Photocatalytic Evolution of Hydrogen on CuFe2O4

Abstract

We investigated the technical feasibility of photochemical hydrogen release based on CuFe 2 O 4 powder dispersion in an aqueous electrolyte containing a reducing agent (S 2 O 3 −2). The oxide combines an average resistance to corrosion and an optimum inter-referred band Eg of 1.67 eV. The intercalation of a small amount of oxygen should be accompanied by partial oxidation of Cu + to Cu 2+ involving a p-type semi-conductivity. The oxidation S 2− inhibits the photo-corrosion, and the evolution of H 2 increases in parallel with the formation of polysulfides. Most of H 2 is produced when p-CuFe 2 O 4 is connected to n-ZnO formed in situ. The release of H 2 is mainly on CuFe 2 O 4, whereas, the oxidation of S 2− takes place on the surface of ZnO and the hetero-system CuFe 2 O 4 /ZnO is optimized with respect to certain physical parameters. The photoelectrochemical production of H 2 is a multi-step process whose decisive step is the arrival of electrons at the interface due to their low mobility. Remarkable performance with a rate of 6.74 (μmol g −1 min −1) cm 3 h −1 hydrogen evolution in 0.1 M S 2 O 3 −2 (pH 13) is recorded.