Abstract

We investigate the adsorption of As nano-clusters on graphene sheets in various environments, including vacancies and anchors with Fe and/or O impurities. To achieve this, we conducted Density-Functional Theoretical (DFT) calculations using the freely distributed SIESTA code. Our findings reveal a direct correlation between the number of vacancies and the adsorption energy, indicating that a higher number of vacancies result in higher adsorption of As-clusters. Additionally, as the As-n-cluster size increases, the adsorption energy decreases. Furthermore, our results suggest that transition metal impurities (such as Fe) serve as effective elements for functionalizing graphene facilitating the adsorption of metallic clusters in this way, making it suitable for applications in wastewater filtration or the purification of toxic elements in water. Finally, we address finite size effects on the adsorption of graphene sheets by perform calculations on graphene flakes of different sizes saturated in different ways.