthermore, compound 3 displays a neutral layered network, which is decorated by the directly coordinated organic ligand.
Co-reporter:Rui-Qing Fan, Ping Wang, Yu-Lin Yang, Yan-Jiao Zhang, Yan-Bing Yin, Wuliji Hasi
Polyhedron 2010 29(14) pp: 2862-2866
Publication Date(Web):
DOI:10.1016/j.poly.2010.07.012
Co-reporter:Ruiqing Fan, Yulin Yang, Yanbin Yin, WuLiJi Hasi and Ying Mu
Inorganic Chemistry 2009 Volume 48(Issue 13) pp:6034-6043
Publication Date(Web):June 3, 2009
DOI:10.1021/ic900339u
Seven five-coordinate 2,6-bis(imino)pyridyl mercury complexes, [2,6-(ArN═CMe)2C5H3NHgCl2·nCH3CN] (Ar = C6H5, n = 1.5, 1; Ar = 2,6-iPr2C6H3, n = 0, 2; Ar = 2,6-Me2C6H3, n = 1, 3; Ar = 2-MeC6H4, n = 1, 4; Ar = 4-MeC6H4, n = 1, 5; Ar = 2,4,6-Me3C6H2, n = 1, 6; Ar = 2,6-Et2C6H3, n = 0, 7), were synthesized by reactions of the corresponding bis(imino)pyridine ligands with HgCl2 in CH3CN, and in good yield. The structures of complexes 1−6 were determined by single-crystal X-ray diffraction. In all complexes, the metal center is tridentately chelated by the ligand and further coordinated by two chlorine atoms, resulting in a distorted trigonal bipyramidal geometry. All complexes have blue luminescence at room temperature in solution and the solid state. At 293 K in a CH2Cl2 solution, the fluorescent emission maxima for complexes 1−7 are at λ = 395, 400, 407, 403, 427, 415, and 403 nm, respectively, which can be attributed to ligand-centered π* → π transitions.
Co-reporter:Xin Wang;Yulin Yang;Zhaohua Jiang ;Ruiqing Fan
European Journal of Inorganic Chemistry 2009 Volume 2009( Issue 23) pp:3481-3487
Publication Date(Web):
DOI:10.1002/ejic.200900134
Abstract
As part of our efforts to find a way to control the concentration of N-doped TiO2, TiNxO2–x powders were prepared by a device of our own design. In this research, photoelectrodes are generated using N-doped TiO2 materials where the concentrations are adjusted by the amount of NH3 under middle pressure, which is seldom reported. Considerable efforts have been directed to the study of the optical absorption edge that is redshifted towards the visible-light region. Therefore, N-doped TiO2 electrodes are characterized by SPS and TPV analyses as experimental and theoretical studies. Experimental results indicate that the band gap of the semiconductor has been narrowed by increasing the concentration of the N-doped TiO2. The overall conversion efficiency of the solar cell has shown that the photoelectrical properties of the N-doped TiO2 have greatly improved with different concentrations. It can therefore be concluded that the synthesis route we found through this study is an effective way to adjust the relationship between the concentration and the band gap of the N-doped TiO2 photoelectrodes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Co-reporter:Ruiqing Fan, Yanjiao Zhang, Yanbin Yin, Qing Su, Yulin Yang, Wuliji Hasi
Synthetic Metals 2009 Volume 159(Issue 11) pp:1106-1111
Publication Date(Web):June 2009
DOI:10.1016/j.synthmet.2009.04.007
Two novel complexes [Cd(phen)(NO3)(NO2)(H2O)]n (1) and Cd(phen)2(NO3)(NO2) (2) (phen = 1,10-phenanthroline) have been synthesized by the reductive reaction of metal source Cd(NO3)2·4H2O with phen and benzidine in the mixed solution of DMF, ethanol and water. Crystal structures of complexes 1 and 2 were determined by single-crystal X-ray diffraction. Complex 1 is a one-dimensional (1D) zig-zag infinite chain in which (phen)Cd(II) units were bridged by two O atoms of NO2−. The three-dimensional (3D) supramolecular structure of 1 is constructed through hydrogen-bond and aromatic π–π stacking interactions between adjacent metal–organic polymeric coordination chains. Complex 2 is a mononuclear structure, and self-assembled through π–π stacking interactions to form a three-dimensional (3D) supramolecular structure. The complex 1 exhibits luminescent property in the near-UV at room temperature in solutions of DMSO and DMF with the emission energy following the order DMF < DMSO, which might be ascribed to the presence of a highly polarized ground state. Complexes 1 and 2 have blue-purple luminescence at room temperature in the solid state. The blue-purple luminescence of the complexes is due to π* → π transition of phen.Two new complexes [Cd(phen)(NO3)(NO2)(H2O)]n (1) and Cd(phen)2(NO3)(NO2) (2) (phen = 1,10-phenanthroline) were synthesized, which exhibit blue-purple luminescence at room temperature in solid state.
