Water Oxidation by Manganese Oxide Electrocatalytic Films Synthesized by Chemical Solution Deposition Method

Water splitting catalyzed by low cost and earth abundant material is critically important issue in mass production of hydrogen from water using electrical energy. In this study, we developed highly efficient manganese oxide (MnO x ) electrocatalytic films by a simple chemical solution deposition (CSD) method for oxygen evolution reaction (OER). Specifically, the MnO x electrocatalytic films were synthesized at different annealing temperatures at 350, 450, and 550°C after the precursor solution coating on fluorine-doped tin oxide (FTO) glass substrates. The MnO x electrocatalytic film prepared at 450°C has exhibited the most catalytic activity for OER with the overpotential of 387 mV at 10 mA/cm 2 in 1 M NaOH alkaline solution. We suggested that this high OER activity of MnO x electrocatalytic film arise from the higher surface area, richer Mn 3+ state on the catalysts surface, and low charge transfer resistance between electrocatalytic film and electrolyte based on electrochemical surface area (ECSA), X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) analysis.