The adsorption and diffusion of lithium on silicene are studied by using the first-principles method.It is found that the adsorption energy of Li adsorbing on silicene is significantly larger than that of Li adsorbing...The adsorption and diffusion of lithium on silicene are studied by using the first-principles method.It is found that the adsorption energy of Li adsorbing on silicene is significantly larger than that of Li adsorbing on graphene.With the increasing concentration of adsorbed Li atoms,the adsorption energy also increases.The diffusion barrier of Li on silicene is relatively low,which is insensitive to the concentration of adsorbed atoms.展开更多
Using first-principles calculations,we investigate the structural,electronic and hydrogenated properties of the hexagonal BC_(7) sheet.The computed energy bands and density of states indicate that the BC_(7) sheet is ...Using first-principles calculations,we investigate the structural,electronic and hydrogenated properties of the hexagonal BC_(7) sheet.The computed energy bands and density of states indicate that the BC_(7) sheet is a metal,and its metallicity mainly originates from the non-bonding pz electrons of the diagonal carbon of the B atom.When these carbon atoms are fully passivated by H atoms,the BC_(7) sheet becomes a semiconductor with a band gap of 2.41 eV.Our studies demonstrate that changing both the proportion of the boron atoms in the boron carbon sheet and its hydrogenation can tune the electronic properties of boron carbon two-dimensional material.展开更多
The vacancy and H interactions in bcc Nb are important due to their implication in understanding of the H induced damage of Nb metallic membrane used in H2 separation and purification application.Using density functio...The vacancy and H interactions in bcc Nb are important due to their implication in understanding of the H induced damage of Nb metallic membrane used in H2 separation and purification application.Using density functional theory,the vacancy formation energy and vacancy(Vac)−H interaction energies are calculated.The results show that vacancies have a strong trapping effect on H atoms,which lowers the formation energy of Vac-nH clusters substantially.The concentration of Vac−nH clusters is evaluated using a statistical model and the dependence of the concentration on the H−to-M ratio is obtained.It is shown that the concentration of the Vac-nH clusters can be as high as 10−3 at 573 K,i.e.one Vac-nH cluster per 1000 atoms,in good agreement with the experimental observations.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10904054,11264014 and 11234013the Natural Science Foundation of Jiangxi Province under Grant Nos 2009GQW008 and 2010GZW0028the Foundation of Jiangxi Normal University(No 2261),Cultivating Youths of Outstanding Ability in Jiangxi Normal University.
文摘The adsorption and diffusion of lithium on silicene are studied by using the first-principles method.It is found that the adsorption energy of Li adsorbing on silicene is significantly larger than that of Li adsorbing on graphene.With the increasing concentration of adsorbed Li atoms,the adsorption energy also increases.The diffusion barrier of Li on silicene is relatively low,which is insensitive to the concentration of adsorbed atoms.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10964012,10904054,11064004,11264014 and 11234013the Natural Science Foundation of Jiangxi under Grant Nos 2009GQW008 and 2010GZW0028the Cultivating Youths of Outstanding Ability in Jiangxi Normal University,the‘Gan-po talent 555’Project of Jiangxi Province and the Oversea Returned Project from the Ministry of Education.
文摘Using first-principles calculations,we investigate the structural,electronic and hydrogenated properties of the hexagonal BC_(7) sheet.The computed energy bands and density of states indicate that the BC_(7) sheet is a metal,and its metallicity mainly originates from the non-bonding pz electrons of the diagonal carbon of the B atom.When these carbon atoms are fully passivated by H atoms,the BC_(7) sheet becomes a semiconductor with a band gap of 2.41 eV.Our studies demonstrate that changing both the proportion of the boron atoms in the boron carbon sheet and its hydrogenation can tune the electronic properties of boron carbon two-dimensional material.
基金Supported by the National Natural Science Foundation of China under Grant No 11064004the Natural Science Foundation of Jiangxi Province under Grant No 2010GZW0028.
文摘The vacancy and H interactions in bcc Nb are important due to their implication in understanding of the H induced damage of Nb metallic membrane used in H2 separation and purification application.Using density functional theory,the vacancy formation energy and vacancy(Vac)−H interaction energies are calculated.The results show that vacancies have a strong trapping effect on H atoms,which lowers the formation energy of Vac-nH clusters substantially.The concentration of Vac−nH clusters is evaluated using a statistical model and the dependence of the concentration on the H−to-M ratio is obtained.It is shown that the concentration of the Vac-nH clusters can be as high as 10−3 at 573 K,i.e.one Vac-nH cluster per 1000 atoms,in good agreement with the experimental observations.
