Electrostatic layer-by-layer self-assembly multilayer films based on graphene and manganese dioxide sheets as novel electrode materials for supercapacitors

A new class of multilayer films was constructed by electrostatic layer-by-layer self-assembly, using poly(sodium 4-styrenesulfonate) mediated graphene sheets (PSS-GS), manganese dioxide (MnO2) sheets, and poly(diallyldimethylammonium) (PDDA) as building blocks. UV-vis spectroscopy, field-emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the microstructures and morphologies of the multilayer films. Capacitive properties of the synthesized multilayer film electrodes were studied using cyclic voltammetry and galvanostatic charge/discharge in 0.1 M Na2SO4 electrolyte. The specific capacitance of the ITO/(PDDA/PSS-GS/PDDA/MnO2)(10) electrode reached 263 F g(-1) at a discharge current density of 0.283 A g(-1); moreover, this film electrode also shows a good cyclic stability and high Coulombic efficiency. Anticipatedly, the synthesized multilayer films will find promising applications as a novel electrode material in supercapacitors and other devices in virtue of their outstanding characteristics of controllable capacitance, good cycle stability, low cost and environmentally benign nature.