Synthesis of silver-gold-platinum and silver-paladium-platinum trimetallic nanoshells for catalytic applications

• Grant number: 13/14812-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2013
• End date: July 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Pedro Henrique Cury Camargo
• Grantee: Bruna Wadt Farini
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This proposal focuses on the development of multimetallic nanostructures with hollow interiors displaying well-defined and controllable size, shape and composition. In particular, we are interested in the synthesis of nanoshells composed of silver-gold-platinum (Ag-AuPt), silver-palladium-platinum (Ag-PdPt) for applications in catalysis. The first part of this work will address the synthesis of uniform Ag nanospheres 20-40 nm in diameter. In the second stage of this project, the Ag nanospheres will be employed as sacrificial templates in the galvanic replacement reaction with ions AuCl4-, PtCl62-, and/or PdCl42- to produce the corresponding Ag-AuPt and Ag-PdPt nanoshells. In the last stage of this proposal, the catalytic activity of the Ag-AuPt and Ag-PdPt nanoshells will be evaluated as a function of their size, composition and structure (solid vs. hollow interiors). To this end, we will employ the reduction of 4-nitrophenol as a model reaction. As the galvanic replacement reaction enables one to fine-tune the composition (by controlling the molar ratio between Ag and the metal ion precursor during the reaction) and also to obtain hollow interiors (that provide higher surface areas as compared to their solid counterparts), the strategies proposed herein represent a simple, versatile and promising alternative to produce a wealth of nanomaterials with controlled properties for plasmonics and catalysis applications.