采用密度泛函理论中的UB3LYP方法,研究了石墨烯中的Stone-wales缺陷对铂原子催化解离氧气分子的影响.通过计算发现,氧气分子在以Stone-wales缺陷石墨烯片为载体的铂上(Pt-SW)形成3种吸附结构,通过4条路径,最终生成两种产物.氧气分子最...采用密度泛函理论中的UB3LYP方法,研究了石墨烯中的Stone-wales缺陷对铂原子催化解离氧气分子的影响.通过计算发现,氧气分子在以Stone-wales缺陷石墨烯片为载体的铂上(Pt-SW)形成3种吸附结构,通过4条路径,最终生成两种产物.氧气分子最易通过[2+1]环加成作用,吸附在以Stone-wales缺陷石墨烯片为载体的Pt的表面上,吸附能(Eads)为-0.64eV.由于石墨烯片上的Stone-wales缺陷的存在,氧气分子在Pt-SW上解离的4条路径中最有利的解离路径中的决速步能垒都明显高于氧气在以完美石墨烯为载体的Pt(Pt/Graphene)上解离的能垒(1.51eV vs 1.35eV),相应吸收的热量也高于在Pt/Graphene上吸收的热量(0.79eVvs0.15eV).展开更多
By employing atomistic simulations based on an empirical potential model and a self-consistent-charge density-functional tight-binding method, the collision dynamics process of an energetic carbon ion impinging on the...By employing atomistic simulations based on an empirical potential model and a self-consistent-charge density-functional tight-binding method, the collision dynamics process of an energetic carbon ion impinging on the Stone-Wales defect in a single-walled carbon nanotube was investigated. The outwardly and inwardly displacement threshold energies for the primary knock-on atom in the Stone-Wales defect were calculated to be 24.0 and 25.0 eV, respectively. The final defect configuration for each case was a 5-1DB-T（DB=dangling bond） defect formed in the front surface of the nanotube. Moreover, the minimum incident energy of the projectile prompting the primary knock-on atom displacement was predicted to be 71.0 eV, and the time evolutions of the kinetic and potential energies of the projectile and the primary knock-on atom were both plotted to analyze the energy transfer process.展开更多
文摘采用密度泛函理论中的UB3LYP方法,研究了石墨烯中的Stone-wales缺陷对铂原子催化解离氧气分子的影响.通过计算发现,氧气分子在以Stone-wales缺陷石墨烯片为载体的铂上(Pt-SW)形成3种吸附结构,通过4条路径,最终生成两种产物.氧气分子最易通过[2+1]环加成作用,吸附在以Stone-wales缺陷石墨烯片为载体的Pt的表面上,吸附能(Eads)为-0.64eV.由于石墨烯片上的Stone-wales缺陷的存在,氧气分子在Pt-SW上解离的4条路径中最有利的解离路径中的决速步能垒都明显高于氧气在以完美石墨烯为载体的Pt(Pt/Graphene)上解离的能垒(1.51eV vs 1.35eV),相应吸收的热量也高于在Pt/Graphene上吸收的热量(0.79eVvs0.15eV).
基金Supported by the National Natural Science Foundation of China（Nos. 11505003, 11505092）, the Natural Science Foundation of Anhui Province, China（No. 1608085 QA20）, the Postdoctoral Science Foundation of Anhui Province, China（No.2016B091） and the Introduced Doctor＇s Startup Fund from Anhui University of Science and Technology, China（No.ZX944）.
文摘By employing atomistic simulations based on an empirical potential model and a self-consistent-charge density-functional tight-binding method, the collision dynamics process of an energetic carbon ion impinging on the Stone-Wales defect in a single-walled carbon nanotube was investigated. The outwardly and inwardly displacement threshold energies for the primary knock-on atom in the Stone-Wales defect were calculated to be 24.0 and 25.0 eV, respectively. The final defect configuration for each case was a 5-1DB-T（DB=dangling bond） defect formed in the front surface of the nanotube. Moreover, the minimum incident energy of the projectile prompting the primary knock-on atom displacement was predicted to be 71.0 eV, and the time evolutions of the kinetic and potential energies of the projectile and the primary knock-on atom were both plotted to analyze the energy transfer process.
