First-principles density functional study has been performed to systematically investigate the adsorption of CH₃I on Ag(111) and Ag₂O(111) surfaces at different coverages. It is found that the adsorption energy of CH₃I on two surfaces at all sites is coverage-dependent, and the adsorption is thermodynamic favorable. The interaction between CH₃I and two surfaces can be mainly attributed to the hybridization of I(p) state and Ag(d) state. For the adsorption of CH₃I on Ag(111) surface, fcc site is the most stable site whether at lower or higher coverage. For Ag₂O(111) surface, Ag_CUS site and Ag_CUS(Ag_CSA) site is more favorable at lower and higher coverage, respectively. The large adsorption energy occurred on the adsorption of CH₃I on Ag_CUS(Ag_CSA) site is due to the strong interaction between I atom and Ag_CUS atom and the formation of H-O bond according to the LDOS and CDD calculations.

进行了第一性原理密度泛函研究，系统研究了CH ₃ I在不同覆盖率下在Ag（111）和Ag ₂ O（111）表面上的吸附。发现CH ₃ I在所有位点的两个表面上的吸附能是覆盖率依赖性的，并且吸附是热力学有利的。CH ₃ I和两个表面之间的相互作用主要归因于I（p）状态和Ag（d）状态的杂化。对于CH ₃ I在Ag（111）表面的吸附，无论是低覆盖率还是高覆盖率，fcc部位都是最稳定的部位。对于Ag ₂ O（111）表面，Ag _CUS站点和Ag _CUS（Ag _CSA）网站分别在较低和较高的覆盖范围内更有利。根据LDOS和CDD计算，CH ₃ I在Ag _CUS（Ag _CSA）位点上的吸附产生的大量吸附能是由于I原子与Ag _CUS原子之间的强相互作用以及HO键的形成。