Monolayer PC₃: A promising material for environmentally toxic nitrogen-containing multi gases

Carbon and its analogous nanomaterials are beneficial for toxic gas sensors since they are used to increase the electrochemically active surface region and improve the transmission of electrons. The present article addresses a detailed investigation on the potential of the monolayer PC₃ compound as a possible sensor material for environmentally toxic nitrogen-containing gases (NCGs), namely NH₃, NO, and NO₂. The entire work is carried out under the frameworks of density functional theory, ab-initio molecular dynamics simulations, and non-equilibrium Green's function approaches. The monolayer-gas interactions are studied with the van der Waals dispersion correction. The stability of pristine monolayer PC₃ is confirmed through dynamical, mechanical, and thermal analyses. The mobility and relaxation time of 2D PC₃ sensor material with NCGs are obtained in the range of 10¹-10⁴ cm² V^-1 s^-1 and 10¹-10³ fs for armchair and zigzag directions, respectively. Out of six possible adsorption sites for toxic gases on the PC₃ surface, the most prominent site is identified with the highest adsorption energy for all the NCGs. Considering the most stable configuration site of the NCGs, we have obtained relevant electronic properties by utilizing the band unfolding technique. The considerable adsorption energies are obtained for NO and NO₂ compared to NH₃. Although physisorption is observed for all the NCGs on the PC₃ surface, NO₂ is found to convert into NO and O at 5.05 ps (at 300 K) under molecular dynamics simulation. The maximum charge transfer (0.31e) and work function (5.17 eV) are observed for the NO₂ gas molecule in the series. Along with the considerable adsorption energies for NO and NO₂ gas molecules, their shorter recovery time (0.071 s and 0.037 s, respectively) from the PC₃ surface also identifies 2D PC₃ as a promising sensor material for those environmentally toxic gases. The experimental viability and actual implications for PC₃ monolayer as NCGs sensor material are also confirmed by examining the humidity effect and transport properties with modeled sensor devices. The transport properties (I-V characteristics) reflect the significant sensitivity of PC₃ monolayer toward NO and NO₂ molecules. These results certainly confirm PC₃ monolayer as a promising sensor material for NO and NO₂ NCG molecules.