Facile\nCombination of Bismuth Vanadate with Nickel\nTellurium Oxide for Efficient Photoelectrochemical Catalysis of Water\nOxidation Reactions

Bismuth vanadate\n(BVO) having suitable band edges is one of the\neffective photocatalysts for water oxidation, which is the rate-determining\nstep in the water splitting process. Incorporating cocatalysts can\nreduce activation energy, create hole sinks, and improve photocatalytic\nability of BVO. In this work, the visible light active nickel tellurium\noxide (NTO) is used as the cocatalyst on the BVO photoanode to improve\nphotocatalytic properties. Different NTO amounts are deposited on\nthe BVO to balance optical and electrical contributions. Higher visible\nlight absorbance and effective charge cascades are developed in the\nNTO and BVO composite (NTO/BVO). The highest photocurrent density\nof 6.05 mA/cm<sup>2</sup> at 1.23 V versus reversible hydrogen electrode\n(V<sub>RHE</sub>) and the largest applied bias photon-to-current efficiency\n(ABPE) of 2.13% are achieved for NTO/BVO, while BVO shows a photocurrent\ndensity of 4.19 mA/cm<sup>2</sup> at 1.23 V<sub>RHE</sub> and ABPE\nof 1.54%. Excellent long-term stability under light illumination is\nobtained for NTO/BVO with photocurrent retention of 91.31% after 10,000\ns. The photoelectrochemical catalytic mechanism of NTO/BVO is also\nproposed based on measured band structures and possible interactions\nbetween NTO and BVO. This work has depicted a novel cocatalytic BVO\nsystem with a new photocharging material and successfully achieves\nhigh photocurrent densities for catalyzing water oxidation.