Scalable enhancement of graphene oxide properties by thermally driven phase transformation
Scalable enhancement of graphene oxide properties by thermally driven phase transformation
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DOI：
10.1038/nchem.1820
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发表时间：
2014-02-01
期刊：
影响因子：
21.8
通讯作者：
Grossman, Jeffrey C.
中科院分区：
文献类型：
--
作者：
Kumar, Priyank V.;Bardhan, Neelkanth M.;Grossman, Jeffrey C.
石墨烯的化学功能化有望用于各种下一代技术。尽管氧化石墨烯（GO）在该方向上是一种通用材料，但其使用受到在当前合成方案下产生亚稳态、化学不均匀和空间无序的GO结构的限制，这导致较差的光电性能。在这里，我们提出了一个温和的热退火程序，没有涉及化学处理，以操纵合成GO在大规模上，以提高片性能与氧含量保存。使用原子计算支持的实验，我们表明，GO结构进行相变到突出的氧化和石墨域的温度驱动的氧扩散。因此，主要在紫外区吸收的合成GO在可见光区变得强烈吸收，光致发光蓝移，电子电导率增加高达四个数量级。我们的热处理方法提供了一种合适的方式来调整和增强GO的性能，这为各种应用创造了机会。
Chemical functionalization of graphene is promising for a variety of next-generation technologies. Although graphene oxide (GO) is a versatile material in this direction, its use is limited by the production of metastable, chemically inhomogeneous and spatially disordered GO structures under current synthetic protocols, which results in poor optoelectronic properties. Here, we present a mild thermal annealing procedure, with no chemical treatments involved, to manipulate as-synthesized GO on a large scale to enhance sheet properties with the oxygen content preserved. Using experiments supported by atomistic calculations, we demonstrate that GO structures undergo a phase transformation into prominent oxidized and graphitic domains by temperature-driven oxygen diffusion. Consequently, as-synthesized GO that absorbs mainly in the ultraviolet region becomes strongly absorbing in the visible region, photoluminescence is blue shifted and electronic conductivity increases by up to four orders of magnitude. Our thermal processing method offers a suitable way to tune and enhance the properties of GO, which creates opportunities for various applications.