Regensburg 2016 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 4: Nanoparticles, Nanocrystals and Composites I

CPP 4.8: Vortrag

Montag, 7. März 2016, 11:30–11:45, H41

Oxidative etching of silver nanowires for improvement of structural integrity — •Egon Steeg¹, Frank Polzer¹, Holm Kirmse¹, Yan Qiao¹, Jürgen P. Rabe^1,2, and Stefan Kirstein¹ — ¹Department of Physics, Humboldt-Universität zu Berlin — ²IRIS Adlershof, Humboldt-Universität zu Berlin

Silver nanowires with diameter of 6.5 nm are grown within tubular J-aggregates by reduction of silver ions. The nanowire growth starts with small isolated crystallites within the tubular aggregate that grow into pieces of wires that finally coalesce into continuous wires that homogeneously fill the template. This growth continues due to remaining silver ions within solution. The resulting crystals are wire-like, but are inhomogeneous and non-uniform in diameter. Addition of NaCl allows precipitation of the remaining silver ions in form of AgCl at defined times stabilizing the structure of the wires. The influence of oxygen is critical for this process, since the silver can be oxidized by oxygen in the solution with the chloride acting as a ligand due to oxidative etching. This etching is most effective at silver structures that contain defects or twin boundaries. The selective etching efficiency allows removing the parts of the wires that have lower structural integrity which leaves pieces with length of several hundred nanometers. This allows us not only to produce well-defined silver nanowires but to preserve their morphology in solution for weeks.