WO3 anchored Fe single-atom composite for efficient photo-Fenton degradation of organic pollutants

Abstract

The overuse of antibiotics has led to severe environmental pollution, making it increasingly necessary to degrade them efficiently. To address this issue, a highly efficient Fe/WO₃ single-atom catalyst (SAC) has been developed to explore the synergistic effect in the photo-Fenton system for tetracycline degradation. The WO₃ carrier, pretreated in a H₂/Ar atmosphere, possesses abundant oxygen vacancies, which narrow the band gap to enhance the visible-light harvesting ability and trap photogenerated electrons to form ˙O₂⁻ radicals. The Fe single atoms on the surface of WO₃ significantly improve the separation of photogenerated electron–hole pairs due to the interfacial charge transfer effect. The photogenerated electrons can accelerate the Fe(III)/Fe(II) redox cycle. In the presence of H₂O_2, the Fe/WO₃ SAC exhibited outstanding photo-Fenton performance in tetracycline degradation. It showed good stability, as confirmed by tests in a continuous-flow reactor system. Finally, the purification capability was examined by plant growth experiments. The study could pave the way for the rational design of high-efficiency Fe SACs for enhanced Fenton activity for water purification.