As a substitute for synthetic ammonia under mild condition, electrocatalytic nitrogen reduction reaction (NRR) provides a hopeful approach for the development of ammonia. Nevertheless, the current development of NRR electrocatalysts is far from enough and a systematic research is needed to gain a better improvement. This article presents that 2D C₃N₄-NV with a large specific surface area and abundant nitrogen vacancies is prepared by a simple and feasible method, and used as a metal-free catalyst for electrocatalytic NRR. Experiment result and density functional theory (DFT) calculation reveal that nitrogen vacancies in 2D C₃N₄-NV can act as an efficient active site for catalytic NRR, which is conducive to capturing and activating N₂, lowering Gibbs free energy (ΔG) in reaction and inhibiting hydrogen evolution reaction (HER) at the same time. In addition, the larger specific surface area also makes more active site exposed, which is good for the contact between the electrolyte and the active site, thus enhancing its NRR activity. The electrocatalyst shows an excellent catalytic activity for NRR in 0.1 M HCl, including Faradaic efficiency of 10.96%, NH₃ yields of 17.85 μg h⁻¹mg_cat.⁻¹, and good stability (over 20 h).

作为温和条件下合成氨的替代品，电催化氮还原反应（NRR）为氨的开发提供了一种有希望的方法。然而，目前NRR电催化剂的开发还远远不够，需要进行系统的研究以获得更好的改进。本文提出了一种简便易行的方法制备比表面积大，氮空位丰富的二维DC ₃ N ₄ -NV，并将其用作电催化NRR的无金属催化剂。实验结果和密度泛函理论（DFT）计算结果表明，二维DC ₃ N ₄ -NV中的氮空位可以作为催化NRR的有效活性位点，有利于氮的俘获和活化。_{如图2所示}，降低反应中的吉布斯自由能（ΔG）并同时抑制氢释放反应（HER）。另外，较大的比表面积也使更多的活性位点暴露出来，这有利于电解质和活性位点之间的接触，从而增强了其NRR活性。该电催化剂在0.1 M HCl中显示出对NRR的出色催化活性，包括法拉第效率为10.96％，NH ₃产率为17.85μgh ^-1 mg _cat。^-1和良好的稳定性（超过20小时）。