Laboratory for Mechanical Behavior of Materials, MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an 710049, ShaanXi, People's Republic of China.
Phys Chem Chem Phys. 2013 Oct 14;15(38):15964-70. doi: 10.1039/c3cp52840e. Epub 2013 Aug 20.
We have demonstrated significant evidence of a solvent-dependent synthesis of hierarchical Cu7S4 polycrystalline nanocage assemblies with controllable aggregation-based building blocks by a sacrificial Cu2O template approach. The formation of a hierarchical Cu7S4 polycrystalline nanocage is essentially determined by a Kirkendall effect, which is attributed to the tailored-aggregation behaviour of the nanoscale building blocks during the replacement/etching process in different polarities of solvent. The hierarchical Cu7S4 polycrystalline nanocage assembly of nanoparticle building blocks was prepared in pure water, while the hierarchical Cu7S4 polycrystalline nanocage assembly of twinned nanoplate building blocks was successfully synthesized in an anhydrous ethanol capping environment. Such a hierarchical Cu7S4 polycrystalline nanocage assembly of twinned nanoplate building blocks exhibits a higher photocatalytic activity than that of the common polycrystalline ones. A nanotwin-dependent photochemical mechanism has been proposed. Significantly, this study is of great importance in bottom-up assembly of controllable ordered architectures, and offers a good opportunity to understand the fundamental importance of the formation mechanism and growth process of hierarchical Cu7S4 polycrystalline nanocages with controllable aggregation-based building blocks.
我们通过牺牲型 Cu2O 模板法，证明了在溶剂依赖性条件下合成具有可控聚集基元的分级 Cu7S4 多晶纳米笼组装体的重要证据。分级 Cu7S4 多晶纳米笼的形成主要由 Kirkendall 效应决定，这归因于纳米尺度构建块在不同极性溶剂中的替换/刻蚀过程中的定制聚集行为。在纯水中制备了由纳米颗粒构建块组成的分级 Cu7S4 多晶纳米笼组装体，而在无水乙醇封闭环境中成功合成了由孪晶纳米板构建块组成的分级 Cu7S4 多晶纳米笼组装体。这种由孪晶纳米板构建块组成的分级 Cu7S4 多晶纳米笼组装体表现出比普通多晶纳米笼更高的光催化活性。提出了一种基于纳孪晶的光化学机制。值得注意的是，这项研究对于可控有序结构的自下而上组装具有重要意义，并为理解具有可控聚集基元的分级 Cu7S4 多晶纳米笼的形成机制和生长过程提供了良好的机会。
