Soft-chemical exfoliation route to layered cobalt oxide monolayers and its application for film deposition and nanoparticle synthesis

Tae Woo Kim, Eun Jin Oh, Ah Young Jee, Seung Tae Lim, Dae Hoon Park, Minyung Lee, Sang Hoon Hyun, Jin Ho Choy, Seong Ju Hwang

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A colloidal suspension of exfoliated, layered cobalt oxide nanosheets has been synthesized through the intercalation of quaternary tetramethylammonium ions into protonated lithium cobalt oxide. According to atomic force microscopy, exfoliated nanosheets of layered cobalt oxide show a plateau-like height profile with nanometer-level height, underscoring the formation of unilamellar 2D nanosheets. The exfoliation of layered cobalt oxide was cross-confirmed by X-ray diffraction, UV/Vis spectroscopy, and transmission electron microscopy. The maintenance of the hexagonal inplane structure of the cobalt oxide lattice after the exfoliation process was evidenced by selected-area electron diffraction and Co K-edge X-ray absorption near-edge structure analysis. The zeta-potential measurements clearly demonstrated the negative surface charge of cobalt oxide nanosheets. Adopting the nanosheets of layered cobalt oxide as a precursor, we were able to prepare the monodisperse CoO nanocrystals with a particle size of ≈ 10 nm as well as the heterolayered film composed of cobalt oxide monolayer and polycation.

Original languageEnglish
Pages (from-to)10752-10761
Number of pages10
JournalChemistry - A European Journal
Issue number41
Publication statusPublished - 2009 Oct 19


All Science Journal Classification (ASJC) codes

  • Catalysis
  • Organic Chemistry

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