Ti掺杂SnS_(2)吸附气体分子的第一性原理研究

First-Principle Study of Gas Molecules Adsorption on Ti-Doped SnS_(2)

基于第一性原理构建了本征SnS_(2)和Ti原子替换Sn原子掺杂SnS_(2)的几何结构,分析了CO、NO_(2)、NO、SO_(2)、NH_(3)五种气体在两种材料表面的吸附特性。对每种气体分子测试了三种吸附位置并确定了最佳吸附位置,计算了吸附能、转移电荷、恢复时间、态密度、功函数以了解吸附机理。研究发现,CO和SO_(2)在本征SnS_(2)上的吸附能力较弱,NO、NO_(2)和NH_(3)在本征SnS_(2)上的吸附能力较强。而Ti原子替换Sn原子掺杂SnS_(2)的结构是相对稳定的,其形成能为-8.028eV。同时这五种气体分子在其表面上的吸附能都有不同程度的增加。结果表明,Ti原子替换Sn原子掺杂SnS_(2)提高了SnS_(2)材料的气体吸附性能,同时其制备方法贴合实际,可以考虑用于制作气体传感器的材料。

Based on first-principle,the geometric structures of intrinsic SnS_(2) and SnS_(2) doped with Ti atom replacing Sn atom were constructed,and the adsorption characteristics of five gases,namely CO,NO_(2),NO,SO_(2) and NH_(3) on the surfaces of the two materials were analyzed.Three adsorption sites were tested for each gas molecule and the best adsorption site was determined.The adsorption energy,transfer charge,recovery time,density of states and work function were researched to understand the adsorption mechanism.It is found that the adsorption capacities of CO and SO_(2) on the intrinsic SnS_(2) are weaker,while the adsorption capacities of NO,NO_(2) and NH_(3) on the intrinsic SnS_(2) are stronger.The structure of SnS_(2) doped by Ti atom replacing Sn atom is relatively stable,and its formation energy is-8.028 eV.At the same time,the adsorption energies of the five gas molecules on their surfaces increase to different degrees.The results show that SnS_(2) doped by Ti atom replacing Sn atom can improve the gas adsorption performance of SnS_(2) material,and its preparation method is practical,so it can be considered as a material for making gas sensors.