그래핀 옥사이드와 이산화티타늄 조합을 이용한 이산화탄소의 광환원

Abstract

In this study, we synthesized a combination of graphene oxide (GO) and titanium dioxide (TiO2) and confirm that GO can be used for CO2 photoreduction. TiO2 exhibited highly efficient combination with other conventional electric charges generated by the separation phenomenon for suppression of hole-electron recombination. This improved the efficiency of CO2 photoreduction. The synthetic form of GO-TiO2 used in this study was a graphene sheet surrounded by TiO2 powder. Efficiency and stability were enhanced by combination of GO and TiO2. In a CO2 photoreduction experiment, the highest CO conversion rate was 0.652 μmol/g･h in GO10-TiO2 (2.3-fold that of pure TiO2) and the highest CH4 production rate was 0.037 μmol/g･h in GO0.1-TiO2 (2.4-fold that of pure TiO2). GO enhances photocatalytic efficiency by functioning as a support and absorbent, and enabling charge separation. With increasing GO concentration, the CH4 level decreases to ~45% due to decreased transfer of electrons. In this study, TiO2 together with GO yielded a different result than the normal doping effect and selective CO2 photoreduction.