X-ray Absorption Study of Graphene Oxide and Transition Metal Oxide Nanocomposites.
X-ray Absorption Study of Graphene Oxide and Transition Metal Oxide Nanocomposites.
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DOI：
10.1021/jp503941t
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发表时间：
2014-08-14
期刊：
影响因子：
--
通讯作者：
Meyyappan M
中科院分区：
文献类型：
--
作者：
Gandhiraman RP;Nordlund D;Javier C;Koehne JE;Chen B;Meyyappan M
电极材料的表面性质在决定储能装置的性能和效率方面起着至关重要的作用。合成了用于超级电容器电极的氧化石墨烯和三维过渡金属氧化物纳米结构，并利用近边X射线吸收精细结构对其电子结构和氧化态进行了研究。了解氧化石墨烯的化学性质将为其反应性和性质提供有价值的见解，因为氧化石墨烯转化为还原氧化石墨烯是合成电极材料的关键步骤。利用同步辐射X射线的偏振行为和近边X射线吸收精细结构（NEXAFS）的角度依赖性来研究氧化石墨烯和氧化石墨烯-金属氧化物纳米复合材料的σ和π键的取向。单个金属氧化物和氧化石墨烯纳米复合材料的核能级跃迁表明，氧化石墨烯与金属氧化物纳米结构的相互作用并没有改变它们中任何一个的电子结构。由于π网络的恢复对于良好的导电性是重要的，还原的氧化石墨烯纳米复合材料的C K边缘NEXAFS光谱通过sp2衍生的未占据态π* 带的强度增加证实了相同的结果。还原样品的显著角度依赖性和激子峰的形成证实了扩展共轭网络的形成。
The surface properties of the electrode materials play a crucial role in determining the performance and efficiency of energy storage devices. Graphene oxide and nanostructures of 3d transition metal oxides were synthesized for construction of electrodes in supercapacitors, and the electronic structure and oxidation states were probed using near-edge X-ray absorption fine structure. Understanding the chemistry of graphene oxide would provide valuable insight into its reactivity and properties as the graphene oxide transformation to reduced-graphene oxide is a key step in the synthesis of the electrode materials. Polarized behavior of the synchrotron X-rays and the angular dependency of the near-edge X-ray absorption fine structures (NEXAFS) have been utilized to study the orientation of the σ and π bonds of the graphene oxide and graphene oxide–metal oxide nanocomposites. The core-level transitions of individual metal oxides and that of the graphene oxide nanocomposite showed that the interaction of graphene oxide with the metal oxide nanostructures has not altered the electronic structure of either of them. As the restoration of the π network is important for good electrical conductivity, the C K edge NEXAFS spectra of reduced graphene oxide nanocomposites confirms the same through increased intensity of the sp2-derived unoccupied states π* band. A pronounced angular dependency of the reduced sample and the formation of excitonic peaks confirmed the formation of extended conjugated network.
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影响因子：
3.7
作者：
Ganguly, Abhijit;Sharma, Surbhi;Hamilton, Jeremy
通讯作者：
Hamilton, Jeremy
DOI：
10.1016/0368-2048(88)80005-7
发表时间：
1988-01-01
影响因子：
1.9
作者：
ISHII, I;HITCHCOCK, AP
通讯作者：
HITCHCOCK, AP
影响因子：
2.7
作者：
DEGROOT, FMF;ABBATE, M;SETTE, F
通讯作者：
SETTE, F
影响因子：
10.8
作者：
Gomez-Navarro, Cristina;Weitz, R. Thomas;Kern, Klaus
通讯作者：
Kern, Klaus
影响因子：
8.6
作者：
BRUHWILER, PA;MAXWELL, AJ;MARTENSSON, N
通讯作者：
MARTENSSON, N