Boosting Photogenerated Electrons Transfer from FeVO4 to Peroxymonosulfate via Cu Doping for Stable Degradation of Organic Contaminants

Abstract

Electron transfer is an important way to activate persulfate. Currently, the electrons for persulfate activation mainly originate from organic contaminants or the catalyst itself, which can lead to selective activation of persulfate or oxidation of the catalyst, respectively, and thus become a bottleneck restricting its application. In this work, Cu−doped FeVO₄ (Cu−FVO) was prepared, and the results showed that Cu doping can significantly improve the photocatalytic activity and stability of FVO for peroxymonosulfate (PMS) activation. The optimized Cu−FVO/PMS/light system exhibited a high BPA degradation rate that is 4.3 times higher than that of the FVO/PMS/light. This system manifested a broad applicability to various organic contaminants even with complex matrix. Photoelectrochemical analysis and DFT theoretical calculations revealed that Cu doping boosted the photogenerated charge separation and the adsorption of PMS on FVO. Furthermore, Cu doping led to the establishment of an electron transfer channel from Cu−FVO to PMS, through which photogenerated electrons achieved an efficient PMS activation. Meanwhile, holes were consumed by organic contaminants to avoid the oxidation of catalyst. These collectively enhanced the photocatalytic activity and stability of Cu−FVO, which also maintained high catalytic activity even after 20 cycling degradation reactions.