Electrocatalytic Conversion of Carbon Dioxide and Nitrate Ions to Urea by a Titania–Nafion Composite Electrode

Abstract CO 2 and nitrate ions were successfully converted to urea by a TiO 2 –Nafion nanocomposite electrode under ambient conditions. The composite electrode was constructed by dropcasting the mixture of P25 titania and Nafion solution on an indium‐doped tin oxide (ITO) electrode. When the electrode was electrolyzed in CO 2 ‐saturated 0.1 m KNO 3 (pH 4.5) solution at −0.98 V versus Ag/AgCl, urea was formed with a Faradaic efficiency of 40 %. The other reduced products obtained were NH 3 , CO, and H 2 .