Direct observation of spatially heterogeneous single-layer graphene oxide reduction kinetics.
Direct observation of spatially heterogeneous single-layer graphene oxide reduction kinetics.
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DOI：
10.1021/nl402057j
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发表时间：
2013-11
期刊：
影响因子：
10.8
通讯作者：
M. P. McDonald;Ahmed Eltom;Felix Vietmeyer;Janak Thapa;Y. Morozov;D. Sokolov;J. Hodak;K. Vinodgopal-K.-Vi
中科院分区：
文献类型：
--
作者：
M. P. McDonald;Ahmed Eltom;Felix Vietmeyer;Janak Thapa;Y. Morozov;D. Sokolov;J. Hodak;K. Vinodgopal-K.-Vi
氧化石墨烯（GO）是制备化学衍生石墨烯的重要前体。在还原过程中，GO的电导率和带隙逐渐发生变化。掺杂和化学功能化也是可能的，说明GO在通过控制其局部杂交来创建功能器件方面的巨大潜力。在这里，我们表明，激光诱导的光解可控地减少个别单层GO片。通过GO的光致发光效率沿着光谱蓝移的相当大的降低，可以在真实的时间内跟踪反应。所产生的还原氧化石墨烯（rGO）片进行额外的光解，其特征在于显着的发射增强和光谱红移。通过其光致发光动力学的电影来捕获GO的还原和随后向光致增亮的rGO的转化。速率图说明了sp（2）结构域生长中相当大的空间和时间不均匀性，并揭示了还原如何在GO和rGO表中"流动"。观察到的非均相还原动力学提供了对GO转化为化学衍生的石墨烯的机理洞察，并突出了克服其动态化学无序的机会。
Graphene oxide (GO) is an important precursor in the production of chemically derived graphene. During reduction, GO's electrical conductivity and band gap change gradually. Doping and chemical functionalization are also possible, illustrating GO's immense potential in creating functional devices through control of its local hybridization. Here we show that laser-induced photolysis controllably reduces individual single-layer GO sheets. The reaction can be followed in real time through sizable decreases in GO's photoluminescence efficiency along with spectral blueshifts. As-produced reduced graphene oxide (rGO) sheets undergo additional photolysis, characterized by dramatic emission enhancements and spectral redshifts. Both GO's reduction and subsequent conversion to photobrightened rGO are captured through movies of their photoluminescence kinetics. Rate maps illustrate sizable spatial and temporal heterogeneities in sp(2) domain growth and reveal how reduction "flows" across GO and rGO sheets. The observed heterogeneous reduction kinetics provides mechanistic insight into GO's conversion to chemically derived graphene and highlights opportunities for overcoming its dynamic, chemical disorder.