Fe-O-Bi efficient electron transfer channels and photo-Fenton synergy in S-scheme heterojunctions: Insights into interfacial interactions and ofloxacin degradation

Fenton method combined with light to accelerate the production of free radicals from H 2 O 2 can achieve more efficient pollutant degradation. In this paper, a novel BiOI/FeWO 4 S-scheme heterojunction photocatalyst was obtained by in situ synthesis, which can activate H 2 O 2 and degrade the organic pollutant OFC (ofloxacin) under visible light. The S-scheme charge transfer mechanism was confirmed by XPS spectroscopy, in situ KPFM and theoretical calculation. The photogenerated electrons were transferred from FeWO 4 to BiOI driven by the built-in electric field and band bending, which inhibited carrier recombination and facilitated the activation of H 2 O 2 .The BiFe-5/Vis/H 2 O 2 system degraded OFC up to 96.4% in 60 min. This study provides new systematic insights into the activation of H 2 O 2 by S-scheme heterojunctions, which is of great significance for the treatment of antibiotic wastewater. A novel BiOI/FeWO 4 S-scheme heterojunction can activate H 2 O 2 and degrade the organic pollutant OFC under visible light. The S-scheme charge transfer mechanism was confirmed by XPS, in situ KPFM and DFT. The BiFe-5/Vis/H 2 O 2 system degraded OFC up to 96.4% in 60 min. • S-scheme heterojunction FeWO 4 /BiOI exhibited excellent photo-Fenton-like degradation activity. • XPS, in situ KPFM and DFT confirmed the S-scheme charge transfer mechanism. • The Fe-O-Bi interfacial interaction promotes the generation of free radicals by activation of H 2 O 2 .