CN103482671A - A method for preparing Sm(OH)3 nanocrystals by uniform precipitation method - Google Patents

Abstract

A method for preparing Sm(OH) ₃ nanocrystals by a uniform precipitation method, dissolving Sm(NO ₃ ) ₃ 6H ₂ O in an appropriate amount of distilled water to prepare a solution A with a Sm ³⁺ concentration of 0.05-0.30 mol/L; Adjust the pH of solution A to 8.5-10.5 with pure diethylenetriamine, and continue to stir for 1-2 hours to form a reaction precursor; place the reaction precursor in a water bath for aging, and naturally cool to room temperature after the reaction; Centrifuge and wash with water and ethanol, collect the product and dry it in vacuum for 2-4 hours to obtain Sm(OH) ₃ nanocrystals. The method has the advantages of convenient operation, low energy consumption and good safety, and the obtained Sm(OH) ₃ nanocrystals have high purity, strong crystallinity, uniform appearance and good dispersibility.

Description

A method for preparing Sm(OH)3 nanocrystals by uniform precipitation method

technical field

The invention relates to a preparation method of a nano semiconductor material, in particular to a method for preparing Sm(OH) ₃ nanocrystals by a uniform precipitation method.

Background technique

Sm(OH) ₃ is a white powder, insoluble in water but easily soluble in inorganic acids. Sm(OH) ₃ is a typical rare-earth metal hydroxide material. Nanoscale Sm(OH) ₃ has the characteristics of both rare-earth and nano-materials. field has potential application value.

Sm ₂ O ₃ is a new generation of energy conversion materials, semiconductor materials and high-performance catalyst materials. Nano Sm ₂ O ₃ can be used in ceramic capacitors and rare earth permanent magnet materials. However, because the activation energy of the synthesis of Sm ₂ O ₃ is relatively high, Sm(OH) ₃ nanocrystals can be used as a precursor for the preparation of nanoscale Sm ₂ O ₃ . In addition, one-dimensional nanomaterials such as nanorods, nanotubes, nanobelts and other special structures will produce some novel characteristics in the aspects of magnetism, electricity and optics, thus arousing great enthusiasm for research.

The current method of preparing rare earth hydroxides is hydrothermal method [Y.-P.Fang, A.-W.Xu, L.-P.You, Hydrothermal Synthesis of Rare Earth(Tb, Y) Hydroxide and OxideNanotubes[J ], Advanced Functional Materials, 2003, 13(12):955-960]. However, the preparation period of the hydrothermal method is long, the process is complex and the energy consumption is high.

Contents of the invention

The object of the present invention is to provide a kind of homogeneous precipitation method and prepare Sm(OH) ₃ method of nanocrystal, this method is easy to operate, energy consumption is low, and safety is good, the Sm(OH) that obtains ₃ nanocrystal purity height, crystallinity Strong, uniform shape and good dispersion.

In order to achieve the above object, the present invention adopts technical scheme and comprises the following steps:

1) Dissolve Sm(NO ₃ ) ₃ 6H ₂ O in distilled water to prepare solution A with Sm ³⁺ concentration of 0.05-0.30mol/L;

2) Under stirring, use diethylenetriamine to adjust the pH value of solution A to 8.5-10.5, and then continue stirring for 1-2.5 hours to form a reaction precursor;

3) Aging the reaction precursor solution at 65-90°C for 1-3 hours, and then naturally cooling to room temperature to obtain the aging solution;

4) After filtering the aging liquid, the solid product was obtained; the solid product was repeatedly centrifuged and washed 4 to 6 times, and washed with distilled water and absolute ethanol each time, and the washed solid product was placed in a vacuum drying oven at 60 Dry at ~80°C for 2-4 hours to obtain Sm(OH) ₃ nanocrystals.

The Sm(NO ₃ ) ₃ ·6H ₂ O and diethylenetriamine are all analytically pure.

The stirring in the step 2) adopts magnetic stirring.

The reaction solution in step 3) is aged in a water bath.

