PEPTIDE-GRAPHENE COMPOSITE MATERIAL IN THE DEVELOPMENT OF ENERGY STORAGE DEVICES

Peptide-based nanostructures of FF derived from natural amino acids are superior building blocks for biocompatible devices. Graphene is considered an ideal two-dimensional reinforcing component for hybrids or composite materials, possessing an extremely large surface area, superior carrier transport, mechanical flexibility and thermal/chemical stability, among a host of notable characteristics1,2,3. In this work, layered FF-rGO nanocomposite materials were investigated. Using Raman spectroscopy, it is possible to prove that graphene is present in the peptide structures. Analyzing the composite spectrum, it is not possible to identify the CH band in 1200 cm-1 typical of the FF, indicating the interaction of the aromatic rings with the rGO. Possibly this band is overlapping by the typical D band of graphene compounds, indicative of structural disorder. The typical band of FF compounds in 1580 cm-1, related to the presence of the aromatic rings, seems to compose and shift the typical G-band of carbon compounds. In S.E.M images a decrease in the size of the microstructures was observed as a larger amount of graphene was added, a result corroborated by the increase of the D band observed in the Raman spectra. In the T.E.M images it is possible to clearly observe the graphene sheets adhered in the peptide matrix. Cyclic voltammetry data indicate that the material exhibits capacitive properties that vary as a function of the amount of graphene added in the matrix, more studies being carried out to quantify the influence of graphene amount on the peptide. The results obtained indicate that the composite material FF-rOG is very promising from the point of view of charge accumulation and that it will be possible to obtain control of this flow by adequately quantifying the amount of graphene dispersed in the peptide.