Electrochemical reduction of NO on ZnO and In₂O₃ semiconductor electrodes in aqueous K₂SO₄ solutions

NO was efficiently reduced on ZnO and In₂O₃ of n-type semiconductor electrodes in aqueous solutions. Harmless N₂ was obtained as a main reduction product. Current-potential curves on the ZnO and In₂O₃ electrodes under NO were quite similar to those under N₂O. It is proposed that the NO reduction on the ZnO and In₂O₃ electrodes proceeds via the redox mechanism in which oxygen vacancies formed by the electrochemical reduction on the electrode surface play an important role.