Chromium doped copper vanadate photoanodes for water splitting

Abstract

Solar hydrogen obtained from photoelectrochemical water splitting offers a versatile approach towards the substitution of fossil fuels by decentralized and sustainable resources, like water and sun. In the present study we have investigated the Chromium doped Copper Vanadate (Cr:Cu3V2O8) as a candidate photoanode for photoelectrochemical water splitting. We have synthetized this material through a simple aqueous precipitation reaction, which easily allows compositional modifications. We have studied the effect of extrinsic doping with substitutional atoms like Chromium on the optical and photoelectrochemical properties. The main limiting factor for performance is related to the high bulk recombination, which is partially overcome by 0.75 at.% Chromium doping, with a five-fold enhancement of the charge separation efficiency at 1.23 V vs RHE. Despite this remarkable milestone, significant further improvement is needed for the technological exploitation of this material.