Mechanism insights into photo–assisted peroxymonosulfate activation on oxygen vacancy–enriched nolanites via an electron transfer regime

Abstract

The utilization of photo–assisted persulfate activation for the removal of organic contaminants in water has garnered significant research interest in recent times. However, there remains a lack of clarity regarding specific contributions of light irradiation and catalyst structure in this process. Herein, a photo–assisted peroxymonosulfate (PMS) activation system is designed for the highly efficient degradation of organic contaminants on oxygen vacancy–enriched nolanites (Vo–FVO). Results suggest that the degradation of bisphenol A (BPA) in this system is a nonradical–dominated process via an electron transfer regime, in which VO improves the local electron density and thus facilitates the electron shuttling between BPA and PMS. During BPA degradation, PMS adsorbed at the surface of FVO–180 withdraws electrons near VO and forms FVO–PMS* complexes. Upon light irradiation, photoelectrons effectively restore the electron density around VO, thereby enabling a sustainable electron transfer for the highly efficient degradation of BPA. Overall, this work provides new insights into the mechanism of persulfate activation based on defects engineering in nolanite minerals.