Synthesis of NbS2 nanoparticles with (nested) fullerene-like structure (IF)

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.