Graphene oxide, reduced graphene oxide and composite thin films NO2 sensing properties

A graphene oxide (GO), reduced graphene oxide (RGO) and poly(3,4-ethylenedioxytiophene)-reduced graphene oxide (PEDOT-RGO composite) gas sensors were successfully fabricated using an electrodeposition method. The electrodeposition was carried out in aqueous GO dispersions. In order to obtain RGO and PEDOT-RGO, the electrochemical reduction of GO and PEDOT-GO was carried out in 0.1 M KCl at constant potential of -0.85 V. The GO, RGO and PEDOT-RGO composites were characterized by scanning and high resolution transmission electron microscopies with electron energy loss spectroscopy, Fourier-transform infrared and Raman spectroscopies. In this work the effect of GO electrochemical reduction process was discussed. The effects of the humidity and sensing response of GO, RGO and PEDOT-RGO to different gases were investigated. It was found out the PEDOT-RGO response to NO2 was much higher than to the other analyzed gases. The influence of the operating temperature on the gas sensing response was compared. The role of the polymer and RGO in PEDOT-RGO composite has been indicated. The results are discussed in light of recent literature on graphene sensors.