Facile synthesis of ultrafine CoSn2nanocrystals anchored on graphene by one-pot route and the improved electrochemical Li-storage properties
Facile synthesis of ultrafine CoSn2nanocrystals anchored on graphene by one-pot route and the improved electrochemical Li-storage properties
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DOI：
10.1039/c2nj40894e
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发表时间：
2013-01
影响因子：
3.3
通讯作者：
Bin Feng;Jian Xie;G. Cao;T. Zhu;Xinbing Zhao
中科院分区：
文献类型：
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作者：
Bin Feng;Jian Xie;G. Cao;T. Zhu;Xinbing Zhao
在这项工作中，我们成功地合成了CoSn2纳米晶体/石墨烯纳米片（CoSn2/G）杂化物。x射线衍射、x射线光电子能谱和拉曼光谱结果揭示了CoSn2的形成和氧化石墨烯的还原过程。透射电镜观察表明，粒径为2 ~ 4nm的球形CoSn2纳米晶体被固定在石墨烯上。电化学测试结果表明，即使石墨烯含量仅为7.2%，CoSn2/G杂化物的电化学性能也明显优于未添加GO的裸Co-Sn合金。电化学性能的增强可以归因于石墨烯的引入，石墨烯不仅可以构建二维导电网络，还可以分散和限制CoSn2纳米晶体，以及对大体积变化的缓冲作用。
In this work, we succeeded in the synthesis of a CoSn2-nanocrystals/graphene-nanosheets (CoSn2/G) hybrid by a facile in situ one-pot solvothermal route. X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectra results revealed the formation of CoSn2 and the reduction of graphite oxide (GO) to graphene during the one-pot process. Transmission electron microscopy observation indicated that the spherical CoSn2 nanocrystals, with a uniform size of 2–4 nm, are anchored on graphene. The electrochemical tests showed that the CoSn2/G hybrid exhibits obviously improved electrochemical properties compared to the bare Co–Sn alloy prepared by a similar route in the absence of GO, even though the content of graphene is only 7.2 wt%. The enhancement in the electrochemical properties could be attributed to the introduction of graphene that not only constructs two-dimensional conductive networks but also disperses and confines the CoSn2 nanocrystals, in addition to the buffering effect for the large volume changes.