Preparation method of non-water-soluble transition metal disulphide nanosheets

Abstract

The invention relates to a preparation method of non-water-soluble transition metal disulphide nanosheets. The preparation method comprises the following steps that water-soluble salts containing transition metal elements are used as transition metal sources; thiourea is used as a sulphur source; the transition metal sources, the sulphur source and NaCl are added into deionized water to be dissolved according to the mol ratio of transition metal elements in the transition metal sources to the sulphur element in the sulphur source being 1: (1.8 to 2.5) and according to the mol ratio of the transition elements in the transition metal source to the NaCl being 1:(150 to 600); then, freezing and vacuum drying are performed to obtain a mixture; the prepared mixture is ground into powder; the powder is put into a tubular furnace constant-temperature region for calcination and chemical vapor deposition to obtain products; water washing and vacuum drying are carried out; the disulphide nanosheets are obtained. The disulphide nanosheets with the characteristics of high quality, uniform dimension, relatively controllable layer number, higher yield, lower relative preparing cost and the like can be obtained.

Description

technical field [0001] The invention relates to a universal preparation method of water-insoluble transition metal disulfide nanosheets, which can be applied to and not limited to the field of lithium-ion secondary battery electrode materials. Background technique [0002] The nanoscale two-dimensional structure of graphene has more special and magical physical and chemical properties different from the macroscopic two-dimensional structure. Such unique properties have gradually attracted scientists' attention and research on other nanoscale two-dimensional structures. [0003] Monolayer and multilayer water-insoluble transition metal dichalcogenides such as MoS 2 , W 2 , VS 2 , FeS 2 ,CoS 2 etc. Because of its close-packed hexagonal structure and sheet stacking method similar to graphene, it has aroused great research interest of scientists in recent years. Transition metal dichalcogenide nanosheets with two-dimensional structure and ultrathin thickness exhibit unusual...

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Problems solved by technology

The exfoliation method generally uses commercial water-insoluble transition metal dichalcogenide bulk powders as raw materials, and obtains water-insoluble transition metal dichalcogenide nanosheets (Acc. Chem.Res.2014,47,1067-1075)(Adv.Mater.2012,24,772-775)(J.Am.Chem.Soc.2013,135,10274-10277); although the method is simple and direct, the preparation However, there are problems such as serious uneven thickness distribution, poor dispersion, easy agglomeration, easy damage, and poor quality of nanosheets. At the same time, it is accompanied by serious noise pollution and chemical pollution caused by the peeling process.

The chemical synthesis method generally uses transition metal salts and sulfur-containing inorganic substances or polymers as raw materials to obtain water-insoluble transition metal disulfide nanosheets through chemical reactions such as hydrothermal synthesis or chemical vapor deposition (Adv.EnergyMater.2014 , 4, 1301380) (Angew.Chem.2014, 126, 1290–1293) (J.Am.Chem.Soc.2013, 135, 5304-5307); chemical synthesis method can prepare relatively good dispersion and larger area Water-insoluble transition metal dichalcogenide nanosheets are large, high-quality, few-layer or even single-layer, but there are disadvantages such as the product is very sensitive to the reaction conditions, the yield is low, the process requirements are strict, and the energy consumption and cost are high. place

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