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Graphene oxide (GO) films were formed by drop-casting method and were studied by FTIR spectroscopy, micro-Raman spectroscopy (mRS), X-ray photoelectron spectroscopy (XPS), four-points probe method, atomic force microscopy (AFM), and scanning Kelvin probe force (SKPFM) microscopy after low-temperature annealing at ambient conditions. It was shown that in temperature range from 50 to 250 °C the electrical resistivity of the GO films decreases by seven orders of magnitude and is governed by two processes with activation energies of 6.22 and 1.65 eV, respectively. It was shown that the first process is mainly associated with water and OH groups desorption reducing the thickness of the film by 35% and causing the resistivity decrease by five orders of magnitude. The corresponding activation energy is the effective value determined by desorption and electrical connection of GO flakes from different layers. The second process is mainly associated with desorption of oxygen epoxy and alkoxy groups connected with carbon located in the basal plane of GO. AFM and SKPFM methods showed that during the second process, first, the surface of GO plane is destroyed forming nanostructured surface with low work function and then at higher temperature a flat carbon plane is formed that results in an increase of the work function of reduced GO.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2536-z) contains supplementary material, which is available to authorized users.

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Graphene oxide films were formed using the ultrasonic spray coating method and studied with micro-Raman spectroscopy, atomic force microscopy, and electrical dynamic response of resistance measurements. Effect of different gases (water vapor, ethanol, acetone, ammonia, and isopropyl) on the dynamic response of resistance of the Au / graphene oxide / Au structure has been studied. The dynamic response shows that adsorption of all mentioned gases results in increase of the resistance. For ethanol, acetone and isopropyl adsorption and desorption cycles are almost identical. At the same time, in the case of water vapor and ammonia the cycle of desorption is very week, especially for the former, which attests different mechanisms of adsorption/desorption processes regarding to ethanol, acetone and isopropyl. The mechanisms of studied vapors adsorption/desorption are proposed.