X-ray absorption fine structure (XAFS) analyses of Ni species trapped in graphene sheet of carbon nanofibers
X-ray absorption fine structure (XAFS) analyses of Ni species trapped in graphene sheet of carbon nanofibers
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DOI：
10.1103/physrevb.73.144103
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发表时间：
2006-04
影响因子：
3.7
通讯作者：
M. Ushiro;Kanae Uno;T. Fujikawa;Y. Sato;K. Tohji;F. Watari;W. Chun;Y. Koike;K. Asakura
中科院分区：
文献类型：
--
作者：
M. Ushiro;Kanae Uno;T. Fujikawa;Y. Sato;K. Tohji;F. Watari;W. Chun;Y. Koike;K. Asakura
碳纳米管和碳纳米纤维中的金属杂质对理解其物理和化学性质起着重要作用。我们应用镍K-边X-射线吸收精细结构分析的本地电子和几何结构周围的嵌入式镍杂质作为催化剂在碳纳米管结合多重散射分析。我们发现几乎Ni催化剂作为金属颗粒被除去的纯化处理。即使在纯化之后，残留的IOOppm Ni物质仍然被吸收;它们中的大多数处于具有Ni-C键长的单体结构中，并且它们中的每一个被石墨烯片中的碳原子取代。
Metal impurities in the carbon nanotubes and carbon nanofibers play an important role in understanding their physical and chemical properties. We apply the Ni K-edge x-ray absorption fine structure analyses to the local electronic and geometric structures around embedded Ni impurities used as catalysts in a carbon nanofiber in combination with multiple scattering analyses. We find almost Ni catalysts as metal particles are removed by the purification treatment. Even after the purification, residual 100 ppm Ni species are still absorbed; most of them are in monomer structure with Ni-C bond length 1.83 A, and each of them is substituted for a carbon atom in a graphene sheet.