The adsorption of CO and CO₂ gases on (6,4) and (7,7) AlN nanotubes for enhanced sensor applications: A DFT approach

We perform total energy and electronic structure calculations to analyse the adsorption of Carbon dioxide and Carbon monoxide molecules on Si-doped single-walled aluminium nitride nanotubes (AlNNTs) of (7,7) and (6,4) chirality using local density approximation (LDA) in the framework of density functional theory (DFT). The results reveal that doped Si-(7,7) AlNNT system show highest sensing potential of approximately 80% of gas adsorption for both CO₂ and CO. However, Si-(6,4) indicates a recovery time of 1.68 sec, and 6-fold better compared with Si-(7,7). We find that pristine (6,4) adsorbs both gases with longer recovery times, making it unsuitable as gases sensor and suggest that strong bonding exist between them making it difficult to dissociate. These findings demonstrate potential application of Si-doped aluminium nitride nanotubes as highly effective sensor for detecting CO₂ and CO greenhouse gases and paving the way for the development of advance sensing technologies at the nanoscale.