▎ 摘　　要

Mesoporous carbon nitrides (MCNs) are considered as one of the most fascinating materials for a variety of applications because of their low cost, high specific surface area, abundant functionalities, and ordered porous structures. However, pristine MCNs suffer from a poor electrical conductivity, thus an inferior supercapacitive performance. Herein, we synthesized MCN via a nano hard-templating approach (using SBA-15 template) and then composited it with the graphene aerogel (GA). The highly conductive metal-free MCN-GA nanocomposite, in which MCN is firmly grafted onto GA via covalent bonding, exhibits a hierarchical porous structure, and demonstrates an exceptional supercapacitive performance among the different materials of the carbon family. The structure-/composition-tailored MCN-GA nanocomposite electrode possesses a specific capacitance of similar to 240 F g(-1) at 5 mV s(-1) in a 1.0 M H2SO4 electrolyte, which is significantly higher than that of the pristine MCN (142 F g(-1)) and GA (174 F g(-1)) electrodes. The symmetric MCN-GA parallel to MCN-GA supercapacitor exhibits an excellent long-term stability with an impressive capacitance retention of >94% after 10,000 charge-discharge cycles, as well as a high specific energy (11.6 W h kg(-1)) and an outstanding specific power (8.0 kW kg(-1)). These results indicate the potential of the MCN-GA nanocomposite for future energy storage applications as well as the other related technologies.