CN100455518C - Preparation method of nickel sulfide nanorods - Google Patents

Abstract

The invention relates to a method for preparing nickel sulfide nanorods, which belongs to the field of nanomaterial preparation. The improvement lies in dissolving C ₈ -C ₂₂ straight-chain or branched-chain alkyl nickel sulfonate in an ionic liquid, The product was isolated by constant temperature at 140°C-210°C for 5 minutes-3 hours. The ionic liquid is composed of cations and anions, wherein the cations are N,N'-dialkylimidazolium ions, and the anions are BF ₄ ^- , PF ₆ ^- , CF ₃ COO ^- , C ₃ F ₇ COO ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , SbF ₆ ^- or AsF ₆ ^- . The reaction product prepared by the above method is relatively uniform in appearance, and rod-shaped nickel sulfide is formed within 5-7 minutes. This method has the advantages of environmental protection and rapidity, and can be prepared under normal pressure and air environment. The operation process is simple and easy. The reaction time is short, the yield is high, and it is suitable for mass production.

Description

Preparation method of nickel sulfide nanorods

technical field

The invention relates to a method for preparing nanometer materials, in particular to a method for preparing nickel sulfide nanorods.

Background technique

Nanomaterials have many excellent properties different from bulk materials, and have broad application prospects in the fields of chemistry, physics, materials and machinery. One-dimensional nanomaterials exhibit excellent properties different from those of bulk materials and nanoparticles in many aspects, and have very promising application prospects in the connection and composition of nanodevices.

In recent years, room temperature ionic liquids (Room temperature ionic liquids) are being recognized and accepted as a relatively environmentally friendly solvent and catalyst. Ionic liquid has no vapor pressure (non-volatile), non-combustible, good electrical conductivity, high thermal stability, and is in a liquid state in a wide temperature range. It can dissolve many organic and inorganic substances and can be recycled. It is a new type of Based on the above advantages, ionic liquid, as a green solvent, has been more and more widely used in the fields of organic synthesis, catalysis, extraction and separation.

Korgel et al. (Nano Lett., Vol.4, No.4, 2004) used a solvent-free method to pyrolyze nickel thiol derivatives in the presence of octanoate to obtain a mixture of NiS nanorods and nanotriangular sheets , during the preparation process, octanoate was used as a surfactant to modify the surface of NiS. The preparation process of the precursor required by this method is complicated, the reaction product is not single, the nanorods and nanosheets cannot be effectively separated, and the product morphology is not easy to control.

Contents of the invention

The purpose of the present invention is to provide a method for preparing nickel sulfide nanorods with simple operation process, short reaction time and high yield.

To achieve the above object, the present invention adopts the following technical solutions:

The method for preparing nickel sulfide nanorods is improved by dissolving nickel alkylsulfonate in ionic liquid, keeping the temperature at 140° C. 2-210° C. for 5 minutes to 3 hours, and separating the solid to obtain the product.

The alkyl group in the nickel alkyl sulfonate is a C ₈ -C ₂₂ straight chain or a branched alkyl group.

The alkyl group in the nickel alkyl sulfonate is a C ₈ -C ₁₆ straight chain or a branched alkyl group.

Constant temperature at 140℃-210C for 5-30 minutes.

Nickel alkyl sulfonate is obtained by stirring and reacting soluble nickel (II) salt and alkyl sulfonate in alcohol water system.

The ionic liquid is composed of cations and anions, wherein the cations are N,N'-dialkylimidazolium ions, and the anions are BF ₄ ^- , PF ₆ ^- , CF ₃ COO ^- , C ₃ F ₇ COO ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , SbF ₆ ^- or AsF ₆ ^- .

In the present invention, by changing the length of the carbon chain of nickel alkylsulfonate in the reaction, nickel sulfide nanorods with a length from 50nm to 200nm can be obtained. When the reaction continued for 5-7 minutes, what was obtained was nickel sulfide nanorods with a length of 50-60nm and a diameter of 10-15nm; as the reaction time increased, the nanorods continued to grow, and when the reaction time reached half an hour, The nanorods are basically stable, and the length and diameter of the nanorods basically do not change in the later time. However, the aspect ratios of the nanorods obtained after the reaction of nickel sulfogenates with different carbon chain lengths for half an hour are different. big.

