Co-reporter:Longlu Wang;Xia Liu;Jinming Luo;Xidong Duan; John Crittenden; Chengbin Liu;Shuqu Zhang; Yong Pei;Yunxiong Zeng; Xiangfeng Duan
Angewandte Chemie International Edition 2017 Volume 56(Issue 26) pp:7610-7614
Publication Date(Web):2017/06/19
DOI:10.1002/anie.201703066
AbstractThe metallic 1T-MoS2 has attracted considerable attention as an effective catalyst for hydrogen evolution reactions (HERs). However, the fundamental mechanism about the catalytic activity of 1T-MoS2 and the associated phase evolution remain elusive and controversial. Herein, we prepared the most stable 1T-MoS2 by hydrothermal exfoliation of MoS2 nanosheets vertically rooted into rigid one-dimensional TiO2 nanofibers. The 1T-MoS2 can keep highly stable over one year, presenting an ideal model system for investigating the HER catalytic activities as a function of the phase evolution. Both experimental studies and theoretical calculations suggest that 1T phase can be irreversibly transformed into a more active 1T′ phase as true active sites in photocatalytic HERs, resulting in a “catalytic site self-optimization”. Hydrogen atom adsorption is the major driving force for this phase transition.
Co-reporter:Tao Cai, Yutang Liu, Longlu Wang, Shuqu Zhang, Yunxiong Zeng, Jili Yuan, Jianhong Ma, Wanyue Dong, Chengbin Liu, Shenglian Luo
Applied Catalysis B: Environmental 2017 Volume 208(Volume 208) pp:
Publication Date(Web):5 July 2017
DOI:10.1016/j.apcatb.2017.02.065
•The Ag3PO4@RGO@La(*),Cr:SrTiO3 Z-scheme photocatalytic system was fabricated firstly.•Ag3PO4@RGO@La,Cr:SrTiO3 photocatalyts shows great stability and photocatalytic performance.•The hole-protection anti-photocorrosion mechanism was proposed firstly.•This Ag3PO4-based Z-Scheme photocatalytic system can be applied in practice under natural sunlight.The serious photocorrosion of silver phosphate (Ag3PO4) has limited its practical applications. In this work, we propose a strategy to suppress its photocorrosion by the construction of a Z-Scheme photocatalytic system, which composed of reduced graphene oxide-enwrapped Ag3PO4 (Ag3PO4@RGO) and La,Cr-codoped SrTiO3 (La,Cr:SrTiO3). Dramatically, this system shows superior anti-photocorrosion and photocatalytic performances in degradation of both RhB and 2,4-DNP. Especially for RhB, it can be completely degraded after only 5 min under intense sunlight irradiation. The improved photoactivity and anti-photocorrosion of Ag3PO4@RGO@La,Cr:SrTiO3 can be attributed to the following: (i) The sufficient interfacial contact between Ag3PO4 and RGO is favorable to transfer the carriers and lengthen the lifetime of it; (ii) the package of Ag3PO4 with RGO could work as a sheltering layer to protect Ag3PO4 from photocorrosion. (iii) The aggregation of photogenerated holes in the VB of Ag3PO4 makes it a rich-hole region due to Z-Scheme electrons transport mechanism, which can protect Ag3PO4 from the photo-reduction. This strategy provides a new thought of protecting photosensitive semiconductor from photocorrosion and could regard as an efficient application method for environmental cleaning under natural sunlight irradiation. Furthermore, it even could be extended to outdoor or indoor air cleaning in the future.Download high-res image (326KB)Download full-size image
Co-reporter:Yanan Deng, Quanying Chang, Kai Yin, Chengbin Liu, Ying Wang
Chemical Physics Letters 2017 Volume 685(Volume 685) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.cplett.2017.07.044
•CdS nanowires combined with graphene based ECL sensing.•Excellent repeatability and selective specificity.•Supersensitive detection of pentachlorophenol with a wider linear range and a much low detection limit.•Admirable accuracy and reliability for practical application.A highly stable and effective electrochemiluminescence (ECL) sensing system of cadmium sulfide nanowires/reduced graphene oxide (CdS NWS/rGO) hybrid is presented for supersensitive detection of pentachlorophenol (PCP). CdS nanowire is for the first time exploited in ECL sensing. The rGO served as both ECL signal amplifier and immobilization platform, can perfectly enhance the ECL intensity and stability of the sensing system. With S2O82− as coreactant, the ECL signal can be significantly quenched by the addition of PCP. The established ECL sensing system presents a wider linear range from 1.0 × 10−14 to 1.0 × 10−8 M and a much low detection limit of 2 × 10−15 M under the optimum test conditions (e.g., pH 7.0 and 100 mM S2O82−). Furthermore, the ECL sensing system displays a good selectivity for PCP detection. The practicability of the ECL sensing system in real water sample shows that this system could be promisingly applied in the analytical detection of PCP in real water environments.Download high-res image (133KB)Download full-size image
Co-reporter:Meijun Liu;Liming Yang;Tian Liu;Yanhong Tang;Shenglian Luo;Yunxiong Zeng
Journal of Materials Chemistry A 2017 vol. 5(Issue 18) pp:8608-8615
Publication Date(Web):2017/05/10
DOI:10.1039/C7TA01791J
Transition metal phosphides (TMPs) have been one of the ideal candidates as low-cost and high-efficiency catalysts for hydrogen evolution reactions (HERs). We report herein a novel TMP architecture, Fe2P nanoparticles/reduced graphene oxide (rGO) nanosheets/Fe2P nanoparticles (Fe2P@rGO) sandwich-structured (Fe2P@rGO) nanowall arrays on a Ti plate. This nanostructure was easily prepared via one-step electrodeposition followed by a low-temperature phosphidation reaction. The Fe2P@rGO nanowall array film is featured with maximally exposed catalytic sites, fast electron and mass transport, and robust structure stability, and therefore it behaves as an excellent HER electrocatalyst. The Fe2P@rGO shows a low overpotential of 101 mV at a current density of 10 mA cm−2 and a small Tafel slope of 55.2 mV dec−1 with a large exchange current density of 0.146 mA cm−2. Furthermore, the catalyst exhibits superior durability evidenced by about 87% catalytic activity retention against about 55% for the commercial Pt/C catalyst after a 12 h test. The study presents a new nanoengineering strategy for high-performance TMP-based HER catalysts.
