Raghu, S. and Nirmal, R.G. and Mathiyarasu, J. and Sheela, B. and Phani, K.L.N. and Yegnaraman, V. (2007) Platinum–Dendrimer Nanocomposite Films on Gold Surfaces for Electrocatalysis. Catal Lett, 119. pp. 40-49.

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Abstract

In this communication, we report a strategy for the preparation of Pt nanoparticles encapsulated in Generation 4.5 (Polyamido amine) PAMAM dendrimer and subsequent chemical linking of the nanocomposite to the gold electrode through a self assembled cystamine monolayer. The modification resulted in the formation of a robust electrochemically active thin film with very high surface area, reflected by the enhanced hydrogen adsorption coverage. Interestingly, TEM images revealed selfassembly of Pt nanoparticles and the SAED (Selected Area Electron Diffraction) patterns showed the presence of Pt single crystals (111). The Pt-dendrimer nanocomposite film obtained using the novel modification procedure exhibited high electrocatalytic activity for the oxidation of organic fuels like methanol, ethanol and ethylene glycol. The film did not suffer from degradation even after repeated use in solution-phase voltammetry. It is however observed that the intermediate SAM layer and the bulky PAMAM dendrimer (generation 4.5) have slowed down the electron transfer kinetics which is reflected by a relatively high overpotential for methanol oxidation. Nevertheless this shortcoming is more than compensated by the existence of Pt(111) planes, which alleviate CO poisoning.

Item Type:	Article
Uncontrolled Keywords:	Dendrimers; Platinum–dendrimer; nanocomposite; Electrocatalysis; Self-assembly; Cystamine; Template synthesis
Subjects:	Electrodics and Electrocatalysis
Divisions:	UNSPECIFIED
Depositing User:	ttbdar CECRI
Date Deposited:	29 Mar 2012 07:53
Last Modified:	29 Mar 2012 07:53
URI:	http://cecri.csircentral.net/id/eprint/580

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