Enhanced electrocatalytic N2-to-NH3 fixation by ZrS2 nanofibers with a sulfur vacancy.

Industrially, large-scale NH3 production is achieved by the Haber–Bosch process, which operates under a harsh reaction condition with abundant energy consumption and CO2 emission. Electrochemical N2 reduction is an eco-friendly and energy-saving method for artificial N2 to NH3 fixation at ambient reaction condition. Herein, we demonstrate that ZrS2 nanofiber with sulfur vacancy (ZrS2 NF-Vs) behaves as an efficient electrocatalyst for ambient N2 reduction to NH3 with excellent selectivity. In 0.1 M HCl, such ZrS2 NF-Vs attains a large NH3 yield of 30.72 μg h−1 mg−1cat. and a high Faradic efficiency of 10.33% at −0.35 V and −0.30 V vs. reversible hydrogen electrode, respectively. It also shows high electrochemical and structual stability. Density functional theory calculations reveal that the introduction of Vs facilitates the adsorption and activation of N2 molecules.