Bacteriorhodopsin as a superior substitute for hydrazine in chemical reduction of single-layer graphene oxide sheets

Akhavan, O ; Sharif University of Technology | 2015

698 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.carbon.2014.09.044
  3. Publisher: Elsevier Ltd , 2015
  4. Abstract:
  5. Bacteriorhodopsin (bR) molecules were utilized as light-driven proton pumps for green as well as effective reduction of single-layer graphene oxide (GO) sheets. The bR molecules and graphene sheets were separated from each other in an aqueous environment by using a polytetrafluoroethylene membrane filter, in order to prevent their direct interactions (including attachment of the bR molecules onto the GO). Although reduction of GO using hydrazine or bR showed similar deoxygenation levels (based on X-ray photoelectron spectroscopy), the former resulted in formation of CAN bonds which can substantially decrease the electrical conductivity of the reduced sheets. The electrical characteristics of the singlelayer graphene sheets were studied by recording current-voltage curves of the sheets located between two Au electrodes on a SiO2 (300 nm)/Si (100) substrate. The electrical conductivity of the bR-reduced graphene oxide (rGO) sheets was found about one order of magnitude better than that of hydrazine-rGO sheets. The excellent electrical conductivity of the bR-rGO sheets (with sheet resistance of ∼7.1 × 104 X/sq) was assigned to the effective deoxygenation (without formation of any CAN bonds) and better restoration of the graphitic structure of the GO sheets, using the protons pumped by the bR molecules
  6. Keywords:
  7. Electric conductivity ; Hydrazine ; Molecules ; Protons ; Reduction ; X ray photoelectron spectroscopy ; Bacteriorhodopsin (bR) ; Current voltage curve ; Direct interactions ; Electrical characteristic ; Electrical conductivity ; Graphitic structures ; Polytetrafluoroethylene membranes ; Reduced graphene oxides (RGO) ; Graphene
  8. Source: Carbon ; Volume 81, Issue 1 , 2015 , Pages 158-166 ; 00086223 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0008622314008963