摘要
以钛酸丁酯为钛源，采用溶胶一凝胶法制备纳米TiO2，结合TG-DTA，XRD，TEM等分析了不同热处理温度对纳米TiO2的晶型结构、晶粒粒径及微观形貌的影响。以甲基橙溶液为目标降解物，探讨了热处理温度对纳米TiO：光催化活性影响。利用Eastman的粒子生长理论对晶粒生长的动力学过程进行初步分析。研究表明：随着热处理温度升高，Ti02粒径逐渐从11．2nm增大到78．6nm；热处理温度为450-550℃时，纳米TiO2晶粒以锐钛矿为主，温度升至650℃时，出现了锐钛矿和金红石的混合相（质量比A：R=9：1），此时晶粒对甲基橙的降解率达到97．75％。而煅烧温度高于850℃后，TiO：几乎完全为金红石相，光催化活性显著下降。50％锐钛矿型TiO2转变金红石型TiO2的温度约为730℃，锐钛矿和金红石相晶粒表观活化能分别18．15kJ／mol和42．56kJ／mol；晶粒生长最快温度分别为546℃和1280℃。
Nano-titanium dioxide was prepared by sol-gel method using butyl titanate as precursor. The effects of heat treatment temperatures on the crystal structure, grain size and microstructure of nano-TiO2 were analyzed by TG-DTA, XRD, TEM. Meanwhile, the photocatalytic activity of heat treatment temperature on the degradation performance of TiO2 to methyl orange was investigated. The result shows that TiO2 particle size gradually increases from 11.2 nm to 78.6 nm with the heat treatment temperature increasing. At 450-550 ℃, the grain is mainly anatase phase, and there has been a mixed anatase and rutile phase at 650 ℃ （ mass ratio A ： R = 9 ： 1 ）, while the degradation rate of nano-TiO2 on methyl orange reaches 97.75 %. When the calcination temperature exceeds 850 ~C, TiO2 particles are almost entirely composed of rutile phase, and the photocatalytic activity decreased significantly. At 730 ℃, the half of TiO2 crystalline transforms from anatase to rutile. The apparent activation energies of the anatase crystal and rutile crestal of nano-TiO2 are 18.15 kJ/mol and 42.56 kJ/mol, and the fastest temperatures of the grain growth are 546 ℃ and 1280 ℃, respectively.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2015年第7期1826-1831,共6页
Journal of Synthetic Crystals
基金
国家自然科学基金(50708037)
郑州市科技攻关项目(141PPTGG388)
关键词
溶胶-凝胶法
TIO2
热处理温度
光催化
sol-gel method
titanium dioxide
heat treatment temperature
photocatatysis
