Graphene oxide/polypyrrole/polyaniline composite hydrogel synthesized by vapor-liquid interfacial method for supercapacitors

The main research about the preparation of the conducting polymer/graphene composite hydrogel has been focused on the hydrothermal synthesis or the external gel accelerator. Herein, the composite hydrogel based on graphene oxide (GO) and polypyrrole (PPy) and polyaniline (PANI) is fabricated via vapor-liquid interfacial synthesis. FeCl 3 and GO are dispersed in an aqueous solution. Then, the polymerization of pyrrole and aniline occurs on the interface between their vapor and the above aqueous solution. The effect of FeCl 3 and GO on formation, morphology and performance of composite hydrogel of GO/PPy/PANI is investigated. Furthermore, the specific capacitance of hydrogel is larger than that of composite film obtained without the addition of GO. After 2000 electrochemical cycles at a scan rate of 1 A g −1 , about 91% of the specific capacitance of GO/PPy/PANI composite hydrogel is kept, indicating the enhanced cyclic stability of composite hydrogel. Moreover, graphite paper can be coated by GO/PPy/PANI composite hydrogels and used as binder-free electrodes to construct a flexible solid-state symmetric supercapacitor with excellent cyclic stability and rate capability. This work reveals an easy, efficient, and scalable route for the preparation of the conducting composite hydrogel with improved electrochemical performance. • GO/PPy/PANI composite hydrogel is fabricated by vapor-liquid interfacial synthesis. • The effect of GO and FeCl 3 on the composite hydrogel is investigated. • The specific capacitance of composite hydrogel is improved. • The composite hydrogels are further used to construct a flexible supercapacitor.