imec , Kapeldreef 75 , Leuven 3001 , Belgium.
University of Leuven (KUL) , Centre for Surface Chemistry and Catalysis , Kasteelpark Arenberg 23 , Leuven 3001 , Belgium.
ACS Appl Mater Interfaces. 2018 Dec 26;10(51):44634-44644. doi: 10.1021/acsami.8b15888. Epub 2018 Dec 12.
Nanostructured metals with large surface area have a great potential for multiple device applications. Although various metal architectures based on metal nanoligaments and nanowires are well known, they typically show a tradeoff between mechanical robustness, high surface area, and high (macro)porosity, which, when combined, could significantly improve the performance of devices such as batteries, electrolyzers, or sensors. In this work, we rationally designed templated networks of interconnected metal nanowires, combining for the first time high porosity of metal foams, narrowly distributed macropores, and a very high surface area of nanoporous dealloyed metals. Thanks to their structural uniformity, the few-micron thick nanowire meshes are also remarkably flexible and durable. We show how the textural properties of the material can be precisely tuned to optimize the nanowire networks for applications in different devices. In an exemplary application in electrolytic production of hydrogen, thanks to its high surface area, a few-micron thick nanomesh outperformed a 300 times thicker nickel foam. Furthermore, thanks to its high porosity, the Pt-doped nanomesh surpassed a microporous Pt/C cloth, demonstrating benefits of the optimally designed nanowire structure for a simultaneous improvement and miniaturization of electrochemical devices. This work extends the potential of interconnected nanowires to multiple new research and industrial applications requiring highly porous and flexible conductive materials with a high surface-to-volume ratio.
具有大表面积的纳米结构金属在多种器件应用中具有巨大的潜力。虽然基于金属纳米线和纳米丝的各种金属结构已经广为人知，但它们通常在机械强度、高表面积和高（宏观）孔隙率之间存在权衡，当这些特性结合在一起时，可以显著提高电池、电解槽或传感器等器件的性能。在这项工作中，我们合理设计了相互连接的金属纳米线模板网络，首次将金属泡沫的高孔隙率、窄分布的大孔和纳米多孔脱合金金属的高比表面积结合在一起。由于其结构均匀性，几微米厚的纳米线网也具有出色的柔韧性和耐用性。我们展示了如何精确调整材料的结构特性，以优化纳米线网络在不同器件中的应用。在电解制氢的典型应用中，由于其高表面积，几微米厚的纳米网比 300 倍厚的镍泡沫表现更出色。此外，由于其高孔隙率，掺 Pt 的纳米网优于微孔 Pt/C 布，这表明优化的纳米线结构在电化学器件的同时改进和小型化方面具有优势。这项工作将相互连接的纳米线的潜力扩展到多个需要高比表面积和高表面积/体积比的多孔和灵活导电材料的新研究和工业应用中。
