Loading...

Tailoring the graphene polarity through the facile and one-step electrochemical exfoliation in low concentration of exfoliation agents

Goodarzi, M ; Sharif University of Technology | 2020

314 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.flatc.2020.100181
  3. Publisher: Elsevier B.V , 2020
  4. Abstract:
  5. Graphene nanoplatelets with different oxidation degrees, from low polar few-layer graphene (FLG) to high polar graphene oxide (GO) in the same current and concentration of the oxidizing agent in low concentrated electrolytes ((NH4)2SO4, Sodium Do-decyl Sulfate (SDS), and HNO3) are prepared through a one-step and cost-effective electrochemical synthesis route to find the effect of electrolyte on the surface polarity of powders. In order to use a wide variety of electrolytes, basic, neutral, and acidic electrolytes in a concentration as low as 0.2 M are used. Exfoliated graphene nanoplatelets without any further process are obtained to simplify and accelerate the synthesis process. Several characterization methods including XRD, FTIR, TGA, RAMAN, XPS, and UV–Vis tests and electrical conductivity measurement are used to characterize the prepared samples, comprehensively. Results show that the synthesized sample using (NH4)2SO4, neutral electrolyte, is a mixture of FLG and unreacted graphite with the C/O ratio of 4.21, while the sample obtained in SDS, basic electrolyte, is a mixture of FLG, GO, and unreacted graphite with the C/O ration of 2.21. The synthesized sample in HNO3, acidic electrolyte, is a mixture of mainly GO (96.2%) and unreacted graphite (3.8%) with the C/O ratio of 1.22 which is much lower than synthesized powder by Hummers method. The polarity of samples changes dramatically by altering the electrolyte and this can be can be utilized to prepare the graphene nanoplatelets with desired polarity for a specific application. © 2020 Elsevier B.V
  6. Keywords:
  7. Electrochemical exfoliation ; Exfoliation agent ; Graphene ; Surface polarity
  8. Source: FlatChem ; Volume 22 , July , 2020
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S2452262720300301