Highly Concentrated Aqueous Dispersions of Graphene Exfoliated by Sodium Taurodeoxycholate: Dispersion Behavior and Potential Application as a Catalyst Support for the Oxygen‐Reduction Reaction |
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Authors: | Dr. Zhenyu Sun Justus Masa Prof. Dr. Zhimin Liu Prof. Dr. Wolfgang Schuhmann Prof. Dr. Martin Muhler |
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Affiliation: | 1. Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing (P.R. China);2. Laboratory of Industrial Chemistry, Ruhr‐University Bochum, 44780, Bochum (Germany);3. Analytische Chemie‐Elektroanalytik & Sensorik, Ruhr‐University Bochum, 44780 Bochum (Germany) |
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Abstract: | A high‐yielding exfoliation of graphene at high concentrations in aqueous solutions is critical for both fundamental study and future applications. Herein, we demonstrate the formation of stable aqueous dispersions of pristine graphene by using the surfactant sodium taurodeoxycholate under tip sonication at concentrations of up to 7.1 mg mL?1. TEM showed that about 8 % of the graphene flakes consisted of monolayers and 82 % of the flakes consisted of less than five layers. The dispersions were stable regardless of freezing (?20 °C) or heat treatment (80 °C) for 24 h. The concentration could be significantly improved to about 12 mg mL?1 by vacuum‐evaporation of the dispersions at ambient temperature. The as‐prepared graphene dispersions were readily cast into conductive films and were also processed to prepare Pt/graphene nanocomposites that were used as highly active electrocatalysts for the oxygen‐reduction reaction. |
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Keywords: | electrochemistry exfoliation graphene oxygen surfactants |
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