Zhao Li, Yu Jiaguo
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Luoshi Road 122#, Wuhan 430070, PR China.
J Colloid Interface Sci. 2006 Dec 1;304(1):84-91. doi: 10.1016/j.jcis.2006.08.042. Epub 2006 Aug 25.
Highly dispersed TiO2 nanoparticles were successfully synthesized by a wet impregnation method using SBA-15 as hard template for confining the growth of TiO2 nanocrystals, and then calcined at 550 degrees C in muffle furnace for 2 h. The as-synthesized samples were characterized with Fourier transform infrared spectra (FTIR), Raman spectroscopy, diffuse reflectance UV-visible spectroscopy (UV-vis), powder X-ray diffraction (XRD), small-angle X-ray diffraction (SAXRD), nitrogen adsorption, transmission electron microscopy (TEM) and photoluminescence spectra (PL). It was found that SBA-15 contained abundant silanol groups after removal of triblock copolymers by ethanol extraction and could easily adsorb a great number of titanium alkoxide via chemisorption. After subsequent hydrolysis of the anchored Ti complexes and calcination of the amorphous TiO2, anatase TiO2 nanocrystals with spherical shape and uniform particle diameter of about 6 nm were formed. A blue shift was observed in UV-vis absorption spectra due to the quantum size effect of TiO2 nanoparticles. Moreover, the as-prepared TiO2 nanoparticles showed a high PL intensity due to an increase in the recombination rate of photogenerated electrons and holes under UV light irradiation.
采用湿浸渍法，以SBA - 15为硬模板来限制TiO₂纳米晶体的生长，成功合成了高度分散的TiO₂纳米颗粒，然后在马弗炉中于550℃煅烧2小时。采用傅里叶变换红外光谱（FTIR）、拉曼光谱、漫反射紫外 - 可见光谱（UV - vis）、粉末X射线衍射（XRD）、小角X射线衍射（SAXRD）、氮气吸附、透射电子显微镜（TEM）和光致发光光谱（PL）对合成的样品进行了表征。结果发现，通过乙醇萃取去除三嵌段共聚物后，SBA - 15含有丰富的硅醇基团，并且能够通过化学吸附轻松吸附大量的钛醇盐。在随后锚定的Ti配合物水解以及非晶TiO₂煅烧后，形成了球形且粒径均匀约为6 nm的锐钛矿型TiO₂纳米晶体。由于TiO₂纳米颗粒的量子尺寸效应，在UV - vis吸收光谱中观察到蓝移。此外，由于在紫外光照射下光生电子和空穴的复合率增加，所制备的TiO₂纳米颗粒显示出高的PL强度。
