Patent ID: 8709227

Claim:
A method for reducing carbon dioxide using a carbon dioxide reduction device, the method comprising steps of: (a) preparing the carbon dioxide reduction device comprising: a cathode chamber; an anode chamber; a solid electrolyte membrane; a cathode electrode; and an anode electrode, wherein: the cathode electrode comprises copper or copper compound on the surface thereof, the anode electrode comprises a region formed of a nitride semiconductor layer on the surface thereof, an Al x Ga 1-x N layer (0<x≦1) and a GaN layer are stacked in the nitride semiconductor layer, a first electrolytic solution is stored in the cathode chamber, a second electrolytic solution is stored in the anode chamber, the cathode electrode is in contact with the first electrolyte solution, the anode electrode is in contact with the second electrolyte solution, the solid electrolyte membrane is interposed between the cathode chamber and the anode chamber, the first electrolytic solution contains the carbon dioxide, and the cathode electrode is connected to the anode electrode electrically; and (b) irradiating the anode electrode with a light having a wavelength of not more than 350 nanometers to reduce the carbon dioxide contained in the first electrolytic solution on the cathode electrode.