B and N dual-doped carbon fibers loaded with nanocrystalline NiCo: an efficient electrocatalyst for oxygen evolution reaction

Boron and nitrogen dual-doped carbon fibers loaded with nanocrystalline NiCo were derived from carbonization of layers deposited by electrospinning a solution containing precursor reagents of nickel acetate, cobalt acetate, 4-hydroxybenzeneboronic acid, and polyacrylonitrile. This composite with uniformly distributed boron and nitrogen atoms in and NiCo nanoparticles around the carbon skeleton, denoted as NiCo@BNCF-T, where T represented the carbonization temperature in Celsius, possessed a considerable specific surface area. It was demonstrated that the NiCo@BNCF-T electrode, as an electrocatalyst, offered excellent electrocatalytic performance toward oxygen evolution reaction in alkaline environment. For example, the overpotential at 10 mA cm⁻² of the NiCo@BNCF-900 electrode was 268 mV, which was 43 mV lower than that of the RuO₂ electrode. In addition, the NiCo@BNCF-900 electrode exhibited excellent durability of 90% retention after 60-h polarization at 1.60 V. The two-electrode system for electrolytic water splitting, composed of the NiCo@BNCF-900 as the anode and the commercial Pt/C as the cathode, showed a voltage of 1.49 V to afford 10 mA cm⁻² for overall water splitting, which was superior to that of the RuO₂||Pt/C counterpart, which was a complete commercial system using noble metals. This work developed an effective electrocatalyst with non-noble metals (nickel and cobalt) and non-metal elements (boron, carbon and nitrogen), which was demonstrated to be a high-performance catalyst for oxygen evolution reaction.