Trimetallic Nanoparticles Encapsulated into Bamboo‐Like N‐Doped Carbon Nanotubes as a Robust Catalyst for Efficient Oxygen Evolution Electrocatalysis

Abstract High‐efficiency oxygen evolution reaction (OER) electrocatalysts based on transition metal materials are one of the most promising alternatives, but their activity and durability are still far from desirable. Here, we report trimetallic N‐doped carbon nanotubes with rapid electron transport and rapid diffusion of the electrolyte that can significantly enhance the OER. The introduction of a third metal can adjust the electronic structure, thereby causing favorable intermediate adsorption on the catalysts. The optimized catalyst CoFeNi@CNTs exhibits a low overpotential of 287 mV at 10 mA cm⁻² and a small Tafel slope of 32 mV dec⁻¹, which are obviously superior to the precious catalyst IrO₂ and most previously reported catalysts. The CoFeNi@CNTs also exhibit excellent OER stability with small current density decay after 12 h. The outstanding OER activity is ascribed to the unique carbon nanotube structure and strong synergy between three metals.