基底化学吸附对石墨烯机械裁剪性能的影响机制  

Influence Mechanism of Substrate Chemisorption on Mechanical Cutting Properties of Graphene

作　　者：冉迪 郑鹏[1] 苑泽伟[1] 王宁 RAN Di;ZHENG Peng;YUAN Zewei;WANG Ning(School of Mechanical Engineering,Shenyang University of Technology,Shenyang 110870,China;School of Mechanical Engineering,Shenyang Urban Construction University,Shenyang 110167,China;Engineering Training Center,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]沈阳工业大学机械工程学院,沈阳110870 [2]沈阳城市建设学院机械工程学院,沈阳110167 [3]沈阳工业大学工程实训中心,沈阳110870

出　　处：《中国表面工程》2023年第5期179-189,共11页China Surface Engineering

基　　金：国家自然科学基金(52275455);辽宁省教育厅科学研究经费(LJGD2020003,LJKZ0160)资助项目。

摘　　要：机械裁剪法是简单高效制备石墨烯纳米带的加工方法,目前对基底化学吸附如何影响石墨烯机械裁剪行为的认识尚有不足。为探究基底化学吸附对石墨烯机械裁剪性能的影响机制,基于ReaxFF反应力场和Verlet算法,采用反应分子动力学方法对Ni、Pt、Cu金属基底上的石墨烯机械裁剪行为展开研究,根据纳米压痕和机械裁剪中探针与石墨烯(C_(T)-C_(G))、石墨烯层内(C_(G)-C_(G))、石墨烯与基底(C_(G)-M)间键合数量和键合强度的变化规律,分析基底化学吸附对键合性能和石墨烯机械裁剪行为的影响。结果表明:Ni、Pt、Cu基底对石墨烯的化学吸附能力依次减弱,强化学吸附作用增大了C_(G)-M键合强度,促进了C_(T)-C_(G)键合,削弱了C_(G)-C_(G)键合强度,降低了石墨烯的抗破损强度,Ni、Pt、Cu基底上的石墨烯抗破损强度分别为110.19、121.71、176.53 GPa。强化学吸附使石墨烯发生了大面积撕裂破损,弱化学吸附使石墨烯仅发生了部分碳链和碳原子的剥离。强化学吸附基底提高了石墨烯的机械裁剪效率,减小了机械裁剪深度,降低了探针下压载荷,提高了探针对石墨烯的摩擦力,提高了石墨烯的机械裁剪性能。基于反应分子动力学方法可深入探究基底化学吸附对石墨烯机械裁剪性能的影响规律及内在机理,研究结果可为不同化学吸附基底条件下高效、高精度石墨烯纳米带的机械裁剪提供理论依据。Graphene nanoribbons with different directions and widths can adjust the zero-energy bandgap of graphene,allowing wide use of graphene in nano-semiconductor devices.Mechanical cutting is a simple and efficient method for preparing graphene nanoribbons.Most current studies assume that the substrate surface and graphene involve physical adsorptions;however,many substrate surfaces involve chemisorption with graphene in actual mechanical cutting.The effect of substrate chemisorption on the mechanical cutting behavior of graphene is not fully understood.This paper investigates the influence mechanism of substrate chemisorption on the mechanical cutting properties of graphene.Based on the ReaxFF reaction potential function and the Verlet algorithm,the mechanical cutting behavior of graphene on Ni,Pt,and Cu metal substrates was studied through reactive molecular dynamics.The effect of substrate chemisorption on bond properties was analyzed according to the bond number and bond strength between tip and graphene(C_(T)-C_(G)),graphene layers(C_(G)-C_(G)),and graphene and substrate(C_(G)-M)in nanoindentation.Graphene mechanical cutting depth was determined according to the friction and wear mechanism by oblique scratching.The mechanical cutting depth was used to scratch the graphene,intuitively revealing the influence mechanism of substrate chemisorption on the mechanical cutting properties of graphene through the bond changes between the tip,substrate,and graphene.The results show that the chemisorption capacities of Ni,Pt,and Cu substrate to graphene were decreased in turn.A strong chemisorption substrate increased the C_(G)-M bond strength and C_(T)-C_(G) bond strength,weakened the C_(G)-C_(G) bond strength,and greatly reduced the breakage strength of graphene.The breakage strengths of graphene on Ni,Pt,and Cu substrates were 110.19 GPa,121.71 GPa,and 176.53 GPa,respectively,in mechanical cutting.The graphene under the tip center was at the highest stress and most susceptible to breakage.The decrease in C_(G)-C_(G) bond

关 键 词：金属基底 化学吸附 石墨烯 机械裁剪 分子动力学 

分 类 号：TH164[机械工程—机械制造及自动化]