Thermal Synthesis of FeNi@Nitrogen-Doped Graphene Dispersed on Nitrogen-Doped Carbon Matrix as an Excellent Electrocatalyst for Oxygen Evolution Reaction

The fabrication of non-precious-metal and highly active electrocatalytic materials to drive oxygen evolution reaction (OER) at low overpotential from earth-abundant elements by a low-cost and easy method is extremely important for many advanced energy technologies. Herein, a non-noble-metal catalyst with FeNi@nitrogen-doped graphene dispersed on a nitrogen-doped carbon matrix (named FeNi@NGE/NC) is synthesized by a facile one-pot pyrolysis process. In this composite, FeNi alloy nanoparticles encapsulated with few-layer nitrogen-doped graphene are uniformly anchored on a nitrogen-doped carbon matrix. The FeNi@NGE/NC composite exhibits outstanding electrocatalytic performance for OER with a low overpotential of 275 mV at 10 mA cm–2, a small Tafel slope of 41.2 mV dec–1, and high stability in 1 M KOH solution. Even at the low concentration of basic solution (0.1 M KOH), it still displays good activity for OER with an overpotential of 372 mV at 10 mA cm–2. The outstanding OER performance of the FeNi@NGE/NC composite can be mainly attributed to the fast electron transfer from the FeNi alloy to nitrogen-doped graphene shells and the high structural stability due to the protection of graphene shells and the carbon matrix. This work may open a facile and low-cost way for large-scale synthesis of non-noble metals/nitrogen-doped carbon composite electrocatalysts for practical application.