Acta Phys. -Chim. Sin. ›› 2005, Vol. 21 ›› Issue (01): 57-62.doi: 10.3866/PKU.WHXB20050112

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Controlled Synthesis of TiO2 Nanometer Powders by Sol-gel Auto-igniting Process and Their Structural Property

YAN Qing-Zhi;SU Xin-Tai;ZHOU Yan-Ping;GE Chang-Chun   

  1. Laboratory of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, Beijing 100083
  • Received:2004-05-24 Revised:2004-08-27 Published:2005-01-15
  • Contact: GE Chang-Chun

Abstract: Highly dispersed TiO2 nanometer powders with controlled structure were synthesized by chemical complex sol-gel auto-igniting process. The initial oxidant/reductant molar ratio, swelling of gel and temperature schedule were chosen as key variables for the controlled synthesis: by changing the initial oxidant/reductant molar ratio from 2 to 7, TiO2 having a particle size about 30 nm was obtained at 600 ℃ with a mass fraction of rutile ranging from 25% to 68.2%; sufficient swelling and carbonizing of the gels at 150 ℃ removed non-bridging hydroxyl groups and broke down the hydrogen bonds between particles, so the formation of hard agglomerates was avoided; the mass fraction of rutile and particle size of TiO2 increased with increasing of calcination temperature; agglomerates of TiO2 were formed at 800 ℃. The optical absorption edges significantly shifted to longer wavelengths in the UV-Vis diffuse reflectance spectra of the as-prepared TiO2, and the reflectivity was about 10% lower than that of commercial TiO2. It was found that the as-prepared TiO2 with the optimal rutile fraction of 55.5% achieved the best optical absorption.

Key words: Sol-gel auto-igniting process, Titanium dioxide, Nanometer powder,  Controlled synthesis