Controlled-Synthesis, Self-Assembly Behavior, and Surface-Dependent Optical Properties of High-Quality Rare-Earth Oxide Nanocrystals

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• 作者：Rui Si ; Ya-Wen Zhang ; Huan-Ping Zhou ; Ling-Dong Sun ; Chun-Hua Yan
• 刊名：Chemistry of Materials
• 出版年：2007
• 出版时间：January 9, 2007
• 年：2007
• 卷：19
• 期：1
• 页码：18 - 27
• 全文大小：1246K
• 年卷期：v.19,no.1(January 9, 2007)
• ISSN：1520-5002

文摘

Single-crystalline and monodisperse cubic rare-earth (RE = La to Lu, Y) oxide nanocrystals (ultrathinnanoplates and nanodisks) have been synthesized via a nonhydrolytic approach in oleic acid (OA)/oleylamine (OM)/1-octadecene (ODE) using various rare-earth complexes, including acetylacetonate,benzoylacetonate, and acetate, as the precursors. The transformation from the complex precursors toRE₂O₃ was proposed to occur in two stages: first, the formation of rare-earth oleates by ligand exchangein solution, and second, the subsequent decomposition of the oleates into RE₂O₃ catalyzed by the baseof OM. The selective adsorption of coordinating OA ligands onto specific crystal planes of cubic RE₂O₃nanocrystals made them adopt a plate shape with the confined growth of {100} facets and/or a diskshape with the confined growth of {111} facets. Along with delicately tuning the polarity of the dispersant,the RE₂O₃ nanocrystals could be aligned to form "side-to-side" or "face-to-face" self-assembly nanoarrayson carbon-coated copper grids. With the developed synthetic method, we also obtained high-qualityluminescent Y₂O₃:Eu ultrathin nanodisks, which displayed strong surface-dependent, highly pure redemissions that were due to selective incorporation of Eu³⁺ ions in the surface of the nanodisks.