Photodeposition of copper and chromia on gallium oxide: The role of co-catalysts in photocatalytic water splitting

Abstract

Split second: The photocatalytic activity of gallium oxide (β-Ga 2O3) depends strongly on the co-catalysts CuOx and chromia, which can be efficiently deposited in a stepwise manner by photoreduction of Cu2+ and CrO42-. The water-splitting activity can be tuned by varying the Cu loading in the range 0.025-1.5 wt %, whereas the Cr loading is not affecting the rate as long as small amounts (such as 0.05 wt %) are present. Chromia is identified as highly efficient co-catalyst in the presence of CuOx: it is essential for the oxidation of water. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.