The preparation method of the ionic liquid: react the alkylimidazole with the alkyl halide at constant temperature for a certain period of time, and exchange the obtained halide ionic liquid with the corresponding anion after purification and drying to obtain the target product room temperature ionic liquid.

Because ionic liquid has the advantages of good thermal stability and almost no vapor pressure, it is known as a green solvent. It does not use or emit a large amount of toxic and harmful waste liquid and waste gas during the reaction. Therefore, this method can avoid environmental pollution. In our process of preparing nickel sulfide nanorods, the ionic liquid is used as a solvent or a catalyst or a surfactant. In the reaction, no additional surfactant is needed to obtain nickel sulfide nanorods. The morphology of the reaction product is relatively uniform, and the yield is about It is 35%, which is 5% higher than the product yield obtained by the solvent-free method. In the present invention, after the reaction system reaches the set temperature, it only takes 5-7 minutes to generate rod-shaped nickel sulfide, so this method has the advantage of rapid synthesis, and, by properly controlling the synthesis time and alkyl sulfide The length of the alkyl carbon chain in the nickel ortho-acid can obtain nickel sulfide nanorods with different sizes and aspect ratios. When the reaction time is relatively short, the products obtained by the alkyl sulfonate nickel with different carbon chains are all with a diameter of 10-15nm, 50-60nm long nickel sulfide nanorods, as the reaction time increases, the nanorods continue to grow, and the long diameter of the nanorods obtained after half an hour of reaction of nickel sulfonate with different carbon chain lengths The aspect ratio is different, and the aspect ratio of the nanorods increases with the increase of the carbon chain length of nickel alkylsulfonate.

The method has the advantages of environmental protection and rapidity, can be prepared under normal pressure and air environment, has simple and easy operation process, short reaction time and high yield, and is suitable for mass production.

Description of drawings

Fig. 1 is the X-ray powder diffraction (XRD) pattern of the embodiment of the present invention 1;

Fig. 2 is the transmission electron microscope (TEM) figure of embodiment 1 of the present invention;

Fig. 3 is the transmission electron micrograph of embodiment 2 of the present invention;

Fig. 4 is the transmission electron micrograph of embodiment 3 of the present invention;

Fig. 5 is the transmission electron micrograph of embodiment 4 of the present invention;

Fig. 6 is the electron diffraction pattern of embodiment 4 of the present invention;

Fig. 7 is the transmission electron micrograph of embodiment 5 of the present invention;

The instrument used for the TEM photo is a JEM100CX-II type transmission electron microscope (JEOL company in Japan), the accelerating voltage is 100kV, the sample dispersion solvent is acetone, and it is dropped on the copper grid carried by the carbon film for detection; the instrument used for the XRD analysis is an X'pert pro type X-ray Diffractometer (XRD, Philips Company of the Netherlands), using Cu Kα line excitation source, λ = 0.15418366nm, voltage 40kV, current 40mA, the sample can be placed in the groove of the sample table as powder and flattened or the sample is dispersed in acetone and added dropwise on the load. On the glass slide, dry and form a thin film for direct detection.

Detailed ways

Embodiment 1, the preparation steps of nickel sulfide nanorods are: (1) Preparation of nickel octane sulfonate: take _0.005molNiSO 6H ₂ O and dissolve it in water, weigh 0.01mol potassium octanesulfonate for use Methanol was dissolved, and the nickel sulfate aqueous solution was added dropwise into the potassium sulfonate solution to obtain a khaki-yellow precipitate immediately. After the dropwise addition, fully stir. The resulting mixture was filtered with suction, and the filter cake was washed three times with methanol:water at a ratio of 3:1 (volume ratio), and then washed once with methanol, filtered with suction, and the filter cake was vacuum-dried for later use. The resulting product is nickel octane sulfonate. (2) Preparation of ionic liquid: methylimidazole and hexyl bromide 1:1 (molar ratio) were added to the flask, the temperature of the oil bath was slowly raised to 60°C and stirred for 5 hours, then cooled to room temperature, dissolved in distilled water, and the aqueous solution was used Dichloromethane extracted 3 times to wash away unreacted brominated alkanes and methylimidazole. Add NaBF ₄ solution dropwise to the washed aqueous solution, the molar ratio of sodium fluoroborate to methylimidazole is 1:1, after the dropwise addition, stir for 20 minutes, extract 3 times with dichloromethane, dichloromethane extract Then wash 3 times with distilled water to wash off the unreacted sodium fluoroborate and intermediates, dry the dichloromethane solution with anhydrous magnesium sulfate overnight, evaporate the solvent under reduced pressure at 30°C, and remove the existing sodium fluoroborate under reduced pressure at 100°C. little water.

