### 石墨烯表界面化学修饰及其功能调控

1. a 北京大学前沿交叉学科研究院 纳米科学与技术研究中心 北京 100871;
b 北京大学纳米化学研究中心 北京分子科学国家实验室 分子动态与稳态国家重点实验室 化学与分子工程学院 北京 100871;
c 北京大学工学院材料科学与工程系 北京 100871
• 投稿日期:2013-08-29 发布日期:2013-10-30
• 通讯作者: 郭雪峰，E-mail：guoxf@pku.edu.cn；Tel.：0086-010-62757789；Fax：0086-010-62757789 E-mail:guoxf@pku.edu.cn
• 基金资助:

项目受国家自然科学基金（Nos. 21225311，21373014，51121091）和国家重点基础研究发展计划（973）（No. 2012CB921404）资助.

### Chemical Modification of Graphene and Its Applications

Lin Yuanweia,b, Guo Xuefengb,c

1. a Center for Nanoscience and Nanotechnology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871;
b Center for NanoChemistry, Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871;
c Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871
• Received:2013-08-29 Published:2013-10-30
• Supported by:

Project supported by the National Natural Science Foundation of China (Nos. 21225311, 21373014 and 51121091), and the National Key Basic Research Program of China (973) (No. 2012CB921404).

Graphene, a two-dimensional crystalline monolayer made of sp2-hybridized carbon atoms arranged in a honeycomb lattice, holds a set of remarkable electronic and physical properties, such as ballistic transport with low resistivity, high chemical stability, and high mechanical strength. By taking advantage of these, in recent years our research group has performed a series of studies for modifying the surfaces of graphene and tuning its properties. These studies can be mainly divided into two categories. First, we opened graphene's band gap to some extent through covalent and/or noncovalent chemical modifications, and installed sensing functions into graphene. In detail, we grafted nitrophenyl group onto graphene through an electrochemical method and methyl group onto graphene by plasma treatment to open its band gap. Also, we assembled lead sulfide or titanium dioxide onto graphene through electron beam evaporation to achieve optical or gas sensing. A rotaxane molecule with a bistable structure was also assembled onto graphene through π-π stacking to obtain optical switches with logic capability. On the other hand, we also fabricated graphene-based nanoelectrodes for making a new-generation molecular electronic devices with diverse functionalities. In detail, we cut graphene using electron beam lithography and reactive ion etching to obtain graphene electrodes. Poly(3-hexyl thiophene) or copper phthalocyanine was spin-coated onto these electrodes to achieve field effect transistors with the high carrier mobility and photoresponsive property. We further developed graphene nanoelectrodes by dash-line lithography, and molecular bridges with different functions were connected between these nanoelectrodes. These single molecule devices can switch their conductance upon exposure to external stimuli, such as metal ion, pH and light. Looking into the future, graphene, as a representative of carbon-based nanomaterials, will continue to play an important role in the area of nano/molecular electronics.