Greifswald 2024 – scientific programme

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P: Fachverband Plasmaphysik

P 3: Plasma Wall Interaction I

P 3.1: Invited Talk

Monday, February 26, 2024, 14:00–14:30, ELP 6: HS 3

Influence of Nanosecond Pulsed Plasmas in Liquids on Copper Surfaces — •Pia-Victoria Pottkämper, Oliver Krettek, Katharina Laake, and Achim von Keudell — Ruhr-Universität Bochum

One application of plasmas in liquids is the modification of metal surfaces. In this project a plasma is ignited in water at an electrode using high voltages, nanosecond pulses and fast rise times. The plasma is then used to modify a coppper surface in contact with the plasma-activated liquid. The plasma causes a dissociation of the water molecules, leading to the creation of many different reactive species with varying lifetimes such as molecular oxygen and hydrogen, solvated electrons and hydrogen peroxyde. The created electric field with a short rise time leads to a fast pressure increase at the ignition site and an expansion of a shock wave which transports the reactive species to the surface. Here different reactions may occur that lead to the modification of the copper. It is possible to reduce the surface or to initiate growth of nanostructures depending on the experimental conditions. The changes are monitored via FTIR spectroscopy, SEM and XPS. The creation of uniform CuxO nanocubes has been observed under certain conditions. One application of these structures is the catalysis of the electrochemical reduction of CO2. During this reaction the activity of these catalysts decreases over time. The in-liquid plasma can cause a re-oxidation and therefore the formation of new CuxO nanocubes. It is postulated that by an in-situ in-liquid plasma treatment the lifetime of the catalytic surfaces can be extended.

Keywords: in-liquid Plasma; surface modification; copper