Co-Fe-B Nanochain Electrocatalysts for Oxygen Evolution at High Current Density

Constructing earth-abundant, robust, and cheap-tomake electrode materials for the oxygen evolution reaction (OER) is crucial for the practical application of hydrogen energy. In this work, we prepare amorphous cobalt iron boride (Co-Fe-B) nanochains on a nickel foam (labeled as Co-Fe-B/NF) via one-pot sodium borohydride reduction of Co2+ and Fe2+ at room temperature and use them to boost the performance of OER. The as-prepared Co-Fe-B nanochains exhibit promising catalytic activity with low overpotentials of 270 and 280 mV at higher current densities of 50 and 100 mA cm(-2), respectively, and a much lower Tafel slope of 36 mV dec(-1) for OER. In addition, the Co-Fe-B shows excellent stability for more than 50 h at a high current density of 100 mA cm(-2). The satisfactory electrocatalytic performance is mainly due to the synergy between the metal ions (Co and Fe) and plentiful catalytically active sites of the one-dimensional chain-like structure, which improves the atom utilization efficiency.