高等学校化学学报 ›› 2018, Vol. 39 ›› Issue (11): 2372.doi: 10.7503/cjcu20180300

• 研究论文:无机化学 • 上一篇    下一篇

离子液体辅助水热法合成六方片状γ-Al2O3

雷璇璇, 唐韶坤(), 李林, 孙丽伟   

  1. 天津大学化工学院, 绿色合成与转化教育部重点实验室, 天津化学化工协同创新中心, 天津 300354
  • 收稿日期:2018-04-17 出版日期:2018-11-10 发布日期:2018-06-04
  • 作者简介:联系人简介: 唐韶坤, 女, 博士, 教授, 主要从事功能材料的合成与应用研究. E-mail: shktang@tju.edu.cn
  • 基金资助:
    中国石油科技创新基金(批准号: 2013D-5006-0402)资助.

Controllable Synthesis of γ-Al2O3 Hexagonal Nanoplates with Ionic Liquids as the Template

LEI Xuanxuan, TANG Shaokun*(), LI Lin, SUN Liwei   

  1. Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering & Technology, Collaborative Innovation Center of Chemical Center of Chemical Science and Engineering(Tianjin), Tianjin University, Tianjin 300354, China
  • Received:2018-04-17 Online:2018-11-10 Published:2018-06-04
  • Contact: TANG Shaokun E-mail:shktang@tju.edu.cn
  • Supported by:
    † Supported by the PetroChina Innovation Foundation(No.2013D-5006-0402).

摘要:

采用离子液体辅助水热法, 以氯化铝为铝源, 正丁胺为沉淀剂, 离子液体1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4)为模板, 合成了具有特殊晶面取向的六方片状γ-Al2O3介孔材料, 并通过X射线衍射(XRD)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 傅里叶变换红外光谱(FTIR)以及N2等温吸-脱附等方法对产物进行了表征. 结果表明, 离子液体的加入改变了前驱体的晶相组成, 通过调节[Bmim]BF4的用量能够促使前驱体从γ-AlOOH向三水铝石与督三水铝石混合晶相进行相转变, 经过高温焙烧形成相应的氧化铝产物, 最终实现氧化铝从菱形纳米片向六方纳米片的结构转变. 当[Bmim]BF4与铝源的摩尔比为0.15时, 160 ℃下反应24 h能够获得形貌均匀且规整的六方片状γ-Al2O3, 其平均粒径约为600 nm, 厚度为200 nm, 上下基底面为{111}晶面族, 侧面由{110}晶面族组成. 相比于无模板作用下得到的菱形纳米片, 六方片状γ-Al2O3具有更大的比表面积(203 m2/g)和孔径更为均一(4.2 nm)的介孔孔道. 本文还对离子液体控制合成介孔氧化铝的模板机理进行了研究.

关键词: 离子液体, 模板, 氧化铝, 六方纳米片, 可控合成

Abstract:

γ-Al2O3 hexagonal nanoplates with unique crystal orientations were synthesized via an ionic liquid-assisted hydrothermal method using aluminum chloride as the aluminum source, n-butylamine as the precipitant and [Bmim]BF4 as the template. The synthesized products were characterized by means of X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FTIR) and N2 isothermal adsorption-desorption. The results suggested that the crystalline phase of the precursors could be changed with the addition of ionic liquid. By adjusting the content of [Bmim]BF4, the precursors could be transformed from γ-AlOOH to the mixture of gibbsite and diopside. The final alumina products were obtained after high temperature calcination and the structural transformation of alumina from rhombohedral nanosheets to hexagonal nanoplates were achieved. The well-defined γ-Al2O3 hexagonal nanoplates with average diameter of 600 nm and thickness of 200 nm were finally formed after reaction at 160 ℃ for 24 h when the molar ratio of [Bmim]BF4 to aluminum source was 0.15, and their exposed facets consisted of {111} planes as basal surfaces and {110} planes as lateral surfaces. Compared with the rhombohedral nanosheets prepared without [Bmim]BF4 template, the obtained hexagonal nanoplatests possessed relatively larger specific surface area(203 m2/g) and more uniform mesoporous structure(4.2 nm). Meanwhile, the template effect of [Bmim]BF4 on the controllable synthesis of γ-Al2O3 hexagonal nanoplates was investigated in detail.

Key words: Ionic liquid, Template, Alumina, Hexagonal nanoplate, Controllable synthesis

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