For example, the inner cavity of the hollow structure is very essential for drug delivery by offering a large volume transportation for DNA, drugs, and cosmetics. Hollow-structured mesoporous materials with unique features of high surface area, high permeability, low density, confined inner cavity, and optical properties have been of great interest and received much research, which makes them a promising application in drug delivery systems, chemical and catalysts, biological sensors, and solar cells. Therefore, the technique for the preparation of SiO 2/TiO 2 mesoporous double-nanoshell hollow tubes could provide new insights into the construction of mesoporous double-shell and hollow structure for other multicomponent and hierarchical hybrid systems. Plus, the shell thickness of SiO 2 and TiO 2 is controllable depending on the used concentration of TEOS and TEOT during their sol-gel process. Also, mesoporous double-nanoshell SiO 2/TiO 2 hollow tubes have the inner and outer shell thickness of about 80 nm and 120 nm, respectively. The obtained double-nanoshell hollow tubes illustrate a large surface area and high pore volume. During TEOS and TEOT hydrolysis/condensation for the SiO 2 and TiO 2 shell layer formation, cetyltrimethylammonium bromide (CTAB) is adopted both as the structure-directing template and as the mesopore-channel template distributing around the shell. In this paper, we report, for the first time, the double nanoshell SiO 2/TiO 2 hollow tubes prepared through a layer-by-layer deposition method involving the sol-gel process for the SiO 2 and TiO 2 generation. Photobiol., A 84 (1994) 183‒193.Double-shell tubular on-dimensional structure can be fabricated through a layer by layer method, in which the core template was removed to create the tubular shape. Savinov, Photocatalytic methods of water and air purification, Sorosovskij obrazovatel'nyj zhurnal 6 (11) (2000) 52‒56. Magnetic photocatalyst / Hiroshi F., Yukiko H., Michichiro Y. The photodegradation dynamics revealed that even though the oxidation rate decreases over time, about 90% of methyl orange is oxidized during the first 35 min. The photocatalytic activity of Fe 3O SiO 2 nanoparticles was investigated by photodegradation of methyl orange in aqueous solution under UV light irradiation. The resulting particles were separated using a magnet, washed and dried to constant weight, the yield was 70%. Finally, solution of tetrabutoxytitanium was added dropwise to the mixture of Fe 3O 2 nanoparticles under sonication & intense stirring. Secondly, the magnetite nanoparticles were dispersed in ethanol using sonication, and solutions of both ammonia and tetraethoxysilane were added to the suspension under intense stirring, since it was suggested that the introduction of an intermediate passive SiO 2 layer between the Fe 3O 4 and TiO 2 phases inhibits the direct electrical contact and hence prevents the photodissolution of the magnetite phase and deterioration of the surface photocatalytic properties. First the nuclei of magnetite nanoparticles were prepared by co-precipitation of iron (II&III) salts solutions. In this work, the nanosized magnetic Fe 3O 2 photocatalyst was prepared by sol-gel methods.
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