One-step synthesis of NH2-graphene from in situ graphene-oxide reduction and its improved electrochemical properties
✍ Scribed by Linfei Lai; Luwei Chen; Da Zhan; Li Sun; Jinping Liu; San Hua Lim; Chee Kok Poh; Zexiang Shen; Jianyi Lin
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 891 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0008-6223
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✦ Synopsis
Graphene oxide (GO) is reduced and functionalized with primary amine by a one-pot solvothermal process using ethylene glycol as solvent and ammonia water as nitrogen precursor at 180 °C for 10 h. The reaction is featured by nucleophilic substitution of -COOH and C-O-C groups by the ammonia radicals. The presence of primary amine in graphene is identified by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and proton nuclear magnetic resonance spectra. The atomic ratio of N to C can be tuned within 2-10% by changing the ammonia water to GO weight ratio in the reaction system. The resulting amine modified graphene (NH 2 -G) is an excellent electrochemical material and up to 217.8 F/g high specific capacitance is measured on NH 2 -G electrode at a current density of 0.4 A/g, superior over commercially available GO, chemically reduced GO, activated carbon, and CNT. The as-prepared NH 2 -G shows excellent cycle stability, with negligible decrease of specific capacitance value after thousand cycles.