Gas-Phase Photooxidation: Reactors and Materials
Abstract
Photocatalytic vs. photosensitizing materials to be used for gas-phase photooxidation and photooxygenation, respectively, are described. An overview is given on reactive oxygen species specific to photocatalysis and photosensitization as well as on various kinds of gas-phase reactors and photocatalytic materials in order to illustrate the great number of possible configurations and conditions of use. Some efforts towards standardization of gas-phase photocatalytic reactors devoted to indoor- or outdoor-air treatment are mentioned. Examples for application of singlet oxygen in solvent-free photooxygenation reaction of volatile sulfides are given together with the properties of silica-based photosensitizing materials. Various gas-phase reactors and photocatalytic or photosensitizing materials for oxidation of air pollutants are reviewed. Generally speaking, the reactor design mostly depends on the macroscopic shape of the materials and on the light sources. Given the high number of possible configurations, standardized experiments are strongly required.