•We introduced hexylthiophene unit to a triphenylamine based Dye (L1) for L101.•The η of L101 is 5.1% which is higher than L1 (η = 4.7%).•The hexylthiophene moieties can help to achieve better performance.Inspired from the structure of Ru-complex dye C101, the 2-hexylthiophene moieties were introduced to the triphenylamine unit of dye L1 for dye L101 as an attempt to enhance the donor capacity and achieve high overall power conversion efficiency (η). Finally, these two sensitizers were applied to Dye-sensitized solar cells(DSSCs), and their photovoltaic performance were further investigated through spectral, electrochemical, photovoltaic measurements. The η of L101 is 5.1% (Voc = 724 mV, Jsc = 9.24 mA cm−2, FF = 0.76, εmaxabs = 44.4 × 103 M−1 cm−1) which is higher than L1 (η = 4.7%, Voc = 712 mV, Jsc = 8.79 mA cm−2, FF = 0.75, εmaxabs = 23.3 × 103 M−1 cm−1). This slight enhancement is mainly attributed to two reasons: firstly, the light-harvesting capacity is enhanced when introducing hexylthiophene moieties to the triphenylamine donor unit of L1 and contributed to a larger Jsc. Secondly, the introduced 2-hexylthiophene moieties improve the conduction band edge of TiO2 which result in the higher Voc of L101 than L1. These results demonstrate that the introduced 2-hexylthiophene moieties could help to achieve better performance.Download full-size image

A series of microporous imide functionalized 1,3,5-triazine frameworks (named TPIs@IC) were designed by an easy-construction technology other than the known imidization method for the construction of porous triazine-based polyimide networks (TPIs) with the same chemical compositions. In contrast to TPIs, TPIs@IC exhibit much higher Brunauer–Emmett–Teller (BET) surface areas (up to 1053 m2 g−1) and carbon dioxide uptake (up to 3.2 mmol g−1/14.2 wt% at 273 K/1 bar). The presence of abundant ultramicropores at 5.4–6.8 Å, mainly ascribed to a high-level cyano cross-linking, allows the high heat absorption and high selective capture of CO2. The Qst (CO2 esoteric enthalpies) from their CO2 adsorption isotherms at 273 and 298 K are calculated to be in the range 46.1–49.3 kJ mol−1 at low CO2 loading, and the ideal CO2/N2 separation factors are up to 151, exceeding those of the most reported porous organic polymers to date. High storage capacities of TPIs@IC for other small gases like CH4 (5.01 wt% at 298 K/22 bar) and H2 (1.47 wt% at 77 K/1 bar) were also observed, making them promising adsorbents for gas adsorption and separation.

•Two phenoxazine-based dyes have been synthesized for a comparatively study.•The result shows that POZ-2 exhibited higher η of 6.5% than POZ-1 (η = 2.4%).•Conjugated direction is the crucial influential factor of η.Two phenoxazine (POZ)-based organic D–π–A sensitizers (POZ-1 and POZ-2) were synthesized. Then these two dyes were applied in dye-sensitized solar cells (DSSCs) to investigate the influence of different conjugated direction, extra phenyl ring and alkyl chain on the light-harvesting, energy level and photovoltaic properties through a joint spectral, electrochemical and photovoltaic study. The result shows that dye POZ-2 exhibits higher power conversion efficiency (η = 6.5%) than dye POZ-1 (η = 2.4%) under standard illumination (Global Air Mass 1.5). Besides, the geometries of the dyes were optimized to gain insight into the molecular structure and electron distribution. The charge extraction and transient photovoltage decay measurements were further performed to understand the alterative order of efficiency.Two phenoxazine-based organic (POZ-1, POZ-2) dyes were synthesized for a comparatively study.

