Enhancing SO and NO Gas Sensing Using ZnCdO‑Based Porous Nanosheets: A DFT Perspective.

The exceptional electronic properties, high surface area, and structural versatility of two-dimensional materials make them excellent candidates for gas-sensing applications. In this study, we propose novel biphenylene (b) and graphenylene (g) lattices of ZnCdO and explore their potential for detecting NO and SO gases via density functional theory calculations. The dynamic and thermal stability of b-(g)-ZnCdO monolayers is confirmed through phonon dispersion and ab initio molecular dynamics simulations. Both gases exhibit favorable adsorption on the monolayers, with significant charge transfer and electronic interaction. Notably, SO interaction on g-ZnCdO is characterized by weak chemisorption, supported by moderate adsorption energy, long-range interaction, and clear surface bonding, suggesting reusability under ambient conditions. Gas adsorption also induces substantial modulation in the work function, reinforcing the suitability of these monolayers for work-function-type sensing. In particular, the g-ZnCdO+SO system shows an ultrafast recovery time at room temperature, with improved desorption kinetics at elevated temperatures. These insights position b-(g)-ZnCdO monolayers as promising platforms for efficient and reusable toxic gas sensors.