W掺杂二氧化钒的水热晶化机理及其相变性能

发布时间：2018-04-30 22:03

本文选题：二氧化钒 + 水热合成　；参考：《材料工程》2017年11期

【摘要】：以硫酸氧钒为钒源,采用沉淀-胶溶法制备VO_2溶胶。然后向溶胶中加入偏钒酸铵,利用溶胶水热晶化制备出W掺杂二氧化钒(W-VO_2,M相)粉体。通过XRD,FESEM和DSC对合成产物的物相组成、形貌和相变性能进行研究。结果表明:在280℃条件下水热处理4~48h,VO_2溶胶经过水热晶化生成长约1~2μm、直径约100~200nm棒状W-VO_2(B)晶体,伴随着B相向M相晶型转变,W-VO_2(B)逐渐消溶,而W-VO_2(M)逐渐长大,形貌由棒状转变为片状或雪花状;W-VO_2(M)相变温度随着W掺杂量增加而降低,当名义掺杂量为6.0%(原子分数)时,相变温度降低到28℃。根据水热晶化和形貌演变过程,提出了W-VO_2(M)可能的"形核-生长-转化-熟化"形成机理。
[Abstract]:The VO_2 sol was prepared by precipitation colloidal solution method with vanadium sulfate as vanadium source. Then ammonium vanadate was added to the sol and W doped two vanadium oxide (W-VO_2, M phase) powders were prepared by sol hydrothermal crystallization. The phase composition, morphology and phase transition properties of the synthesized products were studied by XRD, FESEM and DSC. The results showed that the heat of the water was at 280 C. 4~48h, VO_2 sol grows about 1~2 mu m with a diameter of about 1~2 micron, with a diameter of about 100~200nm bar like W-VO_2 (B) crystal. With the transformation of B phase to M phase crystal, W-VO_2 (B) gradually dissolves, while W-VO_2 gradually grows, the morphology changes from rod like to flake or snowflake; When the atomic fraction), the phase transition temperature is reduced to 28. The possible formation mechanism of W-VO_2 (M) "nucleation growth transformation and maturation" is proposed based on the crystallization and morphologies of the hydrothermal crystallization.

【作者单位】：北京科技大学材料科学与工程学院;解放军306医院口腔科;北京科技大学天津学院;
【基金】：国家重点研究发展计划资助项目(2016YFC0700901,2016YFC0700607)
【分类号】：TQ135.11

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