Comparison of Thermal and Laser-Reduced Graphene Oxide Production for Energy Storage Applications

A way to obtain graphene-based materials on a large-scale level is by means of chemical methods for the oxidation of graphite to obtain graphene oxide (GO), in combination with thermal, laser, chemical and electrochemical reduction methods to produce reduced graphene oxide (rGO). Among these methods, thermal and laser-based reduction processes are attractive, due to their fast and low-cost characteristics. In this study, first a modified Hummer's method was applied to obtain graphite oxide (GrO)/graphene oxide. Subsequently, an electrical furnace, a fusion instrument, a tubular reactor, a heating plate, and a microwave oven were used for the thermal reduction, and UV and CO2 lasers were used for the photothermal and/or photochemical reduction. The chemical and structural characterizations of the fabricated rGO samples were performed by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectroscopy measurements. The analysis and comparison of the results revealed that the strongest feature of the thermal reduction methods is the production of high specific surface area, fundamental for volumetric energy applications such as hydrogen storage, whereas in the case of the laser reduction methods, a highly localized reduction is achieved, ideal for microsupercapacitors in flexible electronics.

Automated summary

Graphene-based materials can be obtained on a large-scale level by chemical methods for oxidation of graphite to obtain graphene oxide (GO), in combination with thermal and laser-based reduction methods to produce reduced graphene oxide (rGO). The thermal reduction methods produce high specific surface area, suitable for volumetric energy applications, while the laser reduction methods achieve localized reduction and are ideal for microsupercapacitors in flexible electronics. The characteristics of the fabricated rGO samples were analyzed and compared using various chemical and structural characterization techniques.