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.

中文翻译：

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环境空气中直流电弧等离子体合成碳化钼催化剂析氢

摘要 电化学水分解对制氢很有吸引力，但铂等贵金属催化剂的高成本限制了其应用。在此，通过直流电弧放电等离子体在环境空气条件下制备了封装在碳基质中的碳化钼纳米颗粒，作为析氢反应（HER）的高性能和低成本电催化剂。根据XRD图谱，合成产物包括碳化钼（β-Mo2C和Mo1.2C0.8）、钼和石墨晶相。所得材料显示出高度活性的催化性能，起始电位非常小，为 -63 mV，电流密度为 10 mA cm-2 时的过电位为 -226 mV，1.0 M KOH 中的 Tafel 斜率为 66.1 mV.dec-1。在 10 mA cm-2 恒定电流密度下进行 50 h 的长期 HER 稳定性测试证实了合成产物催化性能的稳定性。因此，这种制备用于 HER 电催化剂的钼基材料的方法是有前景的，并且具有实际应用价值。