Chen Xing, Cai Quan, Wang Wei, Mo Guang, Jiang Longsheng, Zhang Kunhao, Chen Zhongjun, Wu Ziyu, Wu Zhonghua
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing, China.
J Phys Chem B. 2008 Oct 2;112(39):12297-303. doi: 10.1021/jp803407a. Epub 2008 Sep 6.
Mesostructured germanium oxide has been well-synthesized by using a surfactant-templated approach under basic hydrothermal conditions. The cationic surfactant cetyltrimethylammonium bromide (CTAB) has formed nanotubes with uniform diameter of about 3.2 nm. Blanket-like morphology of the as-prepared sample has been observed with transmission electron microscopy (TEM). High-resolution TEM image reveals that the nanotubes are connected with inorganic germanium oxide and have self-assembled into periodic mesostructure. In-situ heating X-ray diffraction (XRD) patterns confirm that the germanium oxide is in amorphous phase in the temperature range from room temperature (RT) to 700 degrees C. In-situ heating small-angle X-ray scattering (SAXS) presents the mesostructural change with temperature. The local atomic structures around germanium atom have been obtained with in-situ heating X-ray adsorption fine structure (XAFS) techniques. The stability of this mesostructure has been determined to be correlated with the cationic surfactant CTAB. The structural evolution from the GeO 2/NaOH aqueous solution, the as-prepared sample to the sample heated at 700 degrees C, has been described, and the formation mechanism of mesostructured germanium oxide has been discussed.
通过在碱性水热条件下采用表面活性剂模板法，已成功合成了介孔结构的氧化锗。阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）形成了直径约为3.2 nm的均匀纳米管。用透射电子显微镜（TEM）观察到所制备样品的毯状形态。高分辨率TEM图像显示，纳米管与无机氧化锗相连，并自组装成周期性介孔结构。原位加热X射线衍射（XRD）图谱证实，在从室温（RT）到700摄氏度的温度范围内，氧化锗处于非晶相。原位加热小角X射线散射（SAXS）呈现了介孔结构随温度的变化。利用原位加热X射线吸收精细结构（XAFS）技术获得了锗原子周围的局部原子结构。已确定这种介孔结构的稳定性与阳离子表面活性剂CTAB相关。描述了从GeO₂/NaOH水溶液、所制备样品到在700摄氏度加热的样品的结构演变，并讨论了介孔结构氧化锗的形成机理。
