Synthesis of molybdenum carbide catalyst by DC arc plasma in ambient air for hydrogen evolution

Abstract

Electrochemical water splitting is attractive for hydrogen production, however, high cost of noble metal catalysts, such as platinum, restrict its use. Herein, molybdenum carbide nanoparticles encapsulated within carbon matrices as a high-performance and low-cost electrocatalyst for hydrogen evolution reaction (HER) were prepared by DC arc discharge plasma under ambient air conditions. According to XRD patterns the synthesized product includes molybdenum carbides (β-Mo2C and Mo1.2C0.8), molybdenum and graphite crystalline phases. The resulting material shows highly active catalytic properties with very small onset potential of −63 mV, a low overpotential of −226 mV at current density of 10 mA cm−2 and Tafel slope of 66.1 mV.dec−1 in 1.0 M KOH. The long-term HER stability test for 50 h under constant current density of 10 mA cm−2 confirmed the stability of the catalytic properties of the synthesized product. Therefore, such a method for producing Mo-based material for HER electrocatalysts is promising and can have practical application.