The effect of morphology and crystal structure on the photocatalytic and photoelectrochemical performances of WO ₃

Abstract

A template-based solvothermal method was successfully developed for the controlled synthesis of two-dimensional (2D) monoclinic WO₃ nanoplate/nanosheet arrays and three-dimensional (3D) hexagonal WO₃ nanosphere/nanocage structures with single crystal petals. The structure-directing agents played an important role in controlling the morphology and phase of WO₃ samples. The results showed that the WO₃ nanospheres exhibited the highest visible light absorption capacity and a photocurrent density of 0.37 mA cm^-2 at 1.23 V <i>vs.</i> RHE under simulated sunlight. Moreover, the photocatalytic dye results displayed 83.2% methylene blue degradation and 87.9% rhodamine B degradation within 120 min under visible light irradiation. The high performance of the WO₃ nanospheres, resulted from the hierarchical structure, increased surface area and enhanced light absorption, which improved the photogenerated charge carrier transfer and separation capability.