锐钛矿相纳米TiO2晶体生长动力学及生长过程控制

研究了采用溶胶-凝胶法经由前驱物钛酸四异丙酯水解制备纳米TiO₂结构相变及锐钛矿晶体生长动力学过程. 研究结果表明，在酸性条件下水解，由于高压热处理温度的变化导致锐钛矿向金红石相的结构相变，锐钛矿相纳米TiO₂生长活化能在250℃以下和以上分别为(15.8±4.5)kJ/mol和(80.2±1.0)kJ/mol；而在碱性条件下水解的活化能值为(3.5±0.4)kJ/mol. 在不发生结构相变的条件下，酸性水解条件下锐钛矿相纳米TiO₂生长速 关键词： 2')" href="#">纳米TiO₂ 锐钛矿 生长动力学 溶胶-凝胶法

Growth kinetics and growth process control of nanocrystalline TiO2 anatase

Structural transformation of nanocrystalline titania prepared by sol-gel process with hydrolysis precursor titanium isopropoxide was investigated. The growth kinetics of TiO₂ anatase was also studied. It is found that under acid conditions, the activation energies for the growth of anatase below and above 250℃ are (15.8±4.5) kJ/mol and (80.2±1.0) kJ/mol, respectively, which is due to the structural transformation from anatase to rutile resulting from the increasing temperature during the autoclave heating process. Under base conditions, the activation energy of anatase growth is (3.5±0.4) kJ/mol. The growth of anatase under acid conditions is slower than that under base conditions without phase transformation. That is, the growth of anatase becomes significant at higher temperature under acid conditions, whereas under base conditions, the crystallite growth is obviously accelerated by the longer autoclaving time. The above research results will contribute to realize the control of TiO₂ nanoparticle size and will also provide us the theoretical and experimental bases for the mass production of TiO₂nanoparticles in the future.