Enhanced Adsorption of Pentanal on M Atom (M = Mn, Cr)-Doped and Decorated Arsenene

The adsorption of pentanal (PL), a volatile organic compound (VOC), is investigated on M (M = Mn, Cr) atom-modified arsenene systems using dispersion-corrected density functional theory (DFT+D3) calculations. Mn/Cr doping and/or Mn/Cr decoration strongly influences the electronic properties of arsenene and transform it into a narrow band gap semiconductor or half-metal with significant induced magnetism. The PL molecule is physically adsorbed on arsenene owing to the strong Coulomb repulsion of arsenic (As) atoms toward the molecule. Incorporating M atoms profoundly enhances the sensitivity of arsenene toward PL by forming a strong bridge between the M atom of the adsorbent and the O atom of the molecule. The Mn-doped arsenene (Mn-dp-As) and Cr-dp-As show a strong affinity for pentanal with an adsorption energy of -1.0 eV. The Mn-ads-As (Cr-ads-As) yields an adsorption energy of -0.78 eV (-0.99 eV). The COHP and ELF analyses predict a mixed covalent-ionic bonding for M-O, formed through charge exchange and p-d hybridization.