Tailoring electronic structure of copper nanosheets by silver doping toward highly efficient electrochemical reduction of nitrogen to ammonia

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X-ray photoelectron spectroscopy (XPS) studies reveal that the doping of Ag into Cu nanosheets leads to the modified electronic structures of Cu atoms. Thanks to the modified electronic structures and abundant active sites, the Ag-Cu NS /CP exhibits highly electrocatalytic activity for NRR with an NH 3 yield rate of 61.5 µg h −1 mg -1 cat. with a Faradaic efficiency of 20.9% at −0.4 V versus reversible hydrogen electrode under ambient conditions. • Ag-doped Cu nanosheets grown on carbon paper were synthesized by an electrochemical deposition method. • The doping of Ag leads to the formation of electron-deficient Cu atoms. • Electron-deficient Cu atoms can suppress hydrogen evolution reaction and enhance N 2 adsorption. • Ag-Cu NS /CP gives an ammonia yield rate of 61.5 µg h −1 mg −1 with a Faradaic efficiency of 20.9% for NRR. Electrochemical nitrogen reduction reaction (NRR) at ambient conditions is a highly attractive route for ammonia (NH 3 ) synthesis. However, the NRR suffers from low NH 3 yield and Faradaic efficiency (FE) due to the lack of effective electrocatalyst. Here Ag-doped Cu nanosheets grown on carbon paper (Ag-Cu NS /CP) have been synthesized and utilized as efficient electrocatalysts for NRR. The doping of Ag leads to the formation of electron-deficient Cu atoms in Ag-Cu NS /CP, which can suppress hydrogen evolution reaction and enhance N 2 adsorption in neutral media, leading to enhanced NRR activity. In 0.1 M Na 2 SO 4 electrolyte, the Ag-Cu NS /CP catalyst exhibits a high FE of 20.9% with a NH 3 yield rate of 61.5 µg h −1 mg -1 cat. at −0.4 V versus the reversible hydrogen electrode. This study offers a simple but effective approach to design highly active and selective NRR electrocatalysts for NH 3 synthesis.