Mesoporous MnCo₂O₄, NiCo₂O₄, and ZnCo₂O₄ Thin-Film Electrodes as Electrocatalysts for the Oxygen Evolution Reaction in Alkaline Solutions

The oxygen evolution reaction (OER) is the bottleneck of electrochemical water-splitting process, where use porous metal oxide electrodes beneficial. In this work, we introduce a one-pot synthesis method to fabricate series mesoporous cobaltite (m-MCo2O4, M = Mn, Ni, and Zn) for OER. involves preparation coating homogeneous clear solution all ingredients (metal salts surfactants) over fluorine-doped tin surface as thin lyotropic liquid crystalline film calcination (as low 250 °C) obtain 400 nm thick m-MCo2O4 electrode with spinel structure. Mesophases films are characterized using structural techniques. All stable during test in 1 KOH aqueous perform at 204 mV overpotential mA/cm2 current density; m-MnCo2O4 works densities 1, 10, 100 227, 300, 383 overpotentials after compensating IR drop, respectively. Tafel slope 60 mV/dec m-NiCo2O4 m-ZnCo2O4 electrodes, but it gradually increases 85 by thermal treatment, indicating change OER mechanism.