Arc Spectra of Different Solid Reduced Graphene Oxide Samples under Microwave Irradiation

It is often accompanied by an intense arc when solid-state graphene samples are irradiated by microwaves (MWs); however, arc spectra have not been studied. In this study, the arc spectra of reduced graphene oxide (RGO) powder, three-dimensional (3D) porous RGO, and RGO paper under MW irradiation were measured; these spectra exhibited diverse features. For the same reaction conditions and the same initial sample, the arc spectra should be the same if the reaction process and mechanisms are the same. Further analyses showed that the obtained RGO paper with an evident 2D band, a smaller D band, lower sheet resistance, and lower oxygen content was of higher quality than the RGO powder and 3D porous RGO obtained after MW irradiation. Based on these results, the diverse spectra may suggest different reaction processes and mechanisms. Overall, these findings provide novel insights into the preparation of graphene via MW reduction.