Design of a long-lived Mo2C-MoO2@GC-N electrocatalyst by the ambient DC arc plasma for the hydrogen evolution reaction

Summary: A crucial challenge in hydrogen production through electrolysis is developing inexpensive, earth-abundant, and highly efficient Pt-free electrocatalysts for the hydrogen evolution reaction (HER). Molybdenum carbide is ideal for this application because of its special electrical structure, low cost, and advantageous characteristics. Herein, the long-lived electrocatalysts for HER have been synthesized via the direct current (DC) arc discharge plasma method under ambient air conditions, and the relationship between the properties of materials and catalytic characteristics has been established. The samples differed in the ratio of molybdenum, graphite, and melamine. The sample with the highest proportion of melamine in the initial mixture has Mo2C-MoO2 heterointerfaces, which demonstrates the highest and most stable electrocatalytic activity with the overpotential of 148 mV at 10 mA·cm-2 and Tafel slope of 63 mV·dec−1 in alkaline electrolyte. Meanwhile, the electrodes demonstrated long-lived electrochemical durability for two weeks and investigated the features of forming a stable system for HER.