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Cu2ZnSnSxSe4-x (CZTSSe) counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) are commonly developed with porous structures, but their high surface area could also retard electron transport processes owing to the abundant grain boundaries. Herein, we employed a convenient solution method and a rapid heating process to prepare well crystalline CZTSSe CEs in DSSCs. The influence of crystallization of CZTSSe film on DSSCs performances was discussed in depth. The thermogravimetric analysis, phase morphology, conductivity, and electrochemical characteristics of CZTSSe films were performed. It is found that the rapid heating process is beneficial to the formation of well crystalline film with large grains. As the porosity and grain boundaries in the bulk film are dramatically reduced with the enhanced crystallization, the charge transport process is gradually improved. Using cyclic voltammogram and electrochemical impedance spectroscopy measurements, we propose that the accelerating charge transport is of great importance to the photovoltaic performances of DSSCs due to their superior electrocatalytic activities. As the highest cell efficiency was achieved, well crystalline CZTSSe is an efficient CE catalytic material.

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Exploring inorganic ligand capped nanocrystals (NCs) as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs) with high conversion efficiency. Here, we reported the preparation of inorganic ligand capped CuInS 2 NCs through a ligand exchange strategy. After ligand exchange, the organic ligand capped on the surface of CuInS 2 NCs were exchanged to inorganic ligand S 22 without changing the shape, size distribution and crystal structure of CuInS 2 NCs. When used as CE materials for dye-sensitized solar cells, the inorganic ligand capped CuInS 2 NCs films showed higher electrocatalytic activity and electrical conductivity, thus can significantly improve the efficiency of DSSCs. It should be noted that the conversion efficiency of the DSSC increased by 17 times after the organic ligand capped CuInS 2 NCs were exchanged with the inorganic ligand. The study in this work may pave a new pathway to explore highly electrical conductivity materials for DSSCs.

Reactive extractions of o-, m-, and p-aminophenol (OAP, MAP, and PAP) using trialkylphosphine oxide/kerosene (TRPO/kerosene) have been studied. The equilibrium aqueous pH (pHeq) and the concentrations of TRPO in organic phases were found to be of important effects on the distribution coefficient (D) of OAP, MAP, and PAP between TRPO/kerosene and water. Infrared spectra results suggested pHeq had no influence on the complexes' structures, and TRPO mainly reacted with neutral aminophenol through forming a hydrogen bond between its PO and aminophenol OH. An expression of D was proposed, and the apparent reactive extraction equilibrium constants (K) were calculated by fitting the experimental data. The dissociation constant of the OH group of aminophenol (namely, pK a2) played a vital role that affected K, while the hydrophobic parameter (log P) of aminophenol had little effect. K was statistically calculated to be in accordance with the equation of log K + pK a2 = 10.94 under all experimental test conditions. D values calculated from the model were in good agreement with experimental ones.

CZTS exhibited apparently phase-dependent photocatalytic H2 evolution under visible light. Possible factors for the phase-dependent photocatalytic activity of CZTS were discussed in detail.

The extraction equilibrium of picolinic acid using trialkylamine (N235) dissolved in n-octanol at 298 ± 0.5 K has been studied. The factors that affected distribution coefficients (D), such as aqueous equilibrium pH (pH eq ), N235 concentration, and diluents, were investigated. As diluents, n-octanol showed higher D values than those of tetrachloromethane and kerosene. The maximum D values appeared at a N235 concentration of 0.4218 mol•L −1 , which were in agreement with the results of the apparent alkalinity of N235/n-octanol. The D values were also observed with peak values at pH eq in the range of 4.5−6.0. In addition, D decreased with the increase of the initial picolinic acid concentration. Fourier transform infrared spectrometry confirmed that pH eq had no influence on the complexes' structure and the extraction reaction belonged to the proton-transfer process. The expression of D was proposed based on the mass action law with reasonable assumptions, and the model parameters were calculated by fitting the experimental data. The D values obtained by the model were in good agreement with the experimental ones.