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

Abstract

A robust and efficient route to modify the chemical and physical properties of polycrystalline copper (Cu) wires via versatile plasma electrolysis is presented. Silica (SiO 2 ) nanoparticles (11 nm) are introduced during the electrolysis to tailor the surface structure of the Cu electrode. The influence of these SiO 2 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 Cu 2 O. Furthermore, the oxide film thickness (between 1 and 70 µm), 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.

Synergistic Polarization Loss of MoS2‐Based Multiphase Solid Solution for Electromagnetic Wave Absorption

“…On the one hand, the appearance of Cu peak of Cu@MoS 2 at about 395 eV in whole region XPS spectra (Figure S1, Supporting Information) also verified the modification of Cu ions in MoS 2 . [24] As is shown in Figure 2d, both the Cu 2p 1/2 and Cu 2p 3/2 spectra can be deconvoluted into three parts of Cu 2+ (954.9, 934.8 eV), Cu + (951.9, 932.7 eV), and satellite (963.7, 940.0 eV). [25] On the other hand, there were no diffraction signals of Cu phase in XRD pattern of Cu@MoS 2 , while the (004) diffraction peak in XRD pattern of Cu@MoS 2 shifted to lower Bragg position compared with that of distinct MoS 2 .…”

Cathodic corrosion of Au in aqueous methanolic alkali metal hydroxide electrolytes: Notable role of water

“…The EASA factors are obtained by matching the double-layer capacity of the corroded and as-polished Au electrodes at -0.60 V versus MSE where neither Faraday reactions nor adsorption processes occur. [1,5,19,20] Correction for the IR-drop is considered to determine the actual potentials. Electrochemical impedance spectroscopy measurements were carried out to determine the solution resistance R of the KOH and NaOH electrolytes.…”

“…[1] Furthermore, the EASA factors are determined by equating the double-layer capacitance of the polarized and as-polished Au electrodes at -0.60 V versus MSE where neither Faraday reactions nor adsorption processes appear. [1,5,19,20,27] Figure 2a,b presents the calculated facet distributions and EASA factors. As shown in Figure 2a,b, these factors are substantially varying depending on the experimental conditions.…”

In-Liquid Plasma-Mediated Manganese Oxide Electrocatalysts for Quasi-Industrial Water Oxidation and Selective Dehydrogenation

“…Compared to well-established synthetic approaches, the in-liquid (gas/liquid dual phase) plasma electrolytic oxidation (PEO) is a rapid, nontoxic technique that generates plasma glow discharge at the metal–electrolyte interface (MEI). Under high applied voltages, the PEO generates a harsh environment at the MEI (with a local temperature of 10,000 K and a pressure inside discharge channels of about 10 2 –10 3 MPa). , Such conditions are indeed ideal to form a robust catalyst/substrate interface in the nanostructured anode that can overcome the persistent stability problem during intensive electrocatalytic oxidation ( V < 2.0). Although PEO technique has been widely used for thin metal coatings, , its utilization to fabricate nanostructured anodes for electrocatalysis is relatively unexplored.…”