煅烧条件对介孔TiO_2空心球成形的影响及其结构与性能研究

Influence of calcination condition on the Shape of mesoporous titania hollow sphere and its structure and performance

以三聚氰胺甲醛(MF)微球为硬模板和十六烷基三甲基溴化铵(CTAB)为介孔导向剂,经溶胶-凝胶法和高温煅烧模板辅助法合成了具有介孔结构的TiO_2空心球。探讨了煅烧温度和煅烧时间的改变对介孔TiO_2空心球完整性形成的影响,采用扫描电镜(SEM)、透射电镜(TEM)、红外光谱(FT-IR)、氮气吸附-脱附(BET)、X射线衍射(XRD)、紫外-可见分光光度法等测试手段对成形完整的TiO_2空心球的表面形貌、结构、组分和光谱性质进行了表征。结果表明,在500℃的条件下煅烧3h能形成结构完整的锐钛矿型TiO_2空心球,具有完整的球形空腔、较高的比表面积,其粒径在700nm左右,形成介孔的壳层厚度在75nm左右。另外,介孔TiO_2空心球对亚甲基蓝在紫外光照射下有较高的光催化活性。

Mesoporous TiO_2 hollow spheres were prepared by using melamine formaldehyde（MF）microspheres as hard template and hexadecyl trimethyl ammonium bromide（CTAB）as the soft template via a sol-gel process combining with calcinations.The influence of calcination temperature and time on the formation of spheres were analyzed.Various analytic techniques such as scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,infrared spectroscopy（FT-IR）,nitrogen adsorption-stripping（BET）,X-ray diffraction（XRD）and UV-Vis spectra were utilized to characterize the morphology,structure,composition and optical properties of the resultant spheres.Results revealed that the complete anatase TiO_2 spheres had spherical morphology,relative large specific surface area,the particle size of around700 nm and the mesoporous shell sthickness of about 75 nm,can be formed by calcinations at 500℃ for 3hin air.TiO_2 spheres possessed the superior photocatalytic degradation property to methylene blue under an ultraviolet light exposure.