Preparation of aluminum-copper co-doped BiOBr and the antimicrobial mechanism under visible light

Designing efficient photocatalysts is crucial for enhancing photocatalytic performance, with the separation efficiency of photogenerated charge carriers being a key factor, the improvement of this performance can significantly enhance antibacterial efficiency. To address the limitations of traditional bismuth oxybromide (BiOBr) photocatalysts, this study synthesized visible-light-driven Al/Cu co-doped BiOBr (2ACBB) microspheres via a solvothermal method. Dual metal doping synergistically modifies the band structure, introducing oxygen vacancies that narrow the bandgap (2.69 eV vs. 2.80 eV) while enhancing visible-light absorption and charge separation efficiency. Optimized 2ACBB exhibits a high surface area (27.64 m 2 /g) and demonstrates 3.2-fold greater photocurrent response than pristine BiOBr. EPR analysis reveals superoxide radicals ( · O 2 - ) and electrons as dominant reactive species, enabling exceptional antibacterial performance (99.99 % S. aureus and 97.99 % E. coli inactivation within 40 min). Mechanistic studies confirm that hierarchical architecture promotes bacterial adsorption and light harvesting, while generated · O 2 - and e − disrupt membrane integrity and metabolic processes. This work on the enhanced antimicrobial properties of metal ion-doped photocatalytic materials provides a perspective.