Study On The Preparation And Photocatalytic Performance Of CuWO₄ Thin Films

In the face of the increasingly serious problem about climate and environment,the development of new approaches of obtaining clean energy and the discovery of new energy source,has been a matter of discussion for a long time.Photoelectrochemical(PEC)oxidation in water is a new approach in obtaining clean energy.As a new material of obtaining the clean energy,semiconductor has a promising prospect in application.Cu WO4,with the advantages of its narrow band gap,ideal stability and absorbing partial visible light,has been a focus in science researchers for decades.However,CuWO₄exist the disadvantages,such as the low density of photoelectric current and the low incident photo-to-electron conversion efficiency(IPCE).How to overcome these problems has been the direction of researchers'efforts in recent years.In this research,the liquid phase method and spin coating method are used to introduce Fe dopant into the CuWO₄film.By comparing different Fe sources,CuWO₄film with higher photocatalytic performance is finally obtained.The main content of this paper is divided into three parts:1.The preparation method of CuWO₄ film was explored:the CuWO₄photoanode film was prepared with Cu(NO3)2·3H2O and(NH4)6H2W12O40·4H2O as raw materials,citric acid as the blending agent,and the effects of different preparation conditions on the morphology and properties of CuWO₄were discussed.The results show that CuWO₄films with thickness of 800nm on long FTO base have been successfully prepared by the above method.The morphology and structure of CuWO₄ were characterized by XRD,SEM,AFM and XPS,and the absorbency of the sample was determined by UV-vis.The electrochemical test also showed that the sample had excellent photocatalytic performance and stability.2.The properties of CuWO₄ films were improved by doping Fe,and the effects of different Fe sources and doping concentrations on the samples performance were discussed.The results showed that the performance of the sample was improved the most by doping 0.3%Fe(NO3)3.Analysis by means of XPS,UV-vis,AFM,electrochemical testing and other means shows that the doping can effectively reduce the band gap of Cu WO4,thereby improving the light absorption rate of the film,and some defects were formed on the surface of the doped CuWO₄film,which inhibited the composition of its photogenerated carriers,improved the transport performance of carriers,and thus improved the photocurrent density.Under the redox potential of water(1.23 V vs RHE),the photocurrent density reached 0.476m A/cm²,an increase of 78%.3.Characterize the catalytic activity of CuWO₄ film in the photocatalytic degradation of rhodamine B,discuss the effect of doping on the photocatalytic degradation performance of the film,and discuss its catalytic mechanism.The results show that the prepared Cu WO4film has stronger photocatalytic activity.After 5 h of light,the degradation rate of rhodamine B reaches 79.02%,and it has good stability.Meanwhile,it was found that the degradation rate of the sample was greatly improved by doping Fe(NO₃)₃.