Interfacial Engineering of Bi₃O₄Br/MXene Schottky Junctions for Enhanced Adsorption Enrichment and Photocatalytic Regeneration Active Sites for Water Decontamination

Photocatalytic technology still faces significant challenges in removing trace concentrations of organic pollutants from wastewater. In this study, we synthesized Bi3O4Br/MXene (BOB/M) with a Schottky junction structure, enhancing the continuous adsorption active site regeneration after visible light irradiation for organic pollutant removal. Notably, the adsorption removal rate of tetracycline by BOB/M under light irradiation increased by 29.2% compared to dark conditions, indicating that light exposure regenerates the adsorption active sites. This improvement is mainly attributed to the introduction of MXene, which promotes the formation of reactive species, thereby accelerating the regeneration of the adsorption sites. The composite exhibits superior adsorption performance for electropositive pollutant molecules compared with neutral and negatively charged ones. Moreover, through a series of experiments and analytical characterizations, we identified superoxide radicals as the primary reactive oxygen species responsible for the degradation of tetracycline, facilitating the regeneration of adsorption sites. Furthermore, the BOB/M material exhibits excellent anti-interference capacities and stability. This study provides a novel approach for designing photocatalysts that are effective at targeting trace levels of contaminants.