Surface Enrichment in Au鈥揂g Alloy Nanowires and Investigation of the Dealloying Process

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• 作者：Lo茂c Burr ; Ina Schubert ; Wilfried Sigle ; Christina Trautmann ; Maria Eugenia Toimil-Molares
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：September 10, 2015
• 年：2015
• 卷：119
• 期：36
• 页码：20949-20956
• 全文大小：541K
• ISSN：1932-7455

文摘

The fabrication of nanowires by electrodeposition of Au鈭扐g alloy into the pores of etched ion track polymer membrane is presented. The crystallinity, morphology, and composition of wires with diameters of 85, 45, and 30 nm are investigated by means of X-ray diffraction, high-resolution scanning transmission electron microscopy, and energy-dispersive X-ray analysis. Energy-dispersive X-ray analysis with very high spatial resolution (below 1 nm) reveals the presence of surface enrichment. A Ag-rich layer in Au₄₀Ag₆₀ wires and a Au-rich layer in Au₆₀Ag₄₀ wires with thicknesses between 1 and 4 nm are observed. After dealloying in nitric acid, Ag-rich wires exhibit porous morphologies whereas Au-rich wires remain solid cylinders. The results clearly indicate that the analyzed AuAg alloy nanowires do not consist of homogeneous solid solution, but surface effects before and during the dealloying play an important role for the final morphology of dealloyed nanowires.