Fe3C Nanorods Encapsulated in N-Doped Carbon Nanotubes as Active Electrocatalysts for Hydrogen Evolution Reaction

One of the main challenges to generate hydrogen is to develop cheap and highly active electrocatalysts toward hydrogen evolution reaction (HER). Herein, Fe3C nanorods encapsulated in N-doped carbon nanotubes (Fe3C@NCNT) were synthesized by a simple method involving the pyrolysis of a Fe-based metal organic framework (MOF) and melamine. The hybrid composite showed an excellent catalytic activity toward HER in an acidic electrolyte. The overpotential at the current density of 10 mA cm(-2) was only 154 mV in a 0.5 M H2SO4 solution, which was lower than most of the non-precious metal and metal-free catalysts. Density functional theory (DFT) calculation results suggested that the synergistic effect between Fe3C nanorods and N dopants could effectively tune the H adsorption energy on carbon resulting in an enhanced HER activity.