Facile synthesis and characterization of three-dimensional graphene/polyaniline composites with enhanced electrochemical properties

In situ polymerization of aniline was carried out within graphene hydrogels with the ultrasonic treatment, and thus the polyaniline (PANI) was loaded and the three-dimensional (3D) graphene/PANI aerogel composite (GPA) was facilely obtained after freeze drying. The investigation shows that the polyaniline as twisted nano-rods was formed and scattered in the interconnected porous 3D graphene. When a supercapacitor electrode was fabricated with the composite GPA, the specific capacitance at a current density of 1 A g⁻¹ can reach as high as 618 F g⁻¹. The capacity retains 89% of the initial value in constant current charge–discharge mode (at the current density of 10 A g⁻¹) after 2000 cycles. The improved electrochemical properties were confirmed to be resulted from the unique network morphology, enhanced conductivity and the synergy effect between graphene and polyaniline. The composite GPA is self-supporting and can be directly used as the electrode material without adding binders. This contribution provides a simple method to prepare the electrode material with enhanced electrochemical properties based on graphene. The GPA composite shows great potential for application in supercapacitors.