A new approach to nanoporous graphene sheets via rapid microwave-induced plasma for energy applications

We developed a novel approach to the fabrication of three-dimensional, nanoporous graphene sheets featuring a high specific surface area of 734.9 m² g^-1 and an ultrahigh pore volume of 4.1 cm³ g^-1 through a rapid microwave-induced plasma treatment. The sheets were used as electrodes for supercapacitors and for the oxygen reduction reaction (ORR) for fuel cells. Argon-plasma grown sheets exhibited a 44% improvement of supercapacitive performance (203 F g^-1) over the plasma grown sheets (141 F g^-1). N-doped sheets with Co₃O₄ showed an outstanding ORR activity evidenced from the much smaller Tafel slope (42 mV/decade) than that of Pt/C (82 mV/decade), which is caused by the high electrical conductivity of the graphene sheets, the planar N species content and the nanoporous morphology.