Metallic nickel anchored on amorphous nickel cobalt oxide nanorods as efficient electrocatalysts toward oxygen evolution reaction

Developing high-activity and capital-saving electrocatalysts for the slow kinetics of the oxygen evolution reaction (OER) is important to improve the efficiency of water splitting. Herein, a facile reduction approach is employed to prepare metallic Ni-decorated amorphous nickel cobalt oxide (NiCoOx) nanoarray electro-catalysts, with three-dimensional nickel foam (Ni/NiCoOx/NF) as substrate. Benefiting from abundant oxygen vacancies and preferred electron transport between metallic Ni and the NiCoOx substrate,the Ni/ NiCoOx/NF delivers a current density of 50 mA cm-2 at an overpotential of 348 mV in 1.0 M KOH toward OER, comparable with that of commercial RuO2 (320 mV). Moreover, Ni/NiCoOx/NF is further served as an anodic material to assemble a two-electrode overall water splitting system (commercial Pt/C as the cathode), which achieves a current density of 10 mA cm-2 at a low voltage of 1.589 V and displays reliable durability over at least 50 h (around 30 mA cm-2). This research offers an efficient way for generating catalysts with multi components via reduction of polymetallic oxides for electrocatalytic conversion of small molecules.(c) 2023 Elsevier B.V. All rights reserved.