Direct Adsorption of Graphene Oxide on a Glassy Carbon Electrode: An Investigation of Its Adsorption and Electrochemical Activity

Abstract

Different modes of attachment of graphene oxide (GO) on an electrode surface resulted in unusual catalytic behavior respective of attachment because of film thickness. The present work investigates the direct adsorption of GO to the surface of a glassy carbon (GC) electrode. Scanning electron microscopy images revealed that multilayers of GO get adsorbed on the GC substrate and the adsorption was limited by folding up of the GO sheets at their edges. π–π and hydrogen bonding interactions between the GO and GC substrate flagged the adsorption of GO. pH studies revealed that higher adsorption of GO was achieved at pH = 3 rather than at pH = 7 and 10. Even though the electroactive surface area of adsorbed GO (GOads) was not remarkable (0.069 cm2), upon electrochemical reduction of GOads (Er-GOads), the electroactive surface area was escalated to be 0.174 cm2. Similarly, the R CT of Er-GOads was boosted to 2.9 kΩ compared to GOads which is 19 kΩ. Open circuit voltage was recorded to study the adsorption of GO on the GC electrode. Multilayered GO best fitted with the Freundlich adsorption isotherm, and the Freundlich constants like n and K F were found to be 4 and 0.992, respectively. The Freundlich constant “n” revealed the adsorption of GO on the GC substrate to be a physisorption process. Furthermore, the electrocatalytic performance of Er-GOads was demonstrated by taking uric acid as a probe. The modified electrode showed excellent stability toward the determination of uric acid.

Spontaneous ligand loss by soft landed [Ni(bpy)3]2+ ions on perfluorinated self-assembled monolayer surfaces

“…The line prole of [Ni(bpy) 2 ] 2+ (2) resembles the line prole of (1) at the edges but does not show as much attening of the signal at the center of the deposition spot as (1). Fig.…”

“…The adsorption of molecules or ions is a powerful strategy for designing efficient functional interfaces. [1][2][3][4][5] Recent advances in the fabrication of efficient electrocatalysts, photovoltaic, and photoelectrochemical devices rely on the control of the chemical stability of redox mediators at complex interfaces. [6][7][8][9] Transition metal (TM) complexes are widely used as photosensitizers in photovoltaic devices 10 and as active species for electrocatalytic water and CO 2 reduction reactions [11][12][13] and semihydrogenation of alkynes.…”

Adsorptive avidity of Prussian blue polypyrrole nanocomposite for elimination of water contaminants: a case study of malachite green and isoniazid

“…Cyclic voltammetry (CV) was employed to analyze the electrochemical behaviour, surface area, and kinetics of PB and the PPY/PB nanocomposite following their deposition on glassy carbon electrodes (GCE). 40,41 The voltammograms of an electrochemical probe 6 mM K 3 [Fe(CN) 6 ] with 0.1 M KCl as electrolyte were recorded on PB and PPY/PB modified electrodes at various scan rates (Fig. 5).…”