Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium).
Angew Chem Int Ed Engl. 2014 Apr 7;53(15):3970-4. doi: 10.1002/anie.201309288. Epub 2014 Mar 5.
Gold-silica hybrids are appealing in different fields of applications like catalysis, sensorics, drug delivery, and biotechnology. In most cases, the morphology and distribution of the heterounits play significant roles in their functional behavior. Methods of synthesizing these hybrids, with variable ordering of the heterounits, are replete; however, a complete characterization in three dimensions could not be achieved yet. A simple route to the synthesis of Au-decorated SiO2 spheres is demonstrated and a study on the 3D ordering of the heterounits by scanning transmission electron microscopy (STEM) tomography is presented-at the final stage, intermediate stages of formation, and after heating the hybrid. The final hybrid evolves from a soft self-assembled structure of Au nanoparticles. The hybrid shows good thermal stability up to 400 °C, beyond which the Au particles start migrating inside the SiO2 matrix. This study provides an insight in the formation mechanism and thermal stability of the structures which are crucial factors for designing and applying such hybrids in fields of catalysis and biotechnology. As the method is general, it can be applied to make similar hybrids based on SiO2 by tuning the reaction chemistry as needed.
金-硅杂化物在催化、传感、药物输送和生物技术等不同应用领域具有吸引力。在大多数情况下，杂合体的形态和分布对其功能行为起着重要作用。具有可变杂合体排序的这些杂化物的合成方法很多，但尚未实现完整的三维特性描述。本文展示了一种简单的 Au 修饰的 SiO2 球的合成途径，并通过扫描透射电子显微镜（STEM）层析术研究了杂合体的三维有序性——在最终阶段、形成的中间阶段以及对杂化物进行加热之后。最终的杂化物由 Au 纳米颗粒的软自组装结构演变而来。该杂化物在高达 400°C 的温度下表现出良好的热稳定性，超过此温度后，Au 颗粒开始在 SiO2 基质内迁移。本研究提供了对结构形成机制和热稳定性的深入了解，这对于设计和应用于催化和生物技术领域的此类杂化物至关重要。由于该方法具有通用性，因此可以通过根据需要调整反应化学来制备基于 SiO2 的类似杂化物。
