A single Au nanoparticle anchored inside the porous shell of periodic mesoporous organosilica hollow spheres

An ideal metal catalyst requires easy contact with reaction reagents, a large number of exposed active sites, and high stability against leaching or particle agglomeration. Anchoring a metal core inside a porous shell, though scarcely reported, may combine these advantages owing to the integration of the conventional supported metal arrangement into a core@void@shell architecture. However, achieving this is extremely difficult owing to the weak core-shell affinity. Herein, we report, for the first time, an approach to overcome this challenge by increasing the core-shell interaction. In this regard, we synthesized a novel Au@void@periodic mesoporous organosilica （PMO） architecture in which a single Au core is firmly anchored inside the porous shell of the hollow PMO sphere. The non-covalent interactions between the poly（vinylpyrrolidone） （PVP） groups of functionalized Au and ethane moieties of PMO facilitate the movement of the Au core towards the porous shell during the selective alkaline etching of Au@SiO2@PMO. Shell-anchored Au cores are superior to the suspended cores in the conventional Au@void@PMO in terms of contact with reagents and exposure of active sites, and hence show higher catalytic efficiency for 4-nitrophenol reduction. The methodology demonstrated here provides a new insight for the fabrication of versatile multifunctional nanostructures with cores anchored inside hollow shells.

理想的金属催化剂对沥滤或粒子凝块与反应试剂，很多暴露的活跃地点，和高稳定性要求容易的接触。抛锚尽管几乎没报导，在多孔的壳内的一个金属核心可以由于常规支持的金属安排的集成把这些优点合为 core@void@shell 体系结构。然而，完成这由于弱 coreshell 亲密关系是极其困难的。此处，第一次，我们报导一条途径由增加核心壳相互作用克服这挑战。在这方面，我们综合了一个单个 Au 核心是的新奇 Au@void@periodic mesoporous organosilica (PMO ) 在体系结构坚定地在空 PMO 范围的多孔的壳内抛锚了。在之间的非共有原子价相互作用(vinylpyrrolidone )(PVP ) poly，一些 functionalized Au 和 PMO 的乙烷一半向多孔的壳便于 Au 核心的运动在期间 Au@SiO2@PMO 的选择碱的蚀刻。抛锚壳的 Au 核心以与活跃地点的试剂和暴露的接触比在常规 Au@void@PMO 的推迟的核心优异，并且因此为 4-nitrophenol 减小显示出更高催化的效率。这里表明的方法论提供新卓见因为有核心的万用的多功能的 nanostructures 的制造在空壳内抛锚了。