Insights into oxygen vacancy-enhanced WO3 nanosheets for electrocatalytic nitrogen oxidation to nitrate

Abstract

In this work, WO₃ nanosheets with rich oxygen vacancy (V_O-WO₃ NSs) were prepared as an effective catalyst for electrochemical N₂ fixation. Benefiting from the rich oxygen vacancy, the V_O-WO₃ NSs provide abundant active sites for boosting the adsorption and activation of N₂. As a result, the V_O-WO₃ NSs achieved a faradaic efficiency of 10.01% for NO₃⁻ at 1.5 V vs. RHE. Notably, at 1.9 V vs. RHE, the V_O-WO₃ NSs reached a remarkable NO₃⁻ yield rate of 142.03 μg h⁻¹ mg_cat.⁻¹, which was 1.4 times that (100.84 μg h⁻¹ mg_cat.⁻¹) of pristine WO₃ NSs. The catalyst also exhibited high electrochemical stability and selectivity.