Synthesis of a high-temperature stable electrochemically exfoliated graphene. (February 2020)

• Record Type: Journal Article
• Authors: Sharif, Farbod; Zeraati, Ali Shayesteh; Ganjeh-Anzabi, Pejman; Yasri, Nael; Perez-Page, Maria; Holmes, Stuart M.; Sundararaj, Uttandaraman; Trifkovic, Milana; Roberts, Edward P.L.
• Is Part Of: Carbon. Volume 157(2020)
• Page Start: 681
• Page End: 692
• Publication Date: 2020-02
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2019.10.042
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: A new and facile electrochemical exfoliation approach is proposed to produce better quality electrochemically exfoliated graphene with excellent high-temperature stability. The method is based on graphene exfoliation in inorganic electrolytes (e.g. (NH4 )2 HPO4 and (NH4 )2 SO4 and different combinations of these salts) where the electrolyte composition was found to have a significant impact on the yield, morphology, structure, and high-temperature stability of the graphene sheets. The graphene prepared using (NH4 )2 HPO4 electrolyte showed the lowest level of defects in comparison to the other electrochemically exfoliated graphene and an exceptional high-temperature stability in air, at temperatures of up to 750 °C; much higher than typical high surface area carbon materials which are unstable around 400 °C–500 °C in air. The addition of (NH4 )2 SO4 to the (NH4 )2 HPO4 electrolyte improved the exfoliation process and increased the production of single layer graphene sheets from 19% to ∼50%. These hybrid electrolytes also led to nitrogen, phosphorus, and sulphur tri-doped graphene sheets with a fewer defects and high-temperature stability in air. This simple process offers a promising approach for large scale preparation of doped graphene with fewer defects and exceptional properties for various applications. Graphical abstract: Image 1