Modifying Microenvironment in Van der Waals Gap by Cu/N Co‐Doping Strategy for Highly Efficient Nitrite Reduction to Ammonia
Heen Li, Yuanzhe Wang, Kuo Wei, Maoyue He, Mengmeng Yan, Fei Peng, Faming Gao
Abstract
Abstract Electroreduction of nitrite to ammonia has significant promise for economical NH 3 electrosynthesis and wastewater treatment. Herein, sulfur vacancies rich Cu─N co‐doped SnS 2 nanosheet is designed as a highly active and durable NO 2 RR catalyst. Benefiting from the Cu─N co‐doped strategy, Cu/N‐SnS 2‐x achieves the highest NH 3 yield rate of 18.15mg h −1 mg cat −1 at −0.935 V (vs RHE) and excellent Faradaic Efficiency of 95.73% at −0.835 V (vs RHE). In situ FT‐IR and in situ XPS proves that Cu/N‐SnS 2‐x has a greater capacity for atomic hydrogen generation, which facilitates the conversion of nitrite to ammonia and maintains excellent structural stability during the NO 2 RR process. Theoretical calculations reveal that the introduced sulfur vacancies effectively expose the metal atoms inside SnS 2 and make them adsorb nitrite efficiently, which effectively accelerates the transformation of nitrite to ammonia. Besides, the introduced Cu and N can form a new electronic structure, which induces Cu in an electron‐deficient state promotes the adsorption of reaction intermediates on Cu, and reduces the reaction energy barrier for nitrite reduction on the Cu/N‐SnS 2‐x surface. The current exploration presents fresh prospects for the rational development of an effective electrocatalyst for synthesizing ammonia from nitrite.