Enhanced photoelectrochemical performance of WO_3/Ti photoanode due to in situ formation of a thin interfacial composite layer

摘要

Nanostructured WO_3 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 WO_3 films are having monoclinic crystal structure, porous, polycrystalline with average grain size of ~50nm. The photoelectrochemical responses of WO_3 films prepared on treated Ti sheets were recorded in 0.5 M H_2SO_4 electrolyte under simulated 100 mW/cm2 illumination. WO_3 film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO_3 films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WOx-Tifjy interfacial composite layer and improved adhesion of WO_3 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.