Shaping and Edge Engineering of Few-Layered Freestanding Graphene Sheets in a Transmission Electron Microscope

Zhao，Longze1; Luo，Guangfu2; Cheng，Yong1; Li，Xin1; Zhou，Shiyuan3; Luo，Chenxu3; Wang，Jinming1; Liao，Hong Gang3; Golberg，Dmitri4,5; Wang，Ming Sheng1

2019

10.1021/acs.nanolett.9b04524

NANO LETTERS   影响因子和分区

1530-6984

1530-6992

Full exploitation of graphene's superior properties requires the ability to precisely control its morphology and edge structures. We present such a structure-tailoring approach via controlled atom removal from graphene edges. With the use of a graphitic-carbon-capped tungsten nanoelectrode as a noncontact "milling" tool in a transmission electron microscope, graphene edge atoms approached by the tool tip are locally evaporated, thus allowing a freestanding graphene sheet to be tailored with high precision and flexibility. A threshold for the tip voltage of 3.6 ± 0.4 V, independent of polarity, is found to be the determining factor that triggers the controlled etching process. The dominant mechanisms involve weakening of carbon-carbon bonds through the interband excitation induced by tunneling electrons, assisted with a resistive-heating effect enhanced by high electric field, as elaborated by first-principles calculations. In addition to the precise shape and size control, this tip-based method enables fabrication of graphene edges with specific chiralities, such as "armchair" or "zigzag" types. The as-obtained edges can be further "polished" to become entirely atomically smooth via edge evaporation/reconstruction induced by in situ TEM Joule annealing. We finally demonstrate the potential of this technique for practical uses through creating a graphene-based point electron source, whose field emission characteristics can effectively be tuned via modifying its geometry.

edge engineering Graphene in situ TEM nanomilling subtractive manufacturing

SCI ; EI

英语

NI期刊

其他

Introduced Innovative R&D Team of Guangdong[2017ZT07C062]

Chemistry ; Science & Technology - Other Topics ; Materials Science ; Physics

Chemistry, Multidisciplinary ; Chemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:000526413400009

AMER CHEMICAL SOC

20200107971041

Transmission electron microscopy ; Etching ; Electric excitation ; Calculations ; Electrons ; Electric fields

Electricity: Basic Concepts and Phenomena:701.1 ; Nanotechnology:761 ; Chemical Reactions:802.2 ; Chemical Products Generally:804 ; Mathematics:921

MATERIALS SCIENCE

2-s2.0-85077208726

Scopus

1.Department of Materials Science and Engineering,College of Materials,Pen-Tung Sah Institute of Micro-Nano Science and Technology,Xiamen University,Xiamen, Fujian,361005,China
2.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen, Guangdong,518055,China
3.State Key Lab of Physical Chemistry of Solid Surfaces,Collaborative Innovation Center of Chemistry for Energy Materials,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen,361005,China
4.School of Chemistry,Physics and Mechanical Engineering,Science and Engineering Faculty,Queensland University of Technology (QUT),Brisbane,2nd George Str.,4000,Australia
5.International Center for Materials Nanoarchitectonics (MANA),National Institute for Materials Science (NIMS),Tsukuba, Ibaraki,Namiki 1-1,3050044,Japan

Zhao，Longze,Luo，Guangfu,Cheng，Yong,et al. Shaping and Edge Engineering of Few-Layered Freestanding Graphene Sheets in a Transmission Electron Microscope[J]. NANO LETTERS,2019,20(4):2279-2287.

Zhao，Longze.,Luo，Guangfu.,Cheng，Yong.,Li，Xin.,Zhou，Shiyuan.,...&Wang，Ming Sheng.(2019).Shaping and Edge Engineering of Few-Layered Freestanding Graphene Sheets in a Transmission Electron Microscope.NANO LETTERS,20(4),2279-2287.

Zhao，Longze,et al."Shaping and Edge Engineering of Few-Layered Freestanding Graphene Sheets in a Transmission Electron Microscope".NANO LETTERS 20.4(2019):2279-2287.