Molybdenum-Tungsten carbides based electrocatalysts for hydrogen evolution reaction

Tungsten carbide-based nano-catalysts (Ni-WC, Co-WC and NiCo-WC) and molybdenum carbide-based nano-catalysts (Ni-MoC, Co-MoC and NiCo-MoC) were synthesised using a carbothermal reduction method. X-ray diffraction, scanning electron microscopy coupled with electron dispersive spectroscopy, x-ray photoelectron spectroscopy and cyclic voltammetry were used to evaluate the prepared electrocatalysts. The cyclic voltammetry results showed that Ni-WC coated electrode displayed the best hydrogen evolution reaction catalytic activity with the lowest overpotential of 1.421 V at a current density of 10 mA cm(-2), and a Tafel slope of 135 mV dec(-1) which is marginally lower than the benchmark Pt/C coated electrodes. Ni-MoC and Co-MoC coated electrocatalysts also produced current more effectively with a change in potential as compared to the Pt/C coated electrode. The durability test showed Co-WC, NiCo-WC and Ni-MoC coated electrodes to have high stability within a wide range of current densities.

Automated summary

Tungsten carbide-based and molybdenum carbide-based nano-catalysts were synthesized and evaluated as electrocatalysts. The Ni-WC coated electrode exhibited the best catalytic activity for the hydrogen evolution reaction with the lowest overpotential and Tafel slope compared to Pt/C coated electrodes. The Ni-MoC and Co-MoC coated electrocatalysts also showed improved current production and potential change compared to Pt/C coated electrode. The durability test demonstrated the high stability of Co-WC, NiCo-WC, and Ni-MoC coated electrodes.