Uniformly dispersed NiO/FeNi3 alloy nanoparticles embedded in N-doped porous carbon as electrocatalysts for enhanced oxygen evolution reaction

The oxygen evolution reaction (OER) is a key half-reaction in renewable energy-related technologies, such as the electrocatalytic water splitting process and carbon dioxide reduction reaction. Unfortunately, developing an efficient and stable electrocatalyst to overcome the sluggish kinetics of OER remains a challenge. Herein, uniformly dispersed NiO and FeNi3 alloy nanoparticles anchored on N-doped porous carbon (NC) electrocatalysts were designed and synthesized by a facile two-step calcination strategy. The influence of calcination temperature and the molar ratio of Ni:Fe on electrocatalytic OER activity was particularly studied. With an optimal calcination temperature and Ni/Fe ratio, FeNi3 @NC-800 exhibited outstanding OER performance with a low overpotential of 242 mV at a current density of 10 mA cm-2 and a small Tafel slope of 34.7 mV dec-1 in alkaline media. The enhanced OER activity of FeNi3@NC-800 is mainly due to the synergistic effect of FeNi3 alloy nanoparticles with NC and the high electrical conductivity between FeNi3 and NC. This research will offer a new perspective on the construction of efficient and stable non-noble metal OER electrocatalyst.