Construction Of Cu₂WS₄/NiTiO₃ Composite Catalyst System And Study On Its Photocatalytic Performance

In recent years,the design and development of efficient and durable catalysts with visible-light response for photocatalytic hydrogen production and pollutants degradation is considered as one of the most challenging tasks.In this paper,we mainly adopted the strategy of building composite catalyst,prepared Cu₂WS₄/NiTiO₃composite catalyst system by electrospinning/calcination technology and hydrothermal method,and characterized it comprehensively by various testing methods,and studied its photocatalytic performance and reaction mechanism.The specific research contents are as follows:A novel Cu₂WS₄/NiTiO₃（x Cu₂WS₄/NiTiO₃;x=0.25,0.50,0.75 and 1.00）composite was prepared via a facile electrospinning/calcination technique along with a convenient hydrothermal method.The as-prepared Cu₂WS₄/NiTiO₃ composite was composed of2D Cu₂WS₄ nanosheets and 1D NiTiO₃ nanofibers manifested by SEM and TEM images.The results of XPS verified the interfacial interaction between Cu₂WS₄ and NiTiO₃,confirming the heterojunction formation in composite.Photocatalytic tests demonstrated as-prepared Cu₂WS₄/NiTiO₃ catalysts exhibited outstanding and stable photocatalytic performances for H₂production and pollutants degradation under visible light（λ>420 nm）irradiation.Specially,0.50 Cu₂WS₄/NiTiO₃ sample displayed the highest H₂-evolution activity of 810μmol·g^-1·h^-1with the apparent quantum efficiency（AQE）value of 1.65%at 420 nm.Additionally,it also exhibited the optimal photodegradation properties with the rate constants of 0.030,0.413 and 0.028 min^-1 for TC,Rh B and Cr _VI,respectively.The excellent catalytic activities could be attributed to the enhanced visible-light adsorption,high specific surface area and efficient separation of photogenerated charge carriers.The ESR tests and free radicals capturing experiments confirmed that?O₂^-and h⁺were primary active species for TC/Rh B degradation.Based on the experimental results and energy band structure analysis,we proposed a“Type-II”type catalytic reaction mechanism.The present work provides perspectives of rational design on NiTiO₃-based catalysts with superior photocatalytic performance for energy regeneration and environmental remediation.Through the construction of Cu₂WS₄/NiTiO₃ composite photocatalyst system,the visible light absorption range of NiTiO₃ materials was effectively expanded,the separation efficiency of photogenerated carriers was improved,and the photocatalytic activity was improved.This research project not only lays a foundation for the design and construction of a new NiTiO₃-based composite catalyst system,but also provides a promising idea to solve the problems of environmental pollution and energy shortage in the future.