Formate dehydrogenase–viologen-immobilized electrode for CO2 conversion, for development of an artificial photosynthesis system

Abstract

Formate dehydrogenase (FDH)–viologen with a long alkyl chain (CH3V(CH2) n COOH) immobilized on an indium–tin oxide (ITO) electrode, with the function of reduction of CO2 to formic acid, was investigated as an artificial photosynthesis device based on CO2 reduction. The amount of formic acid produced by use of FDH–CH3V(CH2) n COOH immobilized on ITO in CO2-saturated buffer solution, on application of a potential, as a result of one-electron reduction of viologen, depends on the carbon chain length of CH3V(CH2) n COOH. When a CH3V(CH2)9COOH–FDH/ITO electrode was used, production of formic acid was estimated to be 23 μmol after 3 h.