Open Access Nano Express

In Situ Generation of Two-Dimensional Au–Pt Core–Shell Nanoparticle Assemblies

Madiha Khalid, Natalie Wasio, Thomas Chase and Krisanu Bandyopadhyay*

Author Affiliations

Department of Natural Sciences, University of Michigan—Dearborn, 4901 Evergreen Road, Dearborn, MI, 48128, USA

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Nanoscale Research Letters 2009, 5:61-67  doi:10.1007/s11671-009-9443-2

Published: 14 October 2009

Abstract

Two-dimensional assemblies of Au–Pt bimetallic nanoparticles are generated in situ on polyethyleneimmine (PEI) silane functionalized silicon and indium tin oxide (ITO) coated glass surfaces. Atomic force microscopy (AFM), UV–Visible spectroscopy, and electrochemical measurements reveal the formation of core–shell structure with Au as core and Pt as shell. The core–shell structure is further supported by comparing with the corresponding data of Au nanoparticle assemblies. Static contact angle measurements with water show an increase in hydrophilic character due to bimetallic nanoparticle generation on different surfaces. It is further observed that these Au–Pt core–shell bimetallic nanoparticle assemblies are catalytically active towards methanol electro-oxidation, which is the key reaction for direct methanol fuel cells (DMFCs).

Keywords:
Au–Pt; Bimetallic; Core–shell; Nanoparticle; Cyclic voltammetry; Atomic force microscopy