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

Constructing earth-abundant, robust, and cheap-to-make 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.