High catalytic structure of BiOBr in Fenton system: Synergistic effect of hydroxyl, oxygen vacancy and S-type heterojunction

The enhancement of photo-Fenton performance in BiOBr via a synergistic approach of efficient adsorption and reduced recombination of photogenerated carriers is an innovative strategy. This research employs an in-situ precipitation process to incorporate modified TiO2 onto the surface of BiOBr, while integrating polyethylene glycol to create an S-type heterojunction material (FT-OVs/PEG-BiOBr). The incorporation of hydroxyl groups by PEG facilitates pi- pi conjugation and hydrogen bonding, thereby enhancing the adsorption capacity of FT-OVs/ PEG-BiOBr. The presence of oxygen vacancies extends the absorption spectrum into the infrared region, and the electron trap mechanism substantially decreases the recombination of photogenerated carriers. The developed S-type heterojunction structure efficiently directs electron transport along a specific pathway. Photoluminescence (PL) studies reveal a further reduction in the recombination of photogenerated carriers. Remarkably, there is a significant synergistic effect between adsorption and low recombination of photogenerated carriers. A profound photo-Fenton synergistic effect is observed at pH 3, leading to degradation rates of RhB and TCH of approximately 98% and 85%, respectively, within 10 min. The degradation pathway of RhB has been investigated using LC-MS analysis, and 1 O2 has been identified as the primary active species through ESR testing. This study presents a novel structural approach to significantly enhance the efficiency of catalysts in Fenton systems.