FTIR Study on the Formation of TiO2 Nanostructures in Supercritical CO2
详细信息 查看全文
- 作者：Ruohong Sui ; Amin S. Rizkalla ; Paul A. Charpentier
- 刊名：Journal of Physical Chemistry B
- 出版年：2006
- 出版时间：August 24, 2006
- 年：2006
- 卷：110
- 期：33
- 页码：16212 - 16218
- 全文大小：499K
- 年卷期：v.110,no.33(August 24, 2006)
- ISSN：1520-5207
文摘
TiO<SUB>2 nanospherical and fibered structures were obtained via a one-step sol-gel method in supercritical carbondioxide (scCO2) involving polycondensation of the alkoxide monomers titanium isopropoxide (TIP) and titaniumbutoxide (TBO) with acetic acid (HAc). The resulting materials were characterized by means of electronmicroscopy (SEM and TEM), X-ray diffraction (XRD), thermal analysis (TGA), and attenuated total reflectionFourier transmission infrared (ATR-FTIR) analysis. Depending on the experimental conditions, TiO2 anatasenanospheres with a diameter of 20 nm or TiO2 anatase/rutile nanofibers with a diameter of 10-100 nm wereobtained. Fiber formation was enhanced by a higher HAc/Ti ratio and the use of the titanium isopropoxide(TIP) monomer. The mechanism of the microstructure formation was studied using in situ FTIR analysis inscCO2. The FTIR results indicated that the formation of nanofibers was favored by a titanium hexamer thatleads to one-dimensional condensation, while nanospheres were favored by a hexamer that permits three-dimensional condensation.