Boron-doped molybdenum carbide as a pH-independent electrocatalyst for the hydrogen evolution reaction

Abstract

Development of efficient and highly active non-noble metal electrocatalysts to replace Pt-based catalysts for achieving pH-dependent electrochemical hydrogen generation on a large scale is extremely significant. In this study, a B-doped molybdenum carbide nanocrystal confined in a porous N-doped carbon nanostructure (B–MoC) was synthesized and evaluated as a pH-independent electrocatalyst for the hydrogen evolution reaction (HER). B-doping could modify the electronic structure of MoC by introducing electron deficiency, which resulted in excess electron transfer to MoC nanoparticles, thereby generating many proton adsorption sites and improving the electrocatalytic performance. B-doping could also increase the electrochemical surface area of the catalyst and lower its resistance. Moreover, B–MoC could participate in charge transfer processes and prevent the agglomeration of MoC nanoparticles. B–MoC showed a low overpotential of 285 mV at a current density of 10 mA cm−2, as well as excellent stability for 1000 cycles in an acidic medium. Such remarkable improvements in the activity and stability of B–MoC toward HER were also observed in alkaline and neutral media.