Au(Ru)-SiO2纳米-微米复合粒子的制备及精细结构研究

在制备出高性能的Au(Ru)-SiO2纳米-微米复合粒子的基础上，使用高分辨透射电镜、电子探针和X-射线衍射等现代手段，研究了该复合粒子的精细结构。研究结果表明：所制备的纳米-微米复合粒子在结构上呈现类似天体星云式的多层次结构，可区分为三级，其中一级结构是在微米尺度上，该层次上的SiO2微粒是整个复合粒子的承载骨架，其粒度均匀，分散性好，这在一定程度上大大降低了其所包含的功能金、钌纳米粒子的团聚问题；二级结构是在纳米尺度上，观察发现，金、钌纳米粒子相对均匀地镶嵌在第一结构层次的SiO2微粒中，它们是整个材料的性能载体，对材料性能起决定作用，研究指出进一步适度降低第一层次的SiO2微粒的粒径有望进一步降低甚至消除其中金、钌纳米粒子间的团聚；三级结构为金、钌纳米晶粒的高分辨晶格像，表明纳米晶表面原子点阵存在畸变。研究还指出，在该纳米-微米复合粒子中，金属金、钌的纳米粒子是以机械混合形式存在，不形成合金，也不形成固溶体。

Preparation and Fine Structures of Au(Ru)-SiO2 Micro/nanocomposite particles

In this parer,Au(Ru)-SiO-2 micro/nano-particles were prepared by using sol-gel method.High resolution electron microscope(HRTEM),electron microprobe(EMP) and X-ray diffraction (XRD) were used to investigate their microstructures.Experimental results show that the material has a microstructure like nebulae,which involve three levels.The first level is in micro-scale observed by EMP showing that SiO-2 microparticles are the matrix of the functional Au and Ru nanoparticles.Au and Ru nanoparticles dispersed very well in SiO-2 matrix with a rather even diameter contribution,which was considered to be very important to solve the aggregation of the Au/Ru nanoparticles.The second level is in nano-scale observed by HRTEM indicating that Au/Ru nanopaticles were embodied relative evenly in the SiO-2 matrix with only slightly aggregation.Further decreasing the diameter of the SiO-2 microparticles matrix is expected to further inducing the aggregation of Au/Ru nanoparticles.The third level is in atomic scale indicating the atomic lattice of Au/Ru nanoparticles,showing that the lattice spacings in surface are different from the interplanar spacings.Moreover,Au and Ru nanoparticles were observed to be separately distributed in SiO-2 matrix,no alloy particles of Au and Ru were found.