Co-reporter:Shuqu Zhang, Longlu Wang, Chengbin Liu, Jinming Luo, John Crittenden, Xia Liu, Tao Cai, Jili Yuan, Yong Pei, Yutang Liu
Water Research 2017 Volume 121(Volume 121) pp:
Publication Date(Web):15 September 2017
DOI:10.1016/j.watres.2017.05.013
•Highly stable solar light-driven noble metal-free photocatalyst.•Wastewater purification with simultaneous hydrogen production.•Relationship between hydrogen evolution and energy levels of organic molecules.It is attractive to photocatalytically purify wastewater and simultaneously convert solar energy into clean hydrogen energy. However, it is still a challenge owing to the relatively low photocatalytic efficiency of photocatalysts. In this study, we synthesized a molybdenum disulfide (MoS2) quantum dot-decorated 3D nanoarchitecture (MoS2QDs) of indium zinc sulfide (ZnIn2S4) and reduced grapheme oxide (MoS2QDs@ZnIn2S4@RGO) photocatalyst using a simple solvothermal method. The RGO promotes the electron transfer, and the highly dispersed MoS2QDs provides numerous catalytic sites. The photocatalytic purification of rhodamine B (RhB), eosin Y (EY), fulvic acid (FA), methylene blue (MB) and p-nitrophenol (PNP) in simulated wastewaters were further tested. The degradation efficiencies and TOC removal were 91% and 75% for PNP, 92.2% and 72% for FA, 98.5% and 80% for MB, 98.6% and 84% for EY, and 98.8% and 88% for RhB, respectively (Corganics = 20 mg/L, Ccatalyst = 1.25 g/L, t = 12 h, Ilight = 3.36 × 10−5 E L−1 s−1). Among these tests, the highest hydrogen production was achieved (45 μmol) during RhB degradation. Both experimental and calculational results prove that lower LUMO (lowest unoccupied molecular orbit) level of organic molecules was available for transferring electrons to catalysts, resulting in more efficient hydrogen production. Significantly, the removal efficiencies of natural organic substances in actual river water reached 76.3–98.4%, and COD reduced from 32 to 16 mg/L with 13.8 μmol H2 production after 12 h.Download high-res image (396KB)Download full-size image
Co-reporter:Chenghao Cao, Chujun Zhang, Junliang Yang, Jia Sun, Shuping Pang, Han Wu, Runsheng Wu, Yongli Gao, and Chengbin Liu
Chemistry of Materials 2016 Volume 28(Issue 8) pp:2742
Publication Date(Web):March 28, 2016
DOI:10.1021/acs.chemmater.6b00429
Highly efficient planar heterojunction perovskite solar cells (PHJ–PSCs) with a structure of ITO/PEDOT:PSS/CH3NH3PbI3–xClx/PCBM/C60/Ag was fabricated, in which the compact and pinhole-free CH3NH3PbI3–xClx perovskite thin film was obtained using a mixture of precursors containing lead iodide (PbI2), lead chloride (PbCl2), and methylammonium iodide (CH3NH3I) at an optimized ratio of 1:1:4. The morphology and formation process of CH3NH3PbI3–xClx thin film was closely related to the annealing temperature and time, which would result in the controllable performance for the PHJ–PSC devices. The morphology, crystallization process, and element analysis suggested that the chlorine gradually diffused and sublimated from the film surface while the iodine moved to the surface, together with the removal of the pinholes in the film. The PHJ–PSCs with the as-prepared CH3NH3PbI3–xClx thin film showed good performance and excellent repeatability. The power conversion efficiency (PCE) up to 14.03% was achieved without obvious hysteresis under different scanning conditions. The understanding of the iodine and chlorine element evolving process during the thermal treatment is beneficial to develop a more efficient scalable one-step solution processing method for fabricating large-area, highly efficient CH3NH3PbI3–xClx-based PSCs.
Co-reporter:Yangbin Ding, Wei Bai, Jinhua Sun, Yu Wu, Mushtaque A. Memon, Chao Wang, Chengbin Liu, Yong Huang, and Jianxin Geng
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 19) pp:12165
Publication Date(Web):April 26, 2016
DOI:10.1021/acsami.6b02164
The morphologies of transition metal oxides have decisive impact on the performance of their applications. Here, we report a new and facile strategy for in situ preparation of anatase TiO2 nanospindles in three-dimensional reduced graphene oxide (RGO) structure (3D TiO2@RGO) using cellulose as both an intermediate agent eliminating the negative effect of graphene oxide (GO) on the growth of TiO2 crystals and as a structure-directing agent for the shape-controlled synthesis of TiO2 crystals. High-resolution transmission electron microscopy and X-ray diffractometer analysis indicated that the spindle shape of TiO2 crystals was formed through the restriction of the growth of high energy {010} facets due to preferential adsorption of cellulose on these facets. Because of the 3D structure of the composite, the large aspect ratio of the TiO2 nanospindles, and the exposed high-energy {010} facets of the TiO2 crystals, the 3D TiO2@RGO(Ce 1.7) exhibited excellent capacitive performance as an electrode material for supercapacitors, with a high specific capacitance (ca. 397 F g–1), a high energy density (55.7 Wh kg–1), and a high power density (1327 W kg–1) on the basis of the masses of RGO and TiO2. These levels of capacitive performance far exceed those of previously reported TiO2-based composites.Keywords: anatase TiO2; cellulose; shape-controlled synthesis; supercapacitors; three-dimensional graphene composites
Co-reporter:Yan Yang, Wenqun Wu, Qian Wang, Hua Xiao, Yafei Kuang, Chengbin Liu
Journal of Electroanalytical Chemistry 2016 Volume 772() pp:73-79
Publication Date(Web):1 July 2016
DOI:10.1016/j.jelechem.2016.04.031
•One-step electrodeposition of Pt nanoclusters/graphene hybrid•Anodic electrochemiluminescence emission•Detection of Cu2 + with a wide linear range and a low detection limit•Good reproducibility and applicability for practical applicationAnodic electrochemiluminescence (ECL) emission was for the first time observed from noble metal nanoparticles under coreactants. In this work, we present a novel ECL sensor based on Pt nanoclusters/graphene (Pt NCs/GR) hybrid with triethanolamine (TEA) as the coreactant for the trace detection of copper ion (Cu2 +). GR significantly enhanced the anode ECL signal, due to its superior electron conduction. The ECL intensity could be greatly weakened by addition of Cu2 +. The proposed protocol offered a highly sensitive, selective and recyclable method for detection of Cu2 + with a wide linear range from 1.0 × 10− 4 to 2.0 × 10− 1 mg/L and a low detection limit of 1.0 × 10− 4 mg/L. Furthermore, the practicability of the ECL sensor in real water sample was also tested, showing that the ECL sensor based on Pt NCs/GR could be a promising alternative method for the monitoring of the Cu2 + in real sample.Anodic electrochemiluminescence emission was for the first time observed from noble metal nanoparticles under coreactants. The proposed sensor showed an excellent Cu2 + detection performance with low detection limit, and the immobilized ECL system exhibited a good reproducibility.
