硼酸铝纳米棒的制备、结构及生长机理

以仲丁醇铝和硼酸为原料, 葡萄糖作模板剂, 在水介质中120 ℃形成淡黄色干凝胶, 再于750 ℃焙烧得到尺寸均一的硼酸铝纳米棒. 通过改变仲丁醇铝/硼酸的摩尔比实现了对产物形貌及长径比的控制合成. 采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)对产物结构和形貌进行表征. 结果表明产物为Al4B2O9纳米棒, 直径为15-45 nm, 长度为100-300 nm. 根据表征结果对葡萄糖参与的硼酸铝纳米棒的生长机理进行了探讨. 结果表明, 葡萄糖与硼酸反应产生网状结构的配合物, 同时释放质子, 促使铝源均匀地分散在网格间, 为硼酸铝的生成提供一有利的反应空间. 纳米棒的生长为自催化生长过程, 在750 ℃热处理时沿着(100)面方向生长.

Synthesis, Structure and Growth Mechanism of Aluminum Borate Nanorods

Aluminum borate (AL_4B_2O_9) nanorods were synthesized by the sol-gel method using aluminum tri-sec butoxide(ATSB) and boric acid (H_3BO_3) as reactants as well as glucose as the template. The length and diameter of the nanorods were controlled by adjusting the molar ratio of ATSB/H_3BO_3. The diameters of the nanorods were in the range of 15-45 nm and the lengths were in the range of 100-300 nm. The structures and morphologies of the synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A self-catalytic growth mechanism for these Al_4B_2O_9 nanorods is proposed according to the characterization results. In aqueous solutions, complex network structures are formed after glucose and boric acid react. The aluminum is well dispersed in the network. The nanorods crystal growth occurs along the (100) direction during the calcination at 750 ℃.