Single-Step Fabrication of Nickel Films with Arrayed Macropores and Nanostructured Skeletons
✍ Scribed by X. Zhang; K.-N. Tu; Y.-H. Xie; C.-H. Tung; S. Xu
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 500 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0935-9648
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✦ Synopsis
Porous metals are known to contain large internal surface areas, which, if accessible, can be used in numerous applications including catalysts, batteries, fuel cells, capacitors, and sensors. [1][2][3][4][5][6] Metals with well-ordered porous networks would also exhibit interesting photonic applications. [7][8][9] Template-directed synthesis, an increasingly attractive subject, has recently been adapted to the production of both meso-and macroporous metals with controlled pore size. Templates used in the fabrication processes include liquid-crystalline surfactant assemblies and anodically etched alumina membranes, [10,11] which produce mesoporous metals typically possessing cylindrical voids. More recently, macroporous metals with pore sizes larger than 100 nm have been fabricated by using colloidal crystallites as templates, resulting in three-dimensionally stacked and interconnected spherical voids in the solid matrix. [12][13][14][15][16] So far, each of the approaches has been reported to comprise more than two steps, while a more straightforward and less costly way of making functional metals with embedded porous microstructure has not yet been highlighted. Here, we report an aqueous method for creating metallic, macroporous nickel films using silicon-based macroporous silicon as the template. By simple immersion of the macroporous silicon in a prepared nickel bath, replication has been achieved through complete nickel displacement of the silicon in the pore sidewalls, while the original macroporous structure was maintained. The as-formed nickel films with high-aspectratio macropores were able to self-peel from underneath the nonporous silicon base. Such a freestanding porous metal COMMUNICATIONS