Defective phosphorene for highly efficient formaldehyde detection: Periodic density functional calculations

The exfoliation of black phosphorene has spurred a great deal of research interest in improved sensors and electronic devices in the past few years. This article has dealt with the sensing of formaldehyde (CH2O) molecule over the pristine (BP) and vacancy-doped (DP) phosphorene layers at the HSE06/TZVP level of theory. The lowest-energy configurations of formaldehyde preferred a planar form, which was oriented perpendicular to the surface of the defective sensor. The defect engineering provided improved sensitivities (by about 200% and 20% higher) in terms of work function and electronic conductivity. Meanwhile, the defect engineering preserved the regeneration ability of formaldehyde with a 0.22 ns recovery time at room temperature. Therefore, DP provided higher CH2O sensitivity and reusability compared to BP. Moreover, the selectivity coefficient of formaldehyde was found to be 11.6 in air. These improvements open new insights into the rational design of capable reusable nanosensors for the CH2O molecule. (C) 2020 Elsevier B.V. All rights reserved.