CN105036173A - Preparation method for core-shell structured granular material - Google Patents

Abstract

The invention discloses a method for preparing a particle material with a core-shell structure. Firstly, two kinds of particles with a large difference in isoelectric point and particle sizes of nanometer and micrometer are selected as the interlayer material and the core body material respectively, so that the two kinds The particles form a core-interlayer composite particle skeleton through electrostatic self-assembly in aqueous solution, and then form a shell on the surface of the core-interlayer composite particle, and finally grind and sieve to obtain a core-interlayer-shell structure from the inside to the outside. Core-shell structured granular material. The preparation method introduces nano-interlayers into the core-shell structure, which overcomes the problem of low bonding strength between the core body and the shell layer of the original core-shell structure particle material, or directly combines to generate by-products, and achieves controllable preparation of high-performance particle materials the goal of.

Description

A kind of preparation method of core-shell structure granular material

technical field

The invention belongs to the field of application of nanomaterials and synthesis of functional materials, and more specifically relates to a preparation method of a core-shell structure granular material.

Background technique

Core-shell materials have many unique physical and chemical properties, and have potential applications in superhydrophobic surface coatings, materials science, chemistry, magnetism, electricity, optics, biomedicine, catalysis and other fields. Chemical chain technology is a new type of fossil fuel _CO2 emission reduction technology, which has the potential to reduce emission reduction costs, improve fuel energy utilization efficiency, and reduce and remove other air pollutants. One of its key issues is high-performance oxygen carrier development.

Nanocomposites with a core-shell structure are generally composed of a central core and a shell covering the outside, but in a common core-shell structure, the active shell and the inert core or the active core and the inert shell are in direct contact, and activity will occur. The chemical reaction between the ingredients and the inert carrier directly leads to the reduction of the content of the active ingredient and the reduction of the stability and strength of the inert carrier, thus causing the performance of the material to decay.

Introducing nano interlayers in the synthesis of core-shell materials to form a hierarchical structure of core-interlayer-shell can greatly improve the strength and performance of the material.

Contents of the invention

In view of the above defects or improvement needs of the prior art, the present invention provides a core-shell structure granular material and its self-assembly method, which uses the difference in isoelectric point properties of the core material and the interlayer material to form a high-performance particle through electrostatic self-assembly. granular material. The preparation process of the present invention is energy-saving and environment-friendly, and the prepared granular material with core-shell structure can be used as an oxygen carrier, _CO2 absorber or catalyst, etc., and has the advantages of large loading capacity, high activity, stable performance and long cycle life.

In order to achieve the above object, according to one aspect of the present invention, a method for preparing a core-shell structure granular material is provided, wherein the specific steps include:

Step 1: Disperse the core material and the interlayer material in water, and adjust the pH value with acid or alkali to fully assemble the core material and the interlayer material to obtain a suspension of core-interlayer composite particles. turbid liquid;

Wherein, the core material is a micron particle with a particle diameter of 1 μm to 100 μm, the interposer material is a nanoparticle with a particle diameter of 1 nm to 100 nm, and the mass ratio of the core material to the interposer material is greater than or equal to 2 : 1; IEP ₁ and IEP ₂ are the equipotential points of the core material and the interposer material respectively, and the difference between IEP ₁ and IEP ₂ is greater than or equal to 2.5; pH' is between IEP ₁ and IEP ₂ , and When the pH value is pH', the electrical properties of the Zeta potential of the core material and the interlayer material are opposite and the difference is the largest;

Step 2: Deposit the shell material on the surface of the core-interlayer composite particle, and calcining to form the shell, and finally grind and sieve to obtain the required core-shell structure particle material.

Preferably, the acid in step 1 is acetic acid, hydrochloric acid or nitric acid, and the base is ammonia water.

Preferably, the mass ratio of the core material to the interposer material is 3:1˜15:1.

Preferably, the difference between IEP ₁ and IEP ₂ is greater than or equal to 5.

Preferably, the hydrothermal method is used to prepare the metal oxide shell in step 2, and the specific process is as follows:

Add metal-organic salt to the suspension in step 1 to dissolve it completely, dry it fully, then calcinate, and finally grind and sieve to obtain the required core-shell structure granular material;

During the calcination process, metal organic salts decompose to form metal oxides as shells, and at the same time, water vapor and carbon dioxide are generated as by-products.

