Augmented singlet oxygen ( 1 O 2 ) production via ZnO 2 /Bi 2 O 2 CO 3 heterojunction for photodegradation of tetracycline hydrochloride through in‐situ self‐fenton‐like mechanisms

Abstract In conventional Photo‐Fenton‐like systems, singlet oxygen ( 1 O 2 ) is frequently underestimated due to the predominant activity of hydroxyl radicals (OH). This study reports a nano‐rosa‐chinensis‐like ZnO 2 /Bi 2 O 2 CO 3 heterojunction material, which efficiently generates 1 O 2 and enables the photodegradation of high‐concentration tetracycline hydrochloride (TCH) within a self‐Fenton‐like photocatalysis system. The optimized ZnO 2 /Bi 2 O 2 CO 3 (ZB‐35) photocatalyst exhibits robust environmental adaptability in complex aqueous matrices, along with satisfactory reusability and stability. The heterojunction formation mechanism and interfacial electron transfer pathways were elucidated through combined density functional theory (DFT) calculations and in‐situ irradiation X‐ray photoelectron spectroscopy (IS‐XPS) analyses. Radical quenching experiments and electron paramagnetic resonance (EPR) characterization identified 1 O 2 and superoxide radicals (⋅O 2 − ) as the dominant active species. Mechanistic studies suggest that the generation of ⋅O 2 − originates from the Bi 2 O 2 CO 3 ‐(103) facet adsorbed O 2 is reduced by the electrons captured by oxygen vacancies in the highly exposed (110) facet. Notably, the self‐generated H 2 O 2 facilitates the efficient production of 1 O 2 , which exhibits remarkable degradation performance for high concentrations of TCH through a photo‐Fenton‐like mechanism.