FTO/SnO2/BiVO4 composite photoelectrode for water oxidation under visible light irradiation

摘要

An SnO2 layer prepared from ethanol solution was applied to fabricate an FTO/SnO2/BiVO4 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 BiVO4 increased remarkably when an SnO2 film was layered between the BiVO4 layer and the fluorine-doped tin oxide (FTO) conducting electrode, indicating the efficient charge separation via the electron transfer from BiVO4 to SnO2 and the blocking of the hole transfer from BiVO4 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.