X-ray absorption spectroscopy study on the thermal and hydrazine reduction of graphene oxide
X-ray absorption spectroscopy study on the thermal and hydrazine reduction of graphene oxide
复制标题
氧化石墨烯热还原和肼还原的X射线吸收光谱研究
DOI：
10.1016/j.elspec.2013.10.011
复制
发表时间：
2014-10-01
影响因子：
1.9
通讯作者：
Wu, Ziyu
中科院分区：
文献类型：
--
作者：
Liang, Xianqing;Wang, Yu;Wu, Ziyu
用X射线吸收光谱(XAS)系统地研究了氧化石墨烯(GO)经退火和联氨处理后的脱氧过程。详细介绍了GO的电子结构和化学键的演变过程。C K边XAS谱中pi*共振强度的增强和分裂sigma*共振的出现表明，用热退火或肼还原时，pi共轭的恢复率很高。实验结果表明，在较高的温度下，GO表面的羧基以及环氧化物和羟基首先被热还原，其次是更难去除的羰基和环醚基团。肼还原可以有效地去除环氧化物、羟基和羧基，而随着氮物种的加入，部分羰基被还原。肼还原GO上的残氧官能团在适度的热退火后被进一步去除。有人提出，这两种还原的组合将为石墨烯的生产提供最佳的脱氧效率。(C)2013爱思唯尔B.V.保留所有权利。
X-ray absorption spectroscopy (XAS) was applied to systemically investigate the deoxygenation of graphene oxide (GO) via annealing and hydrazine treatment. Detailed evolution of the electronic structures and chemical bonding of GO was presented. The enhanced intensity of pi* resonance and the appearance of splitting sigma* resonance in C K-edge XAS spectra suggest high extents of recoveries of pi-conjugation upon reduction using thermal annealing or hydrazine. Experimental results revealed that the carboxyl as well as epoxide and hydroxyl groups on the surface of GO were thermally reduced first, followed by the more difficult removal of carbonyl and cyclic ether groups at higher temperatures. The hydrazine reduction could remove epoxide, hydroxyl and carboxyl groups effectively, whereas the carbonyl groups were partially reduced with the incorporation of nitrogen species simultaneously. The residual oxygen functional groups on hydrazine-reduced GO could be further removed after modest thermal annealing. It was proposed that a combination of both types of reductions would give the best deoxygenation efficiency for the production of graphene. (C) 2013 Elsevier B.V. All rights reserved.