Abstract: Bi₂Mo_xW_1-xO₆(x=0~1) solid solutions were successfully synthesized via a facile hydrothermal method. The obtained products were characterized by X-ray diffraction, UV-Vis diffuse reflectance spectra and FT-IR spectrum. With an increase of Mo content, XRD patterns of the as-synthesized products show that the peaks at 2θ=33°, 47°, 56° gradually split, and the value of I(131)/I(200) gradually increases and then slowly decreases. FT-IR absorb band around 821 cm^-1, which refered to the vibration frequency of the metal-oxygen band, is monotonically shifted to 842 cm^-1. According to DRS calculations, the band gap of the samples are 2.75, 2.55, 2.50, 2.45, 2.59 and 2.63 eV when x is 0, 0.25, 0.5, 0.75, 0.9 and 1, respectively. This result demonstrates the formation of soluble solid solution. The photocatalytic activities of the products were evaluated by monitoring the degradation of RhB under visible light. It is found that, among solid solutions, the Bi₂Mo_0.75W_0.25O₆ exhibites the highest photocatalytic activity which mainly attributes to the special structure of solid solution and the lower energy band gap.

Key words: 固溶体, 水热合成, 光催化性能, 带隙