Harnessing Co/Mo dual-atom synergy on N,P-carbon nanofibers for superior bifunctional water splitting

Abstract

Developing cost-effective, active, and durable bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for water electrolysis. However, designing stable and high-performance active sites across diverse electrochemical environments remains challenging. In this work, we fabricate self-supporting N,P-doped carbon nanofibers anchoring Co/Mo dual-atom sites (Co_xMo_y–NPCNFs) via electrospinning, ZIF-8 templating, and thermal treatment, targeting superior bifunctional water splitting. The optimized Co₂Mo₂–NPCNF electrode exhibits outstanding performance in 1.0 M KOH, achieving a current density of 100 mA cm⁻² at low overpotentials of 259.8 mV for the HER and 372.5 mV for the OER. X-ray absorption spectroscopy and other characterization techniques confirm atomic Co/Mo dispersion with direct Co–Mo coordination, fostering potent synergy. This dual-atom synergy, strongly supported by N/P co-doping and a ZIF-8-derived hierarchical porous structure, is pivotal for the enhanced intrinsic activity and stability. Moreover, the catalyst demonstrates excellent long-term operational stability, sustaining operation for approximately 25 hours during the OER and 120 hours during the HER. This work presents a promising strategy for designing advanced bifunctional electrocatalysts with optimized atomic efficiency, highlighting the power of synergistic multi-component design for clean energy applications.