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二氧化钛是一种具有很大应用前景的纳米粉体材料。本文以 1mol/L四氧化钛水溶液为前驱物 ,进行了不同阴离子种类加入的二氧化钛水热合成实验。通过XRD和TEM等分析手段分别对产物的晶相和晶粒形貌进行表征 ,探索了反应介质中硫酸根、硝酸根、氯离子、氟离子、硼酸根和磷酸根离子不同加入量对二氧化钛微晶粉体的结晶晶型及形貌和晶粒度的影响。实验结果表明 :四氯化钛溶液水热合成二氧化钛对硫酸根离子、磷酸根离子和氟离子极其敏感 ,不添加时结晶相全部为金红石 ,当溶液中对应酸浓度达到约 0 .0 0 7mol/L时 ,开始出现部分锐钛矿相 ,当添加量达到 0 .0 2mol/L时 ,结晶相即全部变为锐钛矿相。氯离子、硼酸根离子和硝酸根离子不影响结晶晶型 ,仅稍稍影响结晶形貌。根据这一结果 ,通过一系列实验研究 ,可以任意控制水热产物中金红石相和锐钛矿相比例。最后 ,从晶体生长过程及生长机理的角度初步讨论了氧化钛同质变体的形成机理及阴离子影响晶型形成的机制。
Titanium dioxide is a promising nanopowder material. In this paper, 1mol / L aqueous solution of titanium tetraoxide as a precursor, a different type of anionic titanium dioxide hydrothermal synthesis experiment. The crystal phase and crystal morphology of the product were characterized by means of XRD and TEM, respectively. The effects of different addition amount of sulfate, nitrate, chloride, fluoride, borate and phosphate on the reaction of titanium dioxide micro Crystalline crystal powder crystal morphology and morphology and grain size. The experimental results show that the titanium tetrachloride hydrothermal synthesis of titanium dioxide is extremely sensitive to sulfate ion, phosphate ion and fluoride ion. When the crystal phase is not added, all of the crystal phase is rutile. When the corresponding acid concentration in the solution reaches about 0.0707 mol / L, part of the anatase phase began to appear. When the addition amount reached 0. 02mol / L, the crystalline phase became all anatase phase. Chloride, borate and nitrate ions do not affect the crystalline form, but affect the crystalline morphology only slightly. Based on this result, through a series of experimental studies, the ratio of rutile phase to anatase phase in the hydrothermal product can be arbitrarily controlled. Finally, the formation mechanism of titanium oxide homogenous variants and the mechanism by which anions affect the crystal formation are discussed preliminarily from the perspective of crystal growth and growth mechanism.