Photocatalytic degradation of 4-chlorophenol in a photochemical reactor with an interconnected microchannel and a light guide network

Abstract

Abstract Photocatalytic microchannel reactor with a novel light guide of fused glass beads was developed. Anatase nanoparticle photocatalyst was deposited on the inner surface of the porous glass monolith of the reactor. Activity of the reactor was evaluated based on photocatalytic degradation of 4-chlorophenol. All the glass beads in a glass column were fused with each other and with the inner peripheral of the column to form a glass network, which construct a network of light guide to deliver the incident light from side wall to each bead in the column. In contrast, almost all the voids among the beads connect with each other to form a network of microchannels for substrate solution, where many parallel flow of the substrate solution can pass through the reactor. Microchannel reactors composed of 5 mm or 1 mm glass beads in diameter were investigated, so that the dimension of the channels are evaluated as approximately 750 μm and 150 μm, respectively. The glass web monolith serves as a support of TiO 2 photocatalyst and a light guide to deliver the incident light to activate the photocatalyst on each bead. Photocatalytic activity of the reactor constructed with the 1 mm or the 5 mm glass beads was improved 13 and 3 times as much as that of the simple glass column without the beads, respectively. The ratio in the reactivity was proportional to the ratio in internal surface area of the reactors, supporting the effect of the glass web as light guide and the network of the voids as microchannel.