Partially reduced and nitrogen-doped graphene oxides (PRNGs) were prepared through a one-step hydrothermal method with graphene oxide as raw material and phenylethylamine as reducing-doping agents. Benefiting from nitrogen- and oxygen-containing functional groups, interconnected 3D porous networks and high specific surface area, the as-prepared samples demonstrate good electrochemical performances. Particularly, the PRNG-10 electrodes in the wet state show an enhanced gravimetric and volumetric specific capacitance (264.1 F g(-1) and 211.3 F cm(-3)), good rate capability and excellent cycle stability (101.85% of the initial capacitance after 10000 cycles) in 6 M KOH electrolyte.