Plasma treated gold nanofilms enhance surface-assisted redox activity in electrochemical processes

Abstract

Surface-assisted catalytic activities of two-dimensional (2D) materials are gaining prominence due to their tunable surface area, enhanced active sites, and unique structural properties. In this study, we demonstrate the preparation of a highly reactive gold nanofilm (GNF) with a face-centered cubic structure via thermal deposition, followed by atmospheric nitrogen plasma treatment. X-ray photoelectron spectroscopy (XPS) revealed that plasma treatment increased surface hydroxyl and carbonyl groups, introducing nitrogen as metal-nitride and C-NH₂ species. Raman spectroscopy further confirmed the incorporation of nitrogen and oxygen functionalities, with intense peaks at 790 cm⁻¹ and 946 cm⁻¹, indicating successful surface activation. The electrochemical behavior of the plasma-treated GNF was evaluated using the [FeIII/II(CN)6]^3−/4− redox system through cyclic voltammetry. Notably, the plasma-treated GNF exhibited a substantial increase in anodic and cathodic peak current densities, with the electrochemically active surface area increasing by approximately 276 % and 400 %, respectively, compared to untreated GNF. This enhancement in redox reactivity underscores the potential of plasma-treated GNFs in boosting surface-assisted redox processes. The findings suggest that plasma-modified 2D surfaces hold significant promise for advancing electrochemical sensing and catalysis, offering improved efficiency and reactivity for a range of applications.