Embedding Co6Mo6C2-Mo2C heterostructure nanoparticles in carbon nanofibers as highly efficient electrocatalysts for overall water splitting

Abstract

In this study, carbon nanofibers (CNFs) embedding molybdenum carbide (Mo2C)/cobalt (Co)-molybdenum (Mo) bimetallic carbide heterostructure electrocatalysts (denoted as A-B/CNFs) were prepared via electrospinning and high-temperature carbonization. Owing to the synergistic interaction between Co6Mo6C2 and Mo2C components, the catalyst activity is improved. Furthermore, the rich mesoporous structure and electrical conductivity of CNFs, accelerate the reaction kinetics. As a result, the optimized Co6Mo6C2-Mo2C/CNFs-1 has excellent bifunctional electrocatalytic activity. With the current density of 10 mA cm−2, the hydrogen evolution reaction (HER) overpotential is only 94 mV, and the oxygen evolution reaction (OER) overpotential is 295 mV in an alkaline electrolyte. Building an alkaline electrolyzer with Co6Mo6C2-Mo2C/CNFs-1 as the anode and cathode electrodes requires a low cell voltage of only 1.66 V to achieve the current density of 10 mA cm−2, while maintaining ideal durability. This research offers a versatile and effective approach to creating bimetallic-based monolithic hydrolysis electrocatalysts.