Kazuhito Hashimoto

Electrochemical and Photoelectrochemical Carbon Dioxide Reduction

Two types of electrochemical carbon dioxide reduction systems using light energy as the first energy source will be reported. One is the electrochemical system using a hydrogen storing material as a working electrode. In this system dry Si solar battery is used to convert the light energy to electrical energy. Our idea is to utilize the hydrogen atom stored in the electrode. We observed clearly that the stored hydrogen is used in the carbon dioxide reduction both on Pd and copper modified Pd electrodes. The other is the photoelectrochemical system using p-type semi-conductor electrodes in which solar energy is directly converted to chemical energy on the electrode surface. We found that copper oxide and amorphous SiC photocathodes produce methanol as a main reduction product of carbon dioxide in aqueous electrolytes.