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Synthesis of Nanohole‐Structured Single‐Crystalline Platinum Nanosheets Using Surfactant‐Liquid‐Crystals and their Electrochemical Characterization
Author(s) -
Kijima Tsuyoshi,
Nagatomo Yu,
Takemoto Hirokatsu,
Uota Masafumi,
Fujikawa Daisuke,
Sekiya Yuzo,
Kishishita Teppei,
Shimoda Makoto,
Yoshimura Takumi,
Kawasaki Hideya,
Sakai Go
Publication year - 2009
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200800966
Subject(s) - materials science , chemical engineering , nanostructure , platinum , electrochemistry , nanotechnology , crystallography , electrode , catalysis , organic chemistry , chemistry , engineering
Nanohole‐structured single‐crystalline Pt nanosheets have been synthesized by the borohydride reduction of Na 2 PtCl 6 confined to the lyotropic liquid crystals (LLCs) of polyoxyethylene (20) sorbitan monooleate (Tween 80) with or without nonaethylene‐glycol (C 12 EO 9 ). The Pt nanosheets of around 4–10 nm in central thickness and up to 500 nm or above in diameter have a number of hexagonal‐shaped nanoholes ∼1.8 nm wide. High‐resolution electron microscope images of the nanosheets showed atomic fringes with a spacing of 0.22 nm indicating that the nanosheets are crystallographically continuous through the nanoholed and non‐holed areas. The inner‐angle distributions for the hexagonal nanoholes indicate that the six sides of the nanoholes are walled with each two Pt (111), Pt (1 ${\bar {1}}$ 1) and Pt (010) planes. The formation mechanism of nanoholed Pt nanosheets is discussed on the basis of structural and compositional data for the resulting solids and their precursory LLCs, with the aid of similar nanohole growth observed for a Tween 80 free but oleic acid‐incorporated system. It is also demonstrated that the nanoholed Pt nanostructures loaded on carbon exhibit fairly high electrocatalytic activity for oxygen reduction reaction and a high performance as a cathode material for polymer‐electrolyte fuel cells, along with their extremely high thermostability revealed through the effect of electron‐irradiation.