Co-reporter:Wenqun Wu, Hua Xiao, Shenglian Luo, Chengbin Liu, Yanhong Tang, Liming Yang
Sensors and Actuators B: Chemical 2016 Volume 222() pp:747-754
Publication Date(Web):January 2016
DOI:10.1016/j.snb.2015.09.001
•Electrochemiluminescence function of green CuO was revealed for the first time.•The ECL sensing system showed outstanding stability and durability.•Ultrasensitive detection of pentachlorophenol was successfully achieved.A highly stable and effective electrochemiluminescence (ECL) sensing platform of copper oxide nanowires coupled with reduced graphene oxide (CuO NWs/rGO) is presented for ultrasensitive detection of pentachlorophenol (PCP). The CuO NWs/rGO sensing system is prepared via an electrodeposition technique followed by chemical oxidation and annealing processes. The CuO nanowire is revealed to be electroluminescent for the first time, and the rGO greatly enhances the ECL signal. In the presence of the coreactant S2O82−, the CuO NWs/rGO-based ECL sensor can sensitively and selectively detect PCP with a wide linear range from 1.0 × 10−14 to 1.0 × 10−9 mol L−1 and a very low detection limit of 0.7 × 10−14 mol L−1. The sensor shows excellent recyclability and outstanding durability evidenced by its nearly unchanged ECL signal after the sensing electrode being stored for 10 months in air at room temperature. The proposed ECL sensor could be a promising alternative method for the emergency and routine monitoring of the PCP in real environment.
Co-reporter:Chengbin Liu, Deshui Meng, Yue Li, Longlu Wang, Yutang Liu, Shenglian Luo
Journal of Alloys and Compounds 2015 Volume 624() pp:44-52
Publication Date(Web):5 March 2015
DOI:10.1016/j.jallcom.2014.11.096
•Novel hierarchical heterostructure of TiO2@ZnS–In2S3 solid solution.•Efficient inhibition of ZnS–In2S3 solid solution aggregation.•High visible light photocatalytic activity.•Highly stable recycling performance.A unique hierarchical architecture of ZnS–In2S3 solid solution nanostructures onto TiO2 nanofibers (TiO2@ZnS–In2S3) has been successfully fabricated by simple hydrothermal method. The ZnS–In2S3 solid solution nanostructures exhibit a diversity of morphologies: nanosheet, nanorod and nanoparticle. The porous TiO2 nanofiber templates effectively inhibit the aggregation growth of ZnS–In2S3 solid solution. The formation of ZnS–In2S3 solid solution is proved by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) and the intimate contact between TiO2 nanofibers and ZnS–In2S3 solid solution favors fast transfer of photogenerated electrons. The trinary TiO2@ZnS–In2S3 heterostructures exhibit high adsorption capacity and visible light photocatalytic activity for the degradation of rhodamine B dye (RhB), remarkably superior to pure TiO2 nanofibers or binary structures (ZnS/TiO2 nanofibers, In2S3/TiO2 nanofibers and ZnS–In2S3 solid solution). Under visible light irradiation the RhB photocatalytic degradation rate over TiO2@ZnS–In2S3 heterostructures is about 16.7, 12.5, 6.3, 5.9, and 2.2 times that over pure TiO2 nanofibers, ZnS nanoparticles, In2S3/TiO2 nanofibers, ZnS/TiO2 nanofibers, and ZnS-In2S3 solid solution, respectively. Furthermore, the TiO2@ZnS–In2S3 heterostructures show highly stable recycling performance.A unique hierarchical architecture of ZnS–In2S3 solid solution onto TiO2 nanofibers was fabricated. The hierarchical heterostructures exhibit high visible light photocatalytic activity and outstanding recycling performance.
Co-reporter:Ming-Yue Ding;De-Shui Meng;Yan-Hong Tang;Cheng-Bin Liu
Chemical Papers 2015 Volume 69( Issue 11) pp:1411-1420
Publication Date(Web):2015 November
DOI:10.1515/chempap-2015-0151
One-dimensional (1D) Ag/AgBr/TiO2 nanofibres (NFs) have been successfully fabricated by the one-pot electrospinning method. In comparison with bare TiO2 NFs and Ag/AgBr/PVP (polyvinylpyrrolidone) NFs, the 1D Ag/AgBr/TiO2 NFs photocatalyst exhibits much higher photocatalytic activity in the degradation of a commonly used dye, methylene blue (MB), under visible light. The photocatalytic removal efficiency of MB over Ag/AgBr/TiO2 NFs achieves almost 100 % in 20 min. The photocatalytic reaction follows the first-order kinetics and the rate constant (k) for the degradation of MB by Ag/AgBr/TiO2 NFs is 5.2 times and 6.6 times that of Ag/AgBr/PVP NFs and TiO2 NFs, respectively. The enhanced photocatalytic activity is ascribed to the stronger visible light absorption, more effective separation of photogenerated electron-hole pairs, and faster charge transfer in the long nanofibrous structure. The Ag/AgBr/TiO2 NFs maintain a highly stable photocatalytic activity due to its good structural stability and the self-stability system of Ag/AgBr. The mechanisms for photocatalysis associated with Ag/AgBr/TiO2 NFs are proposed. The degradation of MB in the presence of scavengers reveals that h+ and •O2− significantly contribute to the degradation of MB.
