Visible-light-assisted peroxymonosulfate activation over Fe(II)/V(IV) self-doped FeVO4 nanobelts with enhanced sulfamethoxazole degradation: Performance and mechanism

Advanced oxidation processes involving the visible-light-assisted peroxymonosulfate (PMS) are emerging as promising approaches for treating antibiotic pollutants. Here, Fe(II)/V(IV) self-doped FeVO4 nanobelts were synthesized and employed to build a visible-light-assisted PMS activation system for degrading antibiotic sulfamethoxazole (SMX). Compared with PMS/FeVO4, PMS/Visible light (VL), or PMS system, the PMS/FeVO4/VL system showed 3.9, 14.0, or 14.1 times improved for the removal of SMX, respectively. The reason behind this is the organic combination of the VL photocatalysis and transformation of Fe(II)/V(IV) to Fe(III)/V(V) over FeVO4, namely when photocatalytic behavior over FeVO4 can produce electrons (e-) and holes (h+) to activate PMS or directly degrade SMX, the transformation of Fe(II)/V(IV) to Fe(III)/V(V) will also happen to donate some e- for PMS activation simultaneously. Such a system can also effectively remove SMX from actual water bodies such as medicine wastewater, river water, tap water, and rainwater. This work not only provides an effective system for treating SMX polluted wastewater, but also gives some new insights to understanding the mechanism involving Fe-based binary metal oxide activating peroxymonosulfate.