Synthesis of Zinc and Lead Chalcogenide Core and Core/Shell Nanoplatelets Using Sequential Cation Exchange Reactions

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• 作者：C茅cile Bouet ; Donatien Laufer ; Benoit Mahler ; Brice Nadal ; Hadrien Heuclin ; Silvia Pedetti ; Gilles Patriarche ; Benoit Dubertret
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：May 13, 2014
• 年：2014
• 卷：26
• 期：9
• 页码：3002-3008
• 全文大小：385K
• 年卷期：v.26,no.9(May 13, 2014)
• ISSN：1520-5002

文摘

We present the synthesis of a novel type of chalcogenide nanoplatelets. Starting from CdS core or CdSe/CdS core/shell nanoplatelets, we use sequential cation exchange to copper and then to either zinc or lead to obtain ZnS and PbS core or ZnSe/ZnS and PbSe/PbS core/shell structures. The procedure preserves well the 2D geometry of the nanoplatelets, provided that they are more than 6 monolayers (1.8 nm) thick. The core/shell structure is also well conserved during the cation exchange as verified by TEM images. The nanoplatelets exchanged with Zn crystallize in a zinc blende structure, like the initial Cd-based material, whereas when Pb is used, the final nanoplatelets have a rock-salt crystal structure. We explored the copper cation exchange process using energy dispersive X-ray spectrometry with 1 nm resolution on nanoplatelets standing on their edges, and we show that copper ions diffuse uniformly from the outside of the nanoplatelet to the inside during the exchange.