Hydrothermal Synthesis Of Metal Sulifdes Micro/Nanomaterials

Three-dimensional ordered micro/nanomaterials have better chemical andphysical properties than their bulk phase, and these materials are widely used in manyfields such as catalysis, electrochemistry, magnetics and optics. So far, variousmethods have been applied to prepare three dimensional ordered micro/nanomaterials,and liquid phase method, in particular, has attracted the attention of chemists andresearchers because this method is easy handling, high yielding andenergyeconomical. This paper describes the synthesis of NiS and MoS2micro/nanomaterials based on liquid phase method, and discusses the composition,morphology and structure of the materials.Among various metal sulfides, NiS has complex structures and have beenapplied in magnetics, electricity, optics as well as catalysts in hydrodesulfurizationreactions in industry. Since the properties of nanomaterials are closely related to theirstructures, scientists have focused on making morphologically novel NiSnanomaterials, and have been exploring its mechanism of growth, so that they canmodify and control the size and shape of NiS nanomaterials. Although much progresshas been made in NiS research, low-cost and one-step synthesis of novel materials isalways the aim of our research.MoS2is a diamagnetic, semiconducting layered compound. MoS2has wideapplications as catalysts, electrode materials and lubricants. The synthesis of highquality nanomaterials is the prerequisite for further exploring their properties andapplications. Thus far, various methods for the synthesis of MoS2have been reported,such as high temperature gas phase reduction, sonication-assisted thermaldecomposition, chemical solution method, microwave-assisted method and spraydrying, etc. Different morphological MoS₂nanomaterials has been fabricated usingthese methods, such as nanorods, nanoflowers, microspheres and hollow spheres.Based on the existing situation, this paper discusses the following research:1. NiS is widely used in the Ni-S family of materials. It has expanding potentialsin semiconductors and catalysis. In this paper, we used NiCl₂·6H₂O and thiourea inethanol solution, assisted by hexadecyltrimethylammonium bromide （CTAB）, tosynthesize seaurchin shaped three-dimentional NiS nanomaterials, which wereassembled by nanorods. Different reaction time, surfactants, and ratios of Ni-Sreactants have a significant influence in the final morphology of the NiS nanomaterials.2. We also synthesized flower-shaped MoS2nanomaterials using ammoniummolybdate(（NH₄）₆Mo₇O₂₄·4H₂O)and thiourea under hydrothermal method withoutsurfactants. The influence to the product morphology from sulfur sources, reductantsand concentrations was also discussed.