摘要
用溶胶—凝胶法制备了TiO2纳米粉晶。对TiO2干凝胶粉进行了差热—热重(DTA/TG)分析;对不同温度处理的粉末用X射线衍射(XRD)进行了研究,并进行了比表面积测试。研究发现随着热处理温度的升高,纳米粉末的粒径逐渐增大,比表面积逐渐减小;晶型由锐钛矿变为金红石相。本实验通过光催化降解甲基橙来表征粉末的光催化活性。结果表明,TiO2纳米粉末的粒径、比表面积及晶型严重影响其光催化活性。另外,实验还发现TiO2纳米粉末对于光催化活性存在一个临界尺寸(约10nm),当粉末的粒径小于这个临界尺寸时,其比表面积和光催化活性急剧增大。
TiO 2 nanocrystals were prepared via sol-gel process.Thermal analysis of the gel powders was investigated by DTA/TG;The powders after different thermal treatment were studied by X-ray diffraction(XRD)and testing surface area.As the annealing temperature increased,the grain size of titania became bigger,crystallographic form changed from anatase to rutile,and the surface area became smaller.In this experiment the photocatalytic activity was tested by degradating methyel orange in water.The results manifest that grain size?surface area and crystallographic form have great influence on photocatalytic property.In addition,we also discover that TiO 2 crystal has a critical size(about10nm)on photocatalytic property.When the grain size is less than the critical size,the surface area and photocatalytic activity both have rapid increase.
出处
《中国陶瓷》
CAS
CSCD
2003年第4期24-26,共3页
China Ceramics
基金
山东省自然科学基金课题Y2000F04
