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The Route to Functional Graphene Oxide
Author(s) -
Haubner Kinga,
Murawski Jan,
Olk Phillip,
Eng Lukas M.,
Ziegler Christoph,
Adolphi Barbara,
Jaehne Evelin
Publication year - 2010
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201000132
Subject(s) - graphene , graphite oxide , oxide , thermogravimetric analysis , graphite , photochemistry , raman spectroscopy , methylene blue , fluorescence , molecule , chemistry , quenching (fluorescence) , materials science , organic chemistry , nanotechnology , catalysis , photocatalysis , physics , optics , quantum mechanics
We report on an easy‐to‐use, successful, and reproducible route to synthesize functionalized graphite oxide (GO) and its conversion to graphene‐like materials through chemical or thermal reduction of GO. Graphite oxide containing hydroxyl, epoxy, carbonyl, and carboxyl groups loses mainly hydroxyl and epoxy groups during reduction, whereas carboxyl species remain untouched. The interaction of functionalized graphene with fluorescent methylene blue (MB) is investigated and compared to graphite, fully oxidized GO, as well as thermally and chemically reduced GO. Optical absorption and emission spectra of the composites indicate a clear preference for MB interaction with the GO derivatives containing a large number of functional groups (GO and chemically reduced GO), whereas graphite and thermally reduced GO only incorporate a few MB molecules. These findings are consistent with thermogravimetric, X‐ray photoelectron spectroscopic, and Raman data recorded at every stage of preparation. The optical data also indicate concentration‐dependent aggregation of MB on the GO surface leading to stable MB dimers and trimers. The MB dimers are responsible for fluorescence quenching, which can be controlled by varying the pH value.