Layer-by-layer assembly of graphene/polyaniline multilayer films and their application for electrochromic devices

Graphene/polyaniline (PANI) multilayer films were prepared via alternate deposition of negatively charged graphene oxide (GO) and positively charged PANI upon electrostatic interaction, followed by the reduction of their GO components with hydroiodic acid. The thickness of the multilayer film increased linearly with the number of its bilayers and that of each bilayer was measured to be about 3 nm. Cyclic voltammetry studies indicated that these thin composite films were electroactive, and their redox reactions were related to the insertion-extraction of counter ions in PANI layers. Furthermore, the composite films were tested to be promising electrode materials for electrochromic devices even without using the conventional indium tin oxide (ITO) electrodes.

Highlights► Multilayer films of graphene and polyaniline were prepared by layer-by-layer assembly. ► The multilayer films are conductive, electroactive and transparent. ► The multilayer films are promising electrode materials for electrochromic devices.