However, in the process of preparing metal oxides, soluble metal-organic salts are often not found as raw materials, or the corresponding metal-organic salts are very expensive; therefore, the specific process of step 2 can also be preferably as follows:

Add metal nitrate and fuel to the suspension in step 1 to dissolve it completely, dry it fully, then calcinate, and finally grind and sieve to obtain the required core-shell structure granular material;

Wherein, the fuel is metal acetate or urea. During the calcination process, the metal nitrate and the fuel completely react to form a metal oxide as a shell, and nitrogen, water vapor and carbon dioxide are also produced as by-products.

Suppose the metal is X, and the valence is +n; when the fuel is metal acetate, the reaction equation is as follows:

16X(NO ₃ ) _n +10X(CH ₃ COO) _n →13A ₂ O _n +8nN ₂ +20nCO ₂ +15nH ₂ O

Among them, acetates and nitrates of different metals can be selected to form mixed metal oxides as the shell.

When the fuel is urea, the reaction equation is as follows:

6X(NO ₃ ) _n +5nCO(NH ₂ ) ₂ →3X ₂ O _n +5nCO ₂ +10nH ₂ O+8nN ₂

As a further preference, the metal nitrate and the fuel are dosed according to the stoichiometric ratio of the complete reaction.

When the shell material is metal organic salt, metal nitrate and metal acetate or metal nitrate and urea, there is no difference in the calcination reaction conditions; so in the actual preparation process, the shell material can be arbitrarily selected from the above three groups One or more groups of materials.

The present invention also provides an oxygen carrier obtained by the preparation method, characterized in that:

The core material is α-phase Al ₂ O ₃ particles with a particle size of 37 μm to 75 μm, the interlayer material is rutile phase TiO ₂ nanoparticles with a particle size of 10 nm to 100 nm, and the core material and the interlayer material are The mass ratio is 3.5:1; the shell material is fuel and metal nitrate, the fuel is urea, the metal nitrate is copper nitrate, and the molar ratio of the two is 5:3.

The present invention also provides a _CO2 absorbent obtained by the preparation method, characterized in that:

The core material is α-phase Al ₂ O ₃ particles with a particle size of 37 μm to 75 μm, the interlayer material is rutile phase TiO ₂ nanoparticles with a particle size of 10 nm to 100 nm, and the core material and the interlayer material are The mass ratio of the shell layer is 3:1; the shell material is calcium acetate and calcium nitrate, and the molar ratio of the two is 5:8.

Generally speaking, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

1. Using the difference in the isoelectric point properties of the particles, self-assemble on the core material to form an interlayer. The self-assembly process does not require complex reaction conditions such as surfactants, high temperature and high pressure; the introduction of the interlayer avoids the interaction between the core material and the shell. Layer materials are directly combined to form by-products, which improves the stability and performance of core-shell materials;

2. In the process of preparing the interlayer, the thickness of the interlayer can be controlled according to the mass ratio of the core material and the interlayer material, so as to achieve the effect of controllable preparation of the interlayer;

3. The fuel and metal nitrates are used to generate the shell through combustion reaction, which solves the problem that it is often difficult to find suitable metal organic salts in the traditional hydrothermal method; the heat released by the combustion reaction can reduce the energy consumption in the calcination process, and at the same time effectively The pollutant NOx released by the decomposition of nitrate is reduced, which has the effect of energy saving and environmental protection.

4. The oxygen carrier and _CO2 absorbent prepared by this method have good performance, and the oxygen carrying capacity and _CO2 absorption are close to ideal values.

Description of drawings

Fig. 1 is a schematic diagram of the self-assembly process of the core-shell structure granular material of the present invention.

Figure 2a and Figure 2b are respectively the relationship between the Zeta potential of the core material and the shell material in Example 1 and Example 3 and the pH value of the dispersion measured by the micro-electrophoresis instrument.

Fig. 3 is a comparison of the exhaust gas monitoring results in the combustion process of the oxygen carrier in Example 1 of the present invention and the oxygen carrier prepared by the traditional sol-gel method.

Fig. 4 is a transmission electron micrograph of nm-TiO ₂ particles coated with μm-Al ₂ O ₃ particles in Example 1 and Example 2 of the present invention.

Fig. 5 is a cross-sectional scanning electron microscope image and element distribution diagram of oxygen carrier particles in Example 1 of the present invention.

