The precise synthesis and growth of core-shell nanoparticles within a self-assembled spherical template.
The precise synthesis and growth of core-shell nanoparticles within a self-assembled spherical template.
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DOI：
10.1002/anie.201006965
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发表时间：
2011-05
影响因子：
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通讯作者：
Kosuke Suzuki;K. Takao;Sota Sato;M. Fujita
中科院分区：
文献类型：
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作者：
Kosuke Suzuki;K. Takao;Sota Sato;M. Fujita
具有核-壳结构的纳米粒子具有独特的材料性质，在材料科学、光学、催化和生物物理等领域有着广泛的应用前景。[1-11]核-壳纳米颗粒的精确合成至关重要，因为材料性质取决于纳米颗粒的组成元素以及尺寸和形状。核-壳纳米颗粒的合成通常通过在溶液中用金属离子或金属醇盐涂覆核纳米颗粒的表面来进行，其中核纳米颗粒和外壳的受控生长通过调节合成条件（例如，温度、浓度、溶剂和pH值）来实现。然而，制备高度单分散的核纳米颗粒和随后的核-壳纳米颗粒仍然是困难的。最近，几个小组已经利用中空组件和介质，如反胶束，来控制核壳纳米颗粒的生长，其中中空内部充当模板。[12-14]不幸的是，模板组装本身不是单分散的，因此纳米颗粒生长的精确控制仍然是难以捉摸的。此外，模板组装体的大尺寸阻碍了小尺寸（< 10 nm）核壳纳米粒子的合成。最近，我们发表了利用结构精确的配位球作为模板合成单分散SiO2纳米粒子的研究。[15]M12 L2 - 4球由12个Pd 2+离子（M）和2 - 4个弯曲的桥接配体（L）自组装[15-21]，并呈现出糖衣内部，其使用烷氧基硅烷的溶胶-凝胶缩合精确合成直径为2-4 nm的高度单分散SiO2纳米颗粒。在本文中，我们描述了限制在具有金属氧化物（MO 2;其中M= Ti或Zr）层的模板球体内的单分散SiO2纳米颗粒的制备，以产生单分散核-壳纳米颗粒（图1）。核-壳
Nanoparticles with core–shell structures can exhibit unique material properties and promise a variety of applications in materials science, optics, catalysis, and biophysics.[1–11] The precise synthesis of core–shell nanoparticles is of utmost importance as the material properties depend on the constituent elements as well as the size and shape of the nanoparticles. The synthesis of core–shell nanoparticles is typically carried out by coating the surface of the core nanoparticles with metal ions or metal alkoxides in solution, where the controlled growth of the core nanoparticles and the outer shells is achieved by modulating the synthetic conditions (eg, temperature, concentration, solvent, and pHvalue). However, the preparation of both the highly monodisperse core nanoparticles and the subsequent core–shell nanoparticles remains difficult. Recently, several groups have utilized hollow assemblies and media, such as reverse micelles, to control the growth of core–shell nanoparticles, in which the hollow interior acts as a template.[12–14] Unfortunately, the templating assemblies are themselves not monodisperse and thus the precise control of nanoparticle growth remained elusive. Furthermore, the large size of the template assemblies precludes the synthesis of small (< 10 nm) core–shell nanoparticles.Recently we published the synthesis of monodisperse SiO2 nanoparticles using structurally exact coordination spheres as templates.[15] The M12L24 spheres self-assembled from 12 Pd2+ ions (M) and 24 bent bridging ligands (L)[15–21] and presented a sugar-coated interior that templated the precise synthesis of highly monodisperse SiO2 nanoparticles with diameters of 2–4 nm using the sol-gel condensation of alkoxysilanes. Herein, we describe the elaboration of monodisperse SiO2 nanoparticles confined within the template sphere with a metal oxide (MO2; where M= Ti or Zr) layer to generate monodisperse core–shell nanoparticles (Figure 1). The core–shell