In Situ Study of Fe3Pt鈥揊e2O3 Core鈥揝hell Nanoparticle Formation

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• 作者：Wen-I Liang ; Xiaowei Zhang ; Yunlong Zan ; Ming Pan ; Cory Czarnik ; Karen Bustillo ; Jun Xu ; Ying-Hao Chu ; Haimei Zheng
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：December 2, 2015
• 年：2015
• 卷：137
• 期：47
• 页码：14850-14853
• 全文大小：399K
• ISSN：1520-5126

文摘

We report an in situ study of Fe₃Pt-Fe₂O₃ core鈥搒hell nanoparticle growth using liquid cell transmission electron microscopy. By controlling the Fe-to-Pt ratio in the precursor solution, we achieved the growth of nanoparticles with the formation of an iron鈥損latinum alloy core followed by an iron oxide shell in the electron beam-induced reactions. There was no substantial change in the growth kinetics of the iron oxide shell after the Fe鈥揚t alloy core stopped growing. The core growth was arrested by depletion of the Pt precursor. Heteroepitaxy of Fe₃Pt [101] (core)||伪-Fe₂O₃ [111] (shell) was observed in most of the nanoparticles, while a polycrystalline iron oxide shell is developed eventually for strain relaxation. Our studies suggest that Pt atoms catalyze the reduction of Fe ions to form the Fe₃Pt alloy core, and when Pt is depleted, a direct precipitation of iron oxide results in the core鈥搒hell nanostructure formation.