Single-Atom Fe Anchored Graphdiyne for High-Efficiency Nitrate-to-Ammonia Conversion at Ambient Conditions

The electrocatalytic conversion of wastewater nitrate (NO3-) to ammonia (NH3) under industrial-grade current densities at ambient conditions presents a sustainable alternative to the energy-intensive Haber-Bosch process, yet remains fundamentally challenging. Here, a highly efficient NO3- to NH3 electrocatalyst with single Fe atoms dispersing on graphdiyne (GDY) is constructed through an in-situ growth method. Experimental analysis demonstrates the formation of high-density atomic active sites on GDY, ensuring the high intrinsic activity of the electrocatalyst. Besides, the newly formed sp-C~Fe chemical bonds bridged GDY and Fe atoms provides a well-defined channel for selectively and efficiently transferring electrons from the active sites to the reactants/key intermediates, allowing for the selective NO3- activation and efficient protonation. This atomic-scale electronic modulation enables exceptional nitrate reduction performance, achieving record-high Faradaic efficiency (40.17%) and ammonia yield (106.65 μmol h⁻¹ cm⁻²) while maintaining operational stability.