Detecting toxic gas molecules is of great significance
for industry
and public health. However, how to select and design highly sensitive
and selective gas sensors has been a great challenge. In the present
study, we explore the adsorption properties of monolayer PdS2 for the NH3, N2O, NO2, NO, CO,
H2S, SO2, SO2F2, and SOF2 toxic gas molecules by first-principles calculations. By
combined analyses of adsorption energy, adsorption distance, charge
transfer, electronic structure, work function, and recovery time,
the selectivity and sensitivity of the monolayer PdS2 to
NO2, NO, and SO2 toxic gas molecules are identified.
The adsorptions of NO2, NO, and SO2 lead to
obvious changes of the electronic structure and charge transfer for
the monolayer PdS2, which are further analyzed based on
the frontier molecular orbitals theory. Additionally, NO adsorption
effectively leads the work function of monolayer PdS2 to
reduce by 17%, and the recovery time of the monolayer PdS2 sensor at room temperature is estimated to be considerably short
for NO2, NO, and SO2 gases. The present study
not only uncovered that the monolayer PdS2 can be used
as a promising reusable sensing material featured with high selectivity
and excellent sensitivity for environmentally hazardous gas molecules
but also proposed a strategy for screening suitable sensing material
by comparing the frontier molecular orbitals of the gas molecules
with the band edges of the candidate adsorption materials, which will
attract more attention from the wide audience working in the low-dimensional
material system.
