An iron-based thin film as a highly efficient catalyst for electrochemical water oxidation in a carbonate electrolyte

A highly active iron-based water-oxidation catalyst was electro-deposited from a CO2 saturated bicarbonate solution containing Fe2+. This catalyst (Fe-Ci) produces a current density of 10 mA cm(-2) at an overpotential of 560 mV and the activity remains constant over 18 h in the environmentally benign HCO3-/CO32- buffer (pH 9.75). A Tafel slope of 34 mV dec(-1) was obtained for Fe-Ci, which is lower than other reported values for iron-based catalysts.