Monolayer Selective Methylation of Epitaxial Graphene on SiC(0001) through Two-Step Chlorination鈥揂lkylation Reactions

详细信息    查看全文

• 作者：Md. Zakir Hossain ; Maisarah B. A. Razak ; Hiroyuki Noritake ; Yuichiro Shiozawa ; Shinya Yoshimoto ; Kozo Mukai ; Takanori Koitaya ; Jun Yoshinobu ; Sumio Hosaka
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：September 25, 2014
• 年：2014
• 卷：118
• 期：38
• 页码：22096-22101
• 全文大小：334K
• ISSN：1932-7455

文摘

One of the real challenges in realization of many of graphene鈥檚 anticipated applications is the development of a common chemical route for modifying graphene with varieties of functionalities. Here, we successfully demonstrate the organic modification of epitaxial graphene (EG) grown on the Si-face of SiC substrate through two-step chlorination鈥揳lkylation reactions. Pristine and chemically modified graphene are characterized by scanning tunneling microscope and spectroscopy, X-ray photoelectron spectroscopy, and Raman measurements. The first-step photochlorination is found to occur very selectively on the monolayer graphene region leaving the bi- and trilayer graphene regions clean. Consequently, the CH₃-functionalized graphene is observed only in the monolayer graphene regions after the chlorinated EG was treated with CH₃MgBr in air-free condition. Both Cl and CH₃ are observed to be chemically bonded to the basal plane of the graphene. The CH₃-functionalized graphene is thermally more stable than that of the chlorinated graphene. The present two-step chlorination鈥搈ethylation procedure is expected to open a new route for organic modification of graphene with different functional groups using a variety of Grignard reagents.