▎ 摘　　要

Poly(sodium methacrylic acid) brushes are perpendicularly grafted onto graphene oxide and reduced graphene oxide, and used as templates for loading MnO2 nano-particles. The modified graphene oxide has a high loading amount against modified reduced graphene oxide for the more effective three dimensional polymer structure. The graphene oxide based nanocomposites show an outstanding performance as electrode materials for pseudocapacitance (specific capacitance reaches up to 372 F g(-1) at a current density of 0.5 A g(-1), and only 8% drop after 4000 charge-discharge cycles at the same current density).