Assembly techniques of graphene have attracted intense attention since their performance strongly depends on the manners in which graphene nanosheets are arranged. In this work, we demonstrate a viable process to synthesize winged graphene nanofibers (G-NFs) which could generate optimized pore size distribution by the fiber-like feature of graphene. The G-NF frameworks were achieved by processing the precursor graphene oxide nanosheets with the following procedures: microwave (MW) irradiation, salt addition, freeze-drying, and chemical reduction. The resultant framework composed of winged G-NFs with a diameter of 200-500 nm and a length of 5-20 μm. Moreover, the crimp degree of G-NFs can be rationally controlled by MW irradiation time. A formation mechanism of such winged G-NFs based on the synergistic effects from MW irradiation and solution ionic strength change has been proposed. With a practice in flexible electrode, after decorated with amorphous MnO2, the G-NF frameworks shows an enhanced specific capacitance compared to graphene nanosheets (G-NSs). This research has developed a controllable method to synthesis G-NFs, which can offer hierarchical pore structures, this kind of graphene nanostructure might enhance their performance in supercapacitor and related fields.
Keywords: capacitive performance; graphene nanofiber; ionic strength; microwave irradiation; three-dimensional framework.