Preparation of Partially Reduced Graphene Oxide Nanosheets/Poly(Sodium 4-Styrenesulfonate) Composite with High Capacitance

Partially reduced graphene oxide nanosheet (prGON)/poly(sodium 4-styrenesulfonate) (PSS) composite with very high specific capacitance were prepared. Graphene oxide nanosheets (GON) were firstly partially reduced by a weak reducing agent, and PSS was attached to prGON through π–π stacking, acting as a spacer to prevent prGON from agglomeration. Otherwise, PSS could only bind GON through combining with the hydroxyl groups on GON. The prGON/PSS composite was then potentiostatically reduced at a constant potential. During the electrochemical reduction, the carbonyl groups on the prGON/PSS composite were gradually reduced to other oxygen functionalities instead of being removed. The redox-active oxygen-containing groups on the electrochemically reduced prGON/PSS composite were stable in the potential scanning range, and introduced pseudo-capacitance. The specific capacitance of the prGON/PSS composite after electrochemical reduction reached 367.2 F/g in 1 M KCl aqueous solution at the scanning rate of 5 mV/s, and retained its 93.8% capacitance after 1600 cycles. The superior capacitance performance can be ascribed to the outstanding intrinsic properties of graphene, the PSS spacer attached to prGON through π-π stacking, and the pseudo-capacitance introduced by the oxygen-containing groups.

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