CoSe2 nanowire array enabled highly efficient electrocatalytic reduction of nitrate for ammonia synthesis

The electrocatalytic reduction of nitrate (NO3 -) not only facilitates the environmentally sustainable production of ammonia (NH3 ) but also purifies water by removing NO3 -, thereby transforming waste into valuable resources. The process of converting NO3 - to NH3 is complex, involving eight electron transfers and multiple intermediates, making the choice of electrocatalyst critical. In this study, we report a cobalt selenide (CoSe2 ) nanowire array on carbon cloth (CoSe2 /CC) as an effective electrocatalyst for the NO3 - to NH3 conversion. In an alkaline medium with 0.1 mol/L NO3 -, CoSe2 /CC demonstrates exceptional NH3 Faradaic efficiency of 97.6 % and a high NH3 yield of 517.7 }mol h-1 cm-2 at -0.6 V versus the reversible hydrogen electrode. Furthermore, insights into the reaction mechanism of CoSe2 in the electrocatalytic NO3 - reduction are elucidated through density functional theory calculations. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.