Double Effect Electron Transfer System in the AgBr/ZnO Composite with Enhanced Photocatalytic Degradation Performance against 3-Chlorophenol under Visible Light Irradiation.

Visible light-driven novel and highly efficient AgBr/ZnO photocatalysts were synthesized by a facile precipitation and dehydration methods. The synthesized samples were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL) techniques. Within various combinations of AgBr and ZnO components in the composites, 1AgBr/ZnO showed higher photocatalytic activity against 3-chlorophenol (3-CP). UV-Vis DRS spectra showed that the absorbance of AgBr/ZnO was higher than pure ZnO in the visible light region. The PL results showed that efficient inhibition of the generated electron/hole pairs has occurred during the degradation process due to the formation of heterojunctions. The forming of metallic Ag0 by photogenerated electrons, which captures Ag+ ions, could act as an interfacial charge transmission bridge in the AgBr/ZnO composite. These results provided an important insight into the plasmonic Ag particles to obtain an efficient visible light-driven photocatalyst. In addition, the possible mechanism of charge transfers and separation of electron/hole pairs were also evaluated in detail.