Investigation of rhenium-doped MoS₂ nanoparticles with fullerene-like structure

The synthesis of rhenium-doped fullerene-like MoS₂ nanoparticles (Re:IF-MoS₂) is described. Careful inductively coupled plasma mass spectrometry analysis reveals that the concentration of the rhenium atoms in the IF-MoS₂ lattice is more than 10-fold smaller than the weighted amount of this atom in the precursor powder. High resolution scanning transmission electron microscopy in high angle annular dark field mode is used to decipher the isolated rhenium atoms in the MoS₂ lattice and confirm that these atoms substitute for molybdenum atoms. Scanning electron microscopy analysis shows that, in contrast to the undoped nanoparticles which tend to agglomerate, the Re:IF-MoS₂ nanoparticles self-assemble on substrate surfaces forming an ordered tessellated monolayer. Theoretical quantum-chemical calculations show that the Re level is some 180 meV below the conduction band. Furthermore, the rhenium electrons are fairly localized in the MoS₂ lattice. At a higher concentration the rhenium atoms form a mini-band below the conduction band which coincides with the Fermi level of the lattice.