Photocatalytic Decomposition of Lactic Acid in Water on a Photoelectrochemical Circuit System Consisting of a Rod-type TiO2 Electrode and Silicon Solar Cell

摘要

Lactic acid, a well-known substance causing dental caries, was dissolved in water and completely oxidized into CO2 and H2O on a powdered TiO2 photocatalyst under UV light irradiation. Furthermore, a unique photoelectrochemical circuit system consisting of a rod-type TiO2 electrode and counter electrode connected through a silicon solar cell was constructed and its photocatalytic activity for the decomposition of lactic acid was investigated. The photoelectrochemical circuit system was found to effectively mineralize the lactic acid in water into CO2 while the negative bias applied on the rod-type TiO2 electrode enhanced the photocatalytic decomposition rate of the lactic acid.