Cobalt-doped Ni–Mn layered double hydroxide nanoplates as high-performance electrocatalyst for oxygen evolution reaction

Active, stable and low-cost electrocatalysts are in high demand to replace the traditional noble metal catalysts towards efficient water splitting. Here we report a type of nickel-manganese (Ni–Mn) layered double hydroxide (LDH) with controllable doping content of cobalt as an oxygen evolution reaction (OER) electrocatalyst with excellent performance in alkaline media. Co-doped Ni–Mn LDH nanoplates were synthesized via a facile hydrothermal method. It was found that the doping content of cobalt significantly affected the OER activities. The best electrocatalyst was based on a doping ratio of 21.1% Co, exhibiting a low overpotential of ~310 mV at a current density of 10 mA cm−2, a Tafel slope of ~59 mV dec−1 as well as excellent stability. This work demonstrates a facile synthetic method of rationally doping transition-metal hydroxides to develop new OER electrocatalysts with remarkable performance in water splitting.