Efficient degradation of antibiotic pollutants in water by Ca2+/Ce3+ Co-doped Bi2O2CO3 photocatalysts

Aiming at the bottleneck problems of limited visible light response range and high carrier recombination rate of Bi₂O₂CO₃ (BOC) photocatalyst, Ca²⁺/Ce³⁺ co-doped Bi₂O₂CO₃ composite photocatalyst was constructed by hydrothermal method. The analysis of different characterization techniques shows that double doping can lead to lattice distortion and induce oxygen defects. Under visible light irradiation, the degradation efficiency of ciprofloxacin (CIP) and levofloxacin (LVX) by BOC-Ca-Ce4 reached 92.56 % and 90.39 %, respectively, and maintained a certain degradation efficiency in complex water bodies such as tap water and lake water. ESR and capture experiments confirmed that •O₂⁻ and h⁺ were the dominant active species. Mechanism analysis showed that the valence cycle of Ce³⁺/Ce⁴⁺ and the local electric field of Ca²⁺ synergistically promoted the spatial separation of carriers. Through intermediate product analysis, CIP was finally mineralized to CO₂/H₂O, and the ECOSAR toxicity assessment showed that the ecological toxicity was reduced. This study provides a new design strategy for energy band engineering of two-component doped photocatalysts.