Mo-based materials were recognized as cost-effective electrocatalysts for the hydrogen evolution reaction (HER) in acidic media but were hardly investigated in alkaline media due to the limited active sites, lower conductivity and high water dissociation energy barrier. Herein, a facile, low cost, scalable technique is provided for the synthesis of Mo₂C microspheres by a solvothermal route. Varying the feed ratio of the precursors enabled us to control the valence states of Mo and achieve optimized Mo₂C phase formation for HER catalysis. Electrodes with the microspherical Mo₂C catalyst were stable and exhibited reduced overpotentials of 138 mV at 10 mA cm⁻² in 0.5 M KOH with a Tafel slope of 85 mV dec⁻¹. The formation of an active Mo₂C phase with abundance of Mo³⁺/Mo²⁺ active sites in the suitable ratio, as well as fast charge-transfer kinetics, are proposed as the origin for the efficient HER activity. Notably, we used cyclooctatetraene, an industrial byproduct that can be recycled into functional materials for green energy. Our work provides facile and novel way to design and fabricate Mo₂C-based electrocatalyst for HER and probably other green energy applications.

钼基材料被认为是在酸性介质中进行氢释放反应（HER）的经济有效的电催化剂，但由于其有限的活性位，较低的电导率和较高的水离解能垒，因此在碱性介质中很少进行研究。在此，提供了一种通过溶剂热途径合成Mo ₂ C微球的简便，低成本，可扩展的技术。改变前体的进料比使我们能够控制Mo的化合价态并实现HER催化的优化Mo ₂ C相形成。具有微球形Mo ₂ C催化剂的电极是稳定的，在0.5 M KOH中的10 mA cm ^-2处表现出的过电势降低了138 mV，Tafel斜率为85 mV dec ^-1。提议以合适的比例形成具有大量Mo ³⁺ / Mo ²⁺活性位点的活性Mo ₂ C相，以及快速的电荷转移动力学，作为有效HER活性的起源。值得注意的是，我们使用了环辛酸酯，这是一种工业副产品，可以回收为绿色能源的功能材料。我们的工作为HER和可能的其他绿色能源应用提供了设计新颖的基于Mo ₂ C的电催化剂的设计和制造方法。