Atomic processing of two-dimensional amorphous carbon  

二维非晶碳材料的原子级加工

作　　者：Yunna Guo Hantao Cui Zhangran Ye Xixi Qin Peng Jia Lei Deng Chongchong Ma Chao Tai Liqiang Zhang Bin Wen 郭云娜;崔晗涛;叶张然;秦茜茜;贾鹏;邓蕾;马崇崇;邰超;张利强;温斌

机构地区：[1]Clean Nano Energy Center,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China [2]Center for Extreme Deformation Research,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China

出　　处：《Science China Materials》2024年第12期4059-4064,共6页中国科学（材料科学）（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(52471018,52401298,51925105 and U23A20537);the S&T Program of Hebei(B2023203037 and B2024203054);the Science Research Project of Hebei Education Department(JZX2024022);the Central Guidance Fund for Local Science and Technology Development Project(246Z1101G)。

摘　　要：Two-dimensional amorphous carbon(2DAC)materials possess characteristics such as high conductivity,high flexibility,and chemical stability,making them promising for applications in electronics,sensors,catalysts,superconductors,energy storage,and energy conversion.However,it is still a challenge to directly synthesize 2DAC till now.Meanwhile,many controversies exist in their formation process and structure.Therefore,this article utilizes a top-down etching method to prepare 2DAC in environmental transmission electron microscope(ETEM).By employing electron beam irradiation combined with heating at 650°C in an oxygen atmosphere(0.01 mbar),controllable fabrication of 2DAC is achieved.In this process,the raw diamond sheet first transforms into graphite,and as the reaction goes on,the amount of graphite increases,eventually transitioning into 2DAC.First-principles calculations indicate that it is an energy-favorable process from diamond to graphite.Although there is an energy barrier for graphite-to-amorphous carbon transition,electron beam irradiation induces numerous defects that can overcome this barrier.This method not only fabricates 2DAC with atomic precision but also provides in-situ analysis of its formation process.The research findings contribute to a fundamental understanding of the formation process of 2DAC and offer new insights for the preparation of 2D ultrathin amorphous materials.二维非晶碳(2DAC)具有高导电性、高柔性和高化学稳定性等优异特性,在电子、传感器、催化剂、超导体、储能和能量转换等领域具有广阔的应用前景.然而,二维非晶碳很难直接制备,其形成机理和结构也存在许多争议.本文采用自上而下刻蚀的方法,在环境透射电镜中成功制备了二维非晶碳,在氧气(0.01 mbar)环境和电子束辐照下,将金刚石加热到650°C,金刚石经石墨化转变,最终转变为二维非晶碳.第一性原理计算表明,从金刚石到石墨是一个能量降低的过程,而从石墨向二维非晶碳转变是一个能量增加的过程,电子束辐照有利于克服该能垒.本研究制备了原子级精度的二维非晶碳,并利用原位表征技术揭示了其形成机理.本研究有助于从根本上理解二维非晶碳的形成过程和机理,也可为二维超薄非晶材料制备提供新的思路和见解.

关 键 词：two-dimensional amorphous carbon(2DAC) topdown ETCHING DIAMOND 

分 类 号：TQ127.11[化学工程—无机化工]