Kinetic Study on the Growth of Titania Nanocrystallites
纳米TiO2晶粒生长动力学研究

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.