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Highly Concentrated and Conductive Reduced Graphene Oxide Nanosheets by Monovalent Cation– π Interaction: Toward Printed Electronics
Author(s) -
Jeong Seung Yol,
Kim Sung Hun,
Han Joong Tark,
Jeong Hee Jin,
Jeong Soo Yeon,
Lee GeonWoong
Publication year - 2012
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201200242
Subject(s) - graphene , materials science , oxide , raman spectroscopy , chemical engineering , solvent , nanotechnology , inorganic chemistry , organic chemistry , chemistry , physics , engineering , optics , metallurgy
A novel route to preparing highly concentrated and conductive reduced graphene oxide (RGO) in various solvents by monovalent cation– π interaction. Previously, the hydrophobic properties of high‐quality RGO containing few defects and oxygen moieties have precluded the formation of stable dispersion in various solvents. Cation– π interaction between monovalent cations, such as Na + or K + , and six‐membered sp 2 carbons on graphene were achieved by simple aging process of graphene oxide (GO) nanosheets dispersed in alkali solvent. The noncovalent binding forces introduced by the cation– π interactions were evident from the chemical shift of the sp 2 peak in the solid 13 C NMR spectra. Raman spectra and the I ‐ V characteristics demonstrated the interactions in terms of the presence of n ‐type doping effect due to the adsorption of cations with high electron mobility (39 cm 2 /Vs). The RGO film prepared without a post‐annealing process displayed superior electrical conductivity of 97,500 S/m at a thickness of 1.7 μm. Moreover, mass production of GO paste with a concentration as high as 20 g/L was achieved by accelerating the cation– π interactions with densification process. This strategy can facilitate the development of large scalable production methods for preparing printed electronics made from high‐quality RGO nanosheets.