Iron–Salen Complex and Co²⁺ Ion‐Derived Cobalt–Iron Hydroxide/Carbon Nanohybrid as an Efficient Oxygen Evolution Electrocatalyst

Abstract

Metal-salen complexes are widely used as catalysts in numerous fundamental organic transformation reactions. Here, CoFe hydroxide/carbon nanohybrid is reported as an efficient oxygen evolution electrocatalyst derived from the in situ formed molecular Fe-salen complexes and Co²⁺ ions at a low temperature of 160 °C. It has been evidenced that Fe-salen as a molecular precursor facilitates the confined-growth of metal hydroxides, while Co²⁺ plays a critical role in catalyzing the transformation of organic ligand into nanocarbons and constitutes an essential component for CoFe hydroxide. The resulting Co_1.2Fe/C hybrid material requires an overpotential of 260 mV at a current density of 10 mA cm^-2 with high durability. The high activity is contributed to uniform distribution of CoFe hydroxides on carbon layer and excellent electron conductivity caused by intimate contact between metal and nanocarbon. Given the diversity of molecular precursors, these results represent a promising approach to high-performance carbon-based water splitting catalysts.