Simple Chemical Solution Deposition of Co₃O₄ Thin Film Electrocatalyst for Oxygen Evolution Reaction

Oxygen evolution reaction (OER) is the key reaction in electrochemical processes, such as water splitting, metal-air batteries, and solar fuel production. Herein, we developed a facile chemical solution deposition method to prepare a highly active Co₃O₄ thin film electrode for OER, showing a low overpotential of 377 mV at 10 mA/cm² with good stability. An optimal loading of ethyl cellulose additive in a precursor solution was found to be essential for the morphology control and thus its electrocatalytic activity. Our results also show that the distribution of Co₃O₄ nanoparticle catalysts on the substrate is crucial in enhancing the inherent OER catalytic performance.