서강대학교

초록/요약

Nanoporous TiO2/SiO2 particles were prepared by an aerosol self-assembly method and their characteristics were investigated for photocatalytic application. Colloidal solution containing TiO2 and SiO2 nanoparticles was used as a starting material for the synthesis of nanoporous TiO2/SiO2 particles. The pore size distribution, pore volume and specific surface area of as-prepared particles were analyzed by BET and BJH methods, and the average particle sizes were measured by a laser diffraction method. In addition, SEM and XRD analysis were conducted for the characterization of morphology and crystal structure of product powder, respectively. Nanoporous TiO2/SiO2 particles ranged 4 - 10 ？m in diameter were successfully synthesized by the aerosol self-assembly method. The average particle size increased as the precursor concentration increased and the dispersion gas flowrate decreased. The morphology of nanoporous TiO2/SiO2 particles was spherical and many nanopores ranged 1 - 100 nm in pore diameter were observed in the particles. Nanoporous TiO2/SiO2 particles had the larger specific surface area and pore volume than those of nanoporous TiO2 particles. Photocatalytic activity of the as-prepared TiO2/SiO2 particles for the environmental application was evaluated by measuring the photodegradation of methylene blue (MB) and NOx using an UV spectrometer and a NOx analyzer, respectively under UV irradiation. Furthermore, the photocatalytic activity of nanoporous TiO2/SiO2 particles was compared with those of commercial TiO2 nanoparticles and nanoporous TiO2 particles. The highest photocatalytic activity was obtained when the porous TiO2/SiO2 particles was used. Even though same amount of TiO2 was employed in the nanoporous TiO2/SiO2 particles, we could obtain the higher photocatalytic activity compared with TiO2 nanoparticles.