脱质子化1,3环加成石墨烯外在固定位上的贵金属纳米线(英文)

“External Anchoring Sites” for Noble Metal Nanowires on Deprotonated 1,3-Dipolar Cycloaddition Graphene

为研究纳米线的形成机理,通过密度泛函理论(DFT)研究了贵金属(铂)在脱质子化1,3-环加成石墨烯上的吸附.研究发现:(1)吸附在1,3-环加成石墨烯上的铂原子引起该结构的脱质子化过程并形成脱质子化1,3-环加成石墨烯;(2)贵金属在脱质子化1,3-环加成石墨烯上的锚定位是氮原子邻位的碳原子,这在邻位碳原子的平均巴德电荷分析(高达1.0e)中得到进一步的证实;(3)铂原子在相邻的脱质子化吡啶炔单元上形成金属纳米线,并且该纳米线比相应的铂团簇稳定得多;(4)电子结构分析表明,铂的吸附并没有从根本上改变脱质子化1,3-环加成石墨烯的电子性质.铂金属的掺杂使得Pt6团簇吸附形成的复合物呈现金属性,而Pt6纳米线形成的复合物则为半金属性.

Density functional theory （DFT） calculations were used to study the adsorption of noble metal （Pt） on deprotonated 1,3-dipolar cycloaddition graphene to explore the mechanism of the formation of metal nanowires. The results show that： （1） Pt atoms that adsorb on 1,3-dipolar cycloaddition graphene induce the deprotonation of this 1,3-dipolar cycloaddition graphene and then the configuration changes to a deprotonated 1,3-dipolar cycloaddition graphene; （2） the noble metal anchoring site on the deprotonated 1,3-dipolar cycloaddition graphene is the ortho-carbon of nitrogen in the deprotonated pyridine alkyne, which was further confirmed by the average Bader charge of the ortho-carbon, and the average Bader charge of the ortho-carbon is as high as 1.0e; （3） Ptn nanowire can form between two neighboring deprotonated pyridine alkyne units of deprotonated 1,3-dipolar cycloaddition graphene, and the Ptn （n=3-6） nanowire adsorption configurations are more stable than the corresponding Pt, （n=3-6） cluster adsorption configurations; and （4）the electronic structure analysis of the composite shows that Pt metal adsorption does not essentially change the electronic property of deprotonated 1,3-dipolar cycloaddition graphene. The doped states of the Pt metal result in the Pt6 cluster adsorption composite being metallic while the doped states result in the Pt6 nanowire adsorption composite being semimetallic.