Rapid synthesis of thin amorphous carbon films by sugar dehydration and dispersion

Abstract

We have prepared amorphous carbon films with variable thicknesses down to <5 nm using a simple procedure which takes minutes and employs no special equipment. We prepare a carbonaceous suspension by the dehydration reaction of sulfuric acid with glucose and show that adding this mixture dropwise into water creates a thin carbon film on the water’s surface which can be transferred to an arbitrary substrate. This transparent brown film is non-conductive and has a chemical makeup, excluding hydrogen, of CS0.0213O0.4563. After brief annealing under 10% H2 in argon at 800 °C, the film has a high optical contrast and increased conductivity, with a chemical makeup of CO0.0828, suggesting that the material has at least short-range graphitic order. We repeat the experiment with chitosan replacing glucose and show using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) that it is likely that nitrogen incorporates into the graphitic lattice.