Heterodoped nanoflakes: synthesis and characterization of sulfur‐doped NbSe2 nanoflakes

Abstract

Doping of NbSe2 with heteroatoms is an effective way to tailor its properties. Here, solid phase synthesis process has been utilized for growing uniform and excellent crystalline nano‐NbSe2 by sulfur dopant during the growing process. The sulfur‐doped mechanism of nano‐NbS2xSe2(1‐x)(x = 0.03∼0.2) has been investigated: the sulfur atoms not only replace the Se position but also intercalate in layer gap by one‐step reaction. In the structure of NbSe2, the sulfur atoms replace the positions of Se atoms and then are located in the empty octahedral positions of van der waals gap between the NbSe2 layers with the increase of sulfur content. The lubrication properties of the as‐prepared NbSe2 and sulfur‐doped NbSe2 powders as additives in HVI1500 base oil were discussed. The lubrication properties of base oil was improved by both NbSe2 and sulfur‐doped NbSe2. Furthermore, the lubrication properties of sulfur‐doped (0.1at%) NbSe2 are better than those of pure NbSe2 in HVI1500 base oil, which could be attributed to their thin laminated structure and the sulfur dopant.