Catalytic and Photocatalytic Degradation of Ozone via Utilization of Controllable Nano-Ag Modified on TiO2

To resolve increasing ozone pollution, nano-silver-anchored titanium dioxide (nano-Ag/TiO(2)), with a controllable diameter, synthesized by a photoreduction method, for ozone degradation is presented in this study. In the presence of ultraviolet (UV) irradiation, the nano-Ag/TiO(2) catalyst exhibited high efficiency for ozone degradation, at similar to 98-99% for all experiments. However, the efficiency of pure TiO(2) for ozone degradation rapidly dropped and became inefficient after 160 min. This is because ozone oxidized the surface of TiO(2) and formed an oxidative layer on the TiO(2) surface; then the photocatalytic ability of the re-oxidized TiO(2) for ozone degradation was greatly reduced. The results also indicated that ozone was effectively degraded via the nano-TiO(2) catalyst even without UV irradiation. The catalytic performance of nano-Ag/TiO(2) for ozone degradation was enhanced by reducing the diameters and by effectively dispersing the Ag nanoparticles. In addition, the photocatalytic ozone degradation via nano-Ag/TiO(2) revealed no decay at a relative humidity of 70% during the experimental period. and maintained excellent performance compared with that of pure TiO(2). (C) 2008 American Institute of Chemical Engineers Environ Prog, 27: 496-502, 2008