TiO2-coated optical fiber bundles used as a photocatalytic filter for decomposition of gaseous organic compounds

An optical fiber-based, filter-type photocatalytic reactor was designed and the decomposition reaction of gas phase isopropanol was studied using a recirculating reaction system. Compared to the conventional TiO2-coated glass plate or honeycomb monolith, both higher efficiency of light utility and larger processing capacity were obtained. This good combination was achieved by employing both high input light intensities (1.6 x 10(16) to 2.6 x 10(17) quanta cm(-2) s(-1)) and a large number of glass fibers (18 000 pieces, 125 mu m diameter) in the reactor, which makes it possible for the reaction to occur with a high reaction rates while maintaining a high quantum efficiency. These characteristics can be understood by considering a TiO2-coated single fiber as a micro-reactor distributed with low photon flux, and the corresponding fiber bundles being composed of large number of such micro-reactors. (C) 2000 Published by Elsevier Science S.A.