Unraveling the Differential NO ₂ Gas‐Sensing Mechanisms of p‐Type Boron‐Doped and n‐Type Nitrogen‐Doped Graphene: A First‐Principles Comparative Study

Heteroatom‐doped graphene shows promise for gas sensors, yet fundamental differences in NO 2 sensing between p‐type and n‐type systems remain unclear. This work employs dispersion‐corrected density functional theory to investigate boron‐ and nitrogen‐doped graphene. Boron‐doped graphene donates 0.510 e to NO 2 , with an adsorption energy of −1.440 eV and a distance of 2.030 Å, outperforming nitrogen‐doped graphene (0.433 e, −0.596 eV, and 3.150 Å, respectively). Electronic structure analysis reveals that B 2p z –NO 2 π orbital overlap enables strong interfacial interaction, lowering the Fermi level and increasing the work function, yielding 30.0% sensitivity through hole carrier depletion. Nitrogen‐doped graphene suffers from electrostatic repulsion despite similar local symmetry, resulting in only 5.0% sensitivity. Boron‐doped graphene exhibits superior selectivity against interfering gases (NO, CO 2 , H 2 O, O 2 , NH 3 , and N 2 ), with selectivity coefficients ranging from 2.00 (NO) to 30.00 (N 2 ). These findings establish structure–property relationships for advanced graphene‐based NO 2 sensor design.