Domain-limited anchoring of nano-Co2P on carbon cloth fibers by in-situ carbonization as a high-stability self-supporting electrode for hydrogen evolution reaction

Abstract

Developing highly active and stable electrocatalysts requires adequate exposure of catalyst active sites and improved interfacial bonding between the catalyst and collector. Here in, we fabricated a self-supporting catalyst electrode (Co₂P/NPC/CC) by high-temperature carbonization of carbon cloth (CC) coated with a precursor mixture and subsequent phosphating. Co₂P nanoparticles were uniformly anchored to resin-derived N-doped porous carbon (NPC) on the CC fibers. The precursor mixture included phenolic resin, 1,3,5-Tris(2-hydroxyethyl) cyanuric acid (Theic) and cobalt nitrate. The NPC formed by in-situ carbonization played a domain-limiting and anchoring role for nano Co₂P, ensuring good interfacial bonding among CC, NPC and Co₂P. The Co₂P/NPC/CC catalyst required overpotentials of 94.5 and 96.4 mV to achieve a current density of 10 mA cm⁻² for alkaline artificial seawater and acidic HER, respectively. An alkaline artificial seawater cell with Co₂P/NPC/CC and RuO₂ electrodes exhibited a voltage of 1.69 V to achieve 100 mA cm⁻², comparable to a commercial Pt/C||RuO₂ electrolyzer (1.68 V). Chronopotentiometry stability tests for 60 h at varying current densities (10–100 mA cm⁻²) demonstrated the outstanding stability of Co₂P/NPC/CC. This work offers new insights for designing low-resistance, high-stability self-supporting nanocomposite electrodes for electrocatalytic water splitting.