Rostek A, Loza K, Heggen M, Epple M
Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen Universitätsstr. 5-7 45117 Essen Germany
Ernst Ruska-Center for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH 52425 Jülich Germany.
RSC Adv. 2019 Aug 27;9(46):26628-26636. doi: 10.1039/c9ra05117a. eCollection 2019 Aug 23.
A comparative X-ray powder diffraction study on poly(-vinyl pyrrolidone) (PVP)-stabilized palladium and gold nanoparticles and bimetallic Pd-Au nanoparticles (both types of core-shell nanostructures) was performed. The average diameter of Au and Pd nanoparticles was 5 to 6 nm. The two types of core-shell particles had a core diameter of 5 to 6 nm and an overall diameter of 7 to 8 nm, a shell thickness of 1 to 2 nm. X-ray powder diffraction on a laboratory instrument was able to distinguish between a physical mixture of gold and palladium nanoparticles and bimetallic core-shell nanoparticles. It was also possible to separate the core from the shell in both kinds of bimetallic core-shell nanoparticles due to the different domain size and because it was known which metal was in the core and which was in the shell. The spherical particles were synthesized by reduction with glucose in aqueous media. After purification by multiple centrifugation steps, the particles were characterized with respect to their structural, colloid-chemical, and spectroscopic properties, particle size, morphology, and internal elemental distribution. Dynamic light scattering (DLS), differential centrifugal sedimentation (DCS), atomic absorption spectroscopy (AAS), ultraviolet-visible spectroscopy (UV-vis), high-angle annular dark field imaging (HAADF), and energy-dispersed X-ray spectroscopy (EDX) were applied for particle characterization.
对聚乙烯吡咯烷酮（PVP）稳定的钯和金纳米颗粒以及双金属钯 - 金纳米颗粒（两种核壳纳米结构类型）进行了比较X射线粉末衍射研究。金和钯纳米颗粒的平均直径为5至6纳米。两种核壳颗粒的核直径为5至6纳米，总直径为7至8纳米，壳厚度为1至2纳米。在实验室仪器上进行的X射线粉末衍射能够区分金和钯纳米颗粒的物理混合物与双金属核壳纳米颗粒。由于不同的畴尺寸以及已知哪种金属在核中、哪种金属在壳中，在两种双金属核壳纳米颗粒中也能够将核与壳分离。通过在水介质中用葡萄糖还原合成球形颗粒。经过多次离心步骤纯化后，对颗粒的结构、胶体化学和光谱性质、粒径、形态以及内部元素分布进行了表征。应用动态光散射（DLS）、差示离心沉降（DCS）、原子吸收光谱（AAS）、紫外可见光谱（UV-vis）、高角度环形暗场成像（HAADF）和能量色散X射线光谱（EDX）对颗粒进行表征。
