【摘要】 以钛酸四丁酯为前驱体,采用溶胶-凝胶法制备了TiO2纳米晶和薄膜。分别用X射线衍射(XRD)和差热-热重分析(DTA-TGA)对不同温度热处理的样品进行了表征。XRD分析表明:经过热处理的样品,锐钛矿相TiO2纳米晶平均粒子尺寸为5 3～32 4nm,其薄膜的平均粒子尺寸为6 7～29 6nm,但经相同温度热处理的TiO2纳米晶平均粒子尺寸普遍较薄膜样品大,此外,TiO2薄膜的相转变温度比纳米晶约高150℃,且其锐钛矿相(101)面上具有一定的择优取向,取向因子为0 53;DTA-TGA结果表明,360～500℃,TiO2凝胶从非晶态-锐钛矿相的转变是逐渐转变的过程;实验所制备样品的比表面积可达72 57m2/g,呈现出巨大的表面效应;同时光生载流子能在极短的时间内(<20ps)跃迁到TiO2纳米颗粒表面,有利于电子和空穴的分离。更多还原

【Abstract】 Titania nanocrystals and thin films were prepared by sol-gel process using （Ti（OBu）₄） as the precursor and the samples annealed at different temperatures were characterized by XRD and DTA-TGA.XRD results show that the mean particle size of anatase phase titania nanocrystals is 5.3～32.4 nm and that of thin films is 6.7～29.6 nm after the sintering process,but the mean particle size of anatase phase titania nanocrystals is larger than that of thin films at the same sintering temperature.The phase transitions temperature of thin films is about 150 ℃ higher than that of titania nanocrystals.XRD results also show preferential orientation of anatase films on phase（101） and the orientation factor is 0.53.DTA-TGA results show that the change from amorphous to anatase phase at 360～500 ℃ is a gradual process.In addition,specific surface area of the sample is as high as 72.57 m²/g,so the titania nanocrystals show big surface effect.The carrier charges can transfer rapidly（<20 ps） to the titania grain surface.Accordingly,it is very beneficial to separate electrons and holes.更多还原