Gold and platinum functionalized arsenene for the detection of CH₃Cl and CH₃Br: first-principles insights

In this work adsorption of toxic CH₃X (X = Cl, Br) molecules was studied on pristine arsenene (p-As), single metal atom M (M = Au, Pt) doped arsenene (M-As), and AuPt-dimer decorated arsenene (AuPt-As) using first-principles calculations. The stability of M-As systems was determined with formation energy and molecular dynamics simulations. The electronic structure analysis revealed both M-As systems metallic. The adsorption process was analyzed using adsorption energy, adsorption height, charge transfer, change in electronic and magnetic properties, electron localized function (ELF) and work function. The results showed that CH₃X molecules are physically adsorbed on p-As and M-As. However, decorating arsenene with AuPt-dimer significantly improved the adsorption. Both molecules are chemically adsorbed on AuPt-As with adsorption energy of -0.64 and − 0.78 eV, respectively for CH₃Cl and CH₃Br. These findings predict the potential use of noble metal-based dimers decorated arsenene for the detection of toxic CH₃Cl and CH₃Br molecules.