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以草酸和V_2O_5为原料,采用水热法制备VO_2(B)。通过高温原位X射线衍射技术研究VO_2(B)在氮气保护下升高温度过程中的相变特性,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)和激光拉曼光谱技术分析所制备样品及其在不同温度热相变产物的微观形貌、晶体结构和物相组成。结果表明:以草酸和V_2O_5为原料,用水热法可制得单斜晶系VO_2(B),颗粒呈纳米片状;升温至430~700℃之间,VO_2(B)不可逆转化为四方晶系VO_2(R),形貌由纳米片状变为亚微米及微米近球形;升温至1000℃左右,VO_2(R)开始分解形成Magnéli相系列化合物(V_nO_(2n-1),3≤n≤9);升温至约1200℃完全转变为具有刚玉结构的V_2O_3烧结块。
Using oxalic acid and V_2O_5 as raw materials, hydrothermal method was used to prepare VO_2 (B). The phase transition behavior of VO_2 (B) during elevated temperature under nitrogen protection was investigated by high temperature in situ X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and laser Raman Spectroscopy analysis of the prepared samples and their thermal deformation at different temperatures, the microstructure, crystal structure and phase composition. The results show that monoclinic VO_2 (B) can be obtained by hydrothermal method using oxalic acid and V_2O_5 as raw materials, and the particles are in the form of nanosheets. When heated to 430 ~ 700 ℃, VO_2 (B) irreversibly transformed into tetragonal system VO_2 (R), the morphology changes from nanoflakes to submicron and near-spherical shape. When the temperature rises to about 1000 ℃, VO_2 (R) begins to decompose to form Magnéli phase compounds (V_nO_ (2n-1) ); Heating to about 1200 ℃ completely transformed into a corundum structure V_2O_3 agglomeration.