▎ 摘　　要

Dense 3D graphene macroforms with nanotuned pore sizes have been synthesized using graphene oxide as the precursor and aqueous H2SO4 as the mediator by coupling the hydrothermal method with an evaporation drying process. Depending on the contents of concentrated H2SO4 trapped in the resultant carbons, the pore size of graphene macroforms in the range of about 0.5-4.8 nm can be obtained. The results indicate that liquid H2SO4 trapped in graphene macroforms can act as the spacer of wrinkled graphene sheets, the catalyst of the dehydration, and the electrolyte of the supercapacitor. The pore sizes of the carbons play an important role in the electrochemical performances when used as the supercapacitor electrodes. The graphene macroform with an average pore size of 4.8 nm is an excellent electrode material in H2SO4 electrolyte. Its specific capacitance is up to 230 F g(-1) at the current density of 0.1 A g(-1), and the specific energy density and power density are up to 8.3 Wh kg(-1) and 1000 W kg(-1) in a two-electrode cell, respectively. The good electrochemical properties of as-made carbons may be attributed to the highly efficient ion transport channels in H2SO4-mediated graphene macroforms.