నైరూప్య

The structure change of graphene with few layers via microwave irradiation for different time

Mei Sun, Tianhao Ji, Nan Qie, NanMa, Lifeng Zou

Aseries of graphene products have been prepared throughmechanicalmilling, oxidation treatment andmicrowave irradiation processes.Various measurement results demonstrate that the products are the graphene nanosheetswith fewlayers and little oxygen content due to not any KMnO4 treatment. Under the same experimental condition and procedures, the corresponding products with additional KMnO4 oxidation have also been obtained, and the comparedmeasurements showthat the products not only exhibit better dispersion, but also have much promore oxygen content. Raman spectra reveal that the G-peak of the products appears splitting into G- and G+ peaks owing to a phonon symmetry breaking at à point, and the intensity ratio of the D to G+ peak for the products without KMnO4 oxidation treatment gradually lowerswith prolongingmicrowave irradiation timewithin 48min, indicating the decrease of the structural defects.