Temperature dependence of graphene oxide reduced by hydrazine hydrate
Temperature dependence of graphene oxide reduced by hydrazine hydrate
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水合肼还原氧化石墨烯的温度依赖性
DOI：
10.1088/0957-4484/22/5/055705
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发表时间：
2011-02-04
期刊：
影响因子：
3.5
通讯作者：
Li, Zhong-Ming
中科院分区：
文献类型：
--
作者：
Ren, Peng-Gang;Yan, Ding-Xiang;Li, Zhong-Ming
采用改进的Hummer法成功制备了氧化石墨烯（GO）。采用X射线光电子能谱（XPS）、傅里叶变换红外光谱（FTIR）、元素分析（EA）、X射线衍射（XRD）、拉曼光谱（Raman）和热重分析（TGA）等方法对不同还原温度和时间下水合肼还原GO的效果和机理进行了表征。结果表明，GO的还原效果主要取决于处理温度而不是处理时间。只有在高处理温度下才能获得所需的GO还原。在95 ° C下还原3小时，GO的C/O原子比从3.1增加到15.1，这在低温例如80、60或15 ° C下甚至对于更长的还原时间也不可能获得。XPS、13 C NMR和FTIR结果表明，氧化过程中与石墨结合的环氧基团在高温下被水合肼还原后，大部分从GO上除去，形成sp（2）结构（>60 ℃），导致GO的电导率从1.5 × 10（6）增加到5 S cm（-1），而氧化石墨烯表面的羟基即使在高温下也不能被水合肼去除。此外，FTIR、XRD和拉曼光谱表明，水合肼还原的GO不能完全恢复到原始的石墨结构。XPS和FTIR数据还表明，羰基和羧基可以被水合肼还原，并可能形成腙，但不是C=C结构。
Graphene oxide (GO) was successfully prepared by a modified Hummer's method. The reduction effect and mechanism of the as-prepared GO reduced with hydrazine hydrate at different temperatures and time were characterized by x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA), x-ray diffractions (XRD), Raman spectroscopy and thermo-gravimetric analysis (TGA). The results showed that the reduction effect of GO mainly depended on treatment temperature instead of treatment time. Desirable reduction of GO can only be obtained at high treatment temperature. Reduced at 95 degrees C for 3 h, the C/O atomic ratio of GO increased from 3.1 to 15.1, which was impossible to obtain at low temperatures, such as 80, 60 or 15 degrees C, even for longer reduction time. XPS, 13C NMR and FTIR results show that most of the epoxide groups bonded to graphite during the oxidation were removed from GO and form the sp(2) structure after being reduced by hydrazine hydrate at high temperature (>60 degrees C), leading to the electric conductivity of GO increasing from 1.5 x 10 (6) to 5 S cm(-1), while the hydroxyls on the surface of GO were not removed by hydrazine hydrate even at high temperature. Additionally, the FTIR, XRD and Raman spectrum indicate that the GO reduced by hydrazine hydrate can not be entirely restored to the pristine graphite structures. XPS and FTIR data also suggest that carbonyl and carboxyl groups can be reduced by hydrazine hydrate and possibly form hydrazone, but not a C=C structure.