Co-reporter:Hejie Song;Liming Yang; Yanhong Tang;Dafeng Yan; Chengbin Liu; Shenglian Luo
Chemistry - A European Journal 2015 Volume 21( Issue 46) pp:16631-16638
Publication Date(Web):
DOI:10.1002/chem.201502804
Abstract
A three-dimensional (3D) nitrogen-doped reduced graphene oxide (rGO)–carbon nanotubes (CNTs) architecture supporting ultrafine Pd nanoparticles is prepared and used as a highly efficient electrocatalyst. Graphene oxide (GO) is first used as a surfactant to disperse pristine CNTs for electrochemical preparation of 3D rGO@CNTs, and subsequently one-step electrodeposition of the stable colloidal GO–CNTs solution containing Na2PdCl4 affords rGO@CNTs-supported Pd nanoparticles. Further thermal treatment of the Pd/rGO@CNTs hybrid with ammonia achieves not only in situ nitrogen-doping of the rGO@CNTs support but also extraordinary size decrease of the Pd nanoparticles to below 2.0 nm. The resulting catalyst is characterized by scanning and transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Catalyst performance for the methanol oxidation reaction is tested through cyclic voltammetry and chronoamperometry techniques, which shows exceedingly high mass activity and superior durability.
Co-reporter:Chengbin Liu, Hang Zhang, Yanhong Tang and Shenglian Luo
Journal of Materials Chemistry A 2014 vol. 2(Issue 13) pp:4580-4587
Publication Date(Web):06 Jan 2014
DOI:10.1039/C3TA14137C
Graphene is a promising support for nanosized electrocatalysts, however the conventional stacking arrangement of its graphene sheets substantially decreases the catalytic sites on the catalyst. We report here the fabrication of a graphene/Cu electrocatalyst by the simple cyclic voltammetric electrolysis of graphene oxide (GO) and copper ethylenediamine tetraacetate (Cu–EDTA), and find that the electrochemically reduced GO (RGO) and Cu nanoparticles can be sequentially self-assembled into layer-by-layer, 3D sandwich-type, and homogenous architectures as the concentration ratio of Cu–EDTA/GO increases. The 3D sandwich-type RGO/Cu composite (S-RGO/Cu) shows RGO sheets decorated with Cu nanoparticles which stand nearly perpendicular on the electrode, leading to a significant increase in the electrochemically accessible surface area (0.685 cm2) relative to those of the horizontal layer-by-layer RGO/Cu composite (0.147 cm2) and the homogenous RGO/Cu composite (0.265 cm2). Stemming from its high electrochemical surface area, the S-RGO/Cu composite exhibits a high electrocatalytic activity in hydrazine oxidation in terms of current density and overpotential. Mechanistic analysis of the electrode reactions reveals the reaction pathways of hydrazine on RGO/Cu are closely related to the electrochemical surface area of the RGO/Cu electrocatalyst. The correlation between the architectures and their performances in electrocatalysis presented here can guide the design of novel structures with enhanced properties.
Co-reporter:Yanhong Tang, Xu Hu and Chengbin Liu
Physical Chemistry Chemical Physics 2014 vol. 16(Issue 46) pp:25321-25329
Publication Date(Web):15 Oct 2014
DOI:10.1039/C4CP04057K
An artful graphene sheltering engineering onto TiO2 nanotube array for perfect inhibition of CdS photocorrosion (RGO/CdS–TiO2 NT) has been developed by a one-step electrodeposition method. The CdS photocorrosion driven by both holes and radicals has been systematically investigated and identified. The RGO layer provides a perfect protection to CdS through (i) blocking the attack of active species especially ˙OH radicals and (ii) offering a closed electron-rich microenvironment where the stored electrons RGO(e−) not only reduce intermediate species S˙− to S2− but also compensate the valence band of CdS for its loss of electrons to alleviate CdS photocorrosion from oxidation by holes. The photocatalyst exhibits extremely high stability. RGO/CdS–TiO2 NT shows high visible-light photocatalytic activity for the degradations of organic dye methylene blue (MB), industrial chemical p-nitrophenol (PNP) and herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). This work provides a new insight into the protection of photosensitive semiconductors from photocorrosion.
Co-reporter:Yue Li, Shenglian Luo, Zhendong Wei, Deshui Meng, Mingyue Ding and Chengbin Liu
Physical Chemistry Chemical Physics 2014 vol. 16(Issue 9) pp:4361-4368
Publication Date(Web):06 Jan 2014
DOI:10.1039/C3CP54675F
Electrodeposition is a very versatile tool to fabricate multicomponent TiO2 nanotube array (NTA) composites. However, the understanding of the correlation between the component structure and the fabrication technique has not been clearly investigated yet, though it has been observed that the performance of composites is bound up with the component structure. In this work, the photoelectrochemical properties of In2S3–TiO2 NTA composites prepared by CV electrodeposition, potentiostatic electrodeposition and pulse electrodeposition, respectively, were investigated. The results revealed that the as-prepared photoelectrodes exhibited electrodeposition technique-dependent properties, and the pulse prepared In2S3–TiO2 yielded the highest and stable photocurrent response, consequently exhibiting a superior photocatalytic activity in the degradation of p-nitrophenol (PNP). This may be attributed to the homogeneous, ultra-fine structure of In2S3 nanoparticles (NPs), which brings about a high charge separation efficiency. Furthermore, the trapping tests showed that both radicals and holes were the main active species in the photocatalytic degradation of PNP. This work not only provided a firm basis for maximizing photocatalytic activity via tuning fabrication techniques but also gave a deep insight into the photocatalytic mechanism.
