Developing highly efficient non-precious-metal catalysts for electrochemical reduction reaction is vital for artificial nitrogen fixation under ambient conditions. Herein, we report a bioinspired Fe3C@C composite as an efficient electrocatalyst for nitrogen reduction. The composite based on a leaf skeleton successfully replicates the natural vein structure with multichannels. The Fe3C@C core–shell structure as the real active center contributes to selective electrocatalytic synthesis of ammonia from nitrogen with Faraday efficiency of 9.15% and production rate of 8.53 μg/(h mgcat) or 12.80 μg/(h cm2) at a low potential of −0.2 V versus reversible hydrogen electrode (vs RHE), which is better than that of recently reported carbon- and iron-based materials, even comparable with that of noble-metal-based catalyst. Experiments with density functional theory calculations reveal that graphene-encapsulated Fe3C nanoparticles can improve charge transfer due to core-shell interaction, beneficial for inducing active sites for N2 adsorption and activation and thereby facilitate ammonia synthesis.

Electrochemical water splitting to produce hydrogen as an ideal sustainable energy storage strategy provides a useful approach for the utilization of clean energy due to its high theoretical energy conversion...

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