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

Electrochemical N-2 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 VSe2-x nanosheets with abundant Se-vacancies (a-VSe2-x) delivered a much enhanced NRR activity with an NH3 yield of 65.7 mu g 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 *N-2/*NNH species to result in an energetically favorable NRR process.

Automated summary

In this study, the structural regulation of VSe2 through amorphization engineering led to the development of amorphous VSe2-x nanosheets with enriched Se-vacancies, resulting in significantly enhanced NRR activity. These amorphous VSe2-x nanosheets exhibited high NH3 yield and faradaic efficiency in NH3 synthesis, outperforming their crystalline counterparts.