密度泛函理论研究草甘膦在纯的,金属原子掺杂石墨烯表面的吸附机理

Adsorption mechanism studies of glyphosate on the pure,metal atoms doped graphene surfaces by density functional theory

本研究采用密度泛函理论方法详细讨论了纯的石墨烯及Ti,Fe,Al,Ca原子掺杂石墨烯吸附草甘膦的机理.通过它们之间的吸附能,差分电荷密度,布居电荷,态密度分析发现草甘膦可以被纯的石墨烯及金属原子掺杂石墨烯不同程度地吸附.纯的石墨烯对草甘膦的吸附作用远不及掺杂石墨烯,其中,草甘膦在Ca掺杂石墨烯表面有最强相互作用.这是因为草甘膦与纯的石墨烯之间主要形成了-P=O…π,-COOH…π和-OH…π非共价的相互作用,而与掺杂石墨烯之间主要形成了Metal-O“单齿”和O-Metal-O“双齿”共价相互作用.本研究结果希冀为石墨烯在环境保护方面的应用提供有价值的理论指导.

In this study,the adsorption mechanism of glyphosate on pure graphene and Ti,Fe,Al and Ca atoms doped graphene surfaces is discussed in detail using the density functional theory.It is found that there is a degree adsorption of glyphosate on pure and metal atoms doped graphene surfaces through analyzing the adsorption energy,density of states,differential charge density,Mulliken population density.There are stronger adsorptions of glyphosate on atoms doped graphene surfaces than that on pure graphene surface.The strongest interaction is occurred when glyphosate on Ca doped graphene surface.This is because the-P=O…π,-COOH…π,and-OH…πnon-covalent interactions are formed between glyphosate and pure graphene,whereas Metal-O“monodentate”and O-Metal-O“bidentate”covalent interactions are formed between glyphosate and doped graphenes.The results are hopeful to provide theoretical guidance for the application of graphene in environmental protection.