金属和非金属原子间协同效应调控气体小分子的吸附特性

Adsorption characteristics of small gas molecules regulated by synergetic effect between metal and nonmetal atoms

采用基于密度泛函理论方法系统地研究了单个NO和CO小分子在非金属(B和N)与金属Ni原子共掺杂石墨烯(B_(x)-N_(y)-gra-Ni,x+y=0,1,2,3)表面的吸附特性,分析了吸附气体小分子的几何结构,吸附能,电荷转移量以及引起体系磁性变化等情况.研究结果表明:NO和CO倾向于吸附在Ni原子的顶位,B和N掺杂原子的数量和比例能够有效地调制小分子的吸附强度;与吸附的CO分子相比,B_(x)-N_(y)-gra-Ni表面吸附的NO分子能获得较多的电荷,进而表现出高的稳定性.此外,利用吸附的气体小分子与衬底间相互作用强度和灵敏性的差异、以及引起反应衬底的磁性变化将为设计石墨烯基气敏、催化和电子器件提供重要参考.

The first principles study is performed to the adsorption properties of single NO and CO molecules on the surface of metal Ni and non-metal atoms(B and N)codoped graphene(B_(x)-N_(y)-gra-Ni,x+y=0,1,2,3).The geometric structures,adsorption energies,transferred electrons and magnetic moments of small gas molecules adsorbed systems were investigated systematically.The calculated results show that NO and CO tend to adsorb on the top of Ni atom,the numbers of B and N dopants and their ratio can effectively regulate the adsorption strength of small molecules.Compared with CO molecule,the adsorbed NO gains more transferred charges from the B_(x)-N_(y)-gra-Ni sheets and exhibits the higher stability.In addition,the degree of interaction and gas sensing differences for adsorbates on reactive substrates,and the changed magnetic properties of adsorbed systems can provide an important reference for designing the graphene-based gas sensors,catalysis and electronic devices.