Fe/Ti decorated arsenene for phenoxyethanol detection: DFT and COHP analysis

Abstract

In the modern industrial era, the extensive release of toxic substances into the environment continuously poses a threat to human health. To minimize the loss, it is crucial to carefully monitor and detect such substances by developing efficient sensing materials. Adsorption of hazardous phenoxyethanol PE (C₈H₁₀O₂) was investigated on pristine and X = Fe/Ti modified arsenene using DFT and COHP calculations. The stability of the dopants (adsorbents) in/on arsenene was explored using the binding (adsorption) energy. In all four forms, the X-atom strongly binds to arsenene via p–d overlapping. The unpaired electrons of the X-atom induce magnetization in arsenene. Half-metallic or narrow band gap features can be obtained when arsenene is modified with an X-atom. The given molecule, due to the coulombic repulsion of the paired electrons on As atoms, is weakly adsorbed. However, adsorption is slightly enhanced for the Fe-decorated system and significantly improved for the Ti-decorated ones. Among all cases, the lowest adsorption energy of −2.5 eV was obtained for Ti-adsorbed arsenene (As₅₀Ti) due to reasonable charge exchange, change in actual charge density, and work function. The molecule interacts chemically with As₅₀Ti by forming a Ti–C bridge. The DOS and COHP analysis show that this interaction originates from the overlapping of the Ti-3d orbital with the C-2p of the molecule. The ICOBI analysis predicts a mixed covalent-ionic bonding for the Ti–C pair. The Gibbs free energy calculations reveal that the adsorption of PE has a spontaneous behavior at room temperature. This atomic-level study offers a profound understanding of the interaction between PE and arsenene systems, which is beneficial in designing the desired sensing materials.