Heterostructured S-Scheme BiOBr/Cu₂O 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/Cu₂O heterojunction photocatalysts. Tuning the synthesis condition enhanced the interfacing of BiOBr and Cu₂O nanostructures in the heterojunction photocatalyst, as confirmed by STEM, TEM, XPS, XRD, and BET analysis. The optimized BiOBr/Cu₂O 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 Cu₂O 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.