FTO/SnO(2)/BiVO(4) composite photoelectrode for water oxidation under visible light irradiation

An SnO(2) layer prepared from ethanol solution was applied to fabricate an FTO/SnO(2)/BiVO(4) composite photoelectrode. The layered composite films were characterized by X-ray diffraction, scanning electron microscope, and X-ray photoelectron spectroscopy techniques. The photocurrent efficiency of BiVO(4) increased remarkably when an SnO(2) film was layered between the BiVO(4) layer and the fluorine-doped tin oxide (FTO) conducting electrode, indicating the efficient charge separation via the electron transfer from BiVO(4) to SnO(2) and the blocking of the hole transfer from BiVO(4) to the FTO surface. It was also demonstrated that the sequence for depositing the individual metal oxide layer on the FTO substrate was an important factor for such efficient charge separation of the electrode. (c) 2008 The Electrochemical Society.