Co-reporter:Shenglian Luo, Hua Xiao, Shanli Yang, Chengbin Liu, Jiesheng Liang, Yanhong Tang
Sensors and Actuators B: Chemical 2014 194() pp: 325-331
Publication Date(Web):
DOI:10.1016/j.snb.2013.12.108
Co-reporter:Liming Yang;Dr. Yanhong Tang; Shenglian Luo; Chengbin Liu;Hejie Song;Dafeng Yan
ChemSusChem 2014 Volume 7( Issue 10) pp:2907-2913
Publication Date(Web):
DOI:10.1002/cssc.201402352
Abstract
Reduced graphene oxide (rGO) is a promising support material for nanosized electrocatalysts. However, the conventional stacking arrangement of rGO sheets confines the electrocatalysts between rGO layers, which decreases the number of catalytic sites substantially. We report here a facile synthesis of vertically oriented reduced graphene oxide (VrGO) through cyclic voltammetric electrolysis of graphene oxide (GO) in the presence of Na2PdCl4. Experiments without Pd nanoparticles or with a low loading amount of Pd nanoparticles results in the deposition of rGO parallel to the electrodes. The vertical orientation of Pd/rGO nanoflakes causes a remarkable enhancement of the catalytic activity toward methanol electro-oxidation. The mass activity (620.1 A gPd−1) of Pd/VrGO is 1.9 and 6.2 times that of Pd/flat-lying rGO (331.8 A gPd−1) and commercial Pd/C (100.5 A gPd−1), respectively. Furthermore, the Pd/VrGO catalyst shows excellent resistance to CO poisoning. This work provides a simple wet-chemical method for VrGO preparation.
Co-reporter:Shanli Yang, Jiesheng Liang, Shenglian Luo, Chengbin Liu, and Yanhong Tang
Analytical Chemistry 2013 Volume 85(Issue 16) pp:7720
Publication Date(Web):July 24, 2013
DOI:10.1021/ac400874h
A novel electrochemiluminescence (ECL) sensor based on carbon quantum dots (CQDs) immobilized on graphene (GR) has been first developed for the determination of chlorinated phenols (CPs) in water. The detection is based on the ECL signals from the interaction between the analytes and the excited CQDs (C*+) using S2O82– as coreactant. GR facilitates both C•– and SO4•– production, resulting in a high yield of C*+, and the multistage amplification effect leads to a nearly 48-fold ECL amplification. Pentachlorophenol (PCP) is often monitored as an important indicator for CPs in real environmental samples, but its ultratrace and real-time analysis is an intractable issue in environmental monitoring. The resulting ECL sensor enables the real-time detection of PCP with unprecedented sensitivity reaching 1.0 × 10–12 M concentration in a wide linear range from 1.0 × 10–12 to 1.0 × 10–8 M. The ECL sensor showed high selectivity to CPs, especially to PCP. The practicability of the sensing platform in real water samples showed ideal recovery rates. It is envisaged that the eco-friendly and recyclable sensor could be employed in the identification of key CPs in the environment.
Co-reporter:Yao Chen, Yanhong Tang, Shenglian Luo, Chengbin Liu, Yue Li
Journal of Alloys and Compounds 2013 Volume 578() pp:242-248
Publication Date(Web):25 November 2013
DOI:10.1016/j.jallcom.2013.04.180
•The photocatalyst is prepared by an one-step constant potential deposition process.•The ternary photocatalyst shows effective separation of photogenerated charges.•The photocatalyst displays almost 100% photocatalytic removal of methyl orange.•The photocatalyst is easily recovered with excellent cycling stability.Au nanoparticles and reduced graphene oxide co-loaded TiO2 nanotube arrays (Au/RGO–TiO2 NTs) were prepared through a simple one-step constant-potential electrolysis of chloroauric acid and graphene oxide on TiO2 NTs. Compared with Au–TiO2 NTs, RGO–TiO2 NTs and un-modified TiO2 NTs, the Au/RGO–TiO2 NTs exhibited high efficiency in photocatalytic degradation of methyl orange (MO) under simulated solar light irradiation. The highly efficient photocatalytic activity is associated with broad absorption in the visible light region, increased photoinduced charge separation through transferring photogenerated electrons from TiO2 NTs to both Au and RGO, as well as the strong adsorption ability of RGO to MO molecules. Moreover, the Au/RGO–TiO2 NTs has an excellent stability. This work provides an insight into designing and synthesizing new TiO2 NTs-based hybrid materials for effective visible light-activated photocatalysis.Graphical abstractMethyl orange (MO) can be efficiently removed through photodegradation process using a novel photocatalyst, Au nanoparticles and reduced graphene oxide co-loaded TiO2 nanotube arrays.
Co-reporter:Yanhong Tang, Run Huang, Chengbin Liu, Shanli Yang, Zhenzhen Lu and Shenglian Luo
Analytical Methods 2013 vol. 5(Issue 20) pp:5508-5514
Publication Date(Web):12 Aug 2013
DOI:10.1039/C3AY40742J
A new electrochemical sensor for 4-nitrophenol (4-NP) detection based on the reduced graphene oxide (RGO) and Au nanoparticle composite was developed. The RGO film was first electrodeposited onto a glassy carbon electrode (GCE). Then Au nanoparticles (AuNPs) were electrochemically deposited onto the RGO film. The morphology and electrochemical properties of the AuNP/RGO composite were investigated. The synergic effect of AuNPs and RGO nanosheets as co-modifiers greatly facilitates electron-transfer processes between the electrolyte and the GCE, and thus leads to a remarkably improved sensitivity for 4-NP detection. Two detection modes, differential pulse voltammetry (DPV) and square wave voltammetry (SWV), were applied. A wide linear range of values, 0.05–2.0 μM and 4.0–100 μM for DPV and 0.05–2.0 μM for SWV, were obtained. The limit of detection (LOD) of 4-NP was 0.01 μM and 0.02 μM for DPV and SWV, respectively. This sensor was successfully used in the detection of real water samples from Xiangjiang River.
