掺杂VO_2(B)粉体的水热晶化动力学研究

Study on Crystallization Kinetic of Doped VO_2(B) Powder Prepared by Hydrothermal Method

采用水热法合成了一系列掺杂VO2（B）粉体,并利用XRD对产物的水热晶化过程进行了研究。研究结果表明：元素W和Mo是以W^6＋和Mo^6＋的形式替代了部分V^4＋的位置,与VO2（B）形成了固溶体。掺杂VO2（B）粉体的水热晶化过程是由V2O5·3H2O逐渐向晶体VO2（B）转变的自发成核过程,晶体的生长是速率控制步骤。在水热条件为100℃×4 h＋140℃×20 h＋180℃×（20-24 h）时,计算得到的掺杂VO2粉体的成核诱导期为18.7 h,表观成核速率为0.0535 h^-1,表观晶体生长速率为5.3 h-1。

The hydrothermal crystallization process of the products doped VO2（B） powders which was synthesized by hydrothermal method was characterized by XRD.The results show that the ionic of W^6＋ and Mo^6＋ incorporate into the VO2 lattice and form solid-solution phases with VO2.The crystallization is a spontaneous nucleation process from V2O5·3H2O to doped VO2（B） powder which the crystal growth process is the controlling step.The nucleation period is 18.7 h,the apparent nucleation rate of the crystals is 0.0535 h^-1 and the apparent growth rate of crystals is 5.3 h^-1 under the hydrothermal condition of 100 ℃×4 h＋140 ℃×20 h＋180 ℃×（20-24 h）.