Fig. 6 is a scanning electron microscope image and elemental distribution diagram of the _CO2 absorbent in Example 2 of the present invention.

Figure 7a is a diagram of the change in oxygen carrying capacity of the oxygen carrier in 15 oxygen release-oxygen uptake cycles in Example 1 of the present invention, Figure 7b is the X-ray diffraction pattern of the oxygen carrier in three different states, and Figure 7c is a comparison example X-ray diffraction pattern.

Fig. 8a is the result of 20 carbonation-calcination cycle thermogravimetric experiments of the CO ₂ absorbent in Example 2 of the present invention, and Fig. 8b is the X-ray diffraction patterns of the CO ₂ absorbent in two different states.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

Example 1 CuO (77.5wt%)-TiO ₂ (5wt%)-Al ₂ O ₃ (17.5wt%) oxygen carrier

Step 1: Use 400-mesh and 200-mesh sieves to sieve out α-phase Al ₂ O ₃ particles with a particle size range of 37 μm to 75 μm for use (hereinafter referred to as μm-Al ₂ O ₃ ), and take samples of them on a micro-electrophoresis instrument Measure the Zeta potential under different pH value aqueous solution conditions to determine the isoelectric point IEP _A of the particles; at the same time select the TiO ₂ nanoparticle sample of the rutile phase with a particle size range of 10nm to 100nm (hereinafter referred to as nm-TiO ₂ ), use the same The isoelectric point IEP _T is determined by the method, as shown in Fig. 2a.

Step 2: Pour 300mL of deionized water into the beaker, heat it to 80°C in a water bath, then add 17.5g of μm-Al ₂ O ₃ particles and stir evenly, then add 5.0g of nm-TiO ₂ particles, stir and mix evenly. Use dilute nitric acid and ammonia water to adjust the pH of the dispersion system so that the pH value of the dispersion system is 6. At this time, the electrical properties of the Zeta potentials of the μm-Al ₂ O ₃ particles and the nm-TiO ₂ particles are opposite and the difference is the largest (as shown in Fig. 2a); due to the strong positive and negative potentials on the surface of μm-Al ₂ O ₃ and nm-TiO ₂ particles, they condense under the joint attraction of van der Waals force and electrostatic force to form μm -Al ₂ O ₃ core-interlayer composite particles coated by nm-TiO ₂ , and the aggregation between the same particles is inhibited by strong electrostatic repulsion.

Step 3: Add 97.5g of urea crystals into the dispersion system as fuel, and keep stirring to make it fully dissolved. The addition of urea can stabilize particle clusters through steric hindrance; then add Cu(NO ₃ ) ₂ ·3H ₂ O Crystal 235.4g is as the raw material of shell layer, and continuous stirring makes it fully dissolve; Urea is as fuel, and its addition is determined according to the stoichiometric ratio when fuel and copper nitrate just burn completely, and the beaker is moved in the air blast oven, at 80 After drying at ℃ for 24 hours, the precursor of the core-shell structure granular material was prepared; the precursor was transferred into the porcelain boat, and then the porcelain boat was placed in the muffle furnace to program the temperature to be ignited and calcined; the muffle furnace was set at 20 The heating rate of °C/min was heated from room temperature to 950 °C, and calcined at 950 °C for 2 h. The entire combustion process can be approximated by the following total package thermochemical equation:

3Cu(NO ₃ ) ₂ +5CO(NH ₂ ) ₂ →3CuO+5CO ₂ +10H ₂ O+8N ₂ ; kJ/mol;

During the reaction process, urea is used as a fuel to react with copper nitrate to form an internal heat source, which not only saves external heat consumption but also greatly shortens the calcination time; the product is annealed and cooled, ground, and sieved to obtain particles with a diameter of 75 μm to 300 μm. The desired core-shell structure granular material, which can be used as an oxygen carrier for chemical chain reactions.

The tail gas monitoring of the combustion process in Example 1 found that the NOx emitted during the whole process was greatly reduced compared with the traditional sol-gel preparation process, which is obviously environmentally friendly, as shown in Figure 3.

Example 2CaO (80wt%)-TiO ₂ (5wt%)-Al ₂ O ₃ (15wt%) CO ₂ absorbent

Step 1: Same as Step 1 of Example 1.

Step 2: the same as Step 2 of Example 1, except that the mass of μm-Al ₂ O ₃ particles is 15.0 g.

