Photocatalytic Performance and Degradation Pathways of Z-Scheme BiO_2-X-Ag₃PO₄ Photocatalysts with Oxygen-Deficient Structures

It is a practical way to raise the efficiency of photocatalysis by using oxygen vacancy defect modified materials. In this experiment, a Z-scheme BOA composite photocatalyst with defect structure was prepared by hydrothermal in situ precipitation method. The optimal ratio of 1.5 BOA showed excellent photocatalytic degradation performance for MO, TC and CIP under visible light irradiation, and maintained good structural stability and circulation rate after five cycles. The increased photocatalytic activity of the composite can be explained to the heterojunction interface's synergistic effects and the quicker electron hole transit rate caused by the surface oxygen vacancy defect. XPS and EPR confirmed the existence of anoxic structure in the composite, PL and photocurrent confirmed the high electron hole transfer rate. The active species that contributed to the degradation process were validated by the active species capture experiment and ESR. LC-MS speculated the possible degradation path of CIP. Finally speculated the reaction mechanism of Z-scheme BOA composite photocatalyst. Using the anoxic structure of BiO(2-X )to form a Z-scheme heterostructure with Ag3PO4, the oxygen vacancy as the electron capture center and active site is conducive to improving the photogenerated electron transfer rate, thereby improving the structural stability and photocatalytic performance of the complex.