Preparation of WO3/ZnO Composite Photocatalyst and Its Photocatalytic Performance

A series of WO3/ZnO composite photocatalysts with different WO3 concentrations were prepared by a precipitation-grinding method followed by calcination at different temperatures. The prepared samples were characterized by N-2 physical adsorption, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and photoluminescence spectroscopy. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of acid orange II under UV light (lambda = 365 nm) irradiation. The results showed that at the optimal calcination temperature of 600 degrees C, the WO3/ZnO composite photocatalyst with 2 wt% concentration of WO3 showed about doubled photocatalytic activity compared to pure ZnO. The increase in the photocatalytic activity could be attributed to the coupling of WO3, which suppressed the growth of ZnO particles, increase of the surface area and increased amount of surface OH groups of the sample. The presence of WO3 also restrained the recombination rate of e(-)/h(+) pairs.