•We synthesized three isoindigo based organic dyes (ID1, ID2, ID3).•ID1 shows higher energy conversion efficiency (3.33%).•Double anchor group could affect the progress of electron directional transmission.Novel D-π-A system organic dyes (ID1, ID2 and ID3) based on isoindigo (ID), which contain triphenylamine (ID1) or isoindigo (ID2 and ID3) as electron donors, isoindigo and thiophene as a π-conjugated system and a cyanoacrylic acid moiety as an electron acceptor and anchoring group, have been then synthesized and characterized by 1H NMR, UV–vis, CV. Dye-sensitized solar cells (DSSCs) based on these dyes were also fabricated and tested. As the photovoltaic performance tests demonstrated, the ID1 exhibits broader absorption spectra, higher maximum incident photon-to-current conversion efficiency (IPCE) and maximum photon-to-electron conversion efficiency (η) of 3.33% under 100 mW/cm2 simulated AM 1.5G solar irradiation.

•We have synthesized four phenoxazine-based dyes (POZ-2, POZ-3, POZ-4, POZ-5).•The POZ-3 cell shows the highest η of 7.8%.•The electron donors are the main factor affecting the performance of these cells.A series of organic dyes (POZ-2, POZ-3, POZ-4 and POZ-5) involving phenoxazine were synthesized as sensitizers for application in dye-sensitized solar cells (DSSCs). For comparison, three different electron donors namely 10-phenyl-10H-phe-nothiazine, 10-phenyl-10H-phenoxazine and triphenylamine were separately appended onto the 7-position of the model dye (POZ-2). The obtained four dyes exhibit considerably high values of conversion efficiencies of 6.6%, 7.8%, 7.1% and 6.4%, respectively, under the simulated AM1.5G conditions. The geometries of the dyes were optimized to gain insight into the molecular structure and electron distribution, and then the charge extraction and transient photovoltage decay measurements were further performed to understand the influence of electron donors on the photovoltaic behaviors.A series of phnoxazine dyes containing different chromophores were synthesized as sensitizers for application in dye-sensitized solar cells

The syntheses and properties of phenyl-1,3,5-triazine functional aromatic polyamides are described. From 2,4,6-trichloro-1,3,5-triazine (1), an aromatic diacid, namely 4-(4,6-diphenyl-1,3,5-triazin-2-yl)benzoic acid (6), was prepared by a three-step reaction in satisfactory yields. A model reaction of 6 with aniline (7) was carried out to determine feasibility of amidization. Aromatic poly(phenyl-1,3,5-triazine amide)s (10a–10e) with inherent viscosities ranging from 0.28 to 1.26 dL/g were synthesized from Yamazaki phosphorylation polycondensation of 6 with aromatic diamines (9a–9e). The reactions were conducted in N-methyl-2-pyrrolidone (NMP) to yield high-molecular-weight amorphous polymers in essentially high yields. All polymers are readily soluble in NMP and N,N-dimethylacetamide (DMAc) at room temperature, and formed transparent films from their solution. The films exhibit good mechanical properties with tensile strengths of 71.5–94.7 MPa, elongations at break of 6.1–10.0%, and initial moduli of 2.3–2.8 GPa except that of 10a is slightly brittle. These polymers have high glass transitions from 311 to 330 °C, depending on the aromatic diamines used in the polycondensation, and they demonstrate excellent thermal stabilities in excess of 440 °C (5% weight loss in air). Isothermal TGA measurements reveal that the obtained benzene-1,3-diamine-based poly(phenyl-1,3,5-triazine amide) (10b) belongs to the most superior class of heat resistant polymers such as polyamide Kevlar®.

