Research On The Construction And Performance Of Composite Heterogeneous Junction Catalytic Materials Based On Photoelectric Charge Separation

In this paper,according to the related synergistic effect of composite materials,different modification methods were used to construct heterojunction of materials with a novel structure based on photo-generated charge separation,and the internal electronic structure and energy band structure were analyzed,so as to explore and analyze the reasons affecting photocatalytic activity,and to explore the separation and migration effect of photo-generated electron-hole pairs in the interface reaction process,and to make a guess on the possible mechanism in the photocatalytic reaction.At first,because of the good physical and chemical properties of layered niobate titanate,the unique octahedral structure of Ti O₂can be used as a conductive carrier.the typical Cs Ti₂Nb O₇layered titanate is selected to compound with Ti O₂which is widely studied at present to form a core-shell heterojunction,and then the composite material with high photocatalytic activity is synthesized by doping and modifying non-metallic elements.The strong light absorption and appropriate energy band structure characteristics provide an important guarantee for photocatalytic degradation of pollutants.Secondly,theπconjugate structure,π-πstacking layer,high porosity,and wide visible light absorption range of covalent organic framework materials（COFs）provide a way to build new composite heterojunction materials.Two-dimensional layered Tp Pa-1-COF and g-C₃N₄are selected as research objects,and the stripped and recombined g-C₃N₄NS can effectively improve the light absorption of hybrid heterojunction materials.The unique hybrid heterostructure formed byπ-πconjugation between g-C₃N₄and Tp Pa-1-COF can improve the separation efficiency of photo-excited carriers.The research shows that the photocatalytic hydrogen production rate of hybrid heterostructure material with a mass ratio of 2:1 can reach 1153μmol·g^-1·h^-1.At last,the influence of 2D-2D organic-inorganic materials on photocatalytic hydrogen production performance was studied.Tp Pa-1@Zn In₂S₄composite heterojunction material was synthesized by the two-step hydrothermal method.the results showed that Tp Pa-1 and Zn In₂S₄had strong interface and high surface active area,which showed higher photocatalytic hydrogen production rate under visible light irradiation,and the hydrogen production rate of COF@ZIS-20wt%increasedThe above research contents have certain reference significance in selecting materials with appropriate energy band structure for heterostructure construction,and can also increase the application value of photocatalyst in degrading pollutants and producing clean and pollution-free new energy.