Co-reporter:Yuwei Dong, Ruiqing Fan, Wei Chen, Ping Wang and Yulin Yang
Dalton Transactions 2017 - vol. 46(Issue 20) pp:NaN6775-6775
Publication Date(Web):2017/05/03
DOI:10.1039/C7DT00956A
A new simple ‘dual’ chemosensor MQA ((E)-2-methoxy-N-((quinolin-2-yl)methylene)aniline) for distinguishing Zn2+ and Hg2+ has been designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn2+/Hg2+ over other commonly coexisting cations (such as Na+, Mg2+, Al3+, K+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Ga3+, Cd2+, In3+ and Pb2+) in DMSO–H2O solution (1/99 v/v), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit for Zn2+/Hg2+ by MQA both reached the 10−8 M level. The 1:1 ligand-to-metal coordination patterns of the MQA-Zn2+ and MQA-Hg2+ were calculated through a Job's plot and ESI-MS spectra, and were further confirmed by X-ray crystal structures of complexes MQA-Zn2+ and MQA-Hg2+. This chemosensor can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions. DFT calculations have revealed that the energy gap between the HOMO and LUMO of MQA has decreased upon coordination with Zn(II)/Hg(II).
Co-reporter:Wei Chen, Ruiqing Fan, Huijie Zhang, Yuwei Dong, Ping Wang and Yulin Yang
Dalton Transactions 2017 - vol. 46(Issue 13) pp:NaN4277-4277
Publication Date(Web):2017/02/27
DOI:10.1039/C7DT00218A
A series of lanthanide coordination polymers(LnCPs) containing both light and heavy rare-earth elements, namely {[Eu2(pydc)3(H2O)]·2H2O}n (1-Eu, H2pydc = pyridine-2,3-dicarboxylic acid), [Ln(pyc)2(Hpyc)(NO3)]n (Ln = Nd (2-Nd), Sm (3-Sm), Eu (4-Eu), Gd (5-Gd), Tb (6-Tb), Ho (7-Ho), and Er (8-Er), Hpyc = pyridine-3-carboxylic acid), has been synthesized under hydro(solvo)thermal conditions and fully characterized. The crystal structure analysis indicates that in situ decarboxylation of H2pydc occurred in the synthesis process of 2-Nd–8-Er. Coordination polymer 1-Eu displays a 3-D pcu network with central-symmetric quad-core structural units [Eu4(COO)6] linked by 1-D chains. 2-Nd–8-Er are of triple helical chain enantiomeric pair 61/65 axis, and can be further linked through two separate kinds of H⋯bonding interaction to form a mirror symmetrical 3-D framework; the final topological symbol of the jointly connected network is rare {47·68}. Solid-state luminescence studies show that the emission spectra of these LnCPs cover both the visible and near-infrared luminescence region. 2-Nd exhibits characteristic 4F3/2 → 4IJ/2 (J = 9, 11, 13) transition NIR emission. 1-Eu and 4-Eu provide characteristic 5D0 → 7FJ intense and bright red luminescence, while 4-Eu exhibits better luminescence performance because of the presence of the O–H oscillators within 1-Eu. 6-Tb exhibits characteristic 5D4 → 7FJ intense and bright green luminescence. Furthermore, through doping with PMMA polymer, the luminescence properties of 4-Eu and 6-Tb are all improved. The results show the best doping concentration is 4%. The thermal stabilities of 4-Eu-PMMA and 6-Tb-PMMA increased from 270 to 315 °C when compared with single coordination polymers 4-Eu and 6-Tb. The co-doping of 4-Eu, 5-Gd, and 6-Tb (0.92/0.04/0.04) with PMMA at a total concentration of 4% resulted in a tunable luminescence material W(4-Eu,5-Gd,6-Tb)-PMMA film. When excited at 285 nm, W(4-Eu,5-Gd,6-Tb)-PMMA shows white-light emission with the CIE chromaticity coordinates of (0.33, 0.35). The lifetime of Eu3+ ions in W(4-Eu,5-Gd,6-Tb)-PMMA increased from 1032.24 μs to 1272.26 μs when compared with 4-Eu-PMMA, and the efficiency of energy transfer (ηET) from Tb3+ to Eu3+ within the co-doping PMMA film could be estimated to be 29.9%.
Co-reporter:Yu-Wei Dong, Rui-Qing Fan, Wei Chen, Hui-Jie Zhang, Yang Song, Xi Du, Ping Wang, Li-Guo Wei and Yu-Lin Yang
Dalton Transactions 2017 - vol. 46(Issue 4) pp:NaN1276-1276
Publication Date(Web):2016/12/23
DOI:10.1039/C6DT04159K
A series of Zn(II) complexes with different conjugated systems, [ZnL1Cl2]2 (Zn1), [ZnL2Cl2] (Zn2), [Zn(L3)2]·(ClO4)2 (Zn3), [Zn2L4Cl4] (Zn4), and [ZnL5Cl2] (Zn5), were synthesized and subsequently characterized via single crystal X-ray diffraction, 1H and 13C NMR, FT-IR, elemental analyses, melting point, and PXRD. The X-ray diffraction analyses revealed that the supramolecular frameworks of complexes Zn1–Zn5 are constructed by C–H⋯O/Cl hydrogen bonds and π⋯π interactions. Complexes Zn1–Zn3 feature 3D 6-connected {412·63} topological structures, whereas complex Zn4 exhibits a 3D 7-connected supramolecular framework with a {417·64} topological structure. However, complex Zn5 shows one-dimensional “wave-like” chains. Based on these varied structures, the emission maximum wavelengths of complexes Zn1–Zn5 can be tuned in a wide range of 461–592 nm due to the red shift direction of λem caused by different conjugated systems and their electron donating abilities. Complex Zn3 shows a strong luminescence in the solid state and in the acetonitrile solution. Therefore, a series of Zn3-poly(methylmethacrylate) (Zn3-PMMA) hybrid materials were obtained by controlling the concentration of complex Zn3 in poly(methylmethacrylate) (PMMA). At an optimal concentration of 4%, the doped polymer film of Zn3-PMMA displays strong green luminescence emissions that are 19-fold in the luminescence intensities and 98 °C higher in the thermal stability temperature compared to the Zn3 film.
