Construction of CuBi 2 O 4 /BiOBr/Biochar Z-Scheme Heterojunction for Degradation of Gaseous Benzene Under Visible Light

In this study, a new green composite catalyst was prepared by doping CuBi 2 O 4 /BiOBr into cotton stalk biochar, which was characterized by SEM, XRD, XPS, UV–Vis, i-t and EIS. Gaseous benzene was selected as the target pollutant to investigate the photocatalytic degradation performance of CuBi 2 O 4 /BiOBr/biochar under visible light irradiation. The results show that the photocatalytic degradation performance of CuBi 2 O 4 /BiOBr/biochar was better than those of CuBi 2 O 4 , CuBi 2 O 4 /biochar and CuBi 2 O 4 /BiOBr composites in the photocatalytic degradation of gaseous benzene. This was due to the joint action of biochar and heterojunction, which not only improved the light absorption and response range of the photocatalyst, but also promoted the photogenerated electron–hole separation. The degradation efficiency of gaseous benzene achieved 92% within 5 h. In addition, the Z-type mechanism of CuBi 2 O 4 /BiOBr/biochar photocatalyst was investigated based on electronic structure and electron spin resonance (ESR) measurements. The possible photodegradation mechanism of benzene was proposed. The effects on photocatalytic degradation performance of heterojunction and biochar were analyzed. The addition of biochar had a major effect on the degradation efficiency of gaseous benzene. Overall, CuBi 2 O 4 /BiOBr/biochar composite was a promising photocatalyst for the degradation efficiency of gaseous benzene. Graphical Abstract