Photocatalytic production of oxygen in a dual bed system using a reversible redox mediator on Ir-TiO2 catalyst

Abstract

Photocatalytic O2 evolution by water splitting in an alkaline solution with a redox mediator was investigated in a dual bed system configuration: one bed was used for oxygen evolution and the other for hydrogen evolution. The employed photocatalyst was Ir-TiO2 and the iodate ion, KIO3, was used as a redox mediator. In order to find the optimum conditions for oxygen evolution, the effect of alkaline concentration, KIO3 concentration and the amount of Ir loading on the photocatalytic reactivity was examined in an irradiation area of 0.055 m2 reactor with a 400 W U.V. lamp. The experimentally obtained results showed that oxygen evolution depends on the concentration of the alkaline solution, the potassium iodate concentration and the amount of Ir loading.