Oxygen vacancies-rich molybdenum tungsten oxide nanowires as a highly active nitrogen fixation electrocatalyst

Herein, vacancy engineering is utilized reasonably to explore molybdenum tungsten oxide nanowires (W₄MoO₃ NWs) rich in O-vacancies as an advanced electrochemical nitrogen reduction reaction (eNRR) electrocatalyst, realizing further enhancement of NRR performance. In 0.1 mol/L Na₂SO₄, W₄MoO₃ NWs rich in O vacancies (CTAB-D-W₄MoO₃) achieve a large NH₃ yield of 60.77 µg h^-1 mg^-1_cat. at -0.70 V vs. RHE and a high faradaic efficiency of 56.42 % at -0.60 V, much superior to the W₄MoO₃ NWs deficient in oxygen vacancies (20.26 µg h^-1 mg^-1_cat. and 17.1 % at -0.70 V vs. RHE). Meanwhile, W₄MoO₃ NWs rich in O-vacancies also show high electrochemical stability. Density functional theory (DFT) calculations present that O vacancies in CTAB-D-W₄MoO₃ reduce the energy barrier formed by the intermediate of *N-NH, facilitate the activation and further hydrogenation of *N-N, promote the NRR process, and improve NRR activity.