Abstract
Organic dispersions of graphene oxide can be thermally reduced in polar organic solvents under reflux conditions to afford electrically conductive, chemically active reduced graphene oxide (CARGO) with tunable C/O ratios, dependent on the boiling point of the solvent. The reductions are achieved after only 1 h of reflux, and the corresponding C/O ratios do not change upon further thermal treatment. Hydroxyl and carboxyl groups can be removed when the reflux is carried out above 155 °C, while epoxides are removable only when the temperature is higher than 200 °C. The increasing hydrophobic nature of CARGO, as its C/O ratio increases, improves the dispersibility of the nanosheets in a polystyrene matrix, in contrast to the aggregates formed with CARGO having lower C/O ratios. The excellent processability of the obtained CARGO dispersions is demonstrated via free-standing CARGO papers that exhibit tunable electrical conductivity/chemical activity and can be used as lithium-ion battery anodes with enhanced Coulombic efficiency.
Original language | English (US) |
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Pages (from-to) | 4380-4391 |
Number of pages | 12 |
Journal | ACS nano |
Volume | 5 |
Issue number | 6 |
DOIs | |
State | Published - Jun 28 2011 |
Keywords
- graphene
- graphene oxide
- lithium-ion battery
- surface functionalization
- thermal reduction
ASJC Scopus subject areas
- General Engineering
- General Physics and Astronomy
- General Materials Science