Sustainable oxygen evolution electrocatalysis in aqueous 1 M H(2)SO(4) with earth abundant nanostructured Co(3)O(4)

Earth-abundant electrocatalysts for the oxygen evolution reaction (OER) able to work in acidic working conditions are elusive. While many first-row transition metal oxides are competitive in alkaline media, most of them just dissolve or become inactive at high proton concentrations where hydrogen evolution is preferred. Only noble-metal catalysts, such as IrO(2), are fast and stable enough in acidic media. Herein, we report the excellent activity and long-term stability of Co(3)O(4)-based anodes in 1 M H(2)SO(4) (pH 0.1) when processed in a partially hydrophobic carbon-based protecting matrix. These Co(3)O(4)@C composites reliably drive O(2) evolution a 10 mA cm(–2) current density for >40 h without appearance of performance fatigue, successfully passing benchmarking protocols without incorporating noble metals. Our strategy opens an alternative venue towards fast, energy efficient acid-media water oxidation electrodes.