Mechanism and performance of efficient degradation of bisphenol A by BiOIO3 based on synergistic regulation of bismuth metal loading and iodine ion doping

Abstract

Photocatalytic technology has attracted much attention due to its environmental protection and high efficiency. In this study, BiOIO₃ was in situ reduced by a simple chemical reduction technique to prepare iodine-doped and Bi metal deposition-modified BiOIO₃ with a large number of oxygen vacancies. The results show that the material exhibits optimal performance when the concentration of NaBH₄ is 20 mmol/L, with the degradation rate of bisphenol A reaching three times that of pure BiOIO₃. This enhancement is achieved by varying the concentration of NaBH₄ to control the reduction extent of metallic Bi and the doping level of iodide ions. Moreover, the effects of pH, catalyst dosage, and other parameters on the degradation of bisphenol A were systematically discussed. It was found that I-BB@20 exhibited broad-spectrum degradation ability for rhodamine B, tetracycline, and mixed pollutants (CODcr removal rate 89 %). The material showed good stability and reusability, and its catalytic efficiency remained at 83.5 % after three experimental cycles. Various characterizations confirmed the successful synthesis of BiOIO₃ modified by iodine ion doping and Bi metal deposition, while the mechanism of the photocatalytic reaction was elucidated. Liquid chromatography-mass spectrometry (LC-MS) analysis was used to propose the degradation pathway of bisphenol A (BPA) by the material, and the toxicity of BPA and its metabolites was evaluated using the T.E.S.T. toxicity analysis software. The results demonstrated that the photocatalytic degradation of BPA by I-BB@20 could reduce its biological toxicity to some extent. This work provides a novel approach for developing efficient and environmentally friendly photocatalytic materials.