Ti⁴⁺ Doping-Induced Defect Engineering in Bi₂MoO₆ for Efficient Visible-Light-Driven Photocatalytic Degradation of Ciprofloxacin

Antibiotic pollutants, widely present in aquatic environments, pose significant threats to ecological safety and human health due to their persistence, bioaccumulation, and potential to induce antimicrobial resistance. Traditional wastewater treatment technologies often demonstrate limited efficiency in removing such contaminants. In this study, we developed a series of titanium-doped Bi₂MoO₆ (Ti-BMO) photocatalysts via a simple solvothermal method for the efficient visible-light-driven degradation of ciprofloxacin (CIP). Characterization revealed that Ti⁴⁺ions selectively substituted Bi sites within the lattice, inducing lattice distortion and oxygen vacancy formation for charge compensation. These oxygen vacancies not only function as electron traps, promoting the efficient separation of photogenerated carriers, but also serve as active sites for interfacial reactions. The optimized 3% Ti-BMO catalyst achieved a 94.6% CIP degradation efficiency within 120 min, approximately 1.38 times that of pristine BMO, with a pseudo-first-order rate constant increased by 2.11-fold. Furthermore, the catalyst demonstrated outstanding stability and reusability over five consecutive cycles. Collectively, this study provides mechanistic insights into the theoretical development of doping strategies within layered Aurivillius phase structures, offering scientific references for future catalyst modification approaches and the advancement of photocatalytic technologies.