单原子Al修饰空位缺陷V2C（MXene）对H2气体表面吸附的第一性原理研究

基于第一性原理计算方法，对含空位缺陷的V₂C(MXene)在不同位点修饰单原子Al的相关性能进行系统研究.研究表明，几何优化后得到含空位缺陷的V₂C稳定结构表面能为-3075.53 J/m²,单原子Al修饰本征V₂C单原子的吸附能为1.5511eV、单原子Al修饰空位缺陷V₂C的吸附能为-2.0763 eV,这表明含空位缺陷的V₂C,由于单原子Al的修饰可以明显改善晶体结构稳定性.进一步从态密度、分波态密度、吸氢能力研究发现，各体系态密度和分波态密度均出现分波越过费米能级的现象，表现出较强的金属性；V₂C吸附H₂气体分子吸附能为-7.5867 eV,而空位缺陷V₂C和单原子Al修饰空位缺陷V₂C两个体系对H₂气体分子的吸附能仅为-0.9851 eV、-2.7130 eV,均未能进一步改善V₂C对H₂气体分...

First-principles study on the adsorption of H2 gas on the surface of Al single atom modified vacancy defect V2C (MXene)

Based on the first principle calculation method, the relevant properties of V2C (MXene) containing vacancy defects modified with monoatomic Al at different sites were systematically studied. The results showed that after geometric optimization, the surface energy of stable V2C containing vacancy defects was -3075.53J/m2, the adsorption energy of monoatomic Al-modified intrinsic V2C monoatomic was 1.5511eV, and the adsorption energy of monoatomic Al-modified V2C containing vacancy defects was -2.0763eV, suggesting that the structural stability of V2C containing vacancy defects can be improved significantly due to the modification of monatomic Al. Further study on the density of states (DOS), partial density of states (PDOS) and hydrogen absorption capacity revealed that the DOS and PDOS of all systems crossed the Fermi level, presenting high metallicity. The adsorption energy of V2C for H2 gas molecules was -7.5867eV, while that of V2C containing vacancy defects and monatomic Al-modified V2C containing vacancy defects for H2 gas molecules was only -0.9851eV and -2.7130eV respectively, indicating that the adsorption performance of V2C for H2 gas molecules is not further improved. This study provides certain theoretical guidance for the research and development of hydrogen storage materials.