Synthesis,performance and action mechanism of carbon black/Ag3PO4 photocatalysts

Novel carbon black (CB)/Ag₃PO₄ compound photocatalysts were synthesized from a hydrothermal method and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and electrochemical methods. The photocatalytic oxidation ability of CB/Ag₃PO₄ was evaluated through methyl orange degradation experiments under visible light irradiation. The CB/Ag₃PO₄ showed higher photocatalytic activity than pure Ag₃PO₄. It was indicated the compound catalysts could absorb and utilize more optical energy to improve the photocatalytic activity, which was attributed to the ability of carbon black to accelerate the electron-hole separation. In particular, the methyl orange photocatalytic degradation rate over the 7?mg/L CB/Ag₃PO₄ was 1.6 times that of Ag₃PO₄. And the results of the cyclic experiment show that the photocatalyst has good stability. Moreover, the mechanism about the photocatalytic activity of CB/Ag₃PO₄ compounds was investigated. In this photocatalytic reaction, ?OH was the major active substrate responsible for the visible-light-driven degradation.