As the excellent property of nano molybdenum disulfide, its preparation method has attracted great attention at home and abroad. Currently the chemical synthesis methods of nano molybdenum disulfide mainly include: chemical reduction, chemical decomposition, chemical oxidation, electrochemical, surfactant assisted, hydrothermal and solvothermal synthesis method, natural mineral purification and physical method, etc.
1.0 Chemical reduction method
The pentavalent and hexavalent salt or compound of molybdenum have strong oxidizing property and can be reduced to tetravalent molybdenum under the action of reducing agent. The reducing agents include hydrazine, hydroxylamine and hydrogen, etc. Then nanometer MoS2 can be prepared after adding sulfur or compound to the reaction. During this chemical reaction process, if the surfactant is different, the product dispersion and size will be also obviously different.
2.0 Chemical decomposition method
The chemical property of ammonium thiomolybdate and molybdenum trisulfide are not stable, and they are easy to decompose under high temperature and protective atmosphere. Making use of this kind of characteristic, ammonium thiomolybdate can be decomposed into H2MoS4 in argon to form MoS3, and then prepare nano MoS2.
3.0 Chemical oxidation method
Low valence molybdenum or molybdenum compound can be oxidized to molybdenum tetravalent compound by using oxidant, and then nano MoS2 can be prepared by chemical oxidation synthesis process under suitable conditions.
4.0 Electrochemical method
Electrochemical methods mainly include dipping method and electrochemical deposition method, which can be used to obtain nano MoS2 deposited film on the surface of electrode material.
5.0 Surfactant assisted method
Surfactant plays an important role in the synthesis of nano material. The addition of surfactant can promote the dispersion of nanoparticle and inhibit the growth of nanocrystal, which leads to the formation of nanoparticle.
6.0 Hydrothermal and solvothermal synthesis method
Hydrothermal and solvothermal synthesis method is to put molybdate and sulfide in autoclave, then heat and keep warm for a period of time to prepare various amorphous molybdenum sulfide nano powder. To obtain well crystallized MoS2, the product must be heated and crystallized.
7.0 Natural mineral purification method
The natural mineral purification method is to use the mineral containing MoS2 like molybdenite as raw material, then adopt flotation, chemical leaching and other methods to prepare pure MoS2 by removing the impurity in the mineral, grinding and refining, but the product is a bit large with size. So this method has no advantage compared with other methods.
8.0 Physical method
The physical method is to crush and refine large size MoS2 by means of mechanical, high energy physics and sputtering, then can get the MoS2 with smaller size and nanometer size.
