Ethylene Glycol-Assisted Interfacial Engineering for Efficient Electrocatalytic Nitrate Reduction to Ammonia at...

Constructing synergistic heterointerfaces is recognized as an effective strategy to enhance the efficiency of electrocatalytic nitrate reduction to ammonia (NO₃RR), but the limited utilization of hydrogen species still constrains overall performance. Herein, we fabricate a self-supported EG-CuO_x@Ni(OH)₂ electrode, in which the CuO_x@Ni(OH)₂ heterointerface induces charge redistribution, and the introduction of ethylene glycol (EG) further strengthens electronic coupling between phases, synchronously optimizing the adsorption capability of Cu sites toward NO₃^- and the activation ability of Ni sites toward H₂O. Notably, EG directs the oriented growth of Ni(OH)₂ into uniform, dense flower-like nanoclusters on CuO_x, substantially increasing active site exposure and interfacial contact efficiency. Moreover, EG is beneficial to locally enriching protons, facilitating the efficient hydrogenation of key intermediates by H* species. Benefiting from these synergistic effects, EG-CuO_x@Ni(OH)₂ exhibits outstanding NO₃RR performance, achieving an ammonia half-cell energy efficiency of 39.90%, a Faradaic efficiency of 96.59%, an ammonia production rate of 202.16 mg h^-1·cm^-2, and a current density of 2549.24 mA·cm^-2, while maintaining stable operation for 18 h.