Synthesis of Monodisperse Mesoporous Titania Beads with Controllable Diameter, High Surface Areas, and Variable Pore Diameters (14−23 nm)
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- 作者：Dehong Chen ; Lu Cao ; Fuzhi Huang ; Paolo Imperia ; Yi-Bing Cheng ; Rachel A. Caruso
- 刊名：Journal of the American Chemical Society
- 出版年：2010
- 出版时间：March 31, 2010
- 年：2010
- 卷：132
- 期：12
- 页码：4438-4444
- 全文大小：395K
- 年卷期：v.132,no.12(March 31, 2010)
- ISSN：1520-5126
文摘
Monodisperse mesoporous anatase titania beads with high surface areas and tunable pore size and grain diameter have been prepared through a combined sol−gel and solvothermal process in the presence of hexadecylamine (HDA) as a structure-directing agent. The monodispersity of the resultant titania beads, along with the spherical shape, can be controlled by varying the amount of structure-directing agent involved in the sol−gel process. The diameter of the titania beads is tunable from 320 to 1150 nm by altering the hydrolysis and condensation rates of the titanium alkoxide. The crystallite size, specific surface area (from 89 to 120 m2/g), and pore size distribution (from 14 to 23 nm) of the resultant materials can be varied through a mild solvothermal treatment in the presence of varied amounts of ammonia. On the basis of the results of small-angle XRD, high-resolution SEM/TEM, and gas sorption characterization, a mechanism for the formation of the monodisperse precursor beads has been proposed to illustrate the role of HDA in determining the morphology and monodispersity during the sol−gel synthesis. The approach presented in this study demonstrates that simultaneous control of the physical properties, including specific surface area, mesoporosity, crystallinity, morphology, and monodispersity, of the titania materials can be achieved by a facile sol−gel synthesis and solvothermal process.