Formation, exfoliation and restacking of MoS2 nanostructures

MoS2 nanostructures were prepared by heating MoS3 precursors which were synthesised by acidifying the mixed solution of Na2MoO4 and Na2S or CH3CSNH2 (TAA). The formation mechanism and exfoliation restacking behaviours of the obtained MoS2 nanostructures were investigated. The MoS3 precursor prepared from TAA was composed of hollow nanoballs while that from Na2S comprised microsized particles. Heating the obtained MoS3 hollow nanoballs under H-2 at 780 degrees C led to MoS2 hollow nanoballs. Owing to high temperatures decreased the layer space of MoS2, MoS2 nanoballs were changed into polyhedral structures at 960 degrees C. However, calcining the prepared MoS3 microsized particles resulted in MoS2 nanoplatelets both at 780 and 960 degrees C. The prepared MoS2 nanoballs could exfoliate only partly by the exfoliation technology because of their chemical stability. However, MoS2 nanoplatelets exfoliated completely in exfoliation treatment and formed nano-MoS2 monolayer suspension. The restacked production of the obtained nano-MoS2 monolayer suspension represented similar XRD characteristic with exfoliated nano-MoS2. This indicated that nano-MoS2 monolayers did not restack regularly along c axis.