Enhancing photoelectrochemical water splitting by Nickel-doped WO3 photoanode under visible light irradiation

Since its discovery by Honda and Fujishima in 1972, photoelectrochemical (PEC) water splitting has been intensively studied as a unique and effective approach to generating renewable energy from sunlight [1]. Monoclinic tungsten trioxide (WO3) was recognized as one of the “ideal” materials for solar-driven water splitting because of its photosensitivity, good electron transport property, and photostability against acid corrosion [2,3]. This work describes the fabrication of Nickel-doped tungsten oxide (WO3) photoelectrode by facile and cost-effective electrodeposition method at low temperature to improve the charge separation for enhanced photoelectrochemical water splitting. Photoelectrochemical measurements of the WO3 and Nickel-doped tungsten oxide (WO3) photoanodes were carried out under visible light illumination, in 0.5 M Na2SO4 solution with saturated calomel electrode (SCE) as a reference and a platinum wire as the counter electrode. The Ni-doped WO3 photoanode was shown to greatly improve the PEC water splitting compared to WO3 photoanode.