Real time in situ monitoring the thermal reduction of individual graphene oxide sheets with vibrating scanning polarization force microscope

By controlling the reduction degree of graphene oxide(GO),varied electronic properties of graphene which can be applied in the construction of electronics can be obtained.Vibrating scanning polarization force microscopy(VSPFM) was used to real-time monitor the process of the thermal reduction of GO.The VSPFM images reveal inhomogeneous distribution of the local dielectric constant of the GO sheets during thermal reduction.Our results suggest that reduction of GO is conducted in a domain-by-domain fashion,and the reduction progress in different GO sheets is not synchronized.GO and reduced GO(rGO) sheets show different contrast in the VSPFM images,which can be used to distinguish them on mica,glass surfaces and even on a single GO sheet directly by measuring their apparent heights.This method of real time in situ monitoring the GO sheets with varied reduction degree will push forward its application to nanoscale electronics.