Deakin University, Geelong, Institute for Frontier Materials, Waurn Ponds, Victoria 3216, Australia.
University of Melbourne, Department of Biomolecular and Chemical Engineering, Parkville, Victoria 3052, Melbourne, Australia.
Sci Rep. 2017 Mar 23;7:45112. doi: 10.1038/srep45112.
Nano-porous metallic matrixes (NMMs) offer superior surface to volume ratios as well as enhanced optical, photonic, and electronic properties to bulk metallic materials. Such behaviours are correlated to the nano-scale inter-grain metal domains that favour the presence of electronic vacancies. In this work, continuous 3D NMMs were synthesized for the first time through a simple diffusion-reduction process whereby the aerogel matrix was functionalized with (3-Mercaptopropyl)trimethoxysilane. The surface energy of the silica monolith templates was tuned to improve the homogeneity of the reduction process while thiol functionalization facilitated the formation of a high density of seeding points for metal ions to reduce. The diameter of NMMs was between 2 and 1000 nm, corresponding to a silver loading between 1.23 and 41.16 at.%. A rates of catalytic degradation kinetics of these NMMS which is three orders of magnitude higher than those of the non-functionalized silver-silica structures. Furthermore, the enhancement in mechanical stability at nanoscale which was evaluated by Atomic Force Microscopy force measurements, electronic density and chemical inertness was assessed and critically correlated to their catalytic potential. This strategy opens up new avenues for design of complex architectures of either single or multi-metal alloy NMMs with enhanced surface properties for various applications.
纳米多孔金属基质(NMMs)提供了优越的表面积与体积比,以及增强的光学、光子和电子性能,优于块状金属材料。这种行为与纳米级晶粒间金属域有关,这些金属域有利于电子空位的存在。在这项工作中,首次通过简单的扩散还原工艺合成了连续的 3D NMMs,其中气凝胶基质用(3-巯丙基)三甲氧基硅烷官能化。通过调整二氧化硅整体模板的表面能来提高还原过程的均一性,而巯基官能化则有利于形成高密度的金属离子还原种子点。NMMs 的直径在 2 到 1000nm 之间,相应的银负载量在 1.23 到 41.16 原子%之间。这些 NMMS 的催化降解动力学速率比非功能化的银-硅结构高三个数量级。此外,通过原子力显微镜力测量、电子密度和化学惰性来评估纳米级机械稳定性的增强,并对其催化潜力进行了批判性的关联。该策略为设计具有增强表面性能的复杂单金属或多金属合金 NMMs 结构开辟了新途径,可用于各种应用。