A reliable aerosol-spray-assisted approach to produce and optimize amorphous metal oxide catalysts for electrochemical water splitting.

An aerosol-spray-assisted approach (ASAA) is proposed and confirmed as a precisely controllable and continuous method to fabricate amorphous mixed metal oxides for electrochemical water splitting. The proportion of metal elements can be accurately controlled to within (5±5) %. The products can be sustainably obtained, which is highly suitable for industrial applications. ASAA was used to show that Fe6Ni10O(x) is the best catalyst among the investigated Fe-Ni-O(x) series with an overpotential of as low as 0.286 V (10 mA cm(-2)) and a Tafel slope of 48 mV/decade for the electrochemical oxygen evolution reaction. Therefore, this work contributes a versatile, continuous, and reliable way to produce and optimize amorphous metal oxide catalysts.