Step 3: Same as Step 3 of Example 1, except that 97.5g Ca(CH ₃ COO) ₂ ·H ₂ O powder and 207.5g Ca(NO ₃ ) ₂ ·4H ₂ O crystals were used to replace urea and Cu(NO ₃ ) ₂ 3H ₂ O is used as the shell raw material, and the following reactions occur during the process:

5Ca(CH ₃ COO) ₂ +8Ca(NO ₃ ) ₂ →13CaO+20CO ₂ +15H ₂ O+8N ₂ ;

The sieved particle size ranges from 30 μm to 300 μm, and finally the desired core-shell structure granular material is obtained, which can be used as a _CO2 absorbent.

Example 3CuO (80wt%)-MgO (2wt%)-Al ₂ O ₃ (18wt%) oxygen carrier

Step 1: Same as Step 1 of Example 1, the difference is that the nm- _TiO2 is replaced by MgO particles of 20nm to 80nm (hereinafter referred to as nm-MgO), the isoelectric point IEP _M is measured, and the pH of the solution is adjusted to 11 , as shown in Figure 2b.

Step 2: Same as Step 2 of Example 1, except that the mass of μm-Al ₂ O ₃ particles is 18.0 g, the mass of nm-MgO particles is 2.0 g, and the pH value of the dispersion system is adjusted to be 11.

Step 3: Same as Step 3 of Example 1, except that the fuel urea has a mass of 100.7 g, and the Cu(NO ₃ ) ₂ ·3H ₂ O crystal has a mass of 243.0 g.

Example 4CaO (80wt%)-MgO (2wt%)-Al ₂ O ₃ (18wt%) CO ₂ absorbent

Step 1: Same as Step 1 of Example 3.

Step 2: Same as Step 2 of Example 3, the difference is that dilute hydrochloric acid and ammonia water are used to adjust the pH of the dispersion.

Step 3: Same as Step 3 of Example 1, except that the fuel is 143.0 g urea, and the metal nitrate is 337.4 g Ca(NO ₃ ) ₂ ·4H ₂ O crystals.

Example 5CaO (80wt%)-TiO ₂ (2wt%)-Al ₂ O ₃ (18wt%) CO ₂ absorbent

Step 1: Same as Step 1 of Example 1.

Step 2: Same as Step 2 of Example 1, except that the mass of the μm-Al ₂ O ₃ particles is 18.0 g, and the mass of the nm-TiO ₂ particles is 2.0 g.

Step 3: Same as Step 3 of Example 1, except that the shell material is Ca(CH ₃ COO) ₂ ·H ₂ O powder, and Ca(CH ₃ COO) ₂ ·H ₂ O is decomposed to generate CaO during heating and calcination as a shell.

Embodiment 6CuO (66.4wt%)/CaO (13.6wt%)-TiO ₂ (1wt%)-Al ₂ O ₃ (19wt%)

Step 1: Same as Step 1 of Example 1.

Step 2: Same as Step 2 of Example 1, the difference is that the mass of μm-Al ₂ O ₃ particles is 19.0 g, the mass of nm-TiO ₂ particles is 1.0 g, and the pH of the dispersion system is adjusted with acetic acid and ammonia water.

Step 3: Same as Step 3 of Example 1, the difference is that 83.6g of urea is first added as part of the fuel, then 38.4g of Ca(CH ₃ COO) ₂ ·H ₂ O powder is added as another part of fuel, and then 201.7g of Cu(NO ₃ ) ₂ ·3H ₂ O crystals, in which Cu(NO ₃ ) ₂ ·3H ₂ O crystals and Ca(CH ₃ COO) ₂ ·H ₂ O powder were used as raw materials for mixed active shell CuO/CaO. The sieved particle size ranges from 125 μm to 300 μm, and finally the required core-shell structure granular material is obtained. This material has a mixed shell of CuO/CaO and can be used as a combined cycle carrier for chemical looping combustion and carbon dioxide absorption.

Embodiment 7CuO (66.4wt%)/CaO (13.6wt%)-MgO (5wt%)-Al ₂ O ₃ (15wt%)

Step 1: Same as Step 1 of Example 3.

Step 2: Same as Step 2 of Example 3, except that the mass of the μm-Al ₂ O ₃ particles is 15.0 g, and the mass of the nm-MgO particles is 5.0 g.

