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纳米TiO2晶粒生长动力学研究

刘河洲; 胡文彬; 顾明元; 吴人洁   

  1. 上海交通大学金属基复合材料国家重点实验室, 上海 200030
  • 收稿日期:2001-05-30 修回日期:2001-08-08 出版日期:2002-05-20 网络出版日期:2002-05-20

Kinetic Study on the Growth of Titania Nanocrystallites

LIU He-Zhou; HU Wen-Bin; GU Ming-Yuan; WU Ren-Jie   

  1. State Key Lab. of MMCs; Shanghai Jiao Tong University; Shanghai 200030; China
  • Received:2001-05-30 Revised:2001-08-08 Published:2002-05-20 Online:2002-05-20

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摘要： 研究了纳米ＴｉＯ２粒子热处理过程的晶粒生长,结果表明:低于８２３Ｋ锐钛矿晶粒的长大速率较小,８２３Ｋ后锐钛矿晶粒的长大速率显著增加．锐钛矿晶粒的生长动力学符合五次方方程,表观生长活化能由于纳米尺寸和相变效应的影响在高温区和低温区表现不同,高于８２３Ｋ时为(２０１．５５±５．６２)ｋＪ/ｍｏｌ,低于８２３Ｋ时为(３８．６７±６．３７)ｋＪ/ｍｏｌ;金红石晶粒的生长符合二次方方程,表观生长活化能为(１０８．７２±５．０６)ｋＪ/ｍｏｌ．

关键词: 纳米TiO2, 热处理, 晶粒生长, 锐钛矿, 金红石, 活化能

Abstract: Kinetic study was conducted by X-ray broadening and TEM characterization on the growth of anatase and rutile nanocrystallits in TiO2 nanoparticles during
isothermic heating at different tempretures. Results indicate that the growth of the heat-treated titania nanocrystallites becomes significant as the temperature
increases to higher than 823K, where anatase growth conforms to the fifth order kinetic equation with exponent 1.15 for time t, its apparent activity energy
correlated is (38.67±6.37)kJ/mol at the temperatures lower than 823K, and (201.55±5.62)kJ/mol at the higher temperatures, owing to the effects of
nanometer scale and phase-transformation. The rutile growth closely fits the second order kinetic equation with exponent 1.03 for time t,
its apparent activity energy calculated is (108.72±5.06)kJ/mol from Arrhenius plots.

Key words: titania nanocrystallites, heat-treatment, kinetics, anatase, rutile, apparent activity energy

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