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Formation and Thermal Stability of Gold–Silica Nanohybrids: Insight into the Mechanism and Morphology by Electron Tomography
Author(s) -
Kundu Paromita,
Heidari Hamed,
Bals Sara,
Ravishankar N.,
Van Tendeloo Gustaaf
Publication year - 2014
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201309288
Subject(s) - electron tomography , thermal stability , nanotechnology , materials science , transmission electron microscopy , characterization (materials science) , hybrid material , morphology (biology) , nanoparticle , hybrid , drug delivery , chemical engineering , catalysis , mechanism (biology) , spheres , thermal , chemical physics , scanning transmission electron microscopy , chemistry , organic chemistry , physics , thermodynamics , biology , botany , engineering , genetics , astronomy , quantum mechanics
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 SiO 2 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 SiO 2 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 SiO 2 by tuning the reaction chemistry as needed.