Amorphization engineered VSe2−x nanosheets with abundant Se-vacancies for enhanced N2 electroreduction

Abstract

Electrochemical N₂ fixation through the nitrogen reduction reaction (NRR) is a promising route for sustainable NH₃ synthesis, while exploring high-performance NRR catalysts lies at the heart of achieving high-efficiency NRR electrocatalysis. Herein, we reported the structural regulation of VSe₂ by amorphization engineering, which simultaneously triggered the enriched Se-vacancies. The developed amorphous VSe_2−x nanosheets with abundant Se-vacancies (a-VSe_2−x) delivered a much enhanced NRR activity with an NH₃ yield of 65.7 μg h⁻¹ mg⁻¹ and a faradaic efficiency of 16.3% at −0.4 V, being 8.8- and 3.5-fold higher than those of their crystalline counterparts, respectively. Density functional theory computations combined with molecular dynamics simulations revealed that the amorphization-triggered Se-vacancies could induce the upraised d-band center of unsaturated V atoms, capable of promoting the binding of key *N₂/*NNH species to result in an energetically favorable NRR process.