Photoelectrochemical N₂ reduction reaction (PEC NRR) is a promising method to solve the problems of environmental protection and energy sustainability. However, the strong chemical stability of the N≡N bond and competitive hydrogen evolution reaction (HER) cause the nonideal efficiency of N₂ → NH₃ conversion in actual operation. For the first time, a Mo₂C/C heterostructure was fabricated as a PEC cathode for N₂ reduction under environmental conditions. The Mo₂C/C heterostructure could effectively decrease the coverage of hydrogen spillover and inhibit the competitive HER, resulting in a desirable selectivity for N₂ activation. Meanwhile, the decoration of the C shell further promoted the stability and conductivity of Mo₂C. Mo sites of Mo₂C were considered as activation centers, which played a dominant role in the final PEC performance. An optimal NH₃ yield rate of up to 6.6 μg h^–1 mg^–1 was achieved with the Mo₂C/C heterostructure, which was almost 3 times that with pristine C. The faradic efficiency (FE) of the Mo₂C/C heterostructure was 37.2% at 0.2 V (vs Ag/AgCl). This work not only provides an insight into the interplay between the Mo₂C/C heterostructure and N₂ activation, but also reveals its great potential in NH₃ synthesis by a green route.

中文翻译：

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石墨化碳原位包覆Mo ₂ C促进光电化学N ₂还原

光电化学N ₂还原反应（PEC NRR）是解决环保和能源可持续性问题的一种有前途的方法。然而，N≡N键的强化学稳定性和竞争性的氢释放反应（HER）导致实际操作中N ₂ →NH ₃转化的非理想效率。首次制造了Mo ₂ C / C异质结构作为PEC阴极，用于在环境条件下还原N ₂。Mo ₂ C / C异质结构可有效减少氢溢出的覆盖范围并抑制竞争性HER，从而对N ₂具有理想的选择性激活。同时，C shell中的装饰进一步促进莫的稳定性和导电性₂莫C. Mo位₂ C下视为激活中心，其中在决赛中表现PEC起到了主导作用。Mo ₂ C / C异质结构的最佳NH ₃产率最高可达6.6μgh ^–1 mg ^–1，几乎是原始C的3倍。Mo ₂ C / C的法拉第效率（FE）C异质结构在0.2 V（vs Ag / AgCl）下为37.2％。这项工作不仅提供了对Mo ₂ C / C异质结构和N ₂之间相互作用的深刻理解。活化，但也显示了其通过绿色途径在NH ₃合成中的巨大潜力。