Hierarchical Cu2S NRs@CoS core-shell structure and its derivative towards synergistic electrocatalytic water splitting

Abstract A hierarchical CoS shelled Cu2S nanorods material grown directly on copper foam (denoted as Cu2S NRs@CoS/CF) was prepared for the first time and used as the bifunctional electrocatalyst for both OER and HER in 1 M KOH solution. Resulting from the substrate-integrated synthesis, the highly open spaces and the synergistic effects between Cu2S and CoS active components, the as-obtained core-shell heterostructure and its derivative behaves as a remarkable active bifunctional electrocatalyst towards both water oxidation and hydrogen evolution reaction in 1 M KOH solution (pH 13.7), which only need low overpotentials of 275 and 235 mV to deliver the current density of 50 mA cm−2 with Tafel slopes of 54 and 121 mV dec−1 for OER and HER, respectively, rivalling the catalytic efficiency of most published non-noble metal catalysts. Furthermore, the fabrication strategy presented here is facile and economical which might offer some insights for fabricating other novel water splitting catalysts with high activity.