Co-reporter:Ani Wang, Ruiqing Fan, Yuwei Dong, Wei Chen, Yang Song, Ping Wang, Sue Hao, Zhigang Liu and Yulin Yang
Dalton Transactions 2017 - vol. 46(Issue 1) pp:NaN85-85
Publication Date(Web):2016/11/16
DOI:10.1039/C6DT03853K
Judicious structural design employing 2-quinolinecarboxaldehyde and 4-methylaniline was used to generate the Schiff base ligand (E)-4-methyl-N-((quinolin-2-yl)ethylidene)aniline (L). Five IIB complexes, namely, [ZnLCl2] (1), [ZnL(NO3)2] (2), [ZnL(OAc)2]3 (3), [CdL(OAc)2]3 (4), and [HgLCl2] (5) have been synthesized based on L. Single-crystal X-ray diffraction analysis indicates that complexes 1, 3 and 4 exhibit 3D networks, whereas 2 and 5 form 2D layers and 1D chains, respectively. TD-DFT calculations show a good correlation with the UV-vis absorption assigned to π → π* intraligand transitions. Furthermore, complexes 1–5 displayed strong greenish luminescent emissions (518–524 nm) in the aggregate state but weak emissions in solution (aggregation-induced emission enhancement), which may be due to the existence of C–H⋯Cl/O hydrogen bonding and π⋯π stacking interactions, resulting in restriction of intramolecular rotation (RIR). Variable-concentration 1H NMR studies suggested that the aggregates undergo intramolecular changes in conformation due to intermolecular interactions. Moreover, the emission intensity and lifetime exhibited obvious increases induced by mechanical grinding and temperature reduction, which were also attributed to AIEE properties. Subsequently, complex 1 was incorporated into poly(methyl methacrylate) (PMMA), whereby 1-PMMA exhibited enhanced emission intensity (20-fold increase in comparison with that of 1), which offers opportunities for use in plastic greenhouses to increase leaf photosynthesis.
Co-reporter:Xin Ming Wang, Rui Qing Fan, Liang Sheng Qiang, Wei Qi Li, Ping Wang, Hui Jie Zhang and Yu Lin Yang
Chemical Communications 2014 - vol. 50(Issue 39) pp:NaN5026-5026
Publication Date(Web):2014/03/25
DOI:10.1039/C3CC48867E
Two rare 2D Ga/In-based coordination polymers in which one metal center coexists with three distinct aromatic ligands were synthesized. Helical channels along the 21 screw axis are exhibited to form a hcb net. The compounds exhibit tunable fluorescence from blue, green, white to yellow light by varying the temperature and solvents.
Co-reporter:Song Gao, Rui Qing Fan, Xin Ming Wang, Liang Sheng Qiang, Li Guo Wei, Ping Wang, Hui Jie Zhang, Yu Lin Yang and Yu Lei Wang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 11) pp:NaN6063-6063
Publication Date(Web):2015/01/30
DOI:10.1039/C4TA06671E
Based on a new design of 4-cyanobenzyl-based 1,2,4-triazole ligand 4-(1,2,4-triazolylmethyl) cyanobenzene (TMCB), a series of cadmium complexes 1–5′ from a mononuclear to three-dimensional (3D) structure have been synthesized through hydro(solvo)thermal reactions; they were generally formulated as [Cd(TMCBA)2]n (1), [Cd(TMCB)(1,4-bda)(H2O)]n (2), {[Cd2(TMCB)4(1,4-bda)2(H2O)2]n·3H2O}n (3), {[Cd(TMCB)4(H2O)2]·(NO3)2·(H2O)2}n (4), [Cd1.5(1,4-bda)1.5(DMF)2]2n (5) and [Cd1.5(1,4-bda)1.5(DMF)2]2n (5′) (TMCBA = 4-(1,2,4-triazolylmethyl) benzoic acid, which is formed from the hydrolysis of TMCB; 1,4-H2bda = 1,4-benzenedicarboxylic acid; the difference between two genuine supramolecular isomers of 5 and 5′ is the use of TMCB as the additive agent for the reaction). Complexes 1–5′ exhibit tunable luminescence with emission maxima containing deep blue, blue, light blue, green and deep green region at 298 K or 77 K in both different solvents (polarity: DMSO > CH3OH > CHCl3) and solid state. Interestingly, the good thermal stability accompanied by their compensated adsorption to ruthenium complex N719 in the region of low wavelength, enabled 1 and 4 to serve as co-sensitizers in combination with N719 in dye sensitized solar cells (DSSCs). After co-sensitization with N719, the overall conversion efficiency of 1 and 4 were found to be 7.68% and 6.85%, which are 40.40% and 25.23% higher than that for DSSCs only sensitized by N719 (5.47%) under the same conditions, respectively. The improvement in efficiency is attributed to the fact that complexes 1 and 4 overcome the deficiency of N719 absorption in the low wavelength region of ultraviolet and blue-violet, offset competitive visible light absorption of I3− and reduce charge recombination due to the formation of an effective cover layer of the dye molecules on the TiO2 surface. As a result, the synthesized complexes are promising candidates as co-adsorbents and co-sensitizers for highly efficient DSSCs.
