Mesoporous Co3O4 and CoO@C Topotactically Transformed from Chrysanthemum-like Co(CO3)0.5(OH)•0.11H2O and Their Lithium-Storage Properties
Mesoporous Co3O4 and CoO@C Topotactically Transformed from Chrysanthemum-like Co(CO3)0.5(OH)•0.11H2O and Their Lithium-Storage Properties
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DOI：
10.1002/adfm.201102192
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发表时间：
2012-02-22
影响因子：
19
通讯作者：
Zeng, Hua Chun
中科院分区：
文献类型：
--
作者：
Xiong, Shenglin;Chen, Jun Song;Zeng, Hua Chun
本文采用水热法合成了碳酸氢钴Co（CO 3）0.5（OH）.0.11H2O。在该方法中，氯化钠盐被用于将单晶纳米线组织成类似chelium的分级组装体。通过考察合成过程中不同的反应中间体，研究了这种有机产物的形态演变过程。Co（CO 3）0.5（OH）.0.11H2O的生长和最终组装可以通过选择制备参数，例如起始化学品的摩尔比、添加剂、反应时间和温度进行微调。以花状Co（CO 3）0.5（OH）.0.11H2O为固体前驱体，在空气中热分解制备了准单晶介孔Co 3 O 4纳米线阵列。此外，碳可以通过使用乙炔的化学气相沉积方法添加到尖晶石氧化物上，这导致产生碳包覆的CoO纳米线阵列（CoO@C）。通过晶体结构的比较和分析，可以解释所得产物及其高结晶度是由各自的前体的顺序拓扑结构转变。并对典型钴氧化物产品的电化学性能进行了评价。结果表明，Co 3 O 4产品的表面织构和孔径的调整在锂离子电池应用中是非常重要的。碳修饰的CoO纳米线阵列表现出优异的循环性能，在70次循环的测试范围内具有接近100%的容量保持率。因此，这种CoO@C纳米复合材料可以被认为是一个有吸引力的候选人作为阳极材料进行进一步的研究。
In this work, a novel hydrothermal route is developed to synthesize cobalt carbonate hydroxide, Co(CO3)0.5(OH).0.11H2O. In this method, sodium chloride salt is utilized to organize single-crystalline nanowires into a chrysanthemum-like hierarchical assembly. The morphological evolution process of this organized product is investigated by examining different reaction intermediates during the synthesis. The growth and thus the final assembly of the Co(CO3)0.5(OH).0.11H2O can be finely tuned by selecting preparative parameters, such as the molar ratio of the starting chemicals, the additives, the reaction time and the temperature. Using the flower-like Co(CO3)0.5(OH).0.11H2O as a solid precursor, quasi-single-crystalline mesoporous Co3O4 nanowire arrays are prepared via thermal decomposition in air. Furthermore, carbon can be added onto the spinel oxide by a chemical-vapor-deposition method using acetylene, which leads to the generation of carbon-sheathed CoO nanowire arrays (CoO@C). Through comparing and analyzing the crystal structures, the resultant products and their high crystallinity can be explained by a sequential topotactic transformation of the respective precursors. The electrochemical performances of the typical cobalt oxide products are also evaluated. It is demonstrated that tuning of the surface texture and the pore size of the Co3O4 products is very important in lithium-ion-battery applications. The carbon-decorated CoO nanowire arrays exhibit an excellent cyclic performance with nearly 100% capacity retention in a testing range of 70 cycles. Therefore, this CoO@C nanocomposite can be considered to be an attractive candidate as an anode material for further investigation.