CN101746837B - A preparation method of cobalt sulfide microtubes with hierarchical structure - Google Patents

Abstract

The invention belongs to an inorganic chemical synthesis method and in particular relates to a preparation method of a cobalt sulfide micro tube with hiberarchy structure; in the invention, water-soluble cobalt salt is used as a metal source, thioacetamide is used as a sulphur source, ethanediamine is used as metal chelating agent, and cetyl trimethylammonium bromide CTAB is used as a template agent, in a closed reactor, hydro-thermal reaction is carried out under a certain temperature condition, so as to synthesize the micron tube-like cobalt sulfide with the hiberarchy structure, the outer diameter of the tube is about 1.5micron, the thickness of the tube wall is about 400nm, the average length is about 15micron, the tube wall is a nanoscale hexagonal sheet, and the length and the thickness of the sheet are 90nm and 22nm respectively; the synthesis method has the advantages of cheap and easy-obtaining raw material, simple equipment, low reaction temperature and good process repeatability and overcomes the problem of environment pollution caused by organic solvent in the previous synthesis method; the obtained product has wide application prospect in the field of biology, catalysis and material science and the like.

Description

A preparation method of cobalt sulfide microtubes with hierarchical structure

technical field

The invention belongs to an inorganic chemical synthesis method, in particular to a preparation method of a cobalt sulfide microtube with a hierarchical structure.

Background technique

As an important chalcogen compound, cobalt sulfide has a complex structure and composition and good catalytic, optical, electrical and magnetic properties, and has a wide range of applications in industrial fields such as dearomatization and hydrodesulfurization processes. In addition, It is also widely used in research fields such as solar cell materials. At present, neither the traditional synthesis method nor the method reported in the literature can synthesize cobalt sulfide microtubes with hierarchical structure, which limits the application of cobalt sulfide. For example, "Crystal Growth &Design" (Crystal Growth & Design) 2008, Volume 8, page 3745, reported the synthesis of Co ₃ S ₄ octahedral nanocrystals by using biomolecules as template hydrothermal method; British "Chemical Communications" (Chemical Communications) In 2003, page 2498 reported the synthesis of CoS nanowires by vapor deposition. This method needs to be carried out under the protection of argon at a high temperature of 850°C; the United States "Inorganic Chemistry" (Inorganic Chemistry) reported on page 2621, volume 38, 1999, that toluene solvothermal Co ₉ S ₈ and CoS ₂ nanocrystals are synthesized by the method, the raw materials used in this method are highly toxic, and the obtained cobalt sulfide has irregular morphology and is easy to agglomerate; German "Advanced Functional Materials" (Advanced Functional Materials) 2006, Volume 16, 1389 Page reported the use of Kirkendall effect (Kirkendall effect) to synthesize cobalt sulfide hollow nanocrystals. The synthesis method is complicated to operate and the raw materials used are expensive. Other methods also include synthesizing cobalt sulfide nanotubes by using the sacrificial template method ("Journal of Colloid and Interface Science", 2007, volume 308, page 271), and using metal organic compounds as precursors to prepare cobalt sulfide films ("Chemistry Vapor deposition "Chemical Vapor Deposition, 2005, volume 11, page 91), but it is impossible to synthesize micron tubes with hierarchical cobalt sulfide.

Contents of the invention

In view of the above-mentioned deficiencies in the existing process for preparing nano-cobalt sulfide, the object of the present invention is to provide a method for preparing cobalt sulfide microtubes with a hierarchical structure. The method is simple and reliable in operation, using cheap and easy-to-obtain raw materials, and synthesized cobalt sulfide microtubes with a hierarchical structure under lower temperature and pressure conditions, and the obtained microtubes have a larger specific surface area and a larger specific capacitance. It laid the foundation for the wide application of cobalt sulfide.

The technical scheme provided by the present invention is as follows:

A method for synthesizing cobalt sulfide microtubes with a hierarchical structure, characterized in that the method uses water-soluble cobalt salts, thioacetamide as raw materials, ethylenediamine as a complexing agent, and hexadecyl trimethyl bromide Ammonium CTAB is used as a surfactant to prepare cobalt sulfide micron hollow tubes under hydrothermal conditions. The operation steps are as follows:

(1) At room temperature, prepare a solution according to the volume ratio of water:ethylenediamine of 1:1, add 0.0001 mole of water-soluble cobalt salt into the above solution under stirring conditions, and fully stir for 5 minutes;

(2) 0.00010-0.00028 moles of cetyltrimethylammonium bromide CTAB are mixed with the solution in step (1), slightly heated to dissolve;

(3) Mix thioacetamide with an excess of 3 times the molar amount of water-soluble cobalt salt with the solution prepared in step (2), stir for 15 minutes, put into a closed reactor, and water After thermal reaction for 10-24 hours, cobalt sulfide microtubes can be synthesized, and the ratio of the above raw materials can be scaled up in equal proportions.

