The environmental fate and behavior of arsenic (As) is receiving increased attention due to the As pollution all over the world. Kaolinite is a natural mineral resource that can be used for the removal of pollution as adsorbent. First-principles calculations based on density-functional theory was employed to explore the adsorption behavior of arsenic atoms adsorption on the kaolinite (001) and (00\(\bar {1}\)) surface. The one-fold top site was found to be energetically preferred for the kaolinite (001) and (00\(\bar {1}\)) surface, and the adsorption energy of the former is obviously higher than the latter. The coverage dependence of the adsorption energetics was systematically studied for a wide range of coverage Θ [from 0.11 to 1.0 monolayers (ML)]. The adsorption energy of As decreased with increasing coverage, thus indicating the lower stability of surface adsorption due to the repulsion of neighboring As atoms. The coverage has obvious effects on the arsenic adsorption process. Other properties of the As/kaolinite (001) system, including the lattice relaxation and changes of electronic density of states, were also studied and discussed in detail.

中文翻译：

---

砷在高岭石（001）和（00 $$ \ bar {1} $$1¯）表面的吸附行为的第一性原理研究

由于全世界的砷污染，砷的环境命运和行为受到越来越多的关注。高岭石是一种天然矿物资源，可作为吸附剂用于去除污染。基于密度泛函理论的第一性原理计算被用于探索砷原子在高岭石（001）和（00 \（\ bar {1} \））表面上的吸附行为。发现在能量上首选高岭石（001）和（00 \（\ bar {1} \）的位置是首选位置的一倍）表面，前者的吸附能明显高于后者。系统地研究了吸附能学的覆盖率依赖性，适用于宽范围的覆盖率[从0.11到1.0单层（ML）]。As的吸附能随着覆盖率的增加而降低，这表明由于相邻As原子的排斥，表面吸附的稳定性较低。覆盖率对砷的吸附过程有明显的影响。还研究和讨论了As /高岭土（001）系统的其他特性，包括晶格弛豫和电子态电子密度的变化。