Band gap regulation and a selective preparation method for single-walled silicon carbide nanotubes

•A new theoretical method for the synthesis of various single-wall nanotubes is proposed, which should be helpful and instructive for the synthesis of single-wall SiC nanotubes with desired band gaps as well as other single-wall nanotubes.•The electronic properties of single-walled silicon carbide nanotubes were systematically calculated using density functional theory, and the relationship between tube diameter and band gap of single-walled silicon carbide nanotubes was analyzed.•The electronic properties of silagraphene and some multi-wall silicon carbide nanotubes are calculated, which provides theoretical guidance for the experimental synthesis of multi-wall silicon carbide nanotubes.