Co-reporter:Yang Song, Ruiqing Fan, Ping Wang, Xinming Wang, Song Gao, Xi Du, Yulin Yang and Tianzhu Luan
Journal of Materials Chemistry A 2015 - vol. 3(Issue 24) pp:NaN6259-6259
Publication Date(Web):2015/05/20
DOI:10.1039/C5TC01273B
Poly(methyl methacrylate) (PMMA) films doped with Cu(I)-based imidazole derivative coordination polymers [Cu3I3(bib)1.5]n (1) and [Cu4I4(bix)2]n (2) [bib = 1,4-bis(1-imidazolyl)benzene and bix = 1,4-bis(imidazol-1-ylmethyl)benzene] were synthesized and their photophysical properties were studied. 1 and 2 were prepared by a solvothermal method and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy, 1H NMR, PXRD and thermal gravimetric analyses. Molecular structural analysis reveals that 1 exhibits a unique one-dimensional (1D) infinite triplex chain and 2 is built from a [Cu4I4]n cluster which possesses an interesting two-dimensional (2D) (4,4)-connected sql (square lattice) network. Detailed structural characterization of the supramolecular organization of 1 and 2 revealed overall three-dimensional (3D) interlinked networks driven by extensive π⋯π stacking interactions. Both 1 and 2 display remarkable narrow band emission with a smaller full width at half-maximum (FWHM) (77 K, 34.63 and 60.07 nm; 298 K, 121.95 and 126.83 nm) in the solid state at 77 K, which leads to excellent monochromaticity. The combination of such a narrow FWHM and the large red-shift of 62 nm from 298 K to 77 K endows 2 with a more prominent thermochromism effect than 1, with emissions strongly depending on temperature and tunable from yellow to red by changing the temperature from 298 K to 77 K. Here, the role of the [Cu4I4]n cluster in controlling the performance of thermochromic luminescence is highlighted. Meanwhile, 1 and 2 demonstrate stronger and longer lifetime yellow luminescence emissions at concentrations of 0.8% (τ = 156.62 μs) and 1.0% (τ = 92.28 μs) in poly(methyl methacrylate) (PMMA). Furthermore, development of easy-to-prepare hybrid materials 1–PMMA and 2–PMMA leads to bright yellow luminescence polymer film materials with outstanding thermal stability in daily applications (321 °C and 500 °C).
Co-reporter:Liguo Wei, Yong Na, Yulin Yang, Ruiqing Fan, Ping Wang and Liang Li
Physical Chemistry Chemical Physics 2015 - vol. 17(Issue 2) pp:NaN1280-1280
Publication Date(Web):2014/11/25
DOI:10.1039/C4CP04240A
2,6-Bis[1-(phenylimino)ethyl]pyridine (M0) and its derivatives containing methyl groups on their phenyl rings (M1o, M1p and M2) are employed as co-sensitizers in dye-sensitized solar cells (DSSCs). The prepared co-sensitizers could alleviate the aggregation of ruthenium dye N719 on the TiO2 film, enhance the spectral responses of the co-sensitized TiO2 film in the region from 400 to 750 nm, suppress the electron recombination, prolong the electron lifetime and decrease the total resistance of DSSCs. The number and position of the methyl groups are two key factors that play important roles in the performances of DSSCs. The optimized cell device co-sensitized by the M1p/N719 dye gives a short circuit current density of 16.48 mA cm−2, an open circuit voltage of 0.72 V and a fill factor of 0.62 corresponding to an overall conversion efficiency of 7.32% under standard global AM 1.5 solar irradiation, which is 35% higher than that of a device solely sensitized by N719 under the same conditions.
Co-reporter:Song Gao, Rui Qing Fan, Xin Ming Wang, Li Guo Wei, Yang Song, Xi Du, Kai Xing, Ping Wang and Yu Lin Yang
Physical Chemistry Chemical Physics 2016 - vol. 18(Issue 28) pp:NaN19010-19010
Publication Date(Web):2016/06/22
DOI:10.1039/C6CP02530G
In this work, a rare 2D → 3D single-crystal-to-single-crystal transformation (SCSC) is observed in metal–organic coordination complexes, which is triggered by thermal treatment. The 2D two-fold interpenetrating square lattice layer [Cd(IBA)2]n (1) is irreversibly converted into a 3D four-fold interpenetrating diamond framework {[Cd(IBA)2(H2O)]·2.5H2O}n (2) (HIBA = 4-(1H-imidazol-1-yl)benzoic acid). Consideration is given to these two complexes with different interpenetrating structures and dimensionality, and their influence on photovoltaic properties are studied. Encouraged by the UV-visible absorption and HOMO–LUMO energy states matched for sensitizing TiO2, the two complexes are employed in combination with N719 in dye-sensitized solar cells (DSSCs) to compensate absorption in the ultraviolet and blue-violet region, offset competitive visible light absorption of I3− and reducing charge the recombination of injected electrons. After co-sensitization with 1 and 2, the device co-sensitized by 1/N719 and 2/N719 to yield overall efficiencies of 7.82% and 8.39%, which are 19.94% and 28.68% higher than that of the device sensitized only by N719 (6.52%). Consequently, high dimensional interpenetrating complexes could serve as excellent co-sensitizers and have application in DSSCs.
