Ultrathin graphitic carbon nitride interface layer regulated nickel-iron oxyhydroxide stabilized on nickel foam for efficient oxygen evolution reaction

Abstract

Regulating interfacial properties of electrocatalysts to enhance the performance of oxygen evolution reaction (OER) possesses practical significance for water splitting. Herein, we report a novel strategy to form a graphitic carbon nitride (g-C3N4) interface layer on nickel foam (NF), followed by the growth of nickel-iron (oxy)hydroxides (NiFe-OH). The NiFe-OH nanosheets are tightly anchored on the g-C3N4 layer, exhibiting enhanced surface and structural characteristics. Therefore, the as-prepared NF/g-C3N4/NiFe-OH demonstrates superior OER activity with low overpotentials of 272, 342, and 476 mV at the current densities of 50, 100, and 200 mA cm−2, respectively. The reduced Tafel slope and raised TOF values of the electrode compared to NF/NiFe-OH reveal the promoting roles of g-C3N4, which provides more active sites, induces charge redistribution, and facilitates electron transfer. Furthermore, the electrode presents reliable stability and durability without observable morphological damage, alteration in the surface chemical state, and significant depletion of active components.