Co-reporter:Xuanneng Liu, Yanhong Tang, Shenglian Luo, Yao Wang, Xilin Zhang, Yao Chen, Chengbin Liu
Journal of Photochemistry and Photobiology A: Chemistry 2013 Volume 262() pp:22-27
Publication Date(Web):15 June 2013
DOI:10.1016/j.jphotochem.2013.04.016
•RGO/CuInS2–TiO2 NTs was facilely fabricated by electrodeposition technique.•The new catalyst exhibited significantly photocatalytic activity.•Refractory herbicide 2,4-D was efficiently photocatalytically degraded.Refractory herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) can be efficiently removed by photocatalytic degradation when using reduced graphene oxide (RGO) and CuInS2 nanoparticles (NPs) co-decorated TiO2 nanotube arrays (NTs) (RGO/CuInS2–TiO2 NTs) as a photocatalyst prepared by successive pulse electrodeposition of CuInS2 and RGO film onto the top surface of TiO2 NTs. The new catalyst exhibits significant photocatalytic activity and good removal efficiency of 2,4-D. The photodegradation rate toward 2,4-D over RGO/CuInS2–TiO2 NTs under simulated solar light (or visible light) irradiation is 96.2% (or 87.7%), much higher than 68.0% (or 58.4%) over CuInS2–TiO2 NTs, 50.1% (or 38.1%) over RGO–TiO2 NTs and 36.0% (or 26.3%) over bare TiO2 NTs, respectively, meaning that the photocatalytic performance of TiO2 NTs could be greatly enhanced by the synergetic effect of RGO and CuInS2. This work could provide new insights into the design and fabrication of advanced photocatalysts.Refractory herbicide 2,4-dichlorophenoxyacetic acid was efficiently photocatalytically degraded by reduced graphene oxide and CuInS2 co-decorated TiO2 nanotube arrays fabricated by electrodeposition.
Co-reporter:Zhang Hu
Journal of Polymer Research 2013 Volume 20( Issue 1) pp:
Publication Date(Web):2013 January
DOI:10.1007/s10965-012-0039-7
The nanosheet–shaped polyethylene/graphite oxide (PE/GO) nanocomposites were attained by in situ ethylene polymerization using MAO/Cp2ZrCl2 catalyst system supported on the graphite oxides modified with phenylalanine, butylamine, octylamine or 3–aminopropyltriethoxysilane, respectively. The introduction of the organic guests between graphite oxide sheets led to the nanoscale exfoliation and gradual dispersion of GO in the PE matrix during the in situ ethylene polymerization. Morphological examination of the ultimate PE/GO nanocomposites by TEM, SEM, and XRD techniques revealed effective dispersion in nanoscale of GO in PE matrix. In comparison, the traditional phase separated composite was obtained using unmodified GO–supported metallocene catalyst system. The heat endurance of the PE/GO composite is much better than that of polyethylene from homogeneous polymerization.
Co-reporter:Yao Wang;Yanhong Tang;Yao Chen;Yue Li;Xuanneng Liu
Journal of Materials Science 2013 Volume 48( Issue 18) pp:6203-6211
Publication Date(Web):2013 September
DOI:10.1007/s10853-013-7417-3
A simple one-step electrochemical deposition method was demonstrated to fabricate reduced graphene oxide/Ag nanoparticle co-decorated TiO2 nanotube arrays (RGO/Ag–TiO2NTs) photocatalyst in this study. The structures and properties of these photocatalysts were characterized using scanning electron microscope, X-ray diffraction, UV–Vis diffuse reflection spectra, and photoluminescence. By taking the advantages of TiO2, graphene, and Ag nanoparticles (AgNPs), RGO/Ag–TiO2NTs showed a greatly improved photocatalytic activity compared with the bare TiO2NTs, Ag–TiO2NTs or RGO–TiO2NTs. The deposited RGO and AgNPs not only reduce the recombination of photogenerated electrons and holes, but also increase the surface area of the catalyst. Both photocatalytic performance and adsorptivity of the catalyst have been improved. The ternary photocatalyst exhibited over 93 % removal efficiency of typical herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) under simulated solar light irradiation with good stability and easy recovery, which justifies the photocatalytic system, a promising application for herbicide or other organic pollutant removal from water.
Co-reporter:Yanhong Tang;Na Wu;Shenglian Luo;Ke Wang;Liuyun Chen
Macromolecular Rapid Communications 2012 Volume 33( Issue 20) pp:1780-1786
Publication Date(Web):
DOI:10.1002/marc.201200328
Abstract
One-step fabrication of graphene–polyaniline (graphene–PANI) hybrid film was facilely achieved by cyclic voltammetric electrolysis of a bath containing both graphene oxide (GO) and aniline, where graphene is obtained by electrochemical reduction of GO and PANI is simultaneously obtained by aniline electropolymerization. As there is no strong attraction between aniline and GO under the electrodeposition conditions, the independent depositions of PANI and reduced GO nanosheets at their greatly differed potentials led to alternate layered graphene–PANI films, with the topmost layer being PANI particles or graphene sheets just by changing the initial scan directions. The two kinds of graphene–PANI hybrid films present excellent but different electrical and electrochemical behaviors.
