Investigation into the Performance and Mechanism of BiOX Photocatalytic Degradation of Toluene under Sunlight

The existence of indoor volatile organic compound pollution cannot be ignored. The main representative pollutant, toluene, poses a serious danger to human health. In this study, BiOX (X = Cl, Br, I) nanophotocatalytic materials were synthesized using a straightforward chemical precipitation process. The materials' fundamental structure and characteristics were examined, and it was investigated whether they can remove toluene gas pollutants when put them under sunlight. According to the results, within 120 min, the degradation rates of toluene are ranked as BiOCl > BiOI > BiOBr, with BiOBr achieving 16.16%, BiOI 28.13%, and BiOCl exhibiting the highest degradation efficiency at approximately 56.41%. Toluene was entirely broken down with fewer intermediates, according to the conversion rate of CO₂, the degradation product. There was also extensive research on the photocatalytic mechanism of BiOCl under sunlight. The π-bonds within the toluene benzene ring were broken by the active radicals •OH and •O₂ ^-. Furthermore, the oxygen vacancies and the holes (h⁺) worked in concert to enhance the toluene molecule's adsorption and activation, which accelerated the breakdown of toluene into short-chain molecules, and it became carbon dioxide and water, eventually. These reactions were considered to be environmentally and friendly. The study gives a practical way to lessen indoor VOC pollution and theoretical evidence for BiOCl photocatalytic degradation of toluene gas.