Synthesis of silver-gold, silver-platinum, and silver-palladium nanoshells for applications in catalysis

• Grant number: 11/19957-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2011
• End date: August 31, 2013
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Pedro Henrique Cury Camargo
• Grantee: Mariana Benetti Terra Cardoso
• 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 (Ag-Au), silver-palladium (Ag-Pd), and silver-platinum (Ag-Pt) for applications in catalysis. In the first part of this work, the synthesis and characterization of Ag nanospheres with diameters in the 40-60 nm range. In the second stage of this project, the Ag nanospheres will be employed as sacrificial templates in the galvanic replacement reaction with ions AuCl4-, PdCl42-, or PtCl62- in order to produce the corresponding Ag-Au, Ag-Pd, and Ag-Pt hollow nanostructures (nanoshells). In the last stage of this proposal the Ag-Au, Ag-Pd e Ag-Pt nanoshells will be applied in catalysis. 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 nanoshells with controlled properties for catalysis applications.(AU)