Theoretical insights into the application of petal Graphyne monolayer as a promising sensor for propylene oxide.

Detecting Propylene Oxide (PO) efficiently remains a key challenge in gas sensing technology. To address this, advanced computational analyses were performed to assess the sensing behavior of Petal-Graphyne (PLG). The adsorption energy, estimated at 31.54 kcal/mol, signifies a balanced interaction-strong enough to ensure stability while still allowing reversible gas adsorption. Sensitivity analysis revealed a strong temperature-dependent response, with sensitivity values declining from 3.07 × 108 at 298 K to 3.70 × 102 at 598 K. According to NBO analysis, substantial electron transfer occurs from the oxygen lone pair of PO to the empty π∗ orbitals of PLG, enhancing selective molecular recognition. Visualization through Reduced Density Gradient (RDG) analysis revealed that van der Waals interactions play a dominant role in stabilizing PO adsorption on the PLG surface, supporting the conclusions drawn from adsorption energy data. Taking together, these quantitative and qualitative insights establish Petal-Graphyne (PLG) as a highly promising material for selective, sensitive, and reversible detection of PO gas, with substantial implications for environmental and industrial sensor technologies.