低温燃烧法合成纳米二氧化钛粉体研究

Synthesis of titanium dioxide nanopowders by a low-temperature combustion method

采用一种简便、快速、低温的溶胶凝胶自蔓延燃烧法制备了纳米TiO2粉体颗粒.从柠檬酸络合反应的机理阐释了纳米TiO2粒子的形成过程.通过热综合分析、X射线衍射和透射电镜分析探讨了金属离子与柠檬酸的摩尔比和溶液杂质离子的存在对TiO2粉体颗粒物相组成及粉末晶粒尺寸大小的影响.本实验制备了粒径为40～90 nm分散性较好的球形状TiO2纳米颗粒.X射线衍射结果表明,当摩尔比为0.5时,自燃合成产物中金红石相的质量分数达到91%.

TiO2 nanopowders were synthesized via a simple,quick and sol-gel low-temperature combustion method.Their formation mechanism was explained from the chelating action of citrates.The effects of the molar ratio of metal ions to citric acid and the presence of impurity ions on the phase forming of TiO2 nanoparticles and the crystallite size of the synthesized powders were investigated by thermal analyses（DTA/TG）,X-ray diffraction（XRD） and transmission electron microscopy（TEM）.Spheric TiO2 nanoparticles whose sizes are in the range of 40 to 90 nm are successfully prepared in the experiment.XRD results show that the mass fraction of rutile in the synthesized powers reaches 91% when the molar ratio of metal ions to citric acid is 0.5.