水热法制备纳米二氧化钒粉体

Hydrothermal Synthesis of Nano Vanadium Oxide Powder

以五氧化二钒和无水亚硫酸钠为原料,采用水热法制备纳米VO2粉体。系统地探讨了p H、填充度、反应温度、无水亚硫酸钠用量对VO2产品制备工艺的影响,采用化学法、X射线衍射仪(XRD)、扫瞄电子显微镜(SEM)和差示热扫描仪(DSC)对产品的价态、物相、形貌进行了分析。结果表明,在p H=3、填充度为0.7、物质的量比为n(V2O5)∶n(Na2SO3)=1∶1.2、温度250℃下水热反应24 h,所得到的初产品经氢氧化钠溶液纯化1 h后,质量分数达到98.5%,总产率为85.4%。产品为纯度高的B相VO2,经800℃热处理2 h后由B相转变为M相,热处理后产品的相变点为69.0℃。

Vanadium oxides were synthesized by hydrothermal synthesis with vanadium pentoxide（V2O5） and sodium sulfite anhydrous（Na2SO3） as raw materials.The effects of p H,fullness,reaction temperature and sodium sulfite anhydrous content on the preparation process of vanadium oxides were studied systematically.The valence,phase and morphology of vanadium oxides were analyzed by chemical titration,X-ray diffraction（XRD）,scanning electron microscopy（SEM） and differential scanning calorimetry（DSC）.The results showed that the content of vanadium oxides could reach98.5% and the total yield could reach 85.4% when the p H was 3,fullness was 0.7,reaction temperature was 250 ℃ and n（V2O5） ∶n（Na2SO3） was 1∶1.2.In addition,the obtained B phase can transfer to M phase showing a transformation temperature of 69.0 ℃ after a calcination procedure for 2hours at 800 ℃.