Synergistic coupling of FeNi3 alloy with graphene carbon dots for advanced oxygen evolution reaction electrocatalysis

Realizing the simultaneous morphology and electrical conductivity tuning of non-noble metal nanocatalysts is urgently desired for promoting their intrinsic activity toward oxygen evolution reaction (OER), while it is still challenging. Herein, we have demonstrated that the morphology and conductivity of FeNi3 alloy can be finely tailored via introducing the graphene carbon dots (GCDs). Benefitting from the enlarged active areas, significantly improved electrical conductivity, and strong synergistic coupling effect, the optimized FeNi3@GCDs-10 shows extraordinary electrocatalytic performance towards OER by delivering a current density of 10 mA cm-2 with the overpotential of 238 mV, as well as small Tafel slope of 48.7 mV dec-1. Density functional theory (DFT) calculations reveal that Fe is the dominated active sites for boosting water dissociation. In addition, the incorporation of GCDs can also strength the adsorption of *O and lower the energy barrier for the transformation from *OH to *O, thereby optimizing the free energy of *O and greatly promoting the OER activity.