Synergistic effect of oxygen vacancies and Z-scheme in Ag3PO4/FeSnO(OH)5 for ultrafast degradation of indomethacin via photogenerated h+

Abstract

Ineffective separation of photo-carriers and slow photoreaction rates seriously limit the decontamination effectiveness of the photocatalyst. To overcome these limitations, herein, the oxygen vacancies modified Z-scheme Ag₃PO₄/FeSnO(OH)₅ heterojunction was designed with FeSnO(OH)₅ as a co-catalyst. In this photosystem, Ag₃PO₄ and FeSnO(OH)₅ function as oxidation and reduction centers of Ag₃PO₄/FeSnO(OH)₅ photocatalysts, respectively. Importantly, oxygen vacancies in the Z-scheme heterojunction provide an effective charge transport pathway, which not only inhibits the photocorrosion of Ag₃PO₄ but also reduces electron-hole recombination, significantly boosting the photocatalytic decontamination performance and long-term stability of the Ag₃PO₄/FeSnO(OH)₅ photocatalyst. Remarkably, the Ag₃PO₄/FeSnO(OH)₅ photocatalyst demonstrated outstanding photocatalytic performance, 100% degrading indomethacin (IDM) under visible light in just 30 min through the main generation of h⁺ that attacks the active atoms of IDM, prominently outperforming other counterparts. Besides, three principal degradation pathways were proposed, and the toxicity of the degradation products was significantly reduced. The Ag₃PO₄/FeSnO(OH)₅ exhibited high photocatalytic degradation efficacy across different qualities of water. This research offers an oxygen vacancy modified engineering combined with a Z-scheme heterojunction strategy for constructing extraordinary photocatalysts for environmental purification.