Synergistic Regulation of Active Phases, Carbon Matrix, and Electron Transport in CNT-Incorporated Electrospun Co-Mo/P Polyacrylonitrile-Derived Carbon Nanofibers for Alkaline Hydrogen Evolution

Sluggish alkaline hydrogen evolution reaction (HER) kinetics restrict large-scale applications of non-noble-metal carbon-based electrocatalysts. Herein, CNT-incorporated Co-Mo/P polyacrylonitrile-derived carbon nanofibers were prepared by electrospinning followed by thermal treatment (pre-oxidation and carbonization), where the Co/Mo feed molar ratio, thermal treatment conditions, and CNT content were sequentially optimized. A continuous and uniform polyacrylonitrile-derived carbon nanofiber matrix was obtained, where pre-oxidation helped preserve the fibrous framework during carbonization. Active phases associated with metallic Co, Mo2C, and Co3Mo3C were identified and P-M (M = Co or Mo) bonding was found. Furthermore, conductive networks were formed via doping CNTs in the electrospun Co-Mo/P-based electrocatalyst, enhancing their electron transport. The optimized sample exhibited HER activity with overpotentials of 106 and 312 mV at 10 and 100 mA cm−2 as well as a Tafel slope of 99.1 mV dec−1 in 1 mol L−1 KOH electrolyte. These results demonstrate that the coordinated regulation of active phases, carbon matrix, and electron transport improved the alkaline HER performance of the electrospun Co-Mo/P-based electrocatalyst. This synergistic strategy may offer a potential pathway for developing an efficient, robust, and cheap electrocatalyst for alkaline HER.