The above-mentioned water-soluble cobalt salt may be cobalt acetate, cobalt nitrate or cobalt chloride.

Compared with the prior art, the present invention has the following advantages and beneficial effects: the present invention reports the preparation method of cobalt sulfide microtubes with hierarchical structure for the first time, which overcomes the poisonous, expensive, complex process and low reaction temperature of synthetic cobalt sulfide raw materials in the existing method Advanced problems; the synthesis method has low reaction temperature, cheap and easy-to-obtain raw materials and no pollution to the environment, simple equipment, and good process repeatability; the synthetic product has high yield and regular shape, and is a preparation method for hollow nanomaterials with hierarchical structure. It provides a practical development idea. At the same time, the hierarchical cobalt sulfide microtubes have high specific surface area, large specific capacitance, and excellent electrical and magnetic properties, laying a good foundation for their future application research in the fields of catalysis, biotechnology, and material science.

Description of drawings

Accompanying drawing 1 is the powder X-ray diffraction figure of the cobalt sulfide microtube that makes under the temperature 160 ℃;

Accompanying drawing 2 is the low magnification scanning electron micrograph of the cobalt sulfide microtube that makes under the temperature 160 ℃;

Accompanying drawing 3 is the high-magnification scanning electron microscope photo of the cobalt sulfide microtube prepared under the temperature of 160 ℃;

Accompanying drawing 4 is the transmission electron micrograph of cobalt sulfide microtubes prepared at a temperature of 160°C.

Detailed ways

Example 1:

First, fully mix 4 ml of deionized water with 4 ml of ethylenediamine, weigh 0.0001 mole of cobalt acetate, add it to the above solution under stirring, and continue stirring the mixed solution for 5 minutes; Ammonium bromide CTAB was added to the above solution, slightly heated to dissolve it; then 0.0003 moles of thioacetamide was added to the above mixture, stirred for 15 minutes and then loaded into a stainless steel reactor with a Teflon liner , sealed the reactor, and reacted at 160°C for 24 hours. Then cool to room temperature, open the reactor, filter with Buchner funnel, wash with deionized water and absolute ethanol to obtain a black powder. The product is identified as hexagonal phase cobalt sulfide (Co _1-x S) (X=0.75) (accompanying drawing 1) through X-ray powder diffraction, and the black powder is identified as a micron tube by a low power scanning electron microscope, and the average length of the tube is about 15 mm. Micron (figure 2). A high-magnification scanning electron microscope identified that the tube wall is composed of hexagonal nanosheets, and the side length and thickness of the sheets are about 90 nanometers and 22 nanometers, respectively (Fig. 3). It is further proved by transmission electron microscopy that the cobalt sulfide is a hollow tubular structure, the outer diameter of the tube is about 1.5 microns, and the tube wall thickness is about 400 nanometers (accompanying drawing 4). The microtube has a specific surface area of 46.24m ² /g and a specific capacitance of 201F/g. Magnetic measurements show that the cobalt sulfide microtubes are ferromagnetic at low temperatures.

Example 2:

First, fully mix 4 milliliters of deionized water with 4 milliliters of ethylenediamine, weigh 0.0001 moles of cobalt nitrate, add it to the above solution under stirring conditions, and continue to stir the mixed solution for 5 minutes; Ammonium bromide CTAB was added to the above solution, slightly heated to dissolve it; then 0.0003 moles of thioacetamide was added to the above mixture, stirred for 15 minutes and then loaded into a stainless steel reactor with a Teflon liner , sealed the reactor, and reacted at 160°C for 24 hours. Then cool to room temperature, open the reaction kettle, filter with Buchner funnel, and wash with deionized water and absolute ethanol to obtain cobalt sulfide microtubes with the same length as in Example 1.

Example 3:

First, fully mix 4 milliliters of deionized water with 4 milliliters of ethylenediamine, weigh 0.0001 moles of cobalt chloride, add it to the above solution under stirring conditions, and continue to stir the mixed solution for 5 minutes; Add methyl ammonium bromide CTAB to the above solution, heat it slightly to dissolve it; then add 0.0003 moles of thioacetamide to the above mixture, stir for 15 minutes and then put it into a stainless steel with Teflon lining for reaction In the kettle, seal the reaction kettle, and react at 160° C. for 24 hours. Then cool to room temperature, open the reaction kettle, filter with Buchner funnel, and wash with deionized water and absolute ethanol to obtain cobalt sulfide microtubes with the same length as in Example 1.

