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Hydrothermal Growth of Manganese Dioxide into Three‐Dimensional Hierarchical Nanoarchitectures
Author(s) -
Ding Y.S.,
Shen X.F.,
Gomez S.,
Luo H.,
Aindow M.,
Suib S. L.
Publication year - 2006
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.200500436
Subject(s) - materials science , manganese , template , paramagnetism , hydrothermal circulation , ferromagnetism , nanotechnology , fabrication , spintronics , nanostructure , single crystal , nanoscopic scale , morphology (biology) , crystal growth , crystal (programming language) , hexagonal crystal system , chemical engineering , crystallography , condensed matter physics , medicine , programming language , chemistry , physics , alternative medicine , pathology , biology , computer science , engineering , metallurgy , genetics
Novel three‐dimensional (3D) hierarchical nanoarchitectures of ϵ‐MnO 2 have been synthesized by a simple chemical route without the addition of any surfactants or organic templates. The self‐organized crystals consist of a major ϵ‐MnO 2 dipyramidal single crystal axis and six secondary branches, which are arrays of single‐crystal ϵ‐MnO 2 nanobelts. The growth directions of the nanobelts are perpendicular to the central dipyramidal axis, which shows sixfold symmetry. The shape of the ϵ‐MnO 2 assembly can be controlled by the reaction temperature. The morphology of ϵ‐MnO 2 changes from a six‐branched star‐like shape to a hexagonal dipyramidal morphology when the temperature is increased from 160 to 180 °C. A possible growth mechanism is proposed. The synthesized ϵ‐MnO 2 shows both semiconducting and magnetic properties. These materials exhibit ferromagnetic behavior below 25 K and paramagnetic behavior above 25 K. The ϵ‐MnO 2 system may have potential applications in areas such as fabrication of nanoscale spintronic materials, catalysis, and sensors.