▎ 摘　　要

Mesoporous graphene materials (MG-X) were prepared from potassium humate coupled with magnesium acetate. The freeze-drying pretreatment and MgO particles not only prevent the agglomeration of graphene sheets and form mesopores but also help to reduce the oxygen content and enlarge the sp(2) carbon domain of MG-X. MG-X possess optimized characteristics including large specific surface area (>1100 m(2).g(-1)), high mesoporosity (similar to 90%), and low oxygen content (similar to 7%). When used as supercapacitor electrodes, MG-X demonstrate optimal electrochemical performances among all materials prepared here, such as high gravimetric capacitance (150 F.g(-1) at high current density of 3.3 A.g-(1))and enhanced rate capability with the capacitance retention of similar to 80% from 0.041 to 3.3 A.g(-1). Moreover, MG-5 exhibits good cycling stability with a capacitance retention of 98.6% after 1000 cycles at 2.46 A.g(-1). This work provides a facile and efficient preparation method for mesoporous graphene materials used as supercapacitor electrodes.