Sandwich-like functionalized free-standing and flexible graphene papers for supercapacitors

The development of flexible and free-standing electrodes is a key step for fabrication of flexible and compact electronic and energy devices which is of significant interests in portable electronics. This is increasingly demanded by modern electronics, portable medical products, and compact energy devices. Hybrid electrodes with functional nanocrystals anchored on carbon substrates are under intense research for a broad spectrum of applications in sensing, energy conversion and storage, and catalysis. Among carbon materials, graphene, consisting of a single-layer of sp²-hybridized carbon atoms, has emerged as a new class of supporting scaffolds for nanocrystals because of a unique collection of structural and electronic properties such as large surface areas, chemical inertness, and superior electrical conductivity. As a two-dimensional (2D) transition metal dichalcogenide (TMDC), tin disulfide (SnS₂) is a promising material for multiple applications in supercapacitors, lithium ion batteries and photocatalysis due to its excellent optical and electrical properties. In this poster, we present a facile approach to the preparation of sandwich-like paper electrodes with Au nanoparticle-decorated reduced graphene oxide paper (rGOPAuNPs) as substrates and 2D SnS₂ nanoflake-anchored reduced graphene oxide (SnS₂@rGO) nanosheets as high-performance supercapacitive material. The 2D self-assemblies of Au nanoparticles (AuNPs) on the surface of graphene papers can enhance electrode conductivity and facilitate electron transfer between rGOP and SnS₂@rGO, as well as serve as a strength reinforcing component by forming stable Au-S bonds. The proposed paper electrodes show the combined advantages contributed from both graphene paper substrates and self-assemblied AuNPs layers as well as could improve conductivity of 2D SnS₂ nanoflakes. Our results show the promise that this approach could evolve to be a universal strategy for practical fabrication of multifunctional flexible portable paper electrodes for energy storage and sensing devices.