MOF nanosheet array-derived NiS with Co, N-doped carbon layer: A highly efficient oxygen evolution electrocatalyst

The development of the hydrogen industry from electrolytic water is confined in great measure to the slow kinetics of oxygen evolution reaction (OER), which means the rational design of a stabilized and efficient OER electrode is the key. The construction of easily accessible hydroxide ion (OH−) adsorption sites can effectively accelerate the kinetics of the OER. Herein, the NiS/CoNC electrocatalysts, which can effectively adsorb OH− and exhibited excellent OER performance in an alkaline environment, were obtained by pyrolysis and sulfidation of NiCo-MOF nanosheets on nickel foam (NF). In particular, the optimized NiS/CoNC electrocatalyst achieved an overpotential of 46/106 mV at 10/100 mA cm−2 and Tafel slope of 57.41 mV dec−1, which is superior to most reported materials. The outstanding function of OER results from the NiOOH/CoOOH active component generated by surface reconstruction after activation of the NiS/CoNC catalyst and the excellent charge transfer capability of the NiS component. This work offers a scheme to construct the electrocatalysts derived from MOF with excellent OER performance.