Rare Earth Ions Doping Enhanced Photocatalytic Activity of Bi₅O₇I for Superior Visible Light Driven Degradation of Ciprofloxacin

Enhancing the efficacy of semiconductor photocatalysts through the doping of rare-earth ions is a viable approach for regulating their behaviour. The current study employs a solvothermal method followed by calcination to produce Bi₅O₇I photocatalysts doped with rare earth elements (Sm, Nd, and Dy). Ciprofloxacin was used as the target pollutant for all produced catalysts. Among all, Sm-doped Bi₅O₇I exhibited optimal degradation efficiency against ciprofloxacin. Sm doping was identified to be responsible for increased visible light absorption and enhanced separation of light-induced carriers, leading to increased performance in photocatalysis. The Sm doped Bi₅O₇I also showed good adaptation to higher initial ciprofloxacin concentrations and the requisite photodegradation stability after four cycles. Furthermore, the up-conversion luminescence feature of Sm increased the catalyst's visible light usage range. The scavenging experiment identified ·O₂⁻, h⁺, and ¹O₂ as active chemicals in the photocatalytic degradation of ciprofloxacin. Based on this fact, a possible degradation mechanism was postulated. This work may serve as a guide for creating doped bismuth-rich halides for waste water remediation.