Study on Optimum Preparation Conditions of ZnIn2S4 to Effectively Reduce Cr(VI) under Visible Light Radiation

Previous studies have displayed various conclusions about the effect of preparation factors on the photoreduction property of ZnIn2S4. Therefore, it is not easy to figure out the optimal preparation conditions of ZnIn2S4for Cr(VI) photoreduction. To ensure Cr(VI) reduction efficiency, various ZnIn2S4photocatalysts were prepared in different solvents (i.e., water and ethylene glycol) and temperatures (i.e., 120 °C, 150 °C and 180°C). Different characterization methods were used to explain the difference in optical performance and photocatalytic property among the obtained samples. The results show that all the samples exhibit a similar band gap. The reaction solvent and temperature have a great influence on the surface morphology and optical property, leading to the different photocatalytic properties. ZnIn2S4synthesized at 120 °C in the solvothermal condition shows the optimal efficiency on Cr(VI) photoreduction due to the effective utilization of photo-induced carriers. The reasonable analysis and effective conclusion presented may provide the optimal synthesis method of ZnIn2S4to effectively remove Cr(VI) from water environment.Keywords:ZnIn2S4;Cr(VI);solvothermal;hydrothermal;photoreduction