In-Liquid Plasma for Surface Engineering of Cu Electrodes with Incorporated SiO2 Nanoparticles: From Micro to Nano

A robust and efficient route to modify the chemical and physical properties of polycrystalline copper (Cu) wires via versatile plasma electrolysis is presented. Silica (SiO2) nanoparticles (11 nm) are introduced during the electrolysis to tailor the surface structure of the Cu electrode. The influence of these SiO2 nanoparticles on the structure of the Cu electrodes during plasma electrolysis over a wide array of applied voltages and processing time is investigated systematically. Homogeneously distributed 3D coral-like microstructures are observed by scanning electron microscopy on the Cu surface after the in-liquid plasma treatment. These 3D microstructures grow with increasing plasma processing time. Interestingly, the microstructured copper electrode is composed of CuO as a thin outer layer and a significant amount of inner Cu2O. Furthermore, the oxide film thickness (between 1 and 70 mu m), the surface morphology, and the chemical composition can be tuned by controlling the plasma parameters. Remarkably, the fabricated microstructures can be transformed to nanospheres assembled in coral-like microstructures by a simple electrochemical treatment.

Automated summary

In this study, a robust and efficient method to modify the chemical and physical properties of polycrystalline copper wires via versatile plasma electrolysis was presented. Silica nanoparticles were introduced during the electrolysis to tailor the surface structure of the copper electrode, leading to the formation of homogeneous 3D coral-like microstructures. These microstructures, composed of CuO and Cu2O, can be tuned in terms of oxide film thickness, surface morphology, and chemical composition by controlling the plasma parameters. Additionally, the fabricated microstructures can be transformed into nanospheres assembled in coral-like microstructures through electrochemical treatment.