摘要
nano 建筑学的小心的设计和期望的活跃材料的聪明的杂交能导致更先进的性质。这里，我们设计了新奇层次分叉 Cu/Cu <sub>2</sub > 由联合一个灵巧的热水的方法和随后的控制氧化过程的 O/CuO heteronanostructure。在分支和脊梁之间的好结构和取向附生的关系被高分辨率的传播电子显微镜学调查。而且，分支生长的进化也在 Cu nanowire 表面的渐渐的氧化期间被观察了。试验性的结果建议经由二拍子的圆舞暴露进程要表现到改变湿度以便完成的表面氧化需要优化了核心壳的形成结构化的分叉的建筑学。最后，象在锂离子电池的阳极材料的如此的一个层次框架的功能的 proof-of-concept 被表明。分叉的核心壳 heterostructure 由几个工具改进电池性能：取向附生地成年的分支提供的(i) 为到卷变化的提高的电解质可接近性和高抵抗的一个高表面区域由 Li+ 置闰 / 抽取导致了；(ii ) 有它的明确的异质接面的核心壳结构增加在 lithiation 期间便于有效费用运输的接触区域；(iii ) 铜核心象提供结构的加强一样充当一个当前的收集者。
The careful design of nano-architectures and smart hybridization of expected active materials can lead to more advanced properties. Here we have engineered a novel hierarchical branching Cu/Cu2O/CuO heteronanostructure by combining a facile hydrothermal method and subsequent controlled oxidation process. The fine structure and epitaxial relationship between the branches and backbone are investigated by high-resolution transmission electron microscopy. Moreover, the evolution of the branch growth has also been observed during the gradual oxidation of the Cu nanowire surface. The experimental results suggest that the surface oxidation needs to be performed via a two-step exposure process to varying humidity in order to achieve optimized formation of a core-shell structured branching architecture. Finally, a proof-of-concept of the function of such a hierarchical framework as the anode material in lithium-ion batteries is demonstrated. The branching core-shell heterostructure improves battery performance by several means： （i） The epitaxially grown branches provide a high surface area for enhanced electrolyte accessibility and high resistance to volume change induced by Li^＋ intercalation/extraction; （ii） the core-shell structure with its well-defined heterojunction increases the contact area which facilitates effective charge transport during lithiation; （iii） the copper core acts as a current collector as well as providing structural reinforcement.
基金
We thank Prof. Mingbo Wu （State Key Laboratory of Heavy Oil Processing, China University of Petroleum） for his help in experiments. This work was finandally supported by the Key Joint Foundation of PetroChina, the National Natural Science Foundation of China （Nos. 51271215, U1362202, and 21106185） and the PetroChina Key Programs on Oil Refinery Catalysts （No. 2010E-1908 and 2010E-1903）.
