New Insights Into the Effects of Electrode Polarization of Chitosan on Graphene Nanomaterials

The efficient transfer of electrons between the electrode and the analyte, influenced by electrode polarization (EP), is a crucial yet often overlooked factor in assessing the performance of electrochemical systems. This study explores the use of chitosan as an EP suppressor for graphene oxide (GO) and reduced graphene oxide (RGO) in a ferri/ferro cyanide redox probe, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. The CV results indicate that GO has greater pseudocapacitance than RGO does, indicating a greater abundance of oxygen-containing functional groups that facilitate stronger interfacial interactions with chitosan. By reducing the capacitive current, as shown through EIS, the sensitivity toward the Fe^2+/3+ redox couple at the electrode double layer is enhanced. These findings align with density functional theory (DFT) calculations, which indicate a charge distortion favoring chitosan, thereby allowing more efficient intrinsic electron transfer within the aromatic rings of the GO/RGO graphene nanomaterials. This research holds significant potential for advancing the development of more efficient sensors and energy storage devices.