Abstract (EN):
This review reports different approaches for the intensification of photocatalytic oxidation (PCO) processes towards air streams decontamination. From reactor design to the combination of different oxidative processes, many approaches have been exploited in order to reach higher photocatalytic reaction rates. When it comes to reactor design, enhancing photon transfer is still the biggest challenge to be overcome. Several types of photocatalytic reactors can provide a large surface-to-volume ratio, exhibiting satisfactory mass transfer; however, the irradiation of the entire catalytic coated surface has shown to be quite difficult for some particular reactor geometries. In this context, the use of miniaturized light sources e.g. LEDs has shown to be a promising alternative for a more "customized" irradiation profile, resulting in a more efficient catalytic surface illumination. Coupling PCO with other oxidative processes has been reported to enhance substantially the reaction rates. In fact, synergistic effects have been reported for both ozone and plasma-enhanced photocatalytic systems. The use of vacuum ultraviolet radiation (VUV, lambda < 200 nm) in PCO processes is another commonly used strategy for the intensification of PCO processes. The improved photocatalytic activity for VUV-PCO process is usually related to the ability of VUV light to break most chemical bonds and generate strong oxidants, such as hydroxyl radicals and ozone, through the photolysis of H2O and O-2, respectively.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
20