Near-Unity Nitrate to Ammonia conversion via reactant enrichment at the solid-liquid interface

• Published in: Nature communications Vol. 16; no. 1; pp. 5715 - 12
• Main Authors: Liao, Wanru, Wang, Jun, Tan, Yao, Zi, Xin, Liu, Changxu, Wang, Qiyou, Zhu, Li, Kao, Cheng-Wei, Chan, Ting-Shan, Li, Hongmei, Zhang, Yali, Liu, Kang, Cai, Chao, Fu, Junwei, Xi, Beidou, Cortés, Emiliano, Chai, Liyuan, Liu, Min
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 147/135; 147/143; 639/301/299/886; 639/638/169/896; 639/638/675; 639/638/77/887; Agricultural production; Ammonia; Carbon; Efficiency; Electrolytes; Electrowinning; Energy; Enrichment; Groundwater; Humanities and Social Sciences; Liquid-solid interfaces; Mass transfer; Molybdenum disulfide; Morphology; multidisciplinary; Nitrates; Scanning electron microscopy; Science; Science (multidisciplinary); Silver
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-025-60671-y

Electroreduction of nitrate (NO 3 ‒ ) to ammonia (NH 3 ) is a promising approach for addressing energy challenges. However, the activity is limited by NO 3 ‒ mass transfer, particularly at reduction potential, where an abundance of electrons on the cathode surface repels NO 3 ‒ from the inner Helmholtz plane (IHP). This constraint becomes pronounced as NO 3 ‒ concentration decreases, impeding practical applications in the conversion of NO 3 ‒ -to-NH 3 . Herein, we propose a generic strategy of catalyst bandstructure engineering for the enrichment of negatively charged ions through solid-liquid (S-L) junction-mediated charge rearrangement within IHP. Specifically, during NO 3 ‒ reduction, the formation of S-L junction induces hole transfer from Ag-doped MoS 2 (Ag-MoS 2 ) to electrode/electrolyte interface, triggering abundant positive charges on the IHP to attract NO 3 ‒ . Thus, Ag-MoS 2 exhibits a ~ 28.6-fold NO 3 ‒ concentration in the IHP than the counterpart without junction, and achieves near-100% NH 3 Faradaic efficiency with an NH 3 yield rate of ~20 mg h ‒1 cm ‒2 under ultralow NO 3 ‒ concentrations. Electroreduction of low-concentration NO 3 − to NH 3 is limited by NO 3 − mass transfer. Here, the authors propose a strategy for NO 3 − enrichment through charge rearrangement within the inner Helmholtz plane, achieving near-unity conversion of NO 3 − to NH 3 .