Abstract

NbS₂ nanoparticles with a closed cage structure (inorganic fullerene-like phase—IF) were synthesized by reaction between NbCl₅ vapor and H₂S gas in a reducing atmosphere at 400 °C, and subsequent annealing under a H₂S/H₂ atmosphere at 550 °C. Following the synthesis, the nanoparticles were found to have a large excess of Nb; they were agglomerated; highly dislocated and enfolded by amorphous material. After annealing, most of the amorphous material crystallized into closed NbS₂ shells, and the nanoparticles appeared to be much more faceted. Transmission electron microscopy revealed that the interlayer spacing (c/n) of the annealed particles had decreased. They were also agglomerated, being connected to neighboring nanoparticles through their outer NbS₂ layers after annealing. In related experiments Nb₂O₃ nanofibers, which organize into a nanoflower superstructure, and also NbS₂ nanofibers were synthesized under somewhat different growth conditions.