Photoelectrochemical CO₂ reduction on 3C-SiC photoanode in aqueous solution

Photoelectrochemical (PEC) carbon dioxide (CO₂) reduction on a 3C-SiC photoanode is demonstrated in aqueous solution with Pt and Ag counter electrodes. It is demonstrated that 3C-SiC has sufficient potential for CO₂ reduction by confirming the band-edge structure. Then, the CO₂ reduction is realized by connecting the 3C-SiC photoanode with the counter electrode. As the products of the PEC reaction with an applied bias of 1V (vs counter electrode) to the 3C-SiC photoanode, hydrogen (H₂) and carbon monoxide (CO) were analyzed by highly sensitive micro-gas chromatography, by which the time dependence of the gas products can be analyzed. Under light illumination of the 3C-SiC photoanode, CO₂ reduction occurred while producing 2.5 and 9 nmol of CO gas with the Pt and Ag counter electrodes, respectively, after the reaction for 3000 s.