(3) Preparation of NiS nanorods: Add 0.03 g of nickel octane sulfonate and 3 mL of 1-hexyl-3-methylimidazolium tetrafluoroborate ionic liquid into a 50 mL one-necked bottle, and stir gently with a magnetic stirrer , so that nickel octane sulfonate is uniformly dispersed in the ionic liquid. Put the one-necked bottle into the oil bath, heat the oil bath from room temperature to 140°C slowly, and at the same time stir it magnetically, keep it for 1 hour, then take out the one-necked bottle, and after the solution is cooled to room temperature, separate the product by centrifugation, and the separated The product was washed 5 times with acetone, and then dried at room temperature to obtain the product.

As shown in Figure 1, it is the X-ray powder diffraction figure of embodiment 1, and the diffraction peak in 2θ=20 °～90 ° scope is through with JCPDS (75-0613) standard card contrast, corresponds to the nickel sulfide of hexagonal structure .

As shown in FIG. 2 , the product obtained in the transmission electron microscope image is a nickel sulfide nanorod with a length of about 200 nm and a diameter of about 100 nm, and the aspect ratio of the nanorod is 2.

Embodiment 2, the preparation steps of nickel sulfide nanorods are: (1) Preparation of nickel cetyl sulfonate: the raw material is potassium cetyl sulfonate, and the preparation method is the same as in Example 1. (2) Preparation of ionic liquid: the raw material was changed to potassium hexafluorophosphate, and the preparation method was the same as in Example 1. (3) Preparation of nickel sulfide nanorods: Add 0.03 g of nickel hexadecyl sulfonate and 3 mL of 1-hexyl-3-methylimidazolium hexafluorophosphate ionic liquid into a 50 mL single-necked bottle, and gently stir with a magnetic stirrer. Stir to disperse nickel cetyl sulfonate evenly in the ionic liquid, put the one-necked bottle into the oil bath, and slowly heat the oil bath from room temperature to 170°C, while stirring magnetically, keep it for 5 minutes, then place the one-necked bottle After the solution is cooled to room temperature, the product is separated by centrifugation, and the separated product is washed 5 times with acetone, and then dried at room temperature to obtain a shuttle-shaped nickel sulfide nanorod.

As shown in FIG. 3 , the analysis in the transmission electron microscope shows that the product is a nanorod with a length of about 50 nm and a diameter of about 10 nm, and the aspect ratio of the nanorod is 5.

Embodiment 3, the preparation steps of nickel sulfide nanorods are: (1) Preparation of nickel hexadecyl sulfonate: same as in embodiment 2. (2) The preparation method of the ionic liquid is the same as in Example 2. (3) Preparation of NiS nanorods: Add 0.03g nickel hexadecyl sulfonate and 3mL 1-hexyl-3-methylimidazolium hexafluorophosphate ionic liquid into a 50mL single-necked bottle, and stir gently with a magnetic stirrer , so that nickel hexadecyl sulfonate is evenly dispersed in the ionic liquid, put the one-mouth bottle into the oil bath, and slowly heat the oil bath from room temperature to 210 ° C, while magnetic stirring, keep for 30 minutes, and then take out the one-mouth bottle , after the solution was cooled to room temperature, the product was separated by centrifugation, the separated product was washed 5 times with acetone, and then dried at room temperature to obtain a shuttle-shaped nickel sulfide nanorod.

As shown in FIG. 4 , the analysis in the transmission electron microscope shows that the product is a nanorod with a length of about 200 nm and a diameter of about 25 nm, and the aspect ratio of the nanorod is 8.

Embodiment 4, the preparation steps of nickel sulfide nanorods are: (1) Preparation of nickel hexadecyl sulfonate: same as embodiment 2. (2) The preparation method of the ionic liquid is the same as in Example 2. (3) Add 0.03g of nickel hexadecyl sulfonate and 3mL of 1-hexyl-3-methylimidazolium hexafluorophosphate ionic liquid into a 50mL single-necked bottle, and stir gently with a magnetic stirrer to make hexadecyl Nickel sulfonate is uniformly dispersed in the ionic liquid, put the one-necked bottle into the oil bath, and slowly heat the oil bath from room temperature to 150°C, while stirring magnetically, keep it for 3 hours, then take out the one-necked bottle, and wait for the solution to cool to room temperature Finally, the product was separated by centrifugation, and the separated product was washed 5 times with acetone, and then dried at room temperature to obtain a shuttle-shaped nickel sulfide nanorod.

