Construction of zinc-indium-sulfide/indium oxide step-scheme junction catalyst for enhanced photocatalytic activities of pollutant degradation and hydrogen generation

In this work, a novel zinc-indium-sulfide/indium oxide photocatalyst was prepared via hydrothermal method combining with low temperature self-assembly process for promoting the photocatalytic activity for contaminants degradation and hydrogen production. The Znln2S4 ternary nanoparticles are evenly deposited on the outside of the In2O3 nanoflowers and the step-scheme junction hybrid system is formed. Through the formation of junction, the light absorption efficiency as well as the charge separation efficiency is improved. In all samples irradiated by visible light, the photocatalytic degradation of gaseous acetone over 15% Znln2S4/In2O3 was the highest, up to 93.4% within 3 h. Furthermore, according to the result of in-situ infrared spectra, the main intermediate products were clarified clearly, which strongly supported the proposed photo degradation mechanism over the catalysts. Correspondingly, the 15% Znln2S4/In2O3 exhibited a significant H2 yield from water splitting, up to 5656.8 μmol in 3 h, which was 8.3 times higher than that of single In2O3. Based on these results, the mechanism of the photocatalytic process on the Znln2S4/In2O3 step-scheme heterojunction is proposed and discussed.