Fabrication and Characteristics of Reduced Graphene Oxide Produced with Different Green Reductants.

Changyan Xu,Yunqi Cui,Xiaomei Shi,Lina Shi,An Ji,Chen Zhou,Bing Xu

doi:10.1371/journal.pone.0144842

Changyan Xu, Yunqi Cui + Show 5 more

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https://doi.org/10.1371/journal.pone.0144842

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Journal: PloS one	Publication Date: Dec 14, 2015
Citations: 211	License type: CC BY 4.0

Affiliation: Nanjing Forestry University

Abstract

There has been an upsurge of green reductants for the preparation of graphene materials taking consideration of human health and the environment in recent years. In this paper, reduced graphene oxides (RGOs) were prepared by chemical reduction of graphene oxide (GO) with three green reductants, L-ascorbic acid (L-AA), D-glucose (D-GLC) and tea polyphenol (TP), and comparatively characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectra, Raman spectra and electrical conductivity analysis. Results showed that all these three reductants were effective to remove oxygen-containing functional groups in GO and restore the electrical conductivity of the obtained RGO. The RGO sample with L-ascorbic acid as a reductant and reduced with the existence of ammonia had the highest electrical conductivity (9.8 S·cm-1) among all the obtained RGO samples. The mechanisms regarding to the reduction of GO and the dispersion of RGO in water were also proposed. It is the good dispersibility of reduced graphene oxide in water that will facilitate its further use in composite materials and conductive ink.

Highlights

Graphene, a burgeoning material with a honeycomb-like two-dimensional crystal structure formed by carbon atoms in sp2 hybrid junction, exhibits incomparable electronic, thermal, and mechanical properties [1,2,3]
For the reduced graphene oxides (RGOs) samples reduced by L-ascorbic acid (L-AA) with or without the addition of ammonia, the intensity of peaks assigned to oxygen-containing functional groups decreased significantly after reduction, indicating a considerable deoxygenation of graphene oxide (GO)
When L-AA was used as a reductant without the addition of ammonia, the COOH group in decomposition product of L-AA [39] cannot be neutralized by ammonia, which will be responsible for a higher intensity of COOH in L-AA RGO-2

Summary

Introduction

A burgeoning material with a honeycomb-like two-dimensional crystal structure formed by carbon atoms in sp hybrid junction, exhibits incomparable electronic, thermal, and mechanical properties [1,2,3]. It has been paid much attention since its first appearance in 2004 when Geim et al obtained one atomic layer thickness graphene from graphite by peeling with adhesive tape [4]. Graphene presents great potential applications in various fields, including electrodes [5], supercapacitors [6], composite materials [7,8] and sensors [9]. There are several methods to obtain graphene, such as mechanical exfoliation [4,10], epitaxial growth [11], liquid-phase exfoliation of graphite [12,13], chemical vapor deposition [14,15], as well as chemical reduction of graphene

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