Characterization of the surface redox process of caffeic acid adsorbed at glassy carbon electrodes modified with partially reduced graphene oxide

The Frumkin adsorption isotherm was the best which describes the specific interaction of CA with CGE/ePRGO. The thermodynamic and kinetics of the surface redox couple were studied in 1.0 M HClO4. Therefore, we used the methods of the “quasi-reversible maximum” and the “splitting of the net SW voltammetric peak” to obtain information about the thermodynamic and kinetics of this surface redox couple. Averages values obtained for the formal potential and the anodic transfer coefficient were (0.638 ± 0.005) V and (0.58 ± 0.06), respectively. A value of 40 s− 1 was obtained for the overall formal rate constant. For comparison, CA electrochemical responses were also studied at bare GCE, and GCE modified with a dispersion of graphene oxide (GCE/GO).