Effect Of Defect Behavior On Photocatalytic Performance Of ZnO

The defect engineering in photocatalytic materials has been proved to be an effective method to improve the catalytic performance in photoelectric material fields.In this paper,the structural and optical properties of ZnO crystal were modified by the species and concentrations of intrinsic defects.And the mechanism of oxygen vacancy at the composite interface,the effect of oxygen vacancy position（on surface and in bulk）on the photocatalytic performance of ZnO materials and the degradation of the cyclic stability of the photocatalytic performance caused by the change of oxygen vacancy concentration in photocatalytic process were studied.The main contents as followed:the change of ZnO intrinsic defect concentrations under different atmospheres including neutral,oxidizing and reductive atmospheres,and the investigation of the positions of the intrinsic defects in PL spectra were discussed.The structure properties and catalytic performance of the composite of CuO coated ZnO particles with surface oxygen vacancy defect were analyzed.The interaction between surface oxygen vacancy defects and Cu²⁺was stronger than it of Cu²⁺and the perfect ZnO surface（neutral）.It was showed the surface oxygen vacancy on interface of the composite was beneficial to improve the performance of composite.With the comparison of the performance of oxygen vacancy defects at different positions,the position effects of defects in the photocatalytic process was determined and the role of surface oxygen vacancies in th e photocatalytic process was also discussed.The experiment results showed that the photocatalytic performance was sign ificantly improved by oxygen vacancy defects,however,the p hotocatalytic properties decreased gradually with the decrease of the concent ration of surface oxygen vacancy defects after a certain number of the photocatalysis cycle.How to improve the stability of surface oxygen vacancy in photocatalytic process is the key to solve this problem.