A method to prepare a core-shell structure consisting of a Pt metal core coated with a silica shell (Pt(in)SiO 2) is described herein. A silica shell was grown on poly(vinylpyrrolidone) (PVP)-stabilized Pt nanoparticles 2-3 nm in size through hydrolysis and condensation reactions of tetraethyl orthosilicate (TEOS) in a water/ethanol mixture with ammonia as a catalyst. This process requires precise control of the reaction conditions to avoid the formation of silica particles containing multiple Pt cores and core-free silica. The length of PVP molecules, water content, concentration of ammonia and Pt nanoparticles in solution were found to significantly influence the core-shell structure. By optimizing these parameters, it was possible to prepare core-shell particles each containing a single Pt nanoparticle with a silica layer coating approximately 10 nm thick.
Bibliographical noteFunding Information:
This work was supported by the following: the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 20104010100500 ); the Priority Research Centers Program through the National Research Foundation of Korea (2009-0093823); the National Research Foundation of Korea (NRF-2009-C1AAA001-0092926) funded by the Ministry of Education, Science and Technology .
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)