DFT study of the chemistry of sulfur in graphite, including interactions with defects, edges and folds
DFT study of the chemistry of sulfur in graphite, including interactions with defects, edges and folds
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DOI：
10.1016/j.carbon.2013.05.063
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发表时间：
2013-10
期刊：
影响因子：
10.9
通讯作者：
J. Adjizian;C. D. Latham;S. Öberg;P. Briddon;M. Heggie
中科院分区：
文献类型：
--
作者：
J. Adjizian;C. D. Latham;S. Öberg;P. Briddon;M. Heggie
硫在石墨化过程中有几种理想的和不理想的作用。我们在局部密度近似内执行密度泛函理论计算，以定义石墨中硫的结构和能量学，包括其与点缺陷和边缘的相互作用，以了解其在石墨化后期阶段的作用。我们发现硫不能交联层，除非有缺陷的地方。它与邻近层中的空位反应非常强烈，形成六坐标的分裂空位结构，类似于钻石中的结构。它在基缘位点也高度稳定，在那里，正如预期的那样，硫的大小和价可以很容易地调节。这表明硫在稳定石墨烯边缘方面的作用，由此，我们表明硫二聚体可以快速和放热地打开，即解压缩石墨中的折叠。
Sulfur has several roles, desirable and undesirable, in graphitization. We perform density functional theory calculations within the local density approximation to define the structures and energetics of sulphur in graphite, including its interactions with point defects and edges, in order to understand its role in the later stages of graphitization. We find sulphur does not cross-link layers, except where there are defects. It reacts very strongly with vacancies in neighbouring layers to form a six coordinate split vacancy structure, analogous to that found in diamond. It is also highly stable at basal edge sites, where, as might be expected, the size and valency of sulfur can be easily accommodated. This suggests a role for sulphur in stabilizing graphene edges, and following from this, we show that sulfur dimers can open, i.e. unzip, folds in graphite rapidly and exothermically.