Chauvin Adrien, Delacôte Cyril, Molina-Luna Leopoldo, Duerrschnabel Michael, Boujtita Mohammed, Thiry Damien, Du Ke, Ding Junjun, Choi Chang-Hwan, Tessier Pierre-Yves, El Mel Abdel-Aziz
Institut des Matériaux Jean Rouxel, IMN, Université de Nantes, CNRS , 2 rue de la Houssinière B.P. 32229, 44322 Nantes cedex 3, France.
CEISAM, Université de Nantes, CNRS , 2 rue de la Houssinière B.P. 32229, 44322 Nantes cedex 3, France.
ACS Appl Mater Interfaces. 2016 Mar;8(10):6611-20. doi: 10.1021/acsami.5b11244. Epub 2016 Mar 4.
Nanoporous materials are of great interest for various technological applications including sensors based on surface-enhanced Raman scattering, catalysis, and biotechnology. Currently, tremendous efforts are dedicated to the development of porous one-dimensional materials to improve the properties of such class of materials. The main drawback of the synthesis approaches reported so far includes (i) the short length of the porous nanowires, which cannot reach the macroscopic scale, and (ii) the poor organization of the nanostructures obtained by the end of the synthesis process. In this work, we report for the first time on a two-step approach allowing creating highly ordered porous gold nanowire arrays with a length up to a few centimeters. This two-step approach consists of the growth of gold/copper alloy nanowires by magnetron cosputtering on a nanograted silicon substrate, serving as a physical template, followed by a selective dissolution of copper by an electrochemical anodic process in diluted sulfuric acid. We demonstrate that the pore size of the nanowires can be tailored between 6 and 21 nm by tuning the dealloying voltage between 0.2 and 0.4 V and the dealloying time within the range of 150-600 s. We further show that the initial gold content (11 to 26 atom %) and the diameter of the gold/copper alloy nanowires (135 to 250 nm) are two important parameters that must carefully be selected to precisely control the porosity of the material.
纳米多孔材料在包括基于表面增强拉曼散射的传感器、催化和生物技术在内的各种技术应用中具有极大的吸引力。目前，人们致力于开发多孔一维材料以改善这类材料的性能。迄今为止报道的合成方法的主要缺点包括：（i）多孔纳米线长度较短，无法达到宏观尺度；（ii）合成过程结束时获得的纳米结构组织性较差。在这项工作中，我们首次报道了一种两步法，可制备长度达几厘米的高度有序的多孔金纳米线阵列。这种两步法包括通过磁控共溅射在纳米光栅硅衬底（用作物理模板）上生长金/铜合金纳米线，随后在稀硫酸中通过电化学阳极过程选择性溶解铜。我们证明，通过将脱合金电压调至0.2至0.4 V以及将脱合金时间控制在150 - 600 s范围内，纳米线的孔径可在6至21 nm之间进行调整。我们进一步表明，初始金含量（11至26原子%）和金/铜合金纳米线的直径（135至250 nm）是必须仔细选择的两个重要参数，以精确控制材料的孔隙率。
