Prolonging lifetime of photogenerated carriers in WO3 nanowires by oxygen vacancies engineering for enhanced photoelectrocatalytic oxygen evolution reaction

Abstract

WO3 nanowires (NWs) have emerged as a promising alternative electrocatalyst for the photoelectrochemical (PEC) oxygen evolution reaction (OER), due to their nontoxicity, low cost, good stability, and strong photocatalytic oxidation ability. However, a significant challenge is limited by the poor electrical conductivity and the rapid recombination rate of photogenerated carriers. This paper reports a facile and effective way to synthesize the WO3 NWs with oxygen vacancies (Ov-WO3 NWs), which have high PEC OER activity and good stability. Photoelectric measurements indicate that the Ov-WO3 NW-based device shows a good light-harvesting property under visible light and a prolonged photoresponse time. Electrochemical impedance spectra measurements reveal a reduced value of Rct denoting an improved electrical conductivity, which should be responsible for the superior PEC OER performance. Our work provides a strategy for fabricating efficient water-splitting electrodes to help establish rational design principles for future OER catalysts.