A novel class of xanthan-maleic anhydride (Xan-MA)/poly(N-isopropylacrylamide) hybrid hydrogels was designed and synthesized by solution polymerization. The xanthan-based precursor (Xan-MA) was prepared by substituting the hydroxyl groups in Xan by MA. This Xan-MA precursor was then polymerized with a known temperature sensitive precursor (N-isopropylacrylamide, NIPAAm) to form hybrid hydrogels with a series range of composition ratio of Xan-MA to NIPAAm precursors. These smart hydrogels were characterized by Fourier transform infrared spectroscopy for structural determination, differential scanning calorimertry for thermal property. And maximum swelling ratio, swelling kinetics and temperature response kinetics were studied. The data obtained clearly show that these smart hydrogels are responsive to the external changes of temperature as well as pH value. The magnitudes of smart and hydrogel properties of these hybrid hydrogels depend on the feed composition ratio of the two precursors. With the increase of the content of Xan-MA the maximum swelling ratio, reswelling ratio and thermo-sensitivities increase, and the feed composition ratio of Xan-MA/NIPAAm increases the maximum swelling ratio augment from 13.88 to 23.21. From XMN0, XMN1, XMN3 to XMN5, the lower critical solution temperatures (LCSTs) are 33.02, 36.15, 40.28 and 41.92 °, respectively. By changing the composition ratio of these two precursors, the LCST of the hybrid hydrogels could also be adjusted to be or near the body temperature for the potential applications in bioengineering and biotechnology fields.

(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs) were prepared by in-situ reaction, in which ethyl-orthosilicate (TEOS) was catalyzed by HCl and NH3·H2O, respectively. The ionic conductivity, the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra, contact angle method and TEM. The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10−5 and 1.1×10−5 S/cm respectively at 30 °C. The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2, and influences the surface energy and conductivity of CPE films directly. Meanwhile, the ionic conductivity is related to the surface energy.

Composite polymer electrolytes based on polyethylene oxide(PEO) were prepared by using LiClO4 as doping salt and silane-modified SiO2 as filler. SiO2 was formed in-situ in (PEO)8LiClO4 matrix by the hydrolysis and condensation reaction of Si(OC4H9)4. The crystallinity, morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry, scanning electron microscopy, atom force microscopy and alternating current impedance spectroscopy, respectively. Compared with the crystallinity of the unmodified SiO2 as inert filler, that of composite polymer electrolytes is decreased. The results show that silane-modified SiO2 particles are uniformly dispersed in (PEO)8LiClO4 composite polymer electrolyte film and the addition of silane-modified SiO2 increases the ionic conductivity of the (PEO)8LiClO4 more noticeably. When the mass fraction of SiO2 is about 10%, the conductivity of (PEO)8LiClO4-modified SiO2 attains a maximum value of 4.8×10−5 S·cm−1.

PEO-LiClO4-TiO2 composite polymer electrolyte films were prepared. TiO2 was formed directly in matrix by hydrolysis and condensation reaction of tetrabutyl titanate. The crystallinity, morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry, scanning electron microscopy, atom force microscopy and alternating current impedance spectroscopy, respectively. The glass transition temperature and the crystallinity of composite polymer electrolytes are decreased compared with those of PEO-LiClO4 polymer electrolyte film. The results show that TiO2 particles are uniformly dispersed in PEO-LiClO4-5%TiO2 composite polymer electrolyte film. The maximal conductivity of 5.5×10−5 S/cm at 20 °C of PEO-LiClO4-TiO2 film is obtained at 5% mass fraction of TiO2.

A series of microporous imide functionalized 1,3,5-triazine frameworks (named TPIs@IC) were designed by an easy-construction technology other than the known imidization method for the construction of porous triazine-based polyimide networks (TPIs) with the same chemical compositions. In contrast to TPIs, TPIs@IC exhibit much higher Brunauer–Emmett–Teller (BET) surface areas (up to 1053 m2 g−1) and carbon dioxide uptake (up to 3.2 mmol g−1/14.2 wt% at 273 K/1 bar). The presence of abundant ultramicropores at 5.4–6.8 Å, mainly ascribed to a high-level cyano cross-linking, allows the high heat absorption and high selective capture of CO2. The Qst (CO2 esoteric enthalpies) from their CO2 adsorption isotherms at 273 and 298 K are calculated to be in the range 46.1–49.3 kJ mol−1 at low CO2 loading, and the ideal CO2/N2 separation factors are up to 151, exceeding those of the most reported porous organic polymers to date. High storage capacities of TPIs@IC for other small gases like CH4 (5.01 wt% at 298 K/22 bar) and H2 (1.47 wt% at 77 K/1 bar) were also observed, making them promising adsorbents for gas adsorption and separation.