Oxygen vacancies in Bi2WO6 enable robust nitrate reduction reaction catalysis

The faradaic efficiency of Bi₂WO₆ is 62.0% at -0.3 V vs. RHE, an improvement of 1.4- and 1.8-times relative to Bi₂O₃ and WO₃ for the nitrate reduction reaction. In addition, the catalysis occurring on Bi₂WO₆ follows the pathway: *NO₃-*NO₂-*NO-*NOH-*HNOH-*H₂NOH-*NH₃, as verified by operando Raman spectroscopy and theoretical calculations.