Molybdenum carbide nanoparticles embedded in nitrogen-doped porous carbon nanofibers as a dual catalyst for hydrogen evolution and oxygen reduction reactions

Abstract

An efficient dual catalyst of molybdenum carbide nanoparticles embedded nitrogen-doped porous carbon nanofibers (Mo2C/NPCNFs) has been developed for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). The well-aligned and nanoporous identity of the desirable hybrid Mo2C/NPCNFs by an electrospun approach provides the good conductivity and rich active sites addressing excellent HER catalytic performance with an onset potential of −85 mV, a Tafel slope of 68 mV dec−1, and an exchange current density of 0.178 mA cm−2 in 0.5 M H2SO4. It is noting that the Mo2C/NPCNFs also shows remarkable ORR catalytic activity with an onset potential of ∼0.9 V, a half-potential of ∼0.77 V and a Tafel slope of 60.2 mV dec−1 at 1600 rpm in 0.1 M KOH. In addition, the experimental results demonstrate the core-shell 1D nanostructures boost the Mo2C/NPCNFs' stability of the durable catalytic activity over 10 h for both HER and ORR. This study designs a new structure for carbon-supported Mo2C composites, providing a distinctive course for the development of high-performance non-noble HER and ORR catalysts.