高球形度、高比表面积SiO2/TiO2气凝胶小球的制备和表征

摘要

以正硅酸乙酯(TEOS)和钛酸丁酯(TBT)为共前驱体、乙醇为溶剂、乙酸和氨水为催化剂,采用快速溶胶-凝胶过程和超临界干燥制备得到SiO2/TiO2气凝胶小球.对SiO2/TiO2气凝胶小球进行SEM,TEM,XRD,FT-IR,TG-DTA和氮气吸附-脱附分析测试发现,SiO2/TiO2气凝胶小球粒径为1~8mm,平均粒径约为3.5mm,小球具有纳米多孔网络结构,比表面积高达914.5m2/g,TiO2颗粒均匀分布于气凝胶结构中,并在高温下保持锐钛矿晶型.%The silica-titania aerogel beads were synthesized through sol-gel reaction followed by super-critical drying ,in which TEOS and TBT as co-precursors ,EtOH as solvents ,HAC and NH3 · H2O as catalysts .The as-prepared aerogel beads were characterized by SEM ,TEM ,XRD ,FT-IR ,TG-DTA and nitrogen adsorption-desorption .The results indicate that the diameter distribution of beads are be-tween 1-8mm ,the average diameter of beads is 3 .5mm .The aerogel beads have nanoporous network structure with high specific surface area of 914 .5m2/g ,and the TiO2 particles are distributed in the aerogel uniformly ,which keep the anatase crystal under high temperature .