Hematite modified tungsten trioxide nanoparticle photoanode for solar water oxidation

Hematite (alpha-Fe2O3) film is electrochemically deposited onto the surface of tungsten trioxide (WO3) nanoparticulate film. The synthesis of the WO3 nanostructure is directed by surfactants for control of its morphology. The resulting composite shows visible light harvesting and is tested as photoanodes in heterojunction photoelectrochemical cells for the possibility of direct water splitting under visible illumination. The composite's structural and optical properties are characterized by FESEM, EDS, XRD, XPS, and UV-vis spectrometry; its photocurrent responses are also investigated under simulated solar illumination. Coupling WO3 with hematite results in over 9 times greater photocurrent density than that shown by pure WO3 in sodium sulfate electrolyte. This simple modification can significantly improve the performance of WO3. (C) 2012 Elsevier B.V. All rights reserved.