Mesoporous cobalt oxide for oxygen evolution reaction under alkaline conditions: a comparative study of three synthesis methods

In this work three different synthesis routes were studied for producing mesoporous cobalt oxide. The Silica Template (ST), the Solution Combustion Synthesis (SCS), and the Co-Precipitation (CP) methods are compared. The catalysts synthesized were tested under alkaline conditions by a three-electrode setup and a gas diffusion electrode, in order to evaluated their electrochemical evolution of oxygen from water. Cobalt oxide produced by ST method shows the highest activity through OER and consequently the lowest overpotential. In fact, the onset potential starts at 1.57 V (vs. RHE) with a maximum current density of 19 mA cm–2 at 1.84 V.