Boosted nitrate electroreduction to ammonia on Fe-doped SnS nanosheet arrays rich in S-vacancies.

The electrochemical nitrate reduction reaction (NORR) not only holds great potential for the removal of NO contaminants from the environment, but also potentially provides a renewable-energy-driven NH synthesis method to replace the Haber-Bosch process. Herein, we report that Fe-doped SnS nanosheets enriched with S-vacancies can be used as an efficient NORR catalyst, showing a high NH yield of 7.2 mg h cm (at -0.8 V) and a faradaic efficiency of 85.6% (at -0.7 V). Density functional theory (DFT) calculations revealed that S-vacancies on Fe-SnS serve as the main active sites for the NORR and the Fe-doping can further regulate the electronic structure of S-vacancies to optimize the binding energies of NORR intermediates, resulting in reduced energy barriers and enhanced NORR activity.