State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China 100190.
J Am Chem Soc. 2012 Jul 18;134(28):11602-10. doi: 10.1021/ja302518n. Epub 2012 Jul 3.
Mastery of the structure of nanomaterials enables control of their properties to enhance their performance for a given application. Herein we demonstrate the synthesis of metal nanomaterials with hollow interiors or cage-bell structures based on the inside-out diffusion of Ag in core-shell structured nanoparticles. It begins with the synthesis of core-shell Ag-M or core-shell-shell M(A)-Ag-M(B) nanoparticles in an organic solvent. Ag is then extracted from the core or the inner shell by bis(p-sulfonatophenyl)phenylphosphane, which binds strongly with Ag(I)/Ag(0) to allow the complete removal of Ag in 24-48 h, leaving behind an organosol of hollow or cage-bell structured metal nanomaterials. Because of their relatively lower densities, which usually translate to a higher surface area than their solid counterparts, the hollow and cage-bell structured metal nanomaterials are especially relevant to catalysis. For example, cage-bell structured Pt-Ru nanoparticles were found to display outstanding methanol tolerance for the cathode reaction of direct methanol fuel cells (DMFCs) as a result of the differential diffusion of methanol and oxygen in the cage-bell structure.
掌握纳米材料的结构可以控制其性能，从而提高其在给定应用中的性能。在此，我们展示了基于核壳结构纳米粒子中 Ag 的内扩散，合成具有中空内部或笼状结构的金属纳米材料。它首先在有机溶剂中合成核壳 Ag-M 或核壳壳 M(A)-Ag-M(B)纳米粒子。然后，Ag 被双（对磺酸盐苯基）联苯膦从核心或内壳中提取出来，该分子与 Ag(I)/Ag(0) 结合很强，允许在 24-48 小时内完全去除 Ag，留下中空或笼状结构的金属纳米材料的有机溶胶。由于其相对较低的密度，通常比其固体对应物具有更高的表面积，因此中空和笼状结构的金属纳米材料在催化方面尤为相关。例如，笼状结构的 Pt-Ru 纳米粒子在直接甲醇燃料电池 (DMFC) 的阴极反应中表现出出色的甲醇耐受性，这是由于甲醇和氧气在笼状结构中的差分扩散。
