纳米颗粒切割石墨烯的多尺度模拟
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- 英文论文题名：Multiscale Simulation of nanoparticle cutting of graphene
- 论文作者：邱宗仰 ; 李震宇
- 英文论文作者：Zongyang Qiu ; Zhenyu Li ; Hefei National Laboratory for Physical Sciences at the Microscale ; University of Science and Technology of China
- 年：2016
- 作者机构：中国科学技术大学;
- 论文关键词：镍纳米颗粒 ; 石墨烯切割 ; 多尺度模拟
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十分会：纳米体系理论与模拟
- 语种：中文
- 分类号：O613.71
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十分会 ; 纳米体系理论与模拟
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：163k
- 原文格式：D
- 会议级别：全国
摘要
利用纳米颗粒切割石墨烯有望制备出边界平整的石墨烯纳米条带[1-2]。通过分子动力学模拟,我们发现纳米颗粒中多个相互协同的金属镍原子蚀刻掉石墨烯的边界碳原子。对镍纳米颗粒打开碳碳键,蚀刻碳原子过程的能垒计算证实不同类型边界碳原子的蚀刻难易程度不同。最难蚀刻的锯齿位上的碳原子的蚀刻会导致一整行边界原子被快速蚀刻。基于这一结果,我们对实验上观测到的蚀刻速率与纳米颗粒半径的平方成正比的变化趋势[3-4]给出了新的解释。这一变化关系也在我们的动力学蒙特卡洛模拟中得以重现。因此,我们通过多尺度方法对蚀刻过程的模拟让人们对纳米颗粒切割石墨烯的机理有了新的认识。
Metal nanoparticle catalyzed cutting is a promising way to produce graphene nanostructures with smooth and well-aligned edges. Using a multiscale simulation approach, we unambiguously identify a pacman cutting mechanism, characterized by metal nanoparticle biting off edge carbon atoms via a synergetic effect of multiple metal atoms. By comparing the reaction rates at different types of edge sites, we further recognize that etching of an entire edge carbon row can be triggered by a single zigzag site etching event, which well explains the puzzling linear dependence of the overall carbon atom etching rate on the nanoparticle surface area observed in experiment. With the nanoparticle size effect incorporated, mechanisms revealed here open a new avenue to improve the controllability in graphene cutting.
Metal nanoparticle catalyzed cutting is a promising way to produce graphene nanostructures with smooth and well-aligned edges. Using a multiscale simulation approach, we unambiguously identify a pacman cutting mechanism, characterized by metal nanoparticle biting off edge carbon atoms via a synergetic effect of multiple metal atoms. By comparing the reaction rates at different types of edge sites, we further recognize that etching of an entire edge carbon row can be triggered by a single zigzag site etching event, which well explains the puzzling linear dependence of the overall carbon atom etching rate on the nanoparticle surface area observed in experiment. With the nanoparticle size effect incorporated, mechanisms revealed here open a new avenue to improve the controllability in graphene cutting.
引文
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[2]L.C.Campos;V.R.Manfrinato;J.D.Sanchez-Yamagishi;J.Kong;P.Jarillo-Herrero Nano Lett.2009,9:2600.
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