Simple synthesis and characteristics ofMo/MoS2 inorganic fullerene-like and actinomorphic nanospheres with core–shell structure

Abstract

High yields of Mo/MoS2 inorganic fullerene-like and actinomorphic nanospheres with a core–shell structure havebeen successfully synthesized by the one-step reaction of sulfur and molybdenumnanospheres under a hydrogen atmosphere, in which the Mo nanosphereswere prepared by the wire electrical explosion method. The shell thickness ofMoS2 is about 4–10 nm and exhibit an expansion of about 4.2–1% along thec-axis. Observed from high-resolution transmission electron microscopyimages, unreacted molybdenum lying between the (002) layers ofMoS2 contributes to the larger expansion besides the strain in the bentlayer and the crystal defects; the preferred growth orientations forMoS2 on the surface of Mo have two directions under different annealing temperatures: parallel tothe (110) plane of Mo, presenting an actinomorphic phase, and perpendicular or havingcertain angles to the (110) plane, showing a fullerene-like phase. The actinomorphicMo/MoS2 can be used for catalysis and intercalation. The fullerene-like phase can be applied as asolid lubricant to enhance the structural rigidity and load bearing capacity of hollowMoS2. In addition, the core–shell nanospheres exhibit a little higher onset temperature and a narrowtemperature range against oxidation with a weaker exothermic peak than conventional2H-MoS2.