Experiment and DFT study on the photocatalytic properties of La-doped Bi2WO6 nanoplate-like materials

The La3+-doped Bi2WO6 nanoplate-like photocatalyst was successfully synthesized by the hydrothermal method. The results indicate that the degradation rate constant of RhB by La3+-doped Bi2WO6 is obviously higher than that of pure Bi2WO6. In addition, the ultraviolet–visible spectrum shows that La3+ doping can increase the band gap of Bi2WO6. The band structure, density of states (DOS), and differential charge density were studied using density functional theory (DFT). The possible photocatalytic mechanism of La3+-doped Bi2WO6 was studied by DFT and experiment combined investigations. The results show that La3+-doped Bi2WO6 is conducive to the separation of e- and h+ pairs, and the separated h+ and e- are activated by redox reactions in the valence band (VB) and conduction band (CB) respectively, which significantly improve the photocatalytic degradation process and separation efficiency. This result not only promotes the potential application of Bi2WO6 in semiconductor photocatalysts, but also provides new insights into the doping properties of Bi2WO6.