Photocatalytic fixed bed reactions for contaminant mineralization

Abstract

It is generally concerned that the issues such as mass transport and volume activity resulted from photocatalyst immobilization will undesirably slow photocatalytic reactions. Although certain strategies imitating slurry suspension have been proposed, the photon utilization is evidently lower than the dispersed counterparts. We here review a recently proposed approach to photocatalyst immobilization by cognizing the time constants for the electronic processes and mass transport occurred in actual photocatalytic reaction. By virtue of effective separation of oxidation and reduction half-reactions, the photocatalytic fixed bed reactions formed by anchoring photocatalysts onto the smooth internal wall of the light incident side of the reactors can be superior to slurry suspension in photon utilization. The scalable photocatalytic fixed bed reactions in mineralization of contaminants in wastewater and air, and CO oxidation in hydrogen streams for lossless purification are also reviewed.