Effect of morphology and defect density on electron transfer of electrochemically reduced graphene oxide

Abstract

Electrochemically reduced graphene oxide (ERGO) is widely used to construct electrochemical sensors. Understanding the electron transfer behavior of ERGO is essential for its electrode material applications. In this paper, different morphologies of ERGO were prepared via two different methods. Compared to ERGO/GCEs prepared by electrochemical reduction of pre-deposited GO, more exposed edge planes of ERGO are observed on the surface of ERGO-GCE that was constructed by electrophoretic deposition of GO. The defect densities of ERGO were controlled by tuning the mass or concentration of GO. The electron transfer kinetics (k 0 ) of GCE with different ERGOs was comparatively investigated. Owing to increased surface areas and decreased defect density, the k 0 values of ERGO/GCE initially increase and then decrease with incrementing of GO mass. When the morphology and surface real areas of ERGO-GCE are the same, an increased defect density induces an accelerated electron transfer rate. k 0 valuesof ERGO-GCEs are about 1 order of magnitude higher than those of ERGO/GCEs due to the difference in the amount of edge planes. This work demonstrates that both defect densities and edge planes of ERGO play crucial roles in electron transfer kinetics.

Improving the Voltammetric Determination of Hg(II): A Comparison Between Ligand-Modified Glassy Carbon and Electrochemically Reduced Graphene Oxide Electrodes

“…The surface morphology of unmodified and modified GC-ERGO electrodes was further examined using SEM (Figure S5A,B from Supporting Information). The micrographs reveal an incomplete coverage of the GC substrate with agglomerates consisting of stacked ERGO sheets, in line with previous observations [58]. Moreover, there seems to be no apparent difference between the electrode surface morphology before and after modification.…”

Reduced Graphene Oxides: Influence of the Reduction Method on the Electrocatalytic Effect towards Nucleic Acid Oxidation

“…As an alternative to these rough and defective methods, the hydrothermal and electrochemical reduction methods [ 5 , 19 ] appear as green methods because they use moderate temperatures and pressures in aqueous solutions [ 20 ]. The effects that the morphology and defect density have on the electron transfer of electrochemically reduced graphene oxide were published and indicated that both defect densities and edge planes of ERGO play crucial roles in the electron transfer kinetics [ 21 ].…”

Development of graphene based nanocomposites towards medical and biological applications

“…However, of the large energy demand is one of the major drawbacks for thermal reduction process [32]. Fortunately, a one-step facile route to form rGO from GO suspension on substrate has been identified by electrochemical reduction method, as known as cyclic voltammetry (CV) principle [33].…”