Controllable Synthesis of Hexagonal WO₃ Nanoplates for Efficient Visible-Light-Driven Photocatalytic Oxygen Production

Facilitating charge-carrier separation and transfer is fundamentally important to improve the photocatalytic performance of semiconductor materials. Herein, two-dimensional hexagonal WO₃ nanoplates were synthesized by a two-step route: rapid evaporation and solid-phase sintering. The as-prepared WO₃ exhibits an enhanced activity of photocatalytic water oxidation compared to bulk monoclinic WO₃. The electron dynamics analysis reveals that a more efficient charge-carrier separation in the former can be obtained, the origin of which can be attributed to an increased number of surface defects in hexagonal WO₃ nanoplates. This work not only presents a novel and simple method to produce two-dimensional hexagonal WO₃ nanoplates, but also demonstrates that surface defects and two-dimensional geometric structures can promote the charge separation, which may be extended to the design of other efficient photocatalysts.