CN104591722B - A kind of calcium-titanium ore type nano material and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of calcium-titanium ore type nano material and preparation method thereof, with Nd<i>(</i>NO₃<i>)</i>₃·6H₂O、Ca(NO₃)₂·4H₂O、La(NO₃)₃·6H₂O、Co(NO₃)₃·6H₂O and Fe (NO₃)₃·6H₂O is initiation material, adopts coprecipitation method to prepare nanometer (Ca_xNd_1-x)_0.1La_0.9Co_0.5Fe_0.5O₃The presoma of (x=0.1 ~ 0.4) material; Presoma, through calcining, obtains nanometer (Ca_xNd_1-x)_0.1La_0.9Co_0.5Fe_0.5O₃(x=0.1 ~ 0.4) material. The inventive method raw material is easy to get, preparation method's step is simple, safety, without large-scale special installation, small investment, production cost is lower, life cycle of the product is short, product purity is high, Stability Analysis of Structures, resistance to chemical attack, has good industrial utilization prospect.

Description

A kind of perovskite nanometer material and preparation method thereof

technical field

The invention relates to a nano material, in particular to a perovskite nano material and a preparation method thereof.

Background technique

Perovskite materials belong to the trigonal crystal system, and the basic structure is ABO ₃ (A and B represent cations, and O represents oxygen ions). So far, it has been found that the three ionic radii of the oxide ABO ₃ -type compound with a perovskite structure satisfy the following relationship: R _A +R _O =t 2 ^0.5 (R _B +R _O ) (generally t=0.7 ~1.0). Due to the special structure of perovskite oxide materials, perovskite materials have many special properties, such as thermoelectric properties, superconducting properties, piezoelectric properties, optical properties, magnetic properties, etc. In practical applications, the performance of perovskite materials can be improved by doping. It can be said that perovskite materials are extremely important functional materials with a wide range of applications, such as catalysis, fuel cells, sensors, brakes, light Micro motors, storage devices, substrates or substrates, optoelectronic devices, etc. Nano-perovskite materials have unique nano-grain and high-density grain boundary characteristics and the resulting surface effects, small-size effects and macroscopic quantum tunneling effects, making them widely used in chemistry, mechanics, heat, magnetism, Optical, electrical, acoustic and other properties show a series of essential differences from ordinary polycrystalline and amorphous solids.

Chinese patent CN103449536A discloses a method for preparing perovskite-type nano-Nd _1-x Mg _x CoO ₃ , which uses metal cations to replace the A-site metal ions in the perovskite ABO ₃ -type composite oxide material, which acts as a supporting structure. It causes larger lattice distortion and improves its catalytic and chemical properties.

Contents of the invention

The object of the present invention is to provide a perovskite-type nano material with a molecular formula of (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ , where x=0.1~0.4.

Another object of the present invention is to provide a method for preparing perovskite-type nanomaterials, which has simple and safe steps, does not require large-scale special equipment, requires less investment, lower production costs, short production cycle and high product purity.

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

A perovskite nanomaterial, the molecular formula of the perovskite nanomaterial is (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ , where x=0.1-0.4.

A preparation method of the above-mentioned perovskite nanomaterials, comprising the following steps:

(1) Dissolve a certain amount of Nd ( NO ₃ ) ₃ 6H ₂ O, Ca(NO ₃ ) ₂ 4H ₂ O, La(NO ₃ ) ₃ 6H ₂ O, Co(NO ₃ ) ₃ , respectively in distilled water 6H ₂ O, Fe ₂ (SO ₄ ) ₃ ·9H ₂ O, respectively formulated as Nd ( NO ₃ ) ₃ , Ca(NO ₃ ) ₂ , La(NO ₃ ) ₃ , Co(NO ₃ ) ₃ and Fe ₂ ( SO ₄ ) ₃ solution with a concentration of 0.2~0.5mol·L ^-1 ;

(2) According to the proportion of metal elements in (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material, a certain amount of Nd ( NO ₃ ) ₃ , Ca(NO ₃ ) ₂ , La (NO ₃ ) ₃ , Co(NO ₃ ) ₃ and Fe ₂ (SO ₄ ) ₃ solutions were mixed and ultrasonically dispersed for 8-15 minutes to obtain mixed solution A;

(3) Mix the KOH solution with a concentration of 0.20~0.30mol L ^-1 and the solution with a concentration of 0.05~0.15mol L ^-1 K ₂ CO ₃ at a volume ratio of 1~3:1 to obtain solution B;

(4) Add solution B to solution A drop by drop, stir evenly, disperse by ultrasonic for 30-60 minutes until the pH value of the solution is 10-11, then centrifuge for 3-5 minutes, collect the precipitate, and wash the precipitate with distilled water until it is washed to Suction filtration after neutralization, then dissolve the filter cake with ethanol, continue ultrasonic dispersion for 10-20 minutes, and then perform centrifugation for 3-5 minutes, and repeat this process for 3-5 times to obtain precipitated sample C;

(5) Place the precipitated sample C in an oven and dry it at 100-110°C for 12-24 hours, and finally grind the dried material into powder to obtain (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ (x=0.1~0.4) precursor D, said x=0.1~0.4;

(6) Put the precursor D in an electric furnace, heat it to ^450-500 °C at a heating rate of ^5-10 °C min Continue heating to 800-900°C for 2.0-4.0 hours, then naturally cool down to room temperature to obtain nanometer (Nd _x Ca _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material, where x=0.1-0.4.

