Molten salt defect engineering regulation of Bi4TaO8Cl perovskite structure for boosting photo-Fenton degradation of antibiotics

Defect engineering offers a feasible avenue to ameliorate the photocatalytic activities of semiconductors, but the traditional preparation processes for introducing the defects would destroy the pristine morphology of the materials. Herein, a controllable defect engineering on CeO 2 nanodots loaded Bi 4 TaO 8 Cl perovskite nanosheets was approached to synthesize well-defined CeO 2 /Bi 4 TaO 8 Cl (CE-BTC) heterojunction with stable oxygen vacancies (OVs) via a molten-salt-mediated strategy. Due to the coexistence of OVs and Ce 4+ /Ce 3+ redox couple, the photo-Fenton degradation rate of ofloxacin by optimal CE-BTC heterojunction (0.09610 min −1 ) was 7.78 and 4.98 times higher than that by individual Bi 4 TaO 8 Cl and CeO 2 , respectively. Moreover, the CE-BTC also exhibited excellent degradation performance towards other antibiotics including norfloxacin, ciprofloxacin, tetracycline, and sulfamethoxazole, while maintaining good recyclability and stability. The high efficiency of CE-BTC was also attributed to its enhanced light-harvesting capability, low photogenerated carrier recombination, and minimal electron transfer resistance. Mechanism study indicated that ⋅OH and ⋅O 2 – were the dominant reactive species, whereas h + also participated in the removal of ofloxacin with a lower contribution. This study demonstrated the enormous potential of CE-BTC heterojunction in the degradation and risk control of antibiotics, providing a promising strategy for designing highly dispersed heterojunction catalysts with surface defects.