The interfacial structure and adsorption mechanism of imidazolium-based ionic liquids(ILs)on Au(111)surface were investigated via first-principles calculation.Electron density analysis and Bader charge analysis were u...The interfacial structure and adsorption mechanism of imidazolium-based ionic liquids(ILs)on Au(111)surface were investigated via first-principles calculation.Electron density analysis and Bader charge analysis were used to explore the electronic structure of Au(111)-ILs interface.Computations show that the alkyl chain length and anions play a significant role in designing Au(111)-ILs interfacial structure.On the one hand,the stability of interface and adsorption energy tend to be enhanced as the alkyl chain length increases.It attributes to the methylene group of alkyl chain which could easily anchor on the gold interface.On the other hand,the difference in anions makes the adsorption behavior quite different.The adsorption energy follows the order:[C_(n)mim][Br]>[C_(n)mim][Cl]>[Cnmim][TFSA]>[C_(n)mim][OAc]>[C_(n)mim][PF6]>[C_(n)mim][BF_(4)].The nonfluorinated ILs(containing Br,Cl,and O atoms of anions)always have a drastic charge transfer among gold-ILs interface.However,the larger van der Waals(vdWs)volumes of the fluorinated anions have a more diffused electron density which lead to the relatively weak interaction.To sum up,a detailed and systematic investigation of the variation of anions and alkyl chain length of ILs which will affect the interfacial structure is fully studied.The above study could be helpful to understand electrode-electrolyte microscopic interface and design of functional materials for energy storage.展开更多
The present work proposes kinetics of ionization-recombination to study the charge state distribution of Au plasma. The first step is to calculate the average lifetime, energy level structure, degeneracy and partition...The present work proposes kinetics of ionization-recombination to study the charge state distribution of Au plasma. The first step is to calculate the average lifetime, energy level structure, degeneracy and partition function of Au48+―Au52+ by relativistic quantum mechanics, and next to compute the equilibrium constant and the second-order recombination rate constant by statistical thermodynamics. Based on these data, the differential equations of consecutive reversible ionization-recombination reactions are solved from which the charge state distribution and its average charge are derived. Finally, the influence of electron temperature and density on average charge is given in this paper. It is called the first-principle theory, for no experimental data are needed.展开更多
基金supported by Taishan Scholars Program of Shandong Province(tsqn201909091)National Natural Science Foundation of China(U1704251,21722610)the High-Grade Talents Plan of Qingdao University.
文摘The interfacial structure and adsorption mechanism of imidazolium-based ionic liquids(ILs)on Au(111)surface were investigated via first-principles calculation.Electron density analysis and Bader charge analysis were used to explore the electronic structure of Au(111)-ILs interface.Computations show that the alkyl chain length and anions play a significant role in designing Au(111)-ILs interfacial structure.On the one hand,the stability of interface and adsorption energy tend to be enhanced as the alkyl chain length increases.It attributes to the methylene group of alkyl chain which could easily anchor on the gold interface.On the other hand,the difference in anions makes the adsorption behavior quite different.The adsorption energy follows the order:[C_(n)mim][Br]>[C_(n)mim][Cl]>[Cnmim][TFSA]>[C_(n)mim][OAc]>[C_(n)mim][PF6]>[C_(n)mim][BF_(4)].The nonfluorinated ILs(containing Br,Cl,and O atoms of anions)always have a drastic charge transfer among gold-ILs interface.However,the larger van der Waals(vdWs)volumes of the fluorinated anions have a more diffused electron density which lead to the relatively weak interaction.To sum up,a detailed and systematic investigation of the variation of anions and alkyl chain length of ILs which will affect the interfacial structure is fully studied.The above study could be helpful to understand electrode-electrolyte microscopic interface and design of functional materials for energy storage.
文摘The present work proposes kinetics of ionization-recombination to study the charge state distribution of Au plasma. The first step is to calculate the average lifetime, energy level structure, degeneracy and partition function of Au48+―Au52+ by relativistic quantum mechanics, and next to compute the equilibrium constant and the second-order recombination rate constant by statistical thermodynamics. Based on these data, the differential equations of consecutive reversible ionization-recombination reactions are solved from which the charge state distribution and its average charge are derived. Finally, the influence of electron temperature and density on average charge is given in this paper. It is called the first-principle theory, for no experimental data are needed.
