飞秒激光烧蚀单壁碳纳米管制备碳炔  

Preparation of Polyynes Based on Femtosecond Laser Ablation of Single⁃Walled Carbon Nanotubes

作　　者：陈文彬 冯吉军 廖洋[2] 夏新成 蒋巍 任文波 骆涛 赵新洛[3] Chen Wenbin;Feng Jijun;Liao Yang;Xia Xincheng;Jiang Wei;Ren Wenbo;Luo Tao;Zhao Xinluo(Shanghai Key Laboratory of Modern Optical System,School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Department of Physics,Institute of Low-Dimensional Carbons and Device Physics,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院上海市现代光学系统重点实验室,上海200093 [2]中国科学院上海光学精密机械研究所强场激光物理国家重点实验室,上海201800 [3]上海大学低维碳与器件物理研究所物理系,上海200444

出　　处：《中国激光》2023年第20期194-201,共8页Chinese Journal of Lasers

基　　金：国家重点研发计划(2022YFE0107400);国家自然科学基金(11774235,61705130,11933005);上海市科学技术委员会资助项目(23010503600);上海市高校特聘教授(东方学者)岗位计划(GZ2020015)。

摘　　要：利用重复频率为1 kHz的钛蓝宝石飞秒激光烧蚀悬浮在甲醇中的单壁碳纳米管制备碳炔。利用表面增强拉曼光谱仪和紫外可见吸收光谱仪对样品溶液进行光谱表征,并用高效液相色谱仪对样品进行分离,确认有碳炔(CnH2,n=6,8,10,12,14,16)生成,其中的主要产物是C8H2。对制备碳炔的最佳激光功率与最佳加工时间进行了研究,结果显示:当激光单脉冲能量为0.52 mJ、加工时间为1.5 h时,可以获得最高的碳炔产率。对碳炔的合成机制进行了较深入的解释。激光功率密度存在饱和阈值,该饱和阈值与C2自由基的碎裂程度有关,激光功率密度超过饱和阈值后会打破C2自由的“反向”第四键,进而影响C2自由基合成碳炔。因此,随着激光单脉冲能量增大,碳炔的产率呈现先增加后降低的现象。本研究可为碳炔的大规模制备提供重要参考。Objective Research on carbon nanotubes(CNTs)and graphene is very mature,and has led to substantive breakthroughs in electronics;however,some problems remain.For example,the experimental process for obtaining high-purity,semiconducting CNTs is complex,and the ability to adjust the bandgap of graphene is restricted.However,both these materials encounter limitations when used in electronic devices,among which,Young’s modulus and stiffness are the key criteria.Theoretical research has shown that polyynes exhibit better Young’s modulus and stiffness than graphene,CNTs,and diamond.In particular,polyynes have very high tensile strength,and their performance is unaffected by bending deformation,which cannot be achieved using CNTs and graphene.Thus,the limitations of single-walled CNTs(SWCNTs)and graphene can be overcome.Moreover,polyynes demonstrate excellent electrical properties(such asπ-electronic system)and good hardness(i.e.,40 times that of diamond),providing potential applications in aerospace and nanotechnology.However,polyynes suffer from instability,high preparation costs,and low concentrations.In this study,based on femtosecond laser ablation technology,polyynes were prepared using a Ti∶sapphire femtosecond laser with the repetition rate of 1 kHz to ablate SWCNTs suspended in methanol.The optimal laser power and processing time for preparing polyynes were explored,and the mechanism of polyyne synthesis was detailed,which will play an important role in the large-scale preparation of polyynes.Methods Various methods have been adopted to synthesize polyynes,which can be roughly divided into electrochemical(e.g.,oxidation couples and electric arcs)and laser ablation(e.g.,gas and liquid phases)techniques.Oxidation coupling is complex and impurities can be easily introduced.Arc discharge is commonly used to generate carbon chains,with the arc discharge in water.However,it cannot control the groups capped at both ends,which limits the stability and electronic properties of polyynes.For laser ablation,gas-phase

关 键 词：激光技术 碳炔 飞秒激光烧蚀 激光功率密度饱和阈值 单壁碳纳米管 

分 类 号：TN249[电子电信—物理电子学]