Superior Electrochemical Performance of Graphene via Carboxyl Functionalization and Surfactant Intercalation

Superior capacitance of carboxyl functionalized and surfactant-intercalated graphene were prepared by a relatively simple with two-step solution-based processing technique. In comparison to pristine graphene, surface carboxyl functionalization and surfactant intercalation can tailor its specific capacitance from 50 F/g to 230 F/g. Meanwhile, the modified materials retain more than 95% of their capacitance after 800 charge-discharge cycles, demonstrating good cyclic stability. Surfactant itself cannot improve the performance of pristine graphene as graphene intercalated with surfactant has a specific capacitance of 45 F/g, however, carboxyl groups can dramatically enhance specific capacitance to 130 F/g. The excellent performance of functionalized graphene emphasizes the importance of controlling its surface chemistry.