N-doped hollow nanofibers loaded with RuCoNi ternary alloy as an efficient catalyst for hydrogen evolution reaction

Alloying noble metals with abundant transition metals is an effective strategy for preparing cost-effective electrocatalysts for efficient hydrogen evolution reaction. In this study, hollow carbon nanofibers loaded with RuCoNi ternary alloy nanofiber catalysts (RuCoNi/CNFs) were synthesized by coaxial electrostatic spinning and a high-temperature carbonization approach. The interconnected three-dimensional hollow nanofibers, uniformly loaded with RuCoNi alloy nanoparticles, provided a large specific surface area and a hierarchical porous structure to enhance the interaction between the electrolyte and the active sites. Additionally, the hollow structure facilitated active sites exposure, charge transport, and gas diffusion, resulting in excellent HER activity of RuCoNi/CNFs. The overpotential required to achieve a current density of 10 mA cm ⁻² under alkaline conditions was only 47 mV, outperforming the homemade Pt/C catalyst (54 mV). Moreover, the carbon structure acted as a conductive carrier for efficient electron transfer, protecting the alloy nanoparticles from aggregation and corrosion. The RuCoNi/CNFs demonstrated remarkable stability and durability, maintaining consistent performance even after 100 hours of continuous operation. Importantly, the catalyst also exhibited favorable HER activity (186 mV@100 mA cm ⁻² ) at high current density, highlighting its potential for practical applications in large-scale industry.