Step 3: Same as Step 3 of Example 6.

Embodiment 8NiO (15wt%)-TiO ₂ (5wt%)-Al ₂ O ₃ (80wt%) catalyst

Step 1: Same as Step 1 of Example 1.

Step 2: the same as Step 2 of Example 1, except that there is no water bath heating, and the mass of μm-Al ₂ O ₃ particles is 80.0 g.

Step 3: the same as Step 3 of Example 1, except that the shell material is 58.4 g of Ni(NO ₃ ) ₂ ·6H ₂ O crystals, and 20.1 g of urea. The sieved particle size ranges from 125 μm to 180 μm, and finally obtains the required core-shell structure granular material, which can be used as a catalyst for methane-carbon dioxide reforming or methane-steam reforming to produce synthesis gas.

Embodiment 9Pd (1wt%)-TiO ₂ (10wt%)-Al ₂ O ₃ (89wt%) catalyst

Step 1: the same as Step 1 of Example 1, except that the α-phase Al ₂ O ₃ particles obtained through sieving have a particle size of 1 μm˜37 μm.

Step 2: Same as Step 2 of Example 1, except that 50 mL of deionized water is used without water bath heating, and the masses of nm-TiO ₂ and μm-Al ₂ O ₃ particles are 1.0 g and 8.9 g, respectively.

Step 3: Same as Step 3 of Example 1, except that the shell material precursor is 0.21 g of Pd(C ₂ H ₃ O ₂ ) ₂ powder, and no urea is added. The sieved particle size ranges from 75 μm to 180 μm, and finally obtains the required core-shell structure granular material, which can be used as a catalyst for catalytic combustion of organic waste gas.

Example 10

Example 2 was repeated with the same steps described above, except that the TiO ₂ particles had a particle size of 1 nm to 100 nm and a mass of 7 g; the Al ₂ O ₃ particles had a particle size of 75 μm to 100 μm and a mass of 14 g.

Example 11

Example 2 was repeated with the same steps described above, except that the TiO ₂ particles had a particle size of 1 nm to 100 nm and a mass of 7 g; the Al ₂ O ₃ particles had a particle size of 75 μm to 100 μm and a mass of 14 g.

Example 12

Example 2 was repeated with the same steps described above, except that the TiO ₂ particles had a particle size of 1 nm to 100 nm and a mass of 1 g; the Al ₂ O ₃ particles had a particle size of 75 μm to 100 μm and a mass of 15 g.

Example 13

Disperse 17.5 g of α-phase Al ₂ O ₃ particles with a particle size of 37 μm to 75 μm in deionized water in a beaker, then add 97.5 g of urea crystals as fuel to dissolve it, and then add Cu(NO ₃ ) ₂ ·3H ₂ O 235.4 g of crystals were dissolved. Move the beaker into a blast drying oven, and dry at 80°C for 24 hours to prepare the precursor of the core-shell structure granular material; transfer the precursor into a porcelain boat, and then put the porcelain boat into the muffle furnace. Heating, ignition and calcination; the muffle furnace is set at a heating rate of 20°C/min, heated from room temperature to 950°C, calcined at 950°C for 2 hours, annealed and cooled, ground, and sieved to obtain particles with a diameter of 75 μm to 300 μm, namely A core-shell structure granular material without an interlayer is obtained.

Comparative example CuO(77.5wt%)-TiO ₂ (5wt%)-Al ₂ O ₃ (17.5wt%) oxygen carrier

Repeat Example 1 with the same steps as described, the difference is that in step 2, dilute nitric acid or ammonia water is used to adjust the pH of the dispersion to make the pH of the dispersion 5.

Analysis of results

Observing the core-interposer precursor prepared in Step 2 of Example 1 of the present invention under a transmission electron microscope, it can be seen that nm-TiO ₂ particles are evenly coated with μm-Al ₂ O ₃ particles, as shown in FIG. 4 .

The core-shell structure particle material prepared in Example 1 was embedded in epoxy resin, and then mechanically polished to obtain a cross-section of the particle, and then the microstructure of the particle and the distribution of Cu, Ti, and Al elements were observed under a scanning electron microscope. A clear core-shell structure was found, as shown in Figure 5.

