Defect-induced triple synergistic modulation in copper for superior electrochemical ammonia production across broad nitrate concentrations

Bocheng Zhang; Zechuan Dai; Yanxu Chen; Mingyu Cheng; Huaikun Zhang; Pingyi Feng; Buqi Ke; Yangyang Zhang; Genqiang Zhang

doi:10.1038/s41467-024-47025-w

Defect-induced triple synergistic modulation in copper for superior electrochemical ammonia production across broad nitrate concentrations

Nat Commun. 2024 Apr 1;15(1):2816. doi: 10.1038/s41467-024-47025-w.

Authors

Affiliations

¹ Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
² Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China. gqzhangmse@ustc.edu.cn.

^# Contributed equally.

Abstract

Nitrate can be electrochemically degraded to produce ammonia while treating sewage while it remains grand challenge to simultaneously realize high Faradaic efficiency and production rate over wide-range concentrations in real wastewater. Herein, we report the defect-rich Cu nanowire array electrode generated by in-situ electrochemical reduction, exhibiting superior performance in the electrochemical nitrate reduction reaction benefitting from the triple synergistic modulation. Notably, the defect-rich Cu nanowire array electrode delivers current density ranging from 50 to 1100 mA cm^-2 across wide nitrate concentrations (1-100 mM) with Faradaic efficiency over 90%. Operando Synchrotron radiation Fourier Transform Infrared Spectroscopy and theoretical calculations revealed that the defective Cu sites can simultaneously enhance nitrate adsorption, promote water dissociation and suppress hydrogen evolution. A two-electrode system integrating nitrate reduction reaction in industrial wastewater with glycerol oxidation reaction achieves current density of 550 mA cm^-2 at -1.4 V with 99.9% ammonia selectivity and 99.9% nitrate conversion with 100 h stability, demonstrating outstanding practicability.