As shown in FIG. 5 , the analysis in the transmission electron microscope shows that the product is a nanorod with a length of about 200 nm and a diameter of 25 nm, and the aspect ratio of the nanorod is 8.

As shown in Figure 6, the single hexadecyl sulfonate nickel was used as the precursor, the 1-hexyl-3-methylhexafluorophosphate ionic liquid was used as the reaction medium, and the reaction time was 3 hours. Electron diffraction pattern of nanorods. It can be seen from the figure that the prepared single nanorod is a single crystal.

Embodiment 5, the preparation steps of nickel sulfide nanorods are: (1) Preparation of nickel hexadecyl sulfonate: same as in embodiment 2. (2) Preparation of ionic liquid: Methylimidazole and decane bromide 1:1 (molar ratio) were added to the flask, the temperature of the oil bath was slowly raised to 85°C and stirred for 5 hours, cooled to room temperature, dissolved in distilled water, and used as an aqueous solution Dichloromethane extracted 3 times to wash away unreacted brominated alkanes and methylimidazole. Add trifluoroacetic acid dropwise to the washed aqueous solution, and the molar ratio of trifluoroacetic acid to methylimidazole is also 1:1. After the dropwise addition, stir for 20 minutes, extract 3 times with dichloromethane, dichloromethane extract It was washed with distilled water three times, and the dichloromethane solution was dried overnight with anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure at 30°C, and a small amount of water was evaporated under reduced pressure at 100°C. (3) Add 0.03g nickel hexadecyl sulfonate and 3mL 1-decyl-3-methylimidazolium trifluoroacetate ionic liquid into a 50mL single-necked bottle, stir gently with a magnetic stirrer, and make hexadecyl Nickel alkyl sulfonate is uniformly dispersed in the ionic liquid, put the one-necked bottle into the oil bath, and slowly heat the oil bath from room temperature to 150°C, and at the same time magnetically stir it, keep it for 30 minutes, then take out the one-necked bottle, and wait for the solution to cool After reaching room temperature, the product was separated by centrifugation, and the separated product was washed 5 times with acetone, and then dried at room temperature to obtain shuttle-shaped nickel sulfide nanorods.

As shown in FIG. 7 , the analysis in the transmission electron microscope shows that the product is a nanorod with a length of about 200 nm and a diameter of about 25 nm, and the aspect ratio of the nanorod is 8.

Claims (6)

1. The preparation method of nickel sulfide nanorods is characterized in that, dissolving nickel alkylsulfonate in ionic liquid, keeping the temperature at 140°C-210°C for 5 minutes-3 hours, and separating the solid to obtain the product; The ionic liquid is composed of cations and anions, wherein the cations are N, N'-dialkylimidazolium ions, and the anions are BF ₄ ^- , PF ₆ ^- , CF ₃ COO ^- , C ₃ F ₇ COO ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , SbF ₆ ^- or AsF ₆ ^- . 2. The method for preparing nickel sulfide nanorods according to claim 1, characterized in that the alkyl group in the nickel alkylsulfonate is a C ₈ -C ₂₂ linear chain or a branched chain alkyl group. 3. The method for preparing nickel sulfide nanorods according to claim 2, characterized in that the carbon chain of the alkyl group in the nickel alkylsulfonate is a C ₈ -C ₁₆ straight chain or a branched alkyl group. 4. The method for preparing nickel sulfide nanorods according to claim 1, 2 or 3, characterized in that the temperature is kept constant for 5-30 minutes. 5. The method for preparing nickel sulfide nanorods according to claim 1, 2 or 3, characterized in that the nickel alkyl sulfonate consists of soluble divalent nickel salt and alkyl sulfonate in the alcohol-water system Stir the reaction to get. 6. The method for preparing nickel sulfide nanorods according to claim 4, characterized in that the nickel alkylsulfonate is obtained by stirring and reacting soluble divalent nickel salt and alkylsulfonate in an alcohol-water system.

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