According to the above method for preparing perovskite-type nanomaterials, the oven described in step (5) is a blast drying oven.

According to the above method for preparing perovskite nanomaterials, the particle size of the nano (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material in step (6) is 80-120 nm.

Positive beneficial effect of the present invention:

(1) The present invention uses other metal cations to replace the A-site metal ions in the perovskite ABO ₃ type composite oxide material, which is the main support structure skeleton, causing larger lattice distortion and improving its catalytic and chemical properties; On the basis of substitution by A, other transition metal cations are used to replace the B-site ions that have the main catalytic activity and other functions, and a perovskite-type material with A-site and B-site substitutions and a mixed-valence structure is prepared. The energy of the material system is higher, and the transformation of electronic structure matching can occur only under the driving of a small energy, so as to obtain better magnetic, optical, electrical, surface and catalytic properties.

(2) The perovskite-type nano (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material of the present invention adopts an oxide perovskite material that is replaced by A-site and B-site ions at the same time, and has a large range Internal modulation and control of the ion valence state and crystal defect characteristics in the structure, while maintaining good thermodynamic stability.

(3) The raw materials used in the present invention have a wide range of sources and low prices; the preparation method of the present invention is simple, convenient and safe to operate, requires less equipment, small investment, and is easy to produce; the product has a short production cycle, low cost, high purity, and a particle size of 80-120nm , stable structure, chemical corrosion resistance, and has good industrial application prospects.

Description of drawings

Fig. 1 is the XRD spectrum of the X-ray diffraction of the perovskite type nano material of the embodiment of the present invention 1;

Fig. 2 is the XRD spectrum of the X-ray diffraction of the perovskite nanomaterial of embodiment 2 of the present invention;

FIG. 3 is an XRD pattern of X-ray diffraction of the perovskite nanomaterial of Example 3 of the present invention.

detailed description

The present invention will be further described below in conjunction with some specific examples.

Example 1

A perovskite nanomaterial, the molecular formula of the perovskite nanomaterial is (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ , where x=0.4.

The preparation method of the perovskite nanometer (Ca _0.4 Nd _0.6 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material comprises the following steps:

(1) Weigh 21.9120g of Nd ( NO ₃ ) ₃ 6H ₂ O, 11.8075g of Ca(NO ₃ ) ₂ 4H ₂ O, 21.6500g of La(NO ₃ ) ₃ 6H ₂ O, 17.6500g Co(NO ₃ ) ₃ ·6H ₂ O, 28.1005g of Fe ₂ (SO ₄ ) ₃ ·9H ₂ O, and then add a certain amount of distilled water to prepare Nd ( NO ₃ ) with a concentration of 0.5mol·L ^-1 _3. Ca(NO ₃ ) ₂ , La(NO ₃ ) ₃ , Co(NO ₃ ) ₃ and Fe ₂ (SO ₄ ) ₃ solutions;

(2) According to the stoichiometric ratio of metal elements in (Ca _0.4 Nd _0.6 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material (Ca: Nd: La: Co: Fe = 0.04: 0.06: 0.9: 0.5: 0.5), respectively 4ml of Ca(NO ₃ ) ₂ solution, 6ml of Nd ( NO ₃ ) ₃ solution, 90ml of La(NO ₃ ) ₃ solution, 50ml of Co(NO ₃ ) ₃ solution, 25ml of Fe ₂ solution obtained in the above step (1) (SO ₄ ) ₃ solutions were mixed and ultrasonically dispersed and mixed for 10 minutes to obtain a mixed solution A;

(3) Mix 0.30 mol L ^-1 KOH solution and 0.15 mol L ^-1 K ₂ CO ₃ solution at a volume ratio of 2:1 to obtain solution B;

(4) Add solution B to solution A drop by drop, stir evenly, disperse by ultrasonic for 60 minutes, until the pH value of the solution is 10, then centrifuge for 5 minutes, collect the precipitate, wash the precipitate with distilled water until it is neutral, and then filter it with suction. Then dissolve the filter cake with ethanol, continue to ultrasonically disperse for 20 minutes, and then perform centrifugation for 5 minutes, and repeat this 3 times to obtain precipitated sample C;

(5) Place the precipitated sample C in an oven and dry it at 110°C for 20 hours, and finally grind the dried material into a powder to obtain ((Ca _0.4 Nd _0.6 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ precursor D;

(6) Place the precursor D in an electric furnace, heat it to 500 °C at a heating rate of 5 °C min ^-1 for 3 h, and then

Continue heating at a heating rate of 3°C·min ^-1 to 800°C for 2.0 hours, then cool down to room temperature naturally to obtain nanometer (Ca _0.4 Nd _0.6 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ materials.

