Photochemical Route for the Preparation of Complex Amorphous Water Oxidation Catalyst

摘要

A photochemically initiated decomposition reaction was used to synthesize a series of amorphous mixed-metal oxide films. The series, consisting of mixed-metal oxides included binary and ternary mixtures containing Fe, Co and/or Ni, enabled a systematic evaluation of amorphous metal oxides with complex compositions. X-ray diffraction results indicate that the as-deposited films are amorphous and can be converted to their crystalline form by heating. Infrared spectroscopy of the films indicates the photochemically driven process drives complete loss of the organic constituents from the film. X-ray photoelectron spectroscopy confirmed the loss of the organic ligand and enabled estimation of metal oxidation states. Electrochemical characterization revealed significant variation in catalytic performance toward the oxygen evolving reaction (OER) upon variation of metal oxide composition. Analysis of the Tafel behavior was used to distinguish amorphous mixed-metal oxide films to enable several film compositions to exhibit excellent electrocatalytic OER performance.