Single-Walled Nanotubes (SWNTs) are a type of carbon nanotube (CNT) characterized by their unique structure. These nanotubes consist of a single layer of carbon atoms arranged in a hexagonal lattice, rolled into a cylindrical shape. Unlike multi-walled nanotubes (MWNTs), which have multiple concentric layers, SWNTs have only one layer, granting them distinct properties.