掺杂黑磷烯吸附铬离子的第一性原理计算

First-principles calculations of the adsorption behavior of Cr^(2+) on doped black phosphorus

为了降低有害金属铬离子(Cr^(2+))对水体的污染,应用密度泛函理论研究了黑磷烯对铬离子的吸附行为。以纯净、硼(B)掺杂、硅(Si)掺杂、硫(S)掺杂的4种黑磷烯体系为研究对象,探究了掺杂对黑磷烯吸附Cr^(2+)行为的影响,目的是想通过掺杂来提高黑磷烯对Cr^(2+)的吸附能力,得到理想的吸附材料。对纯净、B掺杂、Si掺杂、S掺杂的4种黑磷烯及其吸附Cr^(2+)体系进行了结构优化,优化后的结果表明:Cr^(2+)在纯净和掺杂黑磷烯上的稳定吸附位置均是褶皱六边形顶部的空心位置。吸附能、态密度、电荷转移、键级的计算结果表明:纯净的黑磷烯对Cr^(2+)有吸附作用,掺杂S可以有效提高黑磷烯对Cr^(2+)的吸附能力,增强黑磷烯与Cr^(2+)之间的共价键和离子键作用。综上,S掺杂的黑磷烯可以用作Cr^(2+)的吸附材料。

In order to reduce the pollution of harmful metal chromium ions to water,the adsorption behavior of black phosphorus to chromium ions was studied by density functional theory.The pure,B-doped,Si-doped,S-doped black phosphorus nanosheets were taken as the research objects,the influence of the doping on the adsorption behavior of black phosphorus to Cr^(2+)was explored.The purpose of this study is to enhance the adsorption capacity of black phosphorus to Cr^(2+)by the doping to obtain the ideal adsorption material.The structures of the pure,B-doped,Si-doped,S-doped black phosphorus and their adsorption Cr^(2+)systems are optimized.The optimized results show that the stable adsorption sites of Cr^(2+)on the pure and doped black phosphorus are all hollow sites on top of a puckered hexagon.The calculated results of adsorption energy,density of state,charge transfer,bond level show that pure black phosphorene has a strong adsorption effect on Cr^(2+),the adsorption capacity of black phosphorus to Cr^(2+)was improved by doping S.Doping S can effectively improve the adsorption capacity of black phosphorene to Cr^(2+)and enhance the covalent and ionic bond between black phosphorene and Cr^(2+).In conclusion,Sdoped black phosphorus can be used as the adsorption material of Cr^(2+).