Fabrication of a stable visible-light photocatalyst p-CuO/n-AgBr through hole transporting

AgBr microparticles decorated by CuO nanoparticles were prepared by a facile direct precipitation method. The composite exhibited enhanced visible-light-driven photocatalytic performance for methyl orange (MO) degradation, about 4.3 times that of pure AgBr. The phases of CuO and AgBr were demonstrated by X-ray diffraction analysis as well as XPS. The SEM images and the cycle experiment revealed that the stability of AgBr was improved significantly by combining with CuO during visible-light illumination. The pH values and the trapping experiments of active species provided good evidences that p–n heterojunction was formed. The high performance and stability of composite were attributed to the crucial role of inner field in p-CuO/n-AgBr, which may transfer holes out of AgBr. The charge transfer mechanism of CuO/AgBr was proposed and discussed in detail.