Binary Transition Metal NiFeOx and CoFeOx Cocatalysts Boost the Photodriven Water Oxidation over Fe2TiO5 Nanoparticles

Although achieving a perfect match between a cocatalyst and a photocatalyst is challenging, it is a key factor to maximize the production of solar fuels. Herein, the nanostructured binary transition metal oxides NiFeOx and CoFeOx, loaded through magnetron sputtering deposition, were employed as cocatalysts for Fe2TiO5 nanoparticles, applied to the oxygen production from solar water splitting. After the coverage of Fe2TiO5 with exceptionally small CoFeOx and NiFeOx nanoparticles, the O-2 evolution boosted from 7.0 (pure Fe2TiO5) to 56.0 and 63.0 mu mol, respectively, under visible light irradiation. To the best of our knowledge, these performance enhancements are the highest reported for the particulate Fe2TiO5 photocatalyst, so far. The improvements result from the alleviation of charge transfer resistance at the solid/liquid interface, as the binary metal oxides aid the charge carriers separation at the heterojunctions and improve the kinetics of the water oxidation reaction.