A facile approach to fabricating ultrathin layers of reduced graphene oxide on planar solids

Fabrication of graphene-based surface coatings through self-assembly may provide an affordable alternative to chemical vacuum deposition. Herein, we exploited the self-assembly of graphene oxide at the oil/water interfaces to form monolayers of 2D carbons on solid surfaces with different surface energy. We showed that interfacial monolayers with controlled packing density of graphene oxide can be deposited on the hydrophilic surfaces such as silicon wafers and quartz glass as well as on the hydrophobic surface of Teflon. Graphene oxide attained flat arrangements in the monolayers on hydrophilic surfaces and yielded the films of partially scrolled particles on the surface of Teflon. The as-formed graphene oxide surface coatings underwent rapid reduction under microwave irradiation at 1000W. The efficiency of reduction was dependent on the ability of the supporting material to absorb microwaves: silicon wafer > quartz glass > Teflon. The single layers of graphene oxide reduced on the surface of silicon wafers showed extraordinary low sheet resistance 1.2 k Omega. sq(-1), whereas those on Teflon exhibited low electrical properties ( 3.0 +/- 10(5) k Omega.sq(-1)). The results suggest that this facile and scalable soft-matter method for producing surface films of graphene oxide can be extended to other practically relevant combinations of graphene-based colloids and supporting materials. (C) 2018 Elsevier Ltd. All rights reserved.