气体分子在类石墨烯材料负载单个金属原子表面的吸附特性

The adsorption characteristics of gas molecules on graphene-like materials supported single metal atoms

采用密度泛函理论方法研究了不同种类和数量的气体小分子在类石墨烯材料(graphenylene)衬底支撑的金属原子(M=Co,Mo和Pd,gra-M)表面的吸附特性,系统地分析了吸附不同数量的NO和CO分子的稳定构型,吸附能,电荷转移量以及引起的体系电子结构和磁性变化.研究结果表明:(1)NO、CO气体小分子的稳定吸附位在金属原子顶位,吸附物与衬底间的电荷转移量表明负载不同的金属原子能够有效地调制类石墨烯材料的气敏特性;(2)单个和两个气体分子吸附能够引起gra-M体系的自旋电荷密度分布发生变化,进而使得气体吸附体系表现出不同磁矩大小.

The adsorption characteristics of different kinds and number of small gas molecules on metal atoms(M=Co,Mo and Pd)supported graphenylene(gra-M)are studied by using density functional theory,the stable configurations,adsorption energies,charge transfer amounts,as well as the electronic structures and magnetic properties caused by the adsorption of NO and CO molecules are systematically analyzed.The calculated results shown that:(1)the stable adsorption sites of NO and CO gas molecules are the top sites of the metal atoms,the number of charge transfer between adsorbate and substrate indicated that the supported metal atoms can effectively modulate the gas sensitivity of the graphenylene-based materials;(2)The adsorptions of single and two gas molecules can cause the redistribution of spin charge densities of gra-M systems,resulting in the gas adsorbed systems exhibit different magnetic moments.