Three-dimensional carbon nanofiber networks encapsulated in cobalt–molybdenum metal clusters on nitrogen-doped carbon as ultra-efficient electrocatalysts for hydrogen evolution reactions

Efficient and cost-effective catalysts have been developed for the production of hydrogen via water electrolysis. In this study, we develop a strategy for the fabrication of carbon nanofiber catalysts loaded with CoMo clusters covered by a nitrogen-doped carbon network (CoMo/CN@CNFs/MEL). The surface of two-dimensional carbon fibers was coated with a nitrogen-doped carbon network via melamine pyrolysis, thereby forming three-dimensional (3D) networks. These 3D network catalysts exhibited excellent catalytic performance in the hydrogen evolution reaction with 1 M KOH, requiring an overpotential of only 148 mV to reach a current density of 10 mA cm−2 owing to synergistic effects resulting from their structure and composition. The catalytic performance of the CoMo/CN@CNFs/MEL catalysts was comparable to that of commercial Pt/C at high current densities owing to their unique structural features, including restricted Co–Mo clusters, porous nitrogen-doped carbon frameworks, continuous conducting carbon nanofibers, and carbon nitride networks. This work provides a promising approach to transition metal-based catalysts with improved stability and atom utilization efficiency.