Synthesis of novel Cd2P2O7/Ag3PO4 photocatalyst with enhanced visible-light photocatalytic performance and the enhancement mechanism

Novel Cd2P2O7/Ag3PO4 photocatalysts containing different mass fractions of Cd2P2O7 were synthesized by a hydrothermal method. The photocatalysts were characterized by X-ray diffractometry, transmission electron microscopy, X-ray photoelectron spectroscopy, Electron spin resonance (ESR), Fourier transform infrared spectrometry, ultraviolet-visible absorption spectroscopy and photoluminescence spectroscopy. Photocatalytic activity was decided by the effective separation and low recombination rate of photogenerated electron-hole pairs. During the experiments, the Cd2P2O7/Ag3PO4 composites possessed fierce electron- hole separation capacity. In particular, the 1 wt% Cd2P2O7/Ag3PO4 catalyst displayed higher photocatalytic performance than pure Ag3PO4 under visible-light irradiation (λ>420 nm). The ESR spectrum showed the main active species during the methyl orange degradation were ·OH and ·O2−.