Photocatalytic fixation of carbon dioxide with conducting polymer

Abstract

Photocatalytic fixation of carbon dioxide has been achieved by utilizing poly(3-alkylthiophene) as a new class of photocatalyst. Irradiation of visible light onto a poly(3-alkylthiophene) film immersed in ethanol solution containing butylphenol under a CO₂ atmosphere resulted in formation of butylsalicyclic acid. The amount of butylsalicyclic acid formed increased with irradiation time. The mechanism of this novel photocatalytic CO₂ fixation reaction was discussed by measuring the quenching effects of carbon dioxide and phenol on the photolumine scence of poly(3-alkylthiophene) and the electrochemical oxidation and reduction potentials of poly(3-alkylthiophene), CO₂, phenol and phenolate anion. By using lithium phenolate as a starting substrate, the reaction rate was enhanced markedly.