Transformation of Carbon Monomers and Dimers to Graphene Islands on Co(0001): Thermodynamics and Kinetics

详细信息    查看全文

• 作者：Lingshun Xu ; Yuekang Jin ; Zongfang Wu ; Qing Yuan ; Zhiquan Jiang ; Yunsheng Ma ; Weixin Huang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：February 14, 2013
• 年：2013
• 卷：117
• 期：6
• 页码：2952-2958
• 全文大小：478K
• 年卷期：v.117,no.6(February 14, 2013)
• ISSN：1932-7455

文摘

Although graphene on metal surfaces has been extensively investigated, the comprehensive and quantitative experimental results exploring the growth mechanism of graphene on metal surfaces are quite few. Employing in situ and time-resolved X-ray photoelectron spectroscopy measurements, we report the comprehensive and quantitative data for the thermodynamics and kinetics of both the C₁-to-graphene transformation reaction on Co(0001) covered with C₁ adatoms and graphene islands and the C₂-to-graphene transformation reaction on Co(0001) covered with C₂ dimers and graphene islands. Both transformation reactions proceed via carbon cluster attachment mechanism. The enthalpy and apparent activation energy were determined, respectively, to be 261 and 139 kJ/mol for the C₁-to-graphene transformation reaction, and 287 and 280 kJ/mol for the C₂-to-graphene transformation reaction. The C₁-to-graphene transformation reaction on Co(0001) likely proceeds without the formation of C₂ dimers. These experimental data provide benchmark experimental results for fundamentally understanding the graphene growth mechanism on metal surfaces.