Preparation And Photocatalytic Performance Of Ag/CuInS₂/BiVO₄ Composite Guar Bean Derivative Hydroge

The rapid development of industrialization has brought a great load on environmental protection and energy development,and environmental pollution has caused great harm to human living environment and energy shortage has limited the rapid development of human society.Photocatalysis technology is considered to be an effective solution to environmental pollution and energy scarcity because it can be driven by direct sunlight and the reaction conditions are mild.Most of the photocatalysts developed so far are in powder form,but the problems such as easy to sink and difficult to recover limit their value in engineering applications.Biomass hydrogels with porous structure have good adsorption effect on pollutants such as BPA,and loading photocatalysts onto biomass hydrogels can effectively solve the problems of powdered catalysts such as easy to sink and difficult to be recovered.In this paper,a photocatalyst composite guar-derived hydrogel was prepared based on the structure design of photocatalytic semiconductor and the material properties of biomass hydrogel,which exhibited excellent photocatalytic performance.In this paper,the structural characterization and key properties of the photocatalytic composite guar derivative hydrogel are fully investigated,and the main research contents are as follows:（1）The S-scheme heterostructures of ternary plasma Ag/CuInS₂/BiVO₄ with decahedral morphology were synthesized by hydrothermal,solvothermal and photodeposition methods.The smooth decahedron is more favorable for the attachment of CuInS₂,and the growth of CuInS₂ is not affected by the surface charge of Bi VO₄.The combination of the two greatly increases the specific surface area of the material and provides more active sites for the photocatalytic reaction.The composition of S-scheme heterojunction and the LSPR effect of Ag nanoparticles effectively improve the photocatalytic performance and photothermal effect.Under visible light irradiation,the degradation rate of Ag/CuInS₂/BiVO₄ for BPA in water reached 98.8%with a hydrogen yield of 6.493 mmol g-1 h-1 while the enhanced photocatalytic performance and the unique broad-spectrum bactericidal effect of Ag nanoparticles made the material bactericidal for E.coli and S.aureus.In addition,this heterojunction showed good stability and recyclability in photocatalytic reactions.This study provides a new strategy for the preparation of efficient heterojunction photocatalysts.（2）Ag/CuInS₂/BiVO₄ composite guar gum hydrogel was synthesized by chemical cross-linking method and introducing the photocatalyst Ag/CuInS₂/BiVO₄.The synthesized hydrogel has the self-floating property and a special loose porous structure,which is convenient for the reaction between the adsorbed pollutants and photocatalysts and makes them full contact with the light source for the reaction.The photocatalytic degradation efficiency of the hydrogel reached 97.3%for BPA under visible light irradiation,and it also showed strong inhibition for two pathogenic bacteria,E.coli and S.aureus.,under light conditions,and this photocatalytic hydrogel had good stability.This can be attributed to the composition of S-scheme heterojunctions in the powder photocatalyst,the effect of LSPR,and the stability of the three-dimensional meshwork structure of guar gum hydrogel.