Synthesis of Tin-Doped Three-Dimensional Flower-like Bismuth Tungstate with Enhanced Photocatalytic Activity.

Photocatalytic degradation of harmful organic matter is a feasible and environmentally friendly method. BiWO has become a hotspot of photocatalysts because of its unique layered structure and visible light response. In the present study, Sn doping was adopted to modified BiWO by hydrothermal method. The Sn-doped BiWO photocatalysts were characterized by XRD, SEM, TEM, BET, XPS, PL, and DRS, respectively. The results show that Sn-doped BiWO shows three-dimensional (3D) flower-like morphology, which is composed of two-dimensional (2D) nanosheets. Sn ions enter into the BiWO lattice, producing a degree of BiWO lattice distortion, which is in favor of reducing the recombination of photogenerated electrons and holes. Moreover, the specific surface area of BiWO is significantly increased after doping, which is beneficial to providing more active sites. The photocatalytic results show that 2%Sn-BiWO exhibits the highest photocatalytic activity. After 60 min of irradiation, the photocatalytic degradation degree of methylene blue (MB) increases from 80.6% for pure BiWO to 92.0% for 2%Sn-BiWO. The first-order reaction rate constant of 2%Sn-BiWO is 0.030 min, which is 1.7 times than that of pure BiWO.