Selective Sequestration of Toxic NOx Gases by P‐Doped Graphene: A Density Functional Theory Study

ABSTRACT Using DFT simulations, this study investigates the selective adsorption and sensing mechanism of phosphorus‐doped graphene (P‐grap) toward NO x (NO and NO 2 ) molecules. The findings reveal that P doping introduces a significant spin density on the graphene surface, which enhances the interaction strength and increases the adsorption energy of NO x species compared to pristine graphene. The electronic structure analysis confirms that NO x adsorption markedly alters hybridization near the Fermi level, indicating a strong interaction and substantial modification of surface properties. The P‐graph demonstrates exceptional selectivity for NO x , maintaining strong adsorption and electronic response while other common environmental gases (CO, CO 2 , NH 3 , SO 2 , and H 2 O) show negligible interaction, confirming its selective robust sensing capability. Furthermore, recovery time calculations suggest that the desorption of NO x molecules from the P‐grap surface is feasible and rapid under temperature variation, ensuring reusability of the sensor material. Overall, the findings highlight that P‐grap exhibits strong affinity, high sensitivity, and remarkable selectivity for NO x molecules while retaining fast recovery at room temperature. These properties suggest that P‐grap is a promising candidate for next‐generation gas sensors capable of operating efficiently under real atmospheric conditions.