Evolutionary Chlorination of Graphene: From Charge-Transfer Complex to Covalent Bonding and Nonbonding

详细信息    查看全文

• 作者：Mingmei Yang ; Lin Zhou ; Jinying Wang ; Zhongfan Liu ; Zhirong Liu
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：January 12, 2012
• 年：2012
• 卷：116
• 期：1
• 页码：844-850
• 全文大小：489K
• 年卷期：v.116,no.1(January 12, 2012)
• ISSN：1932-7455

文摘

Density functional theory (DFT) studies were performed to investigate the chlorination of graphene. Unlike hydrogenation and fluorination, where the adsorption of H and F is always by covalent C鈥揌/C鈥揊 bonding, Cl atoms generate various states when single-sided graphene exposed. In the initial reaction stage, it forms Cl鈥揼raphene charge-transfer complex, where the C orbitals keep sp² hybridization and the graphene is p-type doped. Further chlorination may form two adsorption configurations: one is covalent bonding Cl pairs, where the structure of the C atom is close to sp³ hybridization. With the Cl coverage increases, this configuration may further cluster into hexagonal rings, and the resulting coverage is less than 25%. The other configuration is nonbonding. This configuration is energy preferable, while Cl atoms will form Cl₂ molecules and escaped. When both sides of the graphene are exposed, the most stable adsorption configuration is a homogeneous ordered pattern with a Cl coverage of 25% (C₄Cl) rather than collective clusters. The electronic properties of various chlorinated forms were also obtained; these showed that it is possible to tune the graphene bandgap by chlorination in a range of 0鈥?.3 eV.