Photoelectrochemical Oxidation of Water at Transparent Ferric Oxide Film Electrodes

Abstract

The fabrication of thin-film Fe₂O₃ photoanodes from the spray pyrolysis of Fe(III)-containing solutions is reported along with their structural characterization and application to the photoelectrolysis of water. These films combine good performance, measured in terms of photocurrent density, with excellent mechanical stability. A full investigation into the effects that modifications of the spray-pyrolysis method, such as the addition of dopants or structure-directing agents and changes in precursor species or carrier solvent, have on the performance of the photoanodes has been realized. The largest photocurrents were obtained from photoanodes prepared from ferric chloride precursor solutions, simultaneously doped with Ti⁴⁺ (5%) and Al³⁺ (1%). Doping with Zn²⁺ also shows promise, cathodically shifting the onset potential by ∼0.22 V.