Sulfur dots–graphene nanohybrid: a metal-free electrocatalyst for efficient N2-to-NH3 fixation under ambient conditions

• Published in: Chemical communications (Cambridge, England) Vol. 55; no. 21; pp. 3152 - 3155
• Main Authors: Chen, Hongyu, Zhu, Xiaojuan, Huang, Hong, Wang, Huanbo, Wang, Ting, Zhao, Runbo, Zheng, Hongguo, Asiri, Abdullah M, Luo, Yonglan, Sun, Xuping
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 07.03.2019
• Subjects: Ammonia; carbon dioxide; catalysts; chemical reactions; Chemical reduction; Chemical synthesis; electrochemistry; electrodes; Emissions control; Graphene; greenhouse gas emissions; hydrogen; nanohybrids; nitrogen; Organic chemistry; Selectivity; Sulfur
• ISSN: 1359-7345; 1364-548X; 1364-548X
• DOI: 10.1039/c9cc00461k

NH3 is an important chemical with a wide range of applications, but its synthesis mainly relies upon the harsh Haber–Bosch process with huge CO2 emission. Electrochemical N2 reduction offers a carbon-neutral process to convert N2 to NH3 under ambient conditions, but it requires efficient and stable catalysts to drive the N2 reduction reaction. Herein, we report that a sulfur dots–graphene nanohybrid acts as a metal-free electrocatalyst for ambient N2-to-NH3 conversion with excellent selectivity. When operated in 0.5 M LiClO4, this electrocatalyst achieves a large NH3 yield of 28.56 μg h−1 mgcat.−1 and a high Faradaic efficiency of 7.07% at −0.85 V vs. reversible hydrogen electrode. Notably, it also shows good electrochemical stability.