Example 4:

First, fully mix 4 ml of deionized water with 4 ml of ethylenediamine, weigh 0.0001 mole of cobalt acetate, add it to the above solution under stirring conditions, and continue to stir the mixed solution for 5 minutes; Ammonium bromide CTAB was added to the above solution, slightly heated to dissolve it; then 0.0003 moles of thioacetamide was added to the above mixture, stirred for 15 minutes and then loaded into a stainless steel reactor with a Teflon liner , sealed the reactor, and reacted at 160°C for 24 hours. Then cool to room temperature, open the reaction kettle, filter with Buchner funnel, wash with deionized water and absolute ethanol to obtain cobalt sulfide microtubes, and the average length of the tubes is about 10 microns.

Example 5:

First, fully mix 4 milliliters of deionized water with 4 milliliters of ethylenediamine, weigh 0.0001 moles of cobalt acetate, add it to the above solution under stirring conditions, and continue to stir the mixed solution for 5 minutes; Ammonium bromide CTAB was added to the above solution, slightly heated to dissolve it; then 0.0004 moles of thioacetamide was added to the above mixture, stirred for 15 minutes and then loaded into a stainless steel reactor with a Teflon liner , sealed the reactor, and reacted at 160°C for 24 hours. Then cool to room temperature, open the reaction kettle, filter with Buchner funnel, wash with deionized water and absolute ethanol to obtain cobalt sulfide microtubes, the average length of the tubes is about 12 microns.

Embodiment 6:

First, fully mix 4 ml of deionized water with 4 ml of ethylenediamine, weigh 0.0001 mole of cobalt acetate, add it to the above solution under stirring, and continue stirring the mixed solution for 5 minutes; Ammonium bromide CTAB was added to the above solution, slightly heated to dissolve it; then 0.0003 moles of thioacetamide was added to the above mixture, stirred for 15 minutes and then loaded into a stainless steel reactor with a Teflon liner , sealed the reaction vessel, and reacted at 180° C. for 15 hours. Then cool to room temperature, open the reaction kettle, filter with Buchner funnel, wash with deionized water and absolute ethanol to obtain cobalt sulfide microtubes, the average length of the tubes is about 14 microns.

Embodiment 7:

First, fully mix 4 ml of deionized water with 4 ml of ethylenediamine, weigh 0.0001 mole of cobalt acetate, add it to the above solution under stirring, and continue stirring the mixed solution for 5 minutes; Ammonium bromide CTAB was added to the above solution, slightly heated to dissolve it; then 0.0003 moles of thioacetamide was added to the above mixture, stirred for 15 minutes and then loaded into a stainless steel reactor with a Teflon liner , sealed the reactor, and reacted at 200°C for 10 hours. Then cool to room temperature, open the reaction kettle, filter with Buchner funnel, wash with deionized water and absolute ethanol to obtain cobalt sulfide microtubes, the average length of the tubes is about 14 microns.

Claims (3)

1. the cobaltous sulfide micron tube with hierarchy is characterized in that it is to have Co _1-xThe micron tube that forms by the hexagon nanometer sheet that S forms, wherein X is 0.75; The mean length of described micron tube is 15 microns, and external diameter is 1.5 microns, and thickness of pipe is 400 nanometers.

2. according to the described preparation method of claim 1, it is characterized in that this method comprises the steps: with hierarchy cobaltous sulfide micron tube

(1) under the room temperature, press water: 1: 1 obtain solution of quadrol volume ratio, under the agitation condition 0.0001 mole water soluble cobaltous salt is added in the above-mentioned solution, fully stirred 5 minutes;

(2) 0.00014 mole cetyl trimethylammonium bromide CTAB is mixed with solution in the step (1), heating makes its dissolving;

(3) thioacetamide that will be in excess in 3 times of water soluble cobaltous salt molar weights mixes with the solution of preparation in the step (2), stirs after 15 minutes, puts into closed reactor, under 160-200 ℃ of temperature condition hydro-thermal reaction 10-24 hour, can synthesize the cobaltous sulfide micron tube.

3. it is characterized in that in accordance with the method for claim 2: described water soluble cobaltous salt is cobaltous acetate, Xiao Suangu or cobalt chloride.

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