▎ 摘　　要

We report a simple method to prepare N-doped mesoporous reduced graphene oxide (RGO) via the pyrolysis of poly (methyl methacrylate)-graphene oxide (PMMA-GO) and PMMA-RGO composites in a mixed nitrogen and ammoniac atmosphere. The pyrolysis of the PMMA-GO resulted in a heavily nitrogen-doped RGO aerogel with a nitrogen content of more than 5.0 at%, whereas crumpled RGO with a surface area of up to 766 m(2) g(-1) was obtained by the pyrolysis of PMMA-RGO. A supercapacitor based on the N-doped mesoporous RGOs exhibited an excellent specific capacitance of up to 290 F g(-1) at a current density of 1 A g(-1) and good electrochemical stability with a capacitance retention of about 85% after 1000 cycles. Moreover, by using an ionic liquid as an electrolyte within a potential range of 0-4 V, a remarkable energy density of up to 149 W h kg(-1) was achieved.