The Photocatalytic Z-scheme System Construction Of Artificial Leaf BiVO₄/InVO₄/CdS And Its Properties

Energy crisis and environmental pollution have become the main problems facing the development of human society.Using photocatalytic technology to generate hydrogen and degrade organic pollutants is an effective way to solve energy and environmental problems.Inspired by the good light-harvesting structure of leaves in nature,the research group prepared artificial leaves CdS-BiVO₄ photocatalyst that can degrade organic pollutants and generate hydrogen in the early stage.Based on the previous work of the research group,BiVO₄ was modified by the homologous substance InVO₄.Secondly,two Z-type photocatalytic systems,leaf BiVO₄/InVO₄/CdS-CdS and leaf CdS-SBiVO₄/InVO₄/CdS,were prepared using leaves as templates,respectively.The specific research contents are as follows:BiVO₄/InVO₄/CdS photocatalyst was prepared by impregnation calcination method using leaves as biological templates,and the molar ratio of Bi to In in the catalyst was optimized.The results showed that the prepared BiVO₄/InVO₄/CdS photocatalyst combined bionic structure with heterojunction structure,effectively improving the catalytic performance of the catalyst.80% BiVO₄/InVO₄/CdS in the series of catalysts had the highest photocatalytic performance.The internal charge transfer is a Zscheme charge transfer mechanism,and electrons and holes remain on In VO4 CB and BiVO₄ VB respectively.CdS was loaded on the optimized BiVO₄/InVO₄/CdS to prepare leaf BiVO₄/InVO₄/CdS-CdS catalytic material.Its physical and chemical properties were analyzed and its charge separation and carrier transport efficiency were investigated.The residual organic simulated wastewater with a certain concentration of bio-hydrogen production was treated with the catalyst.The results showed that the hydrogen production rate of the catalyst was 360 ?mol g^-1 h^-1,and the mineralized organic rate was 91.85 mmol C/g·h.Through mechanism analysis,it is determined that eremains on CdS in BiVO₄/InVO₄/CdS-CdS catalyst for hydrogen production reaction,and h⁺ remains on VB of BiVO₄ in BiVO₄/InVO₄/CdS for degradation reaction.CdS catalysts were prepared using leaves as templates,and the optimized CdS was loaded with BiVO₄/InVO₄/CdS to prepare leaf CdS-BiVO₄/InVO₄/CdS photocatalyst.Its physical and chemical properties were analyzed and its charge separation and carrier transport efficiency were investigated.The residual simulated organic wastewater with a certain concentration of bio-hydrogen production was treated with the catalyst.The results showed that the hydrogen production rate of leaf CdS-BiVO₄/InVO₄/CdS photocatalyst was 5033?mol g-1 h-1,and the mineralization rate of organic matter was 82.85 mmol C/g·h.The reaction mechanism of the catalyst was investigated.The results showed that the catalytic reaction process followed the Zscheme charge transport mechanism.e^-remained on CdS to generate hydrogen reaction,and h⁺remained on BiVO₄ to react with organic matters.