It can be seen from Figure 1 that the product (Ca _0.4 Nd _0.6 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ perovskite material has high purity, is a single perovskite crystal phase, the average particle size is 80nm, and the conversion rate of raw materials is 99% %.

Example 2

A perovskite nanomaterial, the molecular formula of the perovskite nanomaterial is (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ , where x=0.3.

The preparation method of the perovskite nanometer (Ca _0.3 Nd _0.7 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material comprises the following steps:

(1) First weigh 17.5296g of Nd(NO ₃ ) ₃ ·6H ₂ O, 9.4460g of Ca(NO ₃ ) ₂ ·4H ₂ O, 17.3200g of La(NO ₃ ) ₃ ·6H ₂ O, 14.1200g Co(NO ₃ ) ₃ ·6H ₂ O, ^22.4804g of Fe ₂ (SO ₄ ) ₃ ·9H ₂ O, and then add a certain amount of distilled water to prepare Nd ( NO ₃ ) ₃ , Ca(NO ₃ ) ₂ , La(NO ₃ ) ₃ , Co(NO ₃ ) ₃ and Fe ₂ (SO ₄ ) ₃ solutions;

(2) According to the stoichiometric ratio of metal elements in (Ca _0.3 Nd _0.7 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material (Ca: Nd: La: Co: Fe = 0.03: 0.07: 0.9: 0.5: 0.5), respectively The above step (1) obtained 3ml of Ca(NO ₃ ) ₂ solution, 7ml of Nd(NO ₃ ) ₃ solution, 90ml of La(NO ₃ ) ₃ solution, 50ml of Co(NO ₃ ) ₃ solution, 25ml of Fe ₂ (SO ₄ ) ₃ solution) were mixed, and ultrasonically dispersed and mixed for 8 minutes to obtain a mixed solution A;

(3) Mix 0.20 mol L ^-1 KOH and 0.05 mol L ^-1 K ₂ CO ₃ at a volume ratio of 3:1 to obtain solution B;

(4) Add solution B to solution A drop by drop, stir evenly, disperse by ultrasonic for 50 minutes, until the pH value of the solution is 11, then centrifuge for 4 minutes, collect the precipitate, wash the precipitate with distilled water until it is neutral, and then filter it with suction. Then dissolve the filter cake with ethanol, continue to ultrasonically disperse for 15 minutes, and then perform centrifugation for 4 minutes, and repeat this 4 times to obtain precipitated sample C;

(5) Place the precipitated sample C in a blast oven and dry it at 100°C for 12 hours, and finally grind the dried material into a powder to obtain (Ca _0.3 Nd _0.7 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O precursor _D ;

(6) Put the precursor D in an electric furnace, heat it to 450°C at a heating rate of 8°C min ^-1 and keep it for 2h, then continue heating to 820°C at a heating rate of 4°C min ^-1 for 4.0h , and naturally cooled down to room temperature to obtain nanometer (Ca _0.3 Nd _0.7 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material.

It can be seen from Fig. 2 that the product (Ca _0.3 Nd _0.7 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ perovskite material has high purity and is a single perovskite crystal phase with an average particle size of 100nm and a raw material conversion rate of 100 %.

Example 3

A perovskite nanomaterial, the molecular formula of the perovskite nanomaterial is (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ , where x=0.1.

The preparation method of the perovskite nanometer (Ca _0.1 Nd _0.9 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material comprises the following steps:

(1) First weigh 17.5296g of Nd ( NO ₃ ) ₃ ·6H ₂ O, 9.4460g of Ca(NO ₃ ) ₂ ·4H ₂ O, 17.3200g of La(NO ₃ ) ₃ ·6H ₂ O, 14.1200g Co(NO ₃ ) ₃ ·6H ₂ O, ^22.4804g of Fe ₂ (SO ₄ ) ₃ ·9H ₂ O, and then add a certain amount of distilled water to prepare Nd ( NO ₃ ) ₃ , Ca(NO ₃ ) ₂ , La(NO ₃ ) ₃ , Co(NO ₃ ) ₃ and Fe ₂ (SO ₄ ) ₃ solutions;

