β-antimonide phosphorus nanosheets as a sensing medium for quinone molecules-a first-principles study

Using the density functional theory (DFT) method, we studied the adsorption behaviour of different toxic quinone molecules, including anthraquinone (AQ), naphthoquinone (NQ), and pyrenequinone (PQ), on β-antimonide phosphorus (β-SbP) nanosheet. Initially, we ascertained the geometrical stability of β-SbP with the support of formation energy, phonon band maps, and ab initio molecular dynamics (AIMD). The electronic attributes of β-SbP are investigated using band structure and projected density of states (PDOS) maps, and the energy gap is calculated to be 2.265 eV. The adsorption of quinone molecules induces a relative band gap variation of 33% to 60%. Among the studied quinone molecules, PQ exhibits the highest variation of 60.26% and 58.10% in parallel and perpendicular orientations, respectively. Furthermore, the sensing performance of quinone pollutants on β-SbP material is assessed using adsorption energy, Mulliken charge transfer, sensitivity, selectivity, and work function. The outcomes revealed that the nature of adsorption (chemisorption or physisorption) as well as the significant charge transfer observed in the ranges from 0.148 to 1.038 e, depending on the orientation of molecules adsorbed on β-SbP. A noticeable variation in the work function is observed for complex PQ1, which is recorded as 14.75%. Our findings reveal that β-SbP nanosheets are highly sensitive to these toxic quinones, indicating their suitability as an efficient sensing material.

In this work, all the simulations were carried out using the Quantum ATK package within the framework of the linear combination of atomic orbitals (LCAO) method with norm-conserving PseudoDojo pseudopotentials. We used hybrid GGA with the Heyd-Scuseria-Ernzerhof (HSE06) functional to study the structural, electronic, and adsorption properties of β-SbP nanosheet towards quinone pollutants. The energy and force convergence criteria were set to 10^-6 eV and 0.01 eV/Å, respectively. The vacuum distance was adjusted to $20\mathring{A}$ in order to eliminate the field effect of neighbouring layers. Also, the thermal stability of β-SbP nanosheet under ambient conditions and at elevated temperatures of 400 K and 500 K is explored using ab initio molecular dynamics (AIMD) simulations.