不同构型石墨炔储氢性能的分子动力学比较研究

Comparative Study on the Hydrogen Storage Properties Between Different Types of Graphynes by the Molecular Dynamics Simulation

相关研究表明石墨炔是一种潜在的吸附储氢材料,然而石墨炔有不同的构型,不同构型石墨炔的储氢性能差异及原因尚未明晰。本研究基于分子动力学模拟,对α-GY、β-GY、γ-GY及GDY四种典型构型的石墨炔的吸氢性能进行了对比研究,分析了压力和温度对吸氢性能的影响,并剖析了吸氢性能差异的本质。研究发现β-GY和GDY两种构型的石墨炔吸氢性能在高压下优于其他两种构型,较低的温度有利于提高吸氢能力,而在较高压下提高压力对吸氢能力的影响不大;与石墨烯所要求高压相比,石墨炔在较低的压力下就可以实现高密度的氢气储存,例如α-GY在100 K的温度和0.5 MPa的压力下就可获得ω(H2)=15.28的储氢密度,因此石墨炔有望成为一种性能更佳的吸附储氢材料。

Related studies have shown that the graphyne is a potential hydrogen storage material due to its strong adsorption to hydrogen.However,the graphyne exists in different chemical structures,such as α-GY,β-GY,γ-GY,σ-GY,GDY,etc.,and the mechanism of the difference in hydrogen storage performances between different types of graphynes are not clear.In this study,the hydrogen absorption performances of four typical types of graphynes,α-GY,β-GY,γ-GY and GDY,were comparatively investigated by the molecular dynamics simulation.The in?uences of pressure and temperature on the hydrogen adsorption performances were investigated,and the mechanism of the difference in hydrogen adsorption performances was analyzed.The results showed that the hydrogen adsorption performances of β-GY and GDY are better than those of the other two graphynes at high pressure;and that the lower temperature is bene?cial to improve the hydrogen absorption ability,while increasing the pressure has little effect on the hydrogen absorption ability at high pressure range.Compared with the graphenes,the graphynes can achieve larger hydrogen storage capacity at lower pressure.For example,α-GY can achieve a hydrogen storage capacity ofω(H2)=15.28 at 100K and 0.5 MPa.Therefore,the graphyne is expected to be a type of satisfactory hydrogen storage material.