升温速率对二氧化钛纳米晶形貌的影响

Effect of Heating Rate on the Morphology of Nano Titanium Dioxide

以钛酸四丁酯为钛源,采用十二胺辅助油酸溶剂热技术,在240℃/10min、90℃/10min、40℃/10min和20℃/10min四组不同升温速率下合成了球状、棒状和不规则点状多面体氧化钛纳米晶.分别采用TEM、HRTEM、XRD对样品的形貌特点和物相结构进行表征.结合TEM、HRTEM、XRD的表征结果,分析了不同升温速率下二氧化钛纳米晶的形貌变化和微观生长机制.结果表明,通过严格控制升温速率,能够合成球状、棒状和不规则点状多面体氧化钛纳米晶,随着升温速率的下降,纳米晶沿一维(001)方向生长速率呈现先升高后降低的趋势.

Different shapes of nano titanium dioxide including sphere,rod and irregular-shaped polyhedron were prepared by solvothermal process at heating rates of 240℃/10min,90℃/10min,40℃/10min and 20℃/10min using tetrabutyl titanate as Ti source,oleic acid as solvent,dodecylamine as auxiliary agent.TEM,HRTEM and XRD were adopted to characterize the phase composition morphology and phase structure of the final products.The micro-morphology and growth mechanisms of the titanium dioxide nanocrystals prepared at different heating rates were studied based on the TEM,HRTEM and XRD analyses.The results show that spherical,rod-like,and irregular polyhedral points of titanium dioxide nanocrystals could be synthesized by strictly controlling the heating rate.The growth rate of along the（001）direction of nanocrystal shows a first upward and then downward trend with the decline of the heating rate.