Enhanced Photo-Fenton Removal of Oxytetracycline Hydrochloride via BP/Bi2MoO6 Z-Scheme Heterojunction Photocatalyst

Fenton oxidation technology utilizing hydrogen peroxide is recognized as an effective method for producing reactive oxygen species (ROS) to facilitate the degradation of antibiotics. However, the requirement for strongly acidic conditions during this process significantly restricts its broader applicability. In this study, we synthesized black phosphorus (BP) nanosheets by exposing the {010} crystal planes and then constructed a 0D/2D BP/Bi₂MoO₆ (PBMO) heterojunction to function as a Fenton catalyst. The PBMO-75 heterojunction exhibited a remarkable increase in photo-Fenton catalytic activity towards oxytetracycline (OTC) under neutral conditions, achieving catalytic efficiencies that were 20 and 8 times greater than those of BP and Bi₂MoO₆ (BMO), respectively. This can be attributed to its strong absorption of visible light, the establishment of an internal electric field (IEF) at the interface, and the implementation of a Z-scheme catalytic mechanism. Additionally, the photo-Fenton system was further improved in OTC degradation through the continuous conversion of Mo⁶⁺/Mo⁵⁺ under visible light irradiation in conjunction with H₂O₂. Based on ERS, XPS, and active species trapping experiments, we propose a Z-scheme charge transfer mechanism for PBMO. This research offers compelling evidence that 0D/2D Z-scheme heterojunctions are promising candidates for the photo-Fenton treatment of antibiotic contaminants.