A Facile Route Fabricated Nickel‐Nitrogen‐Doped Carbon Nanoparticle Based Electrocatalysts for the Oxygen Evolution and Hydrogen Evolution Reactions

Abstract

AbstractThe cost‐effective hydrogen production via electrolyser depends on the availability of highly efficient, low‐cost, and robust OER and HER catalysts. We fabricated Ni−NC and NC electrocatalysts via a simple, cheap, and scalable by direct mixing route followed by carbonization at 900 °C under the N2 atmosphere. The addition of Ni into NC substantially increases the crystallite size, particle size, and ID/IG ratio. The Ni−NC sample exhibits excellent bifunctional OER and HER activities. The overpotentials to achieve (−) 10 mA.cm−2 current density for the OER were 400 mV and 263 mV for the HER in 0.1 M NaOH electrolyte. The Tafel slope analysis of the Ni−NC sample for the OER (123 mV.dec−1) revealed the hydroxyl‐ion discharge is the rate‐determining step. In comparison, for the HER (145 mV.dec−1), the Volmer‐Heyrovsky pathway is the rate‐determining step. The short‐term stability test displayed the sustained current density for 10 h at 1.68 V vs. RHE.