Co-reporter:Longlu Wang, Xidong Duan, Gongming Wang, Chengbin Liu, Shenglian Luo, Shuqu Zhang, Yunxiong Zeng, Yuzi Xu, Yutang Liu, Xiangfeng Duan
Applied Catalysis B: Environmental (5 June 2016) Volume 186() pp:
Publication Date(Web):5 June 2016
DOI:10.1016/j.apcatb.2015.12.056
•Well-integrated “cauline leaf” architecture with multiple active materials.•Omnidirectional enhancement of photocatalytic hydrogen evolution.•High HER rate and apparent quantum efficiency.•Excellent long term stability of HER.The scrupulous design and integration of multiple active materials into hierarchical nanoarchitectures is essential for the creation of photocatalytic hydrogen evolution reaction (HER) system that can mimic natural photosynthesis. Here we report the design and preparation of a “cauline leaf”-like structure for highly efficient HER, by decorating TiO2 nanofibers with vertical arrays of atomically-thin MoS2 nanosheets and CdS nanocrystals. The unique integrated “cauline leaf” design can promote light trapping and absorption for highly efficient light harvesting and photocarrier generation, and offer unblocked electron transport pathway for rapid charge separation/transport to suppress charge recombination, as well as high surface area and high density of active sites for highly efficient utilization of photo-generated carriers for productive HER. Structural characterizations by transmission electron microscopy show well-integrated nanoarchitectures. Significantly, photocatalytic studies demonstrate rapid HER rates as high as 12.3 or 6.2 mmol h−1 g−1 under simulated solar light or visible light irradiation, with apparent quantum efficiencies of 70.5% at 365 nm or 57.6% at 420 nm, and excellent long term stability, representing one of the best reported MoS2 hybrid HER photocatalysts. The study could open new opportunities for the rational design of nanoscale architectures for HER or other application.Download full-size image
Co-reporter:Chengbin Liu, Chenghao Cao, Xubiao Luo, Shenglian Luo
Journal of Hazardous Materials (21 March 2015) Volume 285() pp:319-324
Publication Date(Web):21 March 2015
DOI:10.1016/j.jhazmat.2014.12.020
•Ag-bridged Ag2O nanowire network self-stability structure.•Ag2O nanowire network/TiO2 nanotube p–n heterojunction.•High visible light photocatalytic activity.•Highly stable recycling performance.A unique Ag-bridged Ag2O nanowire network/TiO2 nanotube array p–n heterojunction (Ag–Ag2O/TiO2 NT) was fabricated by simple electrochemical method. Ag nanoparticles were firstly electrochemically deposited onto the surface of TiO2 NT and then were partly oxidized to Ag2O nanowires while the rest of Ag mother nanoparticles were located at the junctions of Ag2O nanowire network. The Ag–Ag2O/TiO2 NT heterostructure exhibited strong visible-light response, effective separation of photogenerated carriers, and high adsorption capacity. The integration of Ag–Ag2O self-stability structure and p–n heterojunction permitted high and stable photocatalytic activity of Ag–Ag2O/TiO2 NT heterostructure photocatalyst. Under 140-min visible light irradiation, the photocatalytic removal efficiency of both dye acid orange 7 (AO7) and industrial chemical p-nitrophenol (PNP) over Ag–Ag2O/TiO2 NT reached nearly 100% much higher than 17% for AO7 or 13% for PNP over bare TiO2 NT. After 5 successive cycles under 600-min simulated solar light irradiation, Ag–Ag2O/TiO2 NT remained highly stable photocatalytic activity.A unique Ag-bridged Ag2O nanowire network/TiO2 nanotube array p–n heterojunction was fabricated by simple electrochemical method. The heterostructures exhibit high photocatalytic activity and excellent recycling performance.Download full-size image
Co-reporter:Kai Yin, Fei Li, Ying Wang, Qunying He, Yongxiu Deng, Shuo Chen, Chengbin Liu
Journal of Hazardous Materials (15 May 2017) Volume 330() pp:52-60
Publication Date(Web):15 May 2017
DOI:10.1016/j.jhazmat.2017.02.012
•Transformation pathways of acesulfame oxidation with Mn(VII) were proposed.•New transformation products on acesulfame oxidation were identified.•Environmentally relevant conditions were systematically investigated.•Ecotoxicity of transformation products of acesulfame oxidation was evaluated.•Acesulfame oxidation with Mn(VII) in real water was studied.Acesulfame has attracted much attention due to its wide application, environmental persistence and potential safety risk of transformation products (TPs). Little information is known on acesulfame transformation in the presence of oxidants/disinfectants. The acesulfame oxidation by permanganate (Mn(VII)) in water under environmentally relevant conditions was systematically evaluated. The pH of water showed negligible influence in acesulfame oxidation. Inorganic ligand (pyrophosphate) exhibited insignificant effect whereas organic ligands (oxalate, ethylene diamine tetraacetic acid, and humic acid) exerted obvious suppression on acesulfame oxidation. Natural organic matter in real water had important influence in acesulfame oxidation by Mn(VII). Acesulfame transformation pathways were initiated by the attack of Mn(VII) on double bond of ring via [3 + 2] addition electrocyclic reaction and rich electron of N moiety through electrophilic reaction, followed by oxidation and hydrolysis reactions to produce TPs. Among them, five TPs were for the first time identified. The ecotoxicity tests uncover higher toxicity of the TPs than acesulfame itself. The study on oxidative transformation of acesulfame by Mn(VII) would illumine comprehensive evaluation of this emerging contaminant. Water treatment plants need to consider cautiously to protect the safety of downstream system when using Mn(VII) to dispose the water resource containing acesulfame or other artificial sweeteners.Download high-res image (277KB)Download full-size image
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 20) pp:
Publication Date(Web):
DOI:10.1039/C3AY40742J
A new electrochemical sensor for 4-nitrophenol (4-NP) detection based on the reduced graphene oxide (RGO) and Au nanoparticle composite was developed. The RGO film was first electrodeposited onto a glassy carbon electrode (GCE). Then Au nanoparticles (AuNPs) were electrochemically deposited onto the RGO film. The morphology and electrochemical properties of the AuNP/RGO composite were investigated. The synergic effect of AuNPs and RGO nanosheets as co-modifiers greatly facilitates electron-transfer processes between the electrolyte and the GCE, and thus leads to a remarkably improved sensitivity for 4-NP detection. Two detection modes, differential pulse voltammetry (DPV) and square wave voltammetry (SWV), were applied. A wide linear range of values, 0.05–2.0 μM and 4.0–100 μM for DPV and 0.05–2.0 μM for SWV, were obtained. The limit of detection (LOD) of 4-NP was 0.01 μM and 0.02 μM for DPV and SWV, respectively. This sensor was successfully used in the detection of real water samples from Xiangjiang River.
Co-reporter:Yangbin Ding, Yanhong Tang, Liming Yang, Yunxiong Zeng, Jili Yuan, Tian Liu, Shuqu Zhang, Chengbin Liu and Shenglian Luo
Journal of Materials Chemistry A 2016 - vol. 4(Issue 37) pp:NaN14315-14315
Publication Date(Web):2016/08/16
DOI:10.1039/C6TA05267C
Nitrogen-rich carbon material derived from carbon self-repairing g-C3N4 is self-assembled with graphene oxide (GO) to form a porous structure. Different from the pristine g-C3N4, which has scarcely been employed in supercapacitors because of its low charge mobility, the carbon self-repairing g-C3N4 (C-C3N4) shows an improved electrochemical activity. After carbon-repairing, a delocalized big π-bond can be formed by the homogeneous C-substitution for N atoms or the formation of new interstitial C–N bond. The extending π-conjugation planar layer of C-C3N4 possesses a closer contact with GO to form a three-dimensional (3D) pore structure, which ensures good mobility for electrons and quick access for electrolytes. Under the optimum C-repairing content of 5.99 at%, the C-C3N4@rGO exhibited high specific capacity of 379.7 F g−1 and energy density of 52.7 W h kg−1 at a current density of 0.25 A g−1. Moreover, the electrode kept 85% capacity retention after 10000 cycles at a high constant current density of 10 A g−1. The active sites of pseudocapacitance can be confirmed in the oxygen-containing groups and the carbon atoms close to the nitrogen by the XPS results.
