Solvothermal synthesis of WO₃ photocatalysts and their enhanced activity

Tungsten trioxide (WO₃) is known as a visible light responsive photocatalyst, but its photocatalytic activity is relatively low, as compared to that of anatase titanium dioxide (TiO₂). To enhance the activity, high specific surface areas are necessary. In this study, WO₃ particles with a hierarchical architecture, which was assemblies of spherical particles 20 - 30 nm in diameter, were synthesized by the solvothermal method. The hierarchical WO₃ particles had high specific surface areas and their photocatalytic activity was found to be 2.5 times higher than that of the commercial WO₃.