Co-reporter:Yanxia Jiang, Yulin Yang, Liangsheng Qiang, Ruiqing Fan, Liang Li, Tengling Ye, Yong Na, Yan Shi and Tianzhu Luan
Physical Chemistry Chemical Physics 2015 - vol. 17(Issue 10) pp:NaN6785-6785
Publication Date(Web):2015/02/04
DOI:10.1039/C4CP05795C
A novel heteropolyacid (HPA) K6SiW11O39Ni(H2O)·xH2O (SiW11Ni) modified TiO2 has been successfully synthesized and introduced into the photoanode of dye-sensitized solar cells (DSSCs). The performance of the cell with the HPA-modified photoanode (SiW11Ni/TiO2), mixed with P25 powder in the ratio of 2:8, is better than the cell with a pristine P25 photoanode. An increase of 31% in the photocurrent and 22% improvement in the conversion efficiency are obtained. The effect of the heteropolyacid was well studied by UV-vis spectroscopy, spectro-electrochemical spectroscopy, dark current, intensity-modulated photocurrent spectroscopy and intensity-modulated photovoltage spectroscopy, open-circuit voltage decay and electrochemical impedance spectroscopy. The results show that the interfacial layer modified by SiW11Ni can enhance the injection and transport of electrons, and then retard the recombination of electrons, which results in a longer electron lifetime. What's more, the introduction of SiW11Ni can simultaneously broaden the absorption in the visible region, eventually leading to an efficient increase in energy conversion efficiency.
Co-reporter:Lingyun Zhang, Yulin Yang, Ruiqing Fan, Jia Yu and Liang Li
Journal of Materials Chemistry A 2013 - vol. 1(Issue 39) pp:NaN12073-12073
Publication Date(Web):2013/07/25
DOI:10.1039/C3TA11570D
Pr and N co-doped ZnO (Pr:N:ZnO, doping concentration: 1 mol% Pr, 0.36 mol% N) was synthesized using an annealing method under an atmosphere of NH3 gas in a custom stainless steel autoclave. Scanning electron microscopy (SEM) was used to characterize the morphology of Pr:N:ZnO. The structure and chemical composition of the material were characterized using X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS). The results demonstrated that Pr:N:ZnO maintained a hexagonal wurtzite structure, and that Pr and N atoms were successfully incorporated into the lattice of ZnO. The co-doping of Pr and N has a significant influence on the optical properties of ZnO. UV-visible absorption spectroscopy (UV-vis) showed that Pr and N co-doping led to a red shift of the absorption edge of ZnO into the visible-light region. UV-visible absorption spectroscopy and surface photovoltage spectroscopy (SPS) demonstrated that the band gap of ZnO was narrowed with the dopant atoms generating impurity sub-bands. The incident photon-to-current conversion efficiency (IPCE) spectra demonstrated that Pr and N co-doping could successfully improve the light harvesting of a DSSC. The transient photovoltage (TPV) indicated that Pr and N co-doping increased the rate of charge separation and the electron lifetime. A dye-sensitized solar cell with Pr:N:ZnO as the anode exhibited a short-circuit photocurrent density as high as 13.84 mA cm−2, an open-circuit photovoltage of 590 mV, a fill factor of 0.63, and an overall light conversion efficiency of 5.2% under standard global AM 1.5 solar irradiation conditions.
Co-reporter:Xin Wang, Yu-Lin Yang, Ping Wang, Liang Li, Rui-Qing Fan, Wen-Wu Cao, Bin Yang, Hui Wang and Jing-Yao Liu
Dalton Transactions 2012 - vol. 41(Issue 35) pp:NaN10625-10625
Publication Date(Web):2012/06/19
DOI:10.1039/C2DT30430A
Two lanthanide complexes, Ln(HPDA)3·4EtOH (Ln = Tb, Dy) (H2PDA = pyridine-2,6-dicarboxylic acid, EtOH = ethanol), have been successfully synthesized using hydrothermal or solvothermal methods, and their crystal structures were analyzed by single crystal XRD. Both crystals have orthorhombic symmetry with space group Pbcn, exhibiting three-dimensional (3D) supramolecular architecture through hydrogen bonding interactions. The metal center was coordinated to nine atoms by three pyridine-2,6-dicarboxylic acid ligands. The nine-coordinated lanthanide metal complexes were assembled onto a nanocrystalline TiO2 film to form co-sensitized photoelectrodes with N719 for dye-sensitized solar cells, and their photoelectrochemical performance was studied. In the tandem structure of composite electrodes, the energy levels of lanthanide metal complexes are reorganized in their single-crystal form, as verified by ab initio calculations. The co-sensitized systems are far superior for electron-injection and hole-recovery compared with single N719-sensitized systems. Luminescence properties were measured and electrochemical analysis was also performed on these complexes.