(2) According to the stoichiometric ratio of metal elements in (Ca _0.1 Nd _0.9 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material (Ca: Nd: La: Co: Fe = 0.01: 0.09: 0.9: 0.5: 0.5), respectively The above step (1) obtained 2ml of Ca(NO ₃ ) ₂ solution, 18ml of Nd(NO ₃ ) ₃ solution, 180ml of La(NO ₃ ) ₃ solution, 100ml of Co(NO ₃ ) ₃ solution, 50ml of Fe ₂ (SO ₄ ) ₃ solutions were mixed and ultrasonically dispersed for 15 minutes to obtain a mixed solution A;

(3) Mix 0.20 mol L ^-1 KOH and 0.10 mol L ^-1 K ₂ CO ₃ at a volume ratio of 1:1 to obtain solution B;

(4) Add solution B to solution A drop by drop, stir evenly, disperse by ultrasonic for 30 minutes, until the pH value of the solution is 11, then centrifuge for 3 minutes, collect the precipitate, wash the precipitate with distilled water until it is neutral, and then filter it with suction. Then dissolve the filter cake with ethanol, continue to ultrasonically disperse for 10 minutes, and then perform centrifugation for 3 minutes, and repeat this 5 times to obtain precipitated sample C;

(5) Place the precipitated sample C in a blast oven and dry it at 110°C for 24 hours, and finally grind the dried material into a powder to obtain (Ca _0.1 Nd _0.9 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O precursor _D ;

(6) Put the precursor D in an electric furnace, heat it to 460°C at a heating rate of 10°C min ^-1 and keep it for 1h, then continue heating to 900°C at a heating rate of 6°C min ^-1 for 3.0h , and naturally cooled down to room temperature to obtain a nanometer (Ca _0.1 Nd _0.9 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material.

It can be seen from Figure 3 that the product (Ca _0.1 Nd _0.9 ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ perovskite material has a high purity and is a single perovskite crystal phase with an average particle size of 120nm and a raw material conversion rate of 99%.

Claims (4)

1. A perovskite nanomaterial, characterized in that the molecular formula of the perovskite nanomaterial is (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ , where x=0.1～0.4 . 2. a kind of preparation method of perovskite type nano material according to claim 1, is characterized in that, comprises the following steps: (1) Dissolve a certain amount of Nd(NO ₃ ) ₃ ·6H ₂ O, Ca(NO ₃ ) ₂ ·4H ₂ O, La(NO ₃ ) ₃ ·6H ₂ O, Co(NO ₃ ) ₃ · 6H ₂ O, Fe ₂ (SO ₄ ) ₃ ·9H ₂ O, respectively formulated as Nd(NO ₃ ) ₃ , Ca(NO ₃ ) ₂ , La(NO ₃ ) ₃ , Co(NO ₃ ) ₃ and Fe ₂ ( SO ₄ ) ₃ solution with a concentration of 0.2~0.5mol·L ^-1 ; (2) According to the stoichiometric ratio of metal elements in (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material, a certain amount of Nd(NO ₃ ) ₃ , Ca(NO ₃ ) ₂ , La(NO ₃ ) ₃ , Co(NO ₃ ) ₃ and Fe ₂ (SO ₄ ) ₃ solutions were mixed and ultrasonically dispersed for 8-15 minutes to obtain mixed solution A; (3) Mix the KOH solution with a concentration of 0.20~0.30mol L ^-1 and the solution with a concentration of 0.05~0.15mol L ^-1 K ₂ CO ₃ at a volume ratio of 1~3:1 to obtain solution B; (4) Add solution B to solution A drop by drop, stir evenly, disperse by ultrasonic for 30-60 minutes until the pH value of the solution is 10-11, then centrifuge for 3-5 minutes, collect the precipitate, and wash the precipitate with distilled water until it is washed to Suction filtration after neutralization, then dissolve the filter cake with ethanol, continue ultrasonic dispersion for 10-20 minutes, and then perform centrifugation for 3-5 minutes, and repeat this process for 3-5 times to obtain precipitated sample C; (5) Place the precipitated sample C in an oven and dry it at 100-110°C for 12-24 hours, and finally grind the dried material into powder to obtain (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ precursor D, said x=0.1～0.4; (6) Put the precursor D in an electric furnace, heat it to ^450-500 °C at a heating rate of ^5-10 °C min Continue heating to 800-900°C for 2.0-4.0 hours, then naturally cool down to room temperature to obtain nanometer (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material, where x=0.1-0.4. 3 . The method for preparing perovskite nanomaterials according to claim 2 , wherein the oven described in step (5) is a blast drying oven. 4 . 4. The method for preparing perovskite nanomaterials according to claim 2, characterized in that the nano (Ca _x Nd _1-x ) _0.1 La _0.9 Co _0.5 Fe _0.5 O ₃ material particles described in step (6) The diameter is 80~120nm.