Influence of Gas Adsorption on the Impedance of Graphene Oxide

Graphene oxide (GO) and reduced graphene oxide (rGO) films were formed by ultrasonic spray coating method and were studied by micro-Raman spectroscopy (mRS), current-voltage characteristics and impedance spectroscopy. Raman spectra of GO and rGO films shows two typical peaks, with maxima at ~1350 cm
^-1
and ~1590 cm
^-1
(D and G bands). One semicircle on the Nyquist curve of gold/graphene oxide/gold structure suggests the existence of homogeneous regions. Adsorption of ethanol, acetone and isopropyl vapors changes electrical conductivity of graphene oxide films in different way. The sensing mechanisms to the organic vapors are discussed.