Fluorine-Doped Tin Oxide/Alumina as Long-Term Robust Conducting Support for Earth-Abundant Water Oxidation Electrocatalysts

In this work we apply a novel and simple methodology to develop a composite that consists of anodic aluminum oxide (AAO) covered by a fluorine-doped tin oxide (FTO) film. The composite presents suitable morphological and electrical properties to be used as support for water electrooxidation catalysts based on non-noble metals. AAO substrates were decorated with FTO via spray pyrolysis, followed by deposition of catalyst nanoparticles consisting of a cobalt-analogue of Prussian Blue that promotes the oxygen evolution reaction. The electrodes were characterized by X-ray Diffraction, Environmental Scanning Electron Microscopy and resistivity measurements. A promising electrocatalytic activity of the optimized AAO/FTO/PB electrode was observed at neutral pH and ambient conditions. The obtained results open a feasible strategy in the search for competitive water oxidation electrodes based on the combination of earth-abundant metal catalysts on FTO-covered anodized alumina supports.