Tubular structures of titanium disulfide TiS2

The atomic models of single wall zigzag (n,0)- and armchair (n,n)- TiS2 nanotubes have been constructed and the structural, electronic properties and stability conditions have been studied by density-functional-based tight-binding method and compared with TiS2 single layers. Different atomic coordinations of titanium (octahedral and trigonal-prismatic) in the structures of TiS2 nanotubes were considered and analyzed. Our calculations showed that all NTs are uniformly semiconducting and their band gaps tends to vanish as the tube diameters decrease. According to our results, the octahedral coordination of Ti atoms in TiS2 NTs is more favourable. The obtained data were compared with band structures of TiS2 single layers.