Electronic and structural modulation of the B- and N-doped phenine nanotubes

Phenine nanotubes (pNTs), constructed from benzene rings, form a new class of porous carbon-based nanostructures with highly tunable structural and electronic features. The influence of boron–nitrogen (BN) substitution and hydrogen depletion on pNT geometry and electronic behavior is investigated across ten configurations, including pristine, single-element (B or N), and mixed B–N substitutions arranged symmetrically and asymmetrically. Among the doped systems, the hydrogenated nitrogen-substituted pNT is the most stable. BN incorporation preserves the tubular framework while subtly reshaping pore size and morphology. Both doping and hydrogenation allow controlled modulation of pore geometry. Hydrogen removal in pristine pNTs induces a semiconductor-to-metal transition, whereas hydrogen-depleted single-element substitutions lead to significant band-gap widening. In contrast, hydrogenated mixed B–N systems show strong gap suppression, often eliminating the bandgap entirely. The combined tunability in porosity and electronic response positions BN-substituted pNTs as promising candidates for future nanoelectronic and sensing technologies. • Systematic DFT study of BN substitution and hydrogen depletion in phenine nanotubes. • All pristine and BN-doped pNT configurations are thermodynamically stable. • BN doping preserves tube integrity while enabling controlled pore-size modulation. • Hydrogen removal drives pristine pNTs metallic; single-element doping widens the gap. • Mixed B–N systems lose their gap upon hydrogenation, tuning electronic behavior.