Co-reporter:Meijun Liu, Liming Yang, Tian Liu, Yanhong Tang, Shenglian Luo, Chengbin Liu and Yunxiong Zeng
Journal of Materials Chemistry A 2017 - vol. 5(Issue 18) pp:NaN8615-8615
Publication Date(Web):2017/04/12
DOI:10.1039/C7TA01791J
Transition metal phosphides (TMPs) have been one of the ideal candidates as low-cost and high-efficiency catalysts for hydrogen evolution reactions (HERs). We report herein a novel TMP architecture, Fe2P nanoparticles/reduced graphene oxide (rGO) nanosheets/Fe2P nanoparticles (Fe2P@rGO) sandwich-structured (Fe2P@rGO) nanowall arrays on a Ti plate. This nanostructure was easily prepared via one-step electrodeposition followed by a low-temperature phosphidation reaction. The Fe2P@rGO nanowall array film is featured with maximally exposed catalytic sites, fast electron and mass transport, and robust structure stability, and therefore it behaves as an excellent HER electrocatalyst. The Fe2P@rGO shows a low overpotential of 101 mV at a current density of 10 mA cm−2 and a small Tafel slope of 55.2 mV dec−1 with a large exchange current density of 0.146 mA cm−2. Furthermore, the catalyst exhibits superior durability evidenced by about 87% catalytic activity retention against about 55% for the commercial Pt/C catalyst after a 12 h test. The study presents a new nanoengineering strategy for high-performance TMP-based HER catalysts.
Co-reporter:Yanhong Tang, Xu Hu and Chengbin Liu
Physical Chemistry Chemical Physics 2014 - vol. 16(Issue 46) pp:NaN25329-25329
Publication Date(Web):2014/10/15
DOI:10.1039/C4CP04057K
An artful graphene sheltering engineering onto TiO2 nanotube array for perfect inhibition of CdS photocorrosion (RGO/CdS–TiO2 NT) has been developed by a one-step electrodeposition method. The CdS photocorrosion driven by both holes and radicals has been systematically investigated and identified. The RGO layer provides a perfect protection to CdS through (i) blocking the attack of active species especially ˙OH radicals and (ii) offering a closed electron-rich microenvironment where the stored electrons RGO(e−) not only reduce intermediate species S˙− to S2− but also compensate the valence band of CdS for its loss of electrons to alleviate CdS photocorrosion from oxidation by holes. The photocatalyst exhibits extremely high stability. RGO/CdS–TiO2 NT shows high visible-light photocatalytic activity for the degradations of organic dye methylene blue (MB), industrial chemical p-nitrophenol (PNP) and herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). This work provides a new insight into the protection of photosensitive semiconductors from photocorrosion.
Co-reporter:Yue Li, Shenglian Luo, Zhendong Wei, Deshui Meng, Mingyue Ding and Chengbin Liu
Physical Chemistry Chemical Physics 2014 - vol. 16(Issue 9) pp:NaN4368-4368
Publication Date(Web):2014/01/06
DOI:10.1039/C3CP54675F
Electrodeposition is a very versatile tool to fabricate multicomponent TiO2 nanotube array (NTA) composites. However, the understanding of the correlation between the component structure and the fabrication technique has not been clearly investigated yet, though it has been observed that the performance of composites is bound up with the component structure. In this work, the photoelectrochemical properties of In2S3–TiO2 NTA composites prepared by CV electrodeposition, potentiostatic electrodeposition and pulse electrodeposition, respectively, were investigated. The results revealed that the as-prepared photoelectrodes exhibited electrodeposition technique-dependent properties, and the pulse prepared In2S3–TiO2 yielded the highest and stable photocurrent response, consequently exhibiting a superior photocatalytic activity in the degradation of p-nitrophenol (PNP). This may be attributed to the homogeneous, ultra-fine structure of In2S3 nanoparticles (NPs), which brings about a high charge separation efficiency. Furthermore, the trapping tests showed that both radicals and holes were the main active species in the photocatalytic degradation of PNP. This work not only provided a firm basis for maximizing photocatalytic activity via tuning fabrication techniques but also gave a deep insight into the photocatalytic mechanism.
Co-reporter:Chengbin Liu, Hang Zhang, Yanhong Tang and Shenglian Luo
Journal of Materials Chemistry A 2014 - vol. 2(Issue 13) pp:NaN4587-4587
Publication Date(Web):2014/01/06
DOI:10.1039/C3TA14137C
Graphene is a promising support for nanosized electrocatalysts, however the conventional stacking arrangement of its graphene sheets substantially decreases the catalytic sites on the catalyst. We report here the fabrication of a graphene/Cu electrocatalyst by the simple cyclic voltammetric electrolysis of graphene oxide (GO) and copper ethylenediamine tetraacetate (Cu–EDTA), and find that the electrochemically reduced GO (RGO) and Cu nanoparticles can be sequentially self-assembled into layer-by-layer, 3D sandwich-type, and homogenous architectures as the concentration ratio of Cu–EDTA/GO increases. The 3D sandwich-type RGO/Cu composite (S-RGO/Cu) shows RGO sheets decorated with Cu nanoparticles which stand nearly perpendicular on the electrode, leading to a significant increase in the electrochemically accessible surface area (0.685 cm2) relative to those of the horizontal layer-by-layer RGO/Cu composite (0.147 cm2) and the homogenous RGO/Cu composite (0.265 cm2). Stemming from its high electrochemical surface area, the S-RGO/Cu composite exhibits a high electrocatalytic activity in hydrazine oxidation in terms of current density and overpotential. Mechanistic analysis of the electrode reactions reveals the reaction pathways of hydrazine on RGO/Cu are closely related to the electrochemical surface area of the RGO/Cu electrocatalyst. The correlation between the architectures and their performances in electrocatalysis presented here can guide the design of novel structures with enhanced properties.
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