Fe3C nanoparticles decorated 3D nitrogen-doped carbon foam as a highly efficient electrocatalyst for nitrate reduction to ammonia

•Fe3C nanoparticles decorated 3D nitrogen-doped carbon foam catalyzes NO3− reduction.•It affords high Faradaic efficiency of 96.9% and a large NH3 yield of 8391.8 μg h−1 cm−2.•It demonstrates high stability. Electrochemical nitrate (NO3−) reduction is considered as a promising strategy to remove NO3−-containing pollution with simultaneous production of ammonia (NH3) under ambient conditions. However, this reaction involves multi-electron transfer steps, which requires active electrocatalysts for high NH3 selectivity. Herein, we demonstrate the development of Fe3C nanoparticles decorated 3D nitrogen-doped carbon foam (Fe3C NPs@NCF) as an efficient electrocatalyst to reduce NO3− to NH3. Such Fe3C NPs@NCF attains a high Faradaic efficiency (96.9%) and a large NH3 yield (8391.8 μg h−1 cm−2). More importantly, Fe3C NPs@NCF also delivers high stability.