Compared with prior art, the beneficial effect of the present invention is:

The present invention prepares the hexagonal phase rod-shaped Sm(OH) ₃ nanocrystals with a uniform precipitation method, and at the same time, utilizes the organic base diethylenetriamine to adjust the pH of the reaction system in the process of preparing the Sm(OH) ₃ nanocrystals; The Sm(OH) ₃ nanocrystals prepared by the precipitation method have high purity, strong crystallinity, uniform appearance and good dispersion. The raw materials of this method are easy to obtain, the process equipment is simple, the energy consumption is low, the reaction is completed in a short period of time in the liquid phase, and the reaction is carried out under normal pressure, and water is used as the reaction solvent, which has good safety and strong feasibility, so It is very economical and practical, and has good industrialization prospect. In addition, the organic base diethylenetriamine used in the process of adjusting the pH value can not only provide an alkaline environment as an alkali source, but also act as a complexing agent to regulate the microstructure of Sm(OH) ₃ nanocrystals.

Description of drawings

Fig. 1 is the Sm(OH) prepared by the embodiment of the present invention 1 ₃ nanocrystal XRD pattern;

FIG. 2 is a SEM image of the Sm(OH) ₃ nanocrystal prepared in Example 1 of the present invention when enlarged 50,000 times.

Detailed ways

Example 1:

1) Dissolve analytically pure Sm(NO ₃ ) ₃ 6H ₂ O in 50 mL of distilled water to prepare solution A with a Sm ³⁺ concentration of 0.05 mol/L;

2) Under magnetic stirring, use analytically pure diethylenetriamine to adjust the pH value of solution A to 9.0, and then continue to stir for 1 hour to form a reaction precursor;

3) Put the reaction precursor solution in a water bath and age it at 80°C for 1.5h, then cool it down to room temperature naturally to obtain the aging solution;

4) After filtering the aging solution, the solid product was obtained; the solid product was washed by centrifugation with distilled water and absolute ethanol in sequence, the number of washings was 4 to 6 times, and then dried in an electric vacuum oven at 60°C for 3 hours, namely The obtained phase is the Sm(OH) ₃ nanocrystal of the hexagonal phase.

It can be seen from Figure 1 that the prepared Sm(OH) ₃ has high purity, strong crystallinity, obvious orientation growth, and the phase is hexagonal phase.

It can be seen from Figure 2 that the appearance of the product is a thin rod-like structure with uniform distribution and good dispersion.

Example 2:

1) Dissolve analytically pure Sm(NO ₃ ) ₃ 6H ₂ O in 50 mL of distilled water to prepare solution A with a Sm ³⁺ concentration of 0.10 mol/L;

2) Under magnetic stirring, use analytically pure diethylenetriamine to adjust the pH value of solution A to 9.5, and then continue to stir for 1.5h to form a reaction precursor;

3) The reaction precursor solution was aged in a water bath at 65°C for 3 hours, and then naturally cooled to room temperature to obtain an aged solution;

4) After filtering the aging liquid, the solid was obtained; the solid product was washed by centrifugation with distilled water and absolute ethanol in sequence, the number of washings was 4 to 6 times, and then dried in an electric vacuum oven at 60°C for 3 hours to obtain The phase is Sm(OH) ₃ nanocrystal of hexagonal phase.

Example 3:

1) Dissolve analytically pure Sm(NO ₃ ) ₃ 6H ₂ O in 50 mL of distilled water to prepare solution A with a Sm ³⁺ concentration of 0.15 mol/L;

2) Under magnetic stirring, use analytically pure diethylenetriamine to adjust the pH value of solution A to 8.5, and then continue stirring for 1 hour to form a reaction precursor;

3) Put the reaction precursor solution in a water bath and age it at 70°C for 2.5 hours, then cool it naturally to room temperature to obtain the aging solution;

4) After filtering the aging liquid, the solid was obtained; the solid product was washed by centrifugation with distilled water and absolute ethanol in sequence, the number of washings was 4 to 6 times, and then dried in an electric vacuum oven at 60°C for 3 hours to obtain The phase is Sm(OH) ₃ nanocrystal of hexagonal phase.

Example 4:

1) Dissolve analytically pure Sm(NO ₃ ) ₃ 6H ₂ O in 30mL distilled water to prepare solution A with Sm ³⁺ concentration of 0.20mol/L;

2) Under magnetic stirring, use analytically pure diethylenetriamine to adjust the pH value of solution A to 10.0, and then continue to stir for 2 hours to form a reaction precursor;

3) The reaction precursor solution was aged in a water bath at 85°C for 1.5 hours, and then naturally cooled to room temperature to obtain an aged solution;

4) After filtering the aging liquid, the solid was obtained; the solid product was washed by centrifugation with distilled water and absolute ethanol in sequence, the number of washings was 4 to 6 times, and then dried in an electric vacuum oven at 60°C for 3 hours to obtain The phase is Sm(OH) ₃ nanocrystal of hexagonal phase.

