Carbon-supported FeCoNiP/FeCoNi Mott-Schottky electrocatalyst for alkaline oxygen evolution reaction

Design of oxygen evolution reaction (OER) electrocatalysts with advanced composition and structure is essential for achieving highly efficient water splitting. Herein, we fabricated a Mott-Schottky electrocatalyst composed of trimetallic alloy and its phosphide (FeCoNiP/FeCoNi) on network-like carbon support. The catalyst was synthesized via a NaCl-template method followed by high-tempreture pyrolysis and low-tempreture phosphorization process. By optimization of the carbonization temperature, the electrocatalyst achieved a ultralow overpotential of 240 mV at 10 mA/cm2 and 302 mV at 100 mA/cm2 for OER, the most excellent OER performance in reported metallic phosphide catalysts and related heterojunction catalysts. The FeCoNiP/FeCoNi Mott-Schottky heterojunction enhanced the mass adsorption and electron transfer in the OER process, responsible for the excellent electrocatalytic activity. Meanwhile, the FeCoNiP on the surface endowed the catalyst good long-term durability in the alkaline electrolyte, even at 10 mA/cm2 for 40 h Our work provided a universal strategy for convenient and controllable synthesis of multi-component Mott-Schottky catalysts, the excellent electrocatalysis performance of which throw new light on the further practical applications.