title: Open-mouthed metallic microcapsules: exploring performance improvements at agglomeration-free interiors.
abstract: Although artificial capsule structures have been thoroughly investigated, functionality at the surfaces of their interiors has been surprisingly overlooked. In order to exploit this aspect of capsular structure, we here report the breakthrough fabrication of metallic (platinum) microcapsules with sufficient accessibility and electroactivity at both interior and exterior surfaces (open-mouthed platinum microcapsules), and also we demonstrate improvements in electrochemical and catalytic functions to emphasize the practical importance of our concept. The open-mouthed platinum microcapsules were prepared by template synthesis using polystyrene spheres, where surface-fused crystalline nanoparticles formed a capsule shell. Subsequent removal of the polystyrene spheres induced formation of mouth-like openings. The open-mouthed platinum microcapsules exhibit a substantial increase of their electrode capability for methanol oxidation and catalytic activities for carbon monoxide (CO) oxidation. Notably, activity loss during CO oxidation due to undesirable particle agglomeration can be drastically suppressed using the open-mouthed microcapsules.
authors.affiliation: WPI Center for Materials Nanoarchitectonics (MANA), National Institute For Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Saikat
authors.initials: S
authors.lastname: Mandal
authors.forename: Marappan
authors.initials: M
authors.lastname: Sathish
authors.forename: Govindachetty
authors.initials: G
authors.lastname: Saravanan
authors.forename: K K R
authors.initials: KK
authors.lastname: Datta
authors.forename: Qingmin
authors.initials: Q
authors.lastname: Ji
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Hill
authors.forename: Hideki
authors.initials: H
authors.lastname: Abe
authors.forename: Itaru
authors.initials: I
authors.lastname: Honma
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ariga
mesh_terms: D002248:Carbon Monoxide / Q000737:chemistry; D004563:Electrochemistry; D008670:Metals / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D010084:Oxidation-Reduction
chemical_list: D008670:Metals; D002248:Carbon Monoxide