Example 5:

1) Dissolve analytically pure Sm(NO ₃ ) ₃ 6H ₂ O in 50 mL of distilled water to prepare solution A with a Sm ³⁺ concentration of 0.30 mol/L;

2) Under magnetic stirring, use analytically pure diethylenetriamine to adjust the pH value of solution A to 10.5, and then continue to stir for 2.5 hours to form a reaction precursor;

3) The reaction precursor solution was aged in a water bath at 90°C for 1 hour, and then naturally cooled to room temperature to obtain an aged solution;

4) After filtering the aging solution, the solid was obtained; the solid product was washed by centrifugation with distilled water and absolute ethanol in sequence, the number of washings was 4 to 6 times, and then dried in an electric vacuum drying oven at 60°C for 3 hours to obtain The phase is Sm(OH) ₃ nanocrystal of hexagonal phase.

Embodiment 6:

1) Dissolve analytically pure Sm(NO ₃ ) ₃ 6H ₂ O in 50 mL of distilled water to prepare solution A with a Sm ³⁺ concentration of 0.30 mol/L;

2) Under magnetic stirring, use analytically pure diethylenetriamine to adjust the pH value of solution A to 10.5, and then continue to stir for 2.5 hours to form a reaction precursor;

3) The reaction precursor solution was aged in a water bath at 90°C for 1 hour, and then naturally cooled to room temperature to obtain an aged solution;

4) After filtering the aging liquid, the solid was obtained; the solid product was washed by centrifugation with distilled water and absolute ethanol in sequence, the number of washings was 4 to 6 times, and then dried in an electric vacuum drying oven at 80°C for 2 hours to obtain The phase is Sm(OH) ₃ nanocrystal of hexagonal phase.

Embodiment 7:

1) Dissolve analytically pure Sm(NO ₃ ) ₃ 6H ₂ O in 50 mL of distilled water to prepare solution A with a Sm ³⁺ concentration of 0.15 mol/L;

2) Under magnetic stirring, use analytically pure diethylenetriamine to adjust the pH value of solution A to 8.5, and then continue stirring for 1 hour to form a reaction precursor;

3) Put the reaction precursor solution in a water bath and age it at 70°C for 2.5 hours, then cool it naturally to room temperature to obtain the aging solution;

4) After filtering the aging solution, the solid was obtained; the solid product was washed by centrifugation with distilled water and absolute ethanol in sequence, the number of washings was 4 to 6 times, and then dried in an electric vacuum drying oven at 70°C for 4 hours to obtain The phase is Sm(OH) ₃ nanocrystal of hexagonal phase.

Claims (4)

1. a sluggish precipitation prepares Sm (OH) ₃nanocrystalline method, is characterized in that, comprises the following steps:

1) by Sm (NO ₃) ₃6H ₂o is dissolved in distilled water and is made into Sm ³⁺the solution A that concentration is 0.05～0.30mol/L;

2) under agitation adopt the pH value to 8.5 of diethylenetriamine regulator solution A～10.5, then continue to stir 1～2.5h, form reaction precursor liquid;

3) by reaction precursor liquid at 65～90 ℃ of lower ageing 1～3h, then naturally cool to room temperature, obtain ageing liquid;

4) after ageing liquid is filtered, obtain solid product; By solid product centrifuge washing 4～6 times repeatedly, and use respectively distilled water and absolute ethanol washing at every turn, the solid product after having washed is placed in vacuum drying oven to dry 2～4h under 60～80 ℃, obtain Sm (OH) ₃nanocrystalline.

2. sluggish precipitation according to claim 1 prepares Sm (OH) ₃nanocrystalline method is characterized in that: described Sm (NO ₃) ₃6H ₂o and diethylenetriamine all adopt analytical pure.

3. sluggish precipitation according to claim 1 prepares Sm (OH) ₃nanocrystalline method is characterized in that: the stirring described step 2) adopts magnetic agitation.

4. sluggish precipitation according to claim 1 prepares Sm (OH) ₃nanocrystalline method is characterized in that: in described step 3), reaction solution is placed in water-bath and carries out ageing.

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