Layer-by-Layer Self-Assembled Graphene Multilayer Films via Covalent Bonds for Supercapacitor Electrodes

To maximize the utilization of its single-atom thin nature, a facile scheme to fabricate graphene multilayer films via a layer-by-layer self-assembled process was presented. The structure of multilayer films was constructed by covalently bonding graphene oxide (GO) using p-phenylenediamine (PPD) as a covalent cross-linking agent. The assembly process was confirmed to be repeatable and the structure was stable. With the pi-pi conjugated structure and a large number of spaces in the framework, the graphene multilayer films exhibited excellent electrochemical performance. The uniform ultrathin electrode exhibited a capacitance of 41.71 mu F/cm(2) at a discharge current of 0.1 mu A/cm(2), and displayed excellent stability of 88.9 % after 1000 charge-discharge cycles.