Photocatalytic activity of Ag/CuO/WO3 under visible-light irradiation

The photocatalytic activity of silver and copper oxide loaded WO3 nanocomposite (Ag/CuO/WO3) was investigated under visible-light using the decolorization of Acid Red 88 (AR 88) dye molecules in solution. The activity of WO3 nanoparticles (NPs) was significantly improved by the binary loading of Ag and CuO as cocatalysts. The photocatalytic mechanism was investigated to understand the enhanced photocatalytic activity, which was mainly attributed to the synergistic effect of the Ag and CuO binary cocatalysts loaded on the WO3 NPs. The Ag cocatalyst acted as an electron trapping center that enhanced electron/hole separation and the CuO cocatalyst significantly promoted four-electron reduction of oxygen for H2O production. The concurrent oxidation of organic dye molecules occurring on WO3 NPs was probably initiated at photogenerated holes with a high oxidation potential. To further improve the photocatalytic activity of the Ag/CuO/WO3 system, WO3 nanotubes (NTs) were synthesized and loaded with Ag and CuO. The photocatalytic activity of Ag/CuO/WO3 NTs in the decolorization of AR 88 after 180 min was approximately 1.5 and 6.4 times greater than that of Ag/CuO/WO3 NPs and N-TiO2, respectively.