High-efficiency Fe(III)-doped ultrathin VO₂ nanobelts boosted peroxydisulfate activation for actual antibiotics photodegradation

It has been challenging for Fe(III) regeneration in Fe-based photocatalysts for continuous peroxydisulfate (PDS) activation due to the lower ability to reduce Fe(III). In this work, Fe-doped ultrathin VO₂ (Fe-VO₂) nanobelts were synthesized for purifying metronidazole (MNZ) via PDS activation. As an efficient Fenton-like catalyst for PDS activation, 2 wt% Fe-doped VO₂ can remove 98 % of MNZ within 40 min and exhibits impressive recyclability. The synergistic effect of Fe-VO₂ and Fe(III) activated PDS boosted the photocatalytic performance. Moreover, SO₄^•−, h⁺, O₂^•−, ¹O₂, and ^•OH were the main reactive radicals. The effects of initial MNZ concentration, Fe-VO_2, PDS dosage, and various anions/cations on MNZ removal by the Fe-VO₂/PDS/Vis system were studied. The intermediates of MNZ degradation and possible pathways were determined by density function theory (DFT) calculations and HPLC-MS. This study provided a sustainable technology using Fe-doped ultrathin VO₂ nanobelts for photocatalytic PDS activation and decontamination of pharmaceutical wastewater.