On the stabilization of gold nanoparticles over silica-based magnetic supports modified with organosilanes

Rafael L Oliveira; Daniela Zanchet; Pedro K Kiyohara; Liane M Rossi

doi:10.1002/chem.201002251

On the stabilization of gold nanoparticles over silica-based magnetic supports modified with organosilanes

Chemistry. 2011 Apr 11;17(16):4626-31. doi: 10.1002/chem.201002251. Epub 2011 Feb 24.

Authors

Rafael L Oliveira¹, Daniela Zanchet, Pedro K Kiyohara, Liane M Rossi

Affiliation

¹ Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748 São Paulo, 05508-000 São Paulo, Brazil.

PMID: 21360597
DOI: 10.1002/chem.201002251

Abstract

The immobilization of gold nanoparticles (Au NPs) on silica is made possible by the functionalization of the silica surfaces with organosilanes. Au NPs could only be stabilized and firmly attached to silica-support surfaces that were previously modified with amino groups. Au NPs could not be stabilized on bare silica surfaces and most of the NPs were then found in the solution. The metal-support interactions before and after the Au NP formation, observed by X-ray absorption fine structure spectroscopy (XAFS), indicate a stronger interaction of gold(III) ions with amino-modified silica surfaces than with the silanol groups in bare silica. An amino-modified, silica-based, magnetic support was used to prepare an active Au NP catalyst for the chemoselective oxidation of alcohols, a reaction of great interest for the fine chemical industry.