Preparation Of Graphene By Electrolytic Exfoliation And Research On Its Structures And Properties

As a new two dimensional nanomaterial, graphene with a number of novel properties has attracted lots of research interests. Different from other carbon materials, both method of massive production and physical properties of graphene need to be investigated more. To obtain more and better graphene in this paper, we research the preparation process and structure properties basing on fabrication by electrochemical exfoliation, main works include:(1) First, graphite paper was used as the raw materials to strip graphite layer by the electrolytic exfoliation method, and then graphene sheets suspensions are got by high-energy ultrasonic dispersion and centrifugal separation in turn. The mixture was prepared including graphene sheets with different sizes and layers by the means of UV-Vis,IR, Raman, XRD, TEM and SEM. Lots of few-layer graphene was prepared when rational speeds are 9000 rpm.(2) The exfoliated parameters was discussed by the orthogonal test method, including the type and concentration of electrolytes, the type of surfactant,and the time of ultrasound. Based on the orthogonal experiment, we also discussed graphite materia、the concentration of surfactant (Polyvinylpyrrolidone, short for PVP) and the order of addition of surfactant and so on. The result was: graphite material was graphite paper, the electrolyte was sodium sulfate whose concentration was 0.15 M, the addition order of the surfactant was before ultrasound and the concentration of surfactant (PVP) was 1Omg mL-1, the ultrasonic time was 30 minutes. concentration of graphene suspensions was 0.18 mg mL-1 after calculation. A graphene membrane was assembled between air and liquid interfaces whose thickness was 27.5μm and its construction unit was 50 nm.