Co-reporter:Song Gao, Rui Qing Fan, Xin Ming Wang, Liang Sheng Qiang, Li Guo Wei, Ping Wang, Yu Lin Yang and Yu Lei Wang
Dalton Transactions 2015 - vol. 44(Issue 41) pp:NaN18195-18195
Publication Date(Web):2015/09/22
DOI:10.1039/C5DT02951A
This work reports on two new complexes with the general formula [Cd3(IBA)3(Cl)2(HCOO)(H2O)]n (1) and {[Cd1.5(IBA)3(H2O)6]·3.5H2O}n (2), which can be synthesized by the reaction of CdII with rigid linear ligand 4-HIBA containing imidazolyl and carboxylate functional groups [4-HIBA = 4-(1H-imidazol-1-yl)benzoic acid]. Single-crystal X-ray diffraction analyses indicate that complex 1 is a 2D “wave-like” layer structure constructed from trinuclear units and complex 2 is just a mononuclear structure. Surprisingly, both complexes 1 and 2 appear as a 3D supramolecular network via intermolecular hydrogen bonding interactions. What's more, due to their strong UV-visible absorption, 1 and 2 can be employed as co-sensitizers in combination with N719 to enhance dye-sensitized solar cell (DSSC) performance. Both of them could overcome the deficiency of the ruthenium complex N719 absorption in the region of ultraviolet and blue-violet, and the charge collection efficiency is also improved when 1 and 2 are used as co-sensitizers, which are all in favor of enhancing the performance. The DSSC devices using co-sensitizers of 1/N719 and 2/N719 show an overall conversion efficiency of 8.27% and 7.73% with a short circuit current density of 17.48 mA cm−2 and 17.39 mA cm−2, and an open circuit voltage of 0.75 V and 0.74 V, respectively. The overall conversion efficiency is 27.23% and 18.92% higher than that of a device solely sensitized by N719 (6.50%). Consequently, the prepared complexes are high efficiency co-sensitizers for enhancing the performance of N719 sensitized solar cells.
Co-reporter:Xin-Ming Wang, Shuo Chen, Rui-Qing Fan, Fu-Qiang Zhang and Yu-Lin Yang
Dalton Transactions 2015 - vol. 44(Issue 17) pp:NaN8125-8125
Publication Date(Web):2015/03/23
DOI:10.1039/C5DT00057B
The photophysical properties of ZnII/HgII Schiff base complexes could be fine and predictably tuned over a wide range of wavelengths by changing the ligand structures. A new series of polydentate Schiff base-type ligands, N,N′-bis(2-pyridinylethylidene)R3-1,2-diamine (L1–L6), which contain a flexible, semi-rigid or rigid group (R3 = butyl, cyclohexane, tolyl and phenylene), has been designed and employed for synthetizing new mononuclear or binuclear trans ZnII/HgII complexes with a general formula of [M(L1)Cl2] (L1 = N,N′-bis(2-pyridinylethylidene)phenylene-1,2-diamine, M = Zn, 1a; M = Hg, 1b), [M(L2)Cl2] (L2 = N,N′-bis(2-pyridinylethylidene)toluene-3,4-diamine, M = Zn, 2a; M = Hg, 2b), [M2(L3)Cl4]·nCH2Cl2 (L3 = N,N′-bis(2-pyridinylmethylene)cyclohexane-1,2-diamine, M = Zn, n = 0, 3a; M = Hg, n = 1, 3b), [M2(L4)Cl4]·nCH3OH (L4 = N,N′-bis(2-pyridinylethylidene)cyclohexane-1,2-diamine, M = Zn, n = 1, 4a; M = Hg, n = 0, 4b), [M2(L5)Cl4] (L5 = N,N′-bis(3-methoxy-2-pyridinylmethylene)-cyclohexane-1,2-diamine, M = Zn, 5a; M = Hg, 5b), [M2(L6)Cl4]·nCH3CN (L6 = N,N′-bis(3-methoxy-2-pyridinylmethylene)butane-1,4-diamine, M = Zn, n = 4, 6a; M = Hg, n = 0, 6b). All the ligands and complexes have been characterized by elemental analyses, IR spectra, and 1H NMR spectra. Twelve structures of L5, L6, 1a–6a, 1b, 3b, 5b and 6b crystallized in three different conditions are further determined by single-crystal X-ray diffraction analyses. Their properties are fully characterized by UV-vis and fluorescence spectra both in solution and the solid state at room temperature. The luminescence color of these ZnII/HgII Schiff base complexes could be tuned from blue to green to red (429–639 nm for 6a–1a, 434–627 nm for 6b–1b) in solution by changing the ligand conjugated systems from flexibile (L6) to semi-rigid (L3–L5) to rigid (L1–L2). The spectra of the free Schiff bases L6–L1 are centered around 402–571 nm, which are perturbed upon the coordination to the ZnII/HgII ion. Both the electrochemical data and TD-DFT calculations show that the HOMO–LUMO band gap from the ligand to the complex is reduced by complexation. Meanwhile, the emission efficiencies of ZnII-complexes are found to be strongly dependent on the Schiff-base ligands with quantum yields ranging from 14% to 25% for 1a–6a. However, the emission efficiencies dramatically decline in HgII-complexes with quantum yields ranging from 4% to 19%, due to the heavy atom effect.
