Electric and Photocatalytic Properties of Graphene Oxide Depending on the Degree of Its Reduction

Abstract

When graphene oxide is reduced, the functional groups are released and the structure becomes more ordered. The degree of reduction might be tunable with the process parameters. In our work, graphene oxide is prepared and the effect of thermal and chemical reduction is investigated. The samples are characterized with TG/DTA-MS, SEM-EDX, TEM, XPS, ATR-FTIR, Raman spectroscopy and XRD. Their electrical resistance, cyclic voltammetry and photocatalytic activity data are investigated. The conductivity can be varied by several orders of magnitude, offering a tool to match its electrical properties to certain applications. Low temperature reduction in air offers a material with the highest capacitance, which might be used in supercapacitors. The bare graphene oxide has considerably larger photocatalytic activity than P25 TiO2. Reduction decreases the activity, meaning that reduced graphene oxide can be used as an electron sink in composite photocatalysts, but does not contribute to the photocatalytic activity by itself.

Tuning the electrical properties of graphene oxide through low-temperature thermal annealing

“…S26b and d, ESI †), yielding capacitance values comparable to the state of the art of TrGO (Table S6, ESI †). 42,62,63,[65][66][67][68] When the reduction is performed under argon, the increase in specific capacitance with the annealing temperature is followed by the increase in both surface area and film conductivity. Differently, when the reduction is carried out under air the same trend also occurs for the specific capacitance and film conductivity but not for the surface area at 150 and 200 °C.…”

Simultaneous quantification of trace heavy metals in mushrooms using a three-dimensional highly reduced graphene oxide/Fe 3O 4 nanocomposite-based electrochemical sensor

“…The presence of electron-withdrawing groups, which are oxygen-containing functional groups, grafted onto graphene oxide, has been found to reduce the efficiency of electron transfer [33] . The reduction of graphene can be assessed by analyzing the intensity of the C atomic and O atomic (IC/IO) ratio using XPS [34,35] .…”

Investigating the Reduction/Oxidation Reversibility of Graphene Oxide for Photocatalytic Applications

“…With heat treatment, the specific capacitance of GO can also be improved. CV results show that the specific capacitance is increased to 164.9 F/g with heat treatment in air at 200 • C [31]. Research suggests that there is a correlation between the electrical properties and the SSA of GO, which might correlate with the degree of oxidation.…”