Heterostructured S-Scheme BiOBr/CuO Nanocomposite for Photocatalytic Degradation of Glyphosate.

Metal oxide semiconductor-activated photocatalysis has become a promising sustainable technology for the mitigation of emerging organic pollutants. The rational design of a photocatalyst heterojunction allows the degradation of a broad range of organic contaminants. Herein, we optimized hydrothermal approaches for the facial synthesis of well-defined BiOBr/CuO heterojunction photocatalysts. Tuning the synthesis condition enhanced the interfacing of BiOBr and CuO nanostructures in the heterojunction photocatalyst, as confirmed by STEM, TEM, XPS, XRD, and BET analysis. The optimized BiOBr/CuO heterostructured photocatalyst demonstrated substantial activity in the degradation of both anionic and cationic dyes compared to the individual components. The enhanced nanocomposite exhibited complete degradation of glyphosate in 10 min of light irradiation and demonstrated high stability after five photocatalytic cycles. Our mechanistic and photoelectrochemical studies suggest that establishing an S-scheme heterojunction between BiOBr and CuO enhances the separation of photogenerated charge carriers and expands the redox potentials of the nanocomposite to allow high catalytic efficiency. These findings indicate that tuning the design of metal oxide heterojunctions promises applications in the remediation of a wide range of organic contaminants.