Co-reporter:Yu-Wei Dong, Rui-Qing Fan, Ping Wang, Li-Guo Wei, Xin-Ming Wang, Hui-Jie Zhang, Song Gao, Yu-Lin Yang and Yu-Lei Wang
Dalton Transactions 2015 - vol. 44(Issue 12) pp:NaN5322-5322
Publication Date(Web):2014/12/24
DOI:10.1039/C4DT03602F
Nine IIB group complexes, [ZnL1Cl2] (Zn1), [CdL1Cl2]2 (Cd1), [HgL1Cl2] (Hg1), [ZnL2Cl2] (Zn2), [CdL2Cl2] (Cd2), [HgL2Cl2] (Hg2), [ZnL3Cl2] (Zn3), [CdL3Cl2] (Cd3) and [HgL3Cl2] (Hg3), have been synthesized from the corresponding ortho-(6-methoxy-pyridyl)(CHNAr) (where Ar = 2,6–iPr2C6H3, L1; 4–MeC6H4, L2; 2–OMeC6H4, L3) Schiff base and structurally characterized by elemental analysis, FT-IR, 1H NMR and X-ray single-crystal analysis. Crystallographic studies reveal that the center metal of the complexes adopts a distorted tetrahedron geometry (except for Cd1 and Cd3, which display square pyramidal geometry) and C–H⋯Cl hydrogen bonds and π⋯π stacking interactions contribute to three-dimensional supramolecular structures. The series of complexes exhibit tunable luminescence from blue, through green, to light yellow by varying the temperature (298 K and 77 K), both in solution and in the solid state. Moreover, the quantum yields range from 0.027 to 0.422, and decrease according to the order of the periodic table (Zn > Cd > Hg). These results indicate that the center atom of the complexes leads to the geometry differences and hence to the tunable luminescence properties. Because Zn1–Zn3 exhibited higher molar extinction coefficients and a distinct absorption region, they were employed as co-sensitizers in ruthenium dye N719-sensitized photoanodes to deliver light-electricity efficiency enhancement, being assembled with counter-electrodes and electrolyte to prepare ZnX/N719 (where ZnX = Zn1, Zn2 and Zn3) co-sensitized dye sensitized solar cell (DSSC) devices. The prepared co-absorbent could overcome the deficiency of N719 absorption in the low-wavelength region of the visible spectrum, and offset competitive visible-light absorption of I3−. Application of these prepared complexes in N719-sensitized solar cells enhanced their performance by 10–36%, which indicated a potential application of these types of complexes in DSSCs.
Co-reporter:Xin-Ming Wang, Ping Wang, Rui-Qing Fan, Meng-Ying Xu, Liang-Sheng Qiang, Li-Guo Wei, Yu-Lin Yang and Yu-Lei Wang
Dalton Transactions 2015 - vol. 44(Issue 11) pp:NaN5190-5190
Publication Date(Web):2015/02/03
DOI:10.1039/C4DT03856H
A novel polydentate Schiff base ligand N1,N3-bis[(6-methoxypyridin-2-yl)methylene]benzene-1,3-diamine (L) and its two dinuclear sandwich-like complexes {[CdL(NO3)(H2O)]·NO3}2 (1) and {[CdL(CH3CN)(H2O)]·(ClO4)2·(CH3CN)2}2 (2) were synthesized. Both C–H⋯O, C–H⋯N and π–π non-covalent interactions had essential roles in constructing the resulting three-dimensional supramolecular networks. L emits a more intense blue-green fluorescence emission around 493 nm than in dilute solution, exhibiting stacking-induced emission properties. Complexes 1 and 2 exhibited the dual properties of exceptional solvatochromism and fluorescence quenching towards CH3OH molecules. As these compounds could overcome the absent absorption of ruthenium complex N719 in the low wavelength region of the visible spectrum, offset the competitive visible light absorption of I3− and reduce the charge recombination of injected electrons, the Schiff base ligand L and complexes 1 and 2 were used as co-sensitizers in combination with N719 to investigate their effect on enhancing the performance of dye-sensitized solar cells. A short circuit current density of 14.37 mA cm−2, an open-circuit voltage of 0.71 V and a fill factor of 0.61 corresponding to an overall conversion efficiency of 6.17% under AM 1.5 G solar irradiation were achieved when 1 was used as a co-sensitizer, which are much higher than the results obtained for dye-sensitized solar cells sensitized by N719 alone (5.06%).
