Rgo-Modified Biox (X=Cl, I, Br) for Enhanced Photocatalytic Eradication of Gaseous Mercury

The photocatalytic oxidation of gaseous heavy metals is an efficient approach to alleviate energy crises and environmental pollution. In this work, a novel two-step solvothermal method is designed to synthesize rGO-modified BiOX (X=Cl, I, Br) nanosheets. The modification of rGO significantly enhances the specific surface area of BiOX (X=Cl, I, Br) nanosheets, reduces the bandgap, improves the light absorption range and intensity, accelerates photogenerated carrier separation rate, and reduces photogenerated electron-hole complexation. Furthermore, both ·O­ 2 - and ·OH are demonstrated to be active species in the reaction. All of these achievements have the potential to greatly improve the photocatalytic performance of the samples. Additionally, the rGO-modified samples exhibit excellent stability and maintain the highest mercury removal efficiency after cycles. However, the samples prepared in this research displayed a high level of moisture resistance. These characteristics could lead to the photocatalytic removal of heavy metals from industrial waste gases utilizing BiOX-based samples