Xie J, Yang X, Han B, Shao-Horn Y, Wang D. Site-selective deposition of twinned platinum nanoparticles on TiSi2 nanonets by atomic layer deposition and their oxygen reduction activities.
ACS NANO 2013;
7:6337-6345. [PMID:
23795615 DOI:
10.1021/nn402385f]
[Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
For many electrochemical reactions such as oxygen reduction, catalysts are of critical importance, as they are often necessary to reduce reaction overpotentials. To fulfill the promises held by catalysts, a well-defined charge transport pathway is indispensable. Presently, porous carbon is most commonly used for this purpose, the application of which has been recently recognized to be a potential source of concern. To meet this challenge, here we present the development of a catalyst system without the need for carbon. Instead, we focused on a conductive, two-dimensional material of a TiSi2 nanonet, which is also of high surface area. As a proof-of-concept, we grew Pt nanoparticles onto TiSi2 by atomic layer deposition. Surprisingly, the growth exhibited a unique selectivity, with Pt deposited only on the top/bottom surfaces of the nanonets at the nanoscale without mask or patterning. Pt {111} surfaces are preferably exposed as a result of a multiple-twinning effect. The materials showed great promise in catalyzing oxygen reduction reactions, which is one of the key challenges in both fuel cells and metal air batteries.
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