O在Au(111)表面吸附的密度泛函理论研究

应用密度泛函理论，本文系统地研究了O在Au(111)表面上的吸附能、吸附结构、功函数、电子密度和投影态密度，给出了覆盖度从0.11ML到1.0ML的范围内，O的吸附特性随覆盖度变化的规律.研究发现O的稳定吸附位为3重面心立方(fcc)洞位，O在fcc洞位的吸附能对覆盖度比较敏感，其值随着覆盖度的增加而减小；O诱导Au(111)表面功函数的变化量与覆盖度成近线性关系，原因是Au表面电子向O偏移，形成表面偶极子；O—Au的相互作用形成成键态和反键态，且反键态都被占据，造成O—Au键很弱，O吸附能较小. 关键词： 表面吸附 Au(111)表面 密度泛函理论 电子特性

Density function theory calculation of oxygen adsorption on Au(111) surface

The oxygen adsorption on Au (111) surface has been studied systematically using density function theory (DFT). The adsorption energies, adsorption structures, work functions, density of electrons and projected density of states have been calculated in wide ranges of coverage. It is found that the fcc-hollow site is the energetically favorable site for all the coverage range considered. The repulsive interaction has been identified, and the adsorption energy decreases with the coverage θ, while work function increases linearly with the coverage. It has been found that the O-Au interaction is very weak due to the fully occupied anti-bonding states from O 2p and Au 5d hybridization.