Enhanced photoelectrochemical performance of WO3/Ti photoanode due to in situ formation of a thin interfacial composite layer

Nanostructured WO3 thin films were prepared on titanium sheet substrates using a doctor blade technique. X-ray diffraction, Raman and field emission scanning electron microscopy studies revealed that the synthesized WO3 films are having monoclinic crystal structure, porous, polycrystalline with average grain size of similar to 50 nm. The photoelectrochemical responses of WO3 films prepared on treated Ti sheets were recorded in 0.5 M H2SO4 electrolyte under simulated 100 mW/cm(2) illumination. WO3 film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO3 films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WOx-TiOy interfacial composite layer and improved adhesion of WO3 nanoparticles owing to increased reactive sites on polished Ti substrate play a significant role in enhancing the photoresponse. Such photoanodes are potential candidates in photoelectrochemical water splitting system for hydrogen generation. (C) 2013 Elsevier B.V. All rights reserved.