We develop a facile and low-cost hydrothermal method to prepare WO3 nanostructures and demonstrate their applications as high-performance photoanodes for solar water oxidation. This present method allow us readily tune the morphology of WO3 nanostructures. By simply adjusting the constitution of the solution, WO3 nanoparticles (NPs-a), cubic-like nanoparticles (NCs) and another nanoparticles (NPs-b) can be obtained on F doped SnO2 glass substrates. Moreover, these WO3 nanostructures exhibit remarkable photoelectrochemical activities under the light irradiation and the WO3 NCs have the best performance than the others due to the enhanced light absorption ability and increased carrier density. (C) 2014 Elsevier B.V. All rights reserved.