Coupling NiFe-MOF with antiperovskite nickel-based nitrides as efficient electrocatalysts for overall water splitting

The exploration of high-performance, durable and cost-effective catalysts for overall water splitting, including the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), has always been a vibrant topic in electrochemical water splitting techniques. Here we report a facile strategy for the synthesis of antiperovskite bimetallic nitrides (FeNNi3 and CuNNi3) and their NiFe-MOF morphology on nickel foams (NF) for HER and OER respectively in alkaline media. The NiFe-MOF and FeNNi3 nanoparticle exhibit strong coupling and synergistic effects, resulting in a solid integrated structure and fast electron transfer. The FeNNi3 towards HER shows an overpotential of 57 mV at 10 mA cm−2 in alkaline media, and its MOF morphology shows a low overpotential of 219 mV at 10 mA cm−2 towards OER. The alkaline electrolyzer of FeNNi3/NF || NiFe-MOF@FeNNi3/NF for overall water splitting demonstrates a low cell voltage of 1.49 V at 10 mA cm−2 with high cycling durability. This work investigates antiperovskite nitrides' capabilities for overall water splitting and provides guidance on designing high-performance catalytic materials.