Transformation graphene quantum dot structure on Ag electrodes under electrochemical reduction

Abstract

In this study, we investigated the effect of electrochemical reduction time on the characteristicsstructural changes of various GQDs on Ag/Cu electrode was investigated. The GQDs were derived from three precursors including materials: Acetic, Glycine, and Bicarbonate were treated under electrochemical reduction conditions for , with reaction times of 15, 30, 45, and 60 minutes respectively. The obtained sSamples from each time period were then tested for their applicability in graphene screen-printed carbon electrodes using cyclic voltammetry techniques. The cyclic voltammetry test results revealed that among all the samples, those derived from Blue CL-GQDs #Acetic at 15 minutes and 60 minutes exhibited the highest current compared to GQDs obtained from Blue CL-GQDs #Glycine, Yellow CL-GQDs #Bicarbonate, and unmodified terminals. These samples proved suitable for use with screen-printed electrodes. Observing the SEM-EDX results showed that the structure appears as a smooth, thin film structure with an sp2 hybridization structure characterized by double atomic bonds, enabling the presence of more excess electrons provide higher conductivity than the sp3 structure with single atomic bonds. This characteristic facilitates better electrical conductivity as electrons can move more freely through this structure. However, the conductivity of GQDs does not depend much on the 2D or 3D structure but is rather affected by the sp2/sp3 ratios and the graphitic content.