Co-reporter:Hui-Jie Zhang, Rui-Qing Fan, Xin-Ming Wang, Ping Wang, Yu-Lei Wang and Yu-Lin Yang
Dalton Transactions 2015 - vol. 44(Issue 6) pp:NaN2879-2879
Publication Date(Web):2014/12/11
DOI:10.1039/C4DT03348E
Poly(methylmethacrylate) (PMMA) doped with Tb-based imidazole derivative coordination polymer {[Tb3(L)(μ3-OH)7]·H2O}n (1) (L = N,N′-bis(acetoxy)biimidazole) was synthesized and its photophysical properties were studied. The L′ (L′ = N,N′-bis(ethylacetate)biimidazole) ligand was synthesized by an N-alkylation reaction process followed by ester hydrolysis to produce ligand L. Polymer 1 and ligand L′ have been characterized by 1H NMR and IR spectroscopy, elemental analysis, PXRD and X-ray single-crystal diffraction. Coordination polymer 1 is the first observation of a CdCl2 structure constructed with hydroxy groups and decorated by ligand L in lanthanide N-heterocyclic coordination polymers. In the 2D layered structure of 1, each Tb3 metal center is connected with three Tb1 and three Tb2 metal centers by seven hydroxyl groups in different directions, resulting in a six-membered ring. After doping, not only the luminescence intensity and lifetime enhanced, but also their thermal stability was increased in comparison with 1. When 1 was doped into poly(methylmethacrylate) (1@PMMA), polymer film materials were formed with the PMMA polymer matrix (w/w = 2.5%–12.5%) acting as a co-sensitizer for Tb3+ ions. The luminescence intensity of the Tb3+ emission at 544 nm increases when the content of Tb3+ was 10%. The lifetime of 1@PMMA (914.88 μs) is more than four times longer than that of 1 (196.24 μs). All τ values for the doped polymer systems are higher than coordination polymer 1, indicating that radiative processes are operative in all the doped polymer films. This is because PMMA coupling with the O–H oscillators from {[Tb3(L)(μ3-OH)7]·H2O}n can suppress multiphonon relaxation. According to the variable-temperature luminescence (VT-luminescence) investigation, 1@PMMA was confirmed to be a stable green luminescent polymer film material.
Co-reporter:Kai Xing, Ruiqing Fan, Song Gao, Xinming Wang, Xi Du, Ping Wang, Ru Fang and Yulin Yang
Dalton Transactions 2016 - vol. 45(Issue 11) pp:NaN4878-4878
Publication Date(Web):2016/02/01
DOI:10.1039/C5DT04759E
Based on a new asymmetric semi-rigid V-shaped tricarboxylate ligand 3-(2′,3′-dicarboxylphenoxy)benzoic acid (H3dpob), a series of zinc/cadmium(II) coordination polymers, {[Cd(Hdpob)(H2O)3]·H2O}n (1), [Cd(Hdpob)(bib)]n (2), [Zn(Hdpob)(bib)0.5]n (3), {[Cd1.5(dpob)(2,2′-bipy)]·0.5H2O}2n (4) and {[Cd3(dpob)2(4,4′-bipy)2]·3H2O}n (5) [bib = 1,4-bis(1-imidazolyl)benzene; 2,2′-bipy = 2,2′-bipyridine; 4,4′-bipy = 4,4′-bipyridine], have been successfully synthesized via hydro(solvo)thermal reactions. 1 forms a three dimensional (3D) supramolecular structure linked by two types of intermolecular hydrogen bonds based on zig-zag 1D chains, whereas 2 and 3 are obtained with a similar 2D layer structure by the same ligands and further connected into a 3D structure through hydrogen bonds. 4 displays a homochiral 2D structure though two achiral ligands 2,2′-bipy and H3dpob, which contains right-handed helical infinite chains. 5 is a 3D structure containing 2D metal-pyridine layer motifs, which are further pillared by beaded dpob3− ligands to complete the structure and form a 6-connected pcu (primitive cubic) net. In DMSO solvent, 1–5 illustrate dual-emission properties but have different low-energy emission (LE) intensities relatively. Extraordinarily, the difference resulting from central metals between 2 and 3 makes the intensity of LE dramatically enhanced and quenched. In this regard, the luminescence of 2 and 3 can be tuned between blue and green regions by varying the excitation light, and the tuning tendency can be tailored with inverse directions. Comparing their tunable-sensitivity to energy quantitatively, the theoretical calculation displays that 3 (4.29%) is little higher than 2 (3.59%) in a relative lower excitation wavelength zone. Meanwhile, five coordination polymers show distinct luminescence thermochromism in the solid state. When the temperature decreases from 298 K to 77 K, the red-shift from blue/green to the pure yellow light region is highlighted. The fantastic and unique luminescence phenomenon not only brings an insight into the synthesis of dual-emissive materials, but helps us to understand the luminescence behavior deeply as well.
![2,6-Bis[1-(2,6-di-i-propylphenylimino)ethyl]pyridine](/data/chemimg/6300/204203-14-5.png)
![2,6-Bis[1-(2,6-di-i-propylphenylimino)ethyl]pyridine](/data/chemimg/6300/204203-14-5_b.png)
![Benzenamine, N-[1-(2-pyridinyl)ethylidene]-](http://img.cochemist.com/ccimg/17500/17424-78-1.png)
![Benzenamine, N-[1-(2-pyridinyl)ethylidene]-](http://img.cochemist.com/ccimg/17500/17424-78-1_b.png)
![[1,1'-Biphenyl]-2,4'-dicarboxylic acid](/data/chemimg/592200/606-80-4.png)
![[1,1'-Biphenyl]-2,4'-dicarboxylic acid](/data/chemimg/592200/606-80-4_b.png)
