Fabrication of electrodes with ultralow platinum loading by RF plasma processing of self-assembled arrays of Au@Pt nanoparticles

Banerjee, Ipshita and Kumaran, V and Santhanam, Venugopal (2016) Fabrication of electrodes with ultralow platinum loading by RF plasma processing of self-assembled arrays of Au@Pt nanoparticles. In: NANOTECHNOLOGY, 27 (30).

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Abstract

Conductive, carbon-free, electrocatalytically active, nanostructured electrodes with ultra-low platinum loading were fabricated using self-assembly of octadecanethiol-coated Au@Pt nanoparticles followed by RF plasma treatment. Bilayer arrays of Au@Pt nanoparticles with platinum loadings of 0.50, 1.04, 1.44, and 1.75 mu g cm(-2) (corresponding to 0.5, 1, 1.5 and 2 atomic layer coverage of platinum on nominally 5 nm gold core) were subjected to RF argon plasma treatment for various durations and their electrical conductivity, morphological evolution, and electrocatalytic activity characterized. Samples with monolayer and above platinum coverages exhibit maximum electrochemically active surface areas values of similar to 100 m(2)/g(pt) and specific activities that are similar to 4x to 6x of a reference platinum nanoparticle bilayer array. The underlying gold core influences the structural evolution of the samples upon RF plasma treatment and leads to the formation of highly active Pt(110) facets on the surface at an optimal plasma treatment duration, which also corresponds to the onset of a sharp decline in lateral sheet resistance. The sample having a two atom thick platinum coating has the highest total mass activity of 48 +/- 3 m(2)/g((pt+au)), corresponding to 44% Pt atom utilization, while also exhibiting enhanced CO tolerance as well as high methanol oxidation reaction and oxygen reduction reaction activity.

Item Type:	Journal Article
Publication:	NANOTECHNOLOGY
Publisher:	IOP PUBLISHING LTD
Keywords:	Au@Pt nanoparticles; ECSA; self-assembly; RF plasma treatment
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	17 Aug 2016 04:00
Last Modified:	17 Aug 2016 04:00
URI:	http://eprints.iisc.ac.in/id/eprint/54257

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