Facile charge transport in $$\hbox {FeN}_{\mathrm{x}}/\hbox {Mo}_{2}\hbox {N/CNT}$$ FeN x / Mo 2 N/CNT nanocomposites for efficient hydrogen evolution reactions

Molybdenum based materials are gaining importance as electrocatalysts for hydrogen evolution reaction because of their low cost and good electrocatalytic efficiency. Introducing iron nitride with molybdenum nitride as a composite results in efficient hydrogen evolution activity with current density of $${\sim }120$$ $$\hbox {mA/cm}^{2}$$ at $$-400 \hbox { mV}$$ vs. RHE. The nanocomposites were characterized using powder XRD, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Electron Diffraction, Thermogravimetric Analysis and FTIR Spectroscopy. The electrochemical investigations suggest that the electrocatalytic activity of the composite increases with iron nitride content. The composite exhibits good electrochemical stability upto 42 hours in acidic medium. The hydrogen evolution reaction (HER) follows Volmer-Heyrovsky mechanism where Volmer reaction is the rate determing step. SYNOPSIS Introducing iron nitride in composite with molybdenum nitride leads to higher HER activity in acidic media. The in-situ growth of CNTs in the composites enhances the conductivity and decreases the charge transfer resistance.