Iridium Co‐Doping on Silicon Carbide Nanotube With Antimony, Aluminum, and Germanium as Sensors for Dibutyl Phthalate (DBP): Insight From Computational Study

Abstract In the plastic industries the commonly used additive in polyvinyl chloride plastic is dibutyl phthalate (DBP), responsible for flexibility and resilience. The risk posed by this compound to human health necessitates sensing its level in the environment as much DBP is exhaled or ingested. This study was modelled using density functional theory (DFT) at the LanL2DZ/AUTO level to understand electronic properties of silicon carbide nanotubes (SiCNTs) co‐doped with iridium, antimony, aluminium, and germanium as a sensor for DBP. To detect DBP, electronic properties (FMO, NBO, DOS), intermolecular analyses (QTAIM, NCI), adsorption studies, and sensor mechanisms were measured. Results showed narrow energy gaps, especially for DBT‐Sb‐Ir@SiCNT (0.3285 eV). QTAIM and NCI analyses identified non‐covalent interactions dominated by van der Waals forces. Adsorption studies revealed negative energies: −0.968 eV for DBT‐Sb‐Ir@SiCNT; −2.236 eV for DBT‐Ir@SiCNT; −1.205 eV for DBT‐Ge‐Ir@SiCNT; and −0.917 eV for DBT‐Al‐Ir@SiCNT. The sensor mechanism gave favorable outcomes, indicated by negative electron localization function (ELF), electron transfer fractions, and dipole moments. Addition of dopants influenced system behavior, with DBP‐Ir@SiCNT proving the best sensor, having highest adsorption energy (−2.236 eV), charge transfer ɸ = −6.3599 eV, and ∆N = −1.1×10⁻⁵ eV. This study proposes these nanostructured materials as effective DBP adsorbents.