In this study, molecular dynamics simulations were conducted to investigate the structural properties of graphene oxide (GO) nanosheets (C8O-polar, C8O-flat, C8(OH)2) as electrode materials for supercapacitors. Electric double layer capacitors (EDLCs) rely on ion adsorption at the electrode-electrolyte interface for charge storage, making it crucial to understand the nanoscale arrangement and mobility of ions near GO surfaces to optimize their performance. The combined distribution function, spatial distribution function, and diffusion coefficients confirm the spontaneous formation of a well-defined electric double layer at the GO-electrolyte interface, highlighting the strong potential of material for high capacitance in EDLC applications. This study specifically addresses whether oxidation enhances or degrades supercapacitor performance. The results indicate that oxidation of graphene nanosheets with hydroxyl functional groups significantly reduces capacitance (2.051 μ F cm−2). Therefore, the use of these oxidized nanosheets as electrodes in supercapacitors may not be recommended. However, a different trend is observed for sheets functionalized with epoxy groups. In C8O-flat (3.102 μ F cm−2), the capacitance is lower than graphene (3.201 μ F cm−2), while in a C8O-polar (4.689 μ F cm−2) with a non-planar structure, the capacitance is higher than graphene. Therefore, factors such as the type of functional group and the structural configuration (planar or non-planar) should be considered during the electrode oxidation process. The results of this study were compared with previous experimental and theoretical findings, demonstrating good agreement. This study also examines the effect of functionalization and provides a clear explanation for the contradictions reported in previous literature.

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