The same method is used to observe the core-shell structure particle material prepared in Example 2 under a scanning electron microscope, and make a section in the middle of the core-shell structure particle for element distribution analysis (Fig. 6a), it can be seen that the Ca element is distributed in the particle In the outermost layer (Figure 6b), the Al element is distributed in the innermost layer of the particle (Figure 6d), and the Ti element is distributed between the two layers (Figure 6c).

The cyclic oxygen release-oxygen absorption performance of the oxygen carrier particles prepared in Example 1 was tested on a thermogravimetric analyzer. Since the oxygen release reaction of pure copper oxide is: 4CuO→2Cu ₂ O+O ₂ , CuO can be calculated according to the chemical equation The theoretical oxygen loading rate of the oxygen carrier is 32/(79.55×4)×100%=10%, and since the mass fraction of the active component CuO in the oxygen carrier is 77.5%, the expected theoretical oxygen carrying capacity of the oxygen carrier is 77.5%×10% = 7.75%, based on the expected theoretical oxygen load, the cycle experiment of oxygen load was carried out, and the test results of 15 cycles are shown in Figure 7a, the oxygen load of the oxygen carrier particles is close to the ideal value, and the performance basically does not appear .

The properties of the oxygen carrier particles prepared in Example 1 and Comparative Example were tested by X-ray diffractometer. The three curves in Figure 7b represent freshly prepared oxygen carriers, oxygen carriers after oxygen release, and oxygen carriers after 15 oxygen release-oxygen uptake cycles. It can be seen that the oxygen carriers have no CuAl ₂ O in the whole use process. _4. CuAlO ₂ is generated; while CuAl ₂ O ₄ is generated in the fresh oxygen carrier prepared in the comparative example, as shown in Figure 7c.

The cyclic carbonation-calcination performance of the _CO2 absorbent prepared in Example 2 was tested on a thermogravimetric analyzer. Since pure calcium oxide absorbs _CO2 and reacts CaO+ _{CO2 →} CaCO3, the CO of CaO can be calculated according to this chemical equation. ₂ The theoretical absorption rate is 44/56×100%=78%, and since the mass fraction of the active ingredient CaO in the absorbent is 80%, the expected theoretical _CO2 absorption of the absorbent is 80%×78%=62%, The 20-cycle test results are shown in Fig. 8a, the absorption capacity of the _CO2 absorbent is close to the ideal value, and there is basically no performance degradation after 20 cycles.

The performance of the _CO2 absorbent prepared in Example 2 is tested with an X-ray diffractometer, and the two curves represent respectively the _CO2 absorbent just prepared and the _CO2 absorbent after 30 calcination-carbonation cycles, as can be seen No Ca ₁₂ Al ₁₄ O ₃₃ , CaAl ₂ O ₄ , and Ca ₃ Al ₂ O ₆ are produced during the entire use of the CO ₂ absorbent, as shown in Figure 8b.

Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (9)

1. a preparation method for core-shell structure particles material, is characterized in that, concrete steps comprise:

Step one: by nucleome material and interlayer dispersion of materials in water, and be pH ' with acid or alkali adjust ph, described nucleome material and described interlayer material are fully assembled, to obtain the suspension liquid of core-interlayer composite particles;

Wherein, described nucleome material is the micron particle of particle diameter 1 μm ~ 100 μm, the nano particle of described interlayer material to be particle diameter be 1nm ~ 100nm, and the mass ratio of described nucleome material and described interlayer material is more than or equal to 2:1; IEP ₁and IEP ₂be respectively the isopotential point of described nucleome material and described interlayer material, and IEP ₁with IEP ₂difference be more than or equal to 2.5; PH ' is at IEP ₁and IEP ₂between, and when pH value is pH ', the Zeta potential of nucleome material and interlayer material electrically contrary and difference is maximum;

Step 2: at core-interlayer composite particles surface deposition shell raw material, and calcining generates shell, namely finally grinding screening obtains required core-shell structure particles material.

2. the preparation method of core-shell structure particles material as claimed in claim 1, it is characterized in that, described in step one, acid is acetic acid, hydrochloric acid or nitric acid, and described alkali is ammoniacal liquor.

3. the preparation method of core-shell structure particles material as claimed in claim 1, it is characterized in that, the mass ratio of described nucleome material and described interlayer material is 3:1 ~ 15:1.

4. the preparation method of core-shell structure particles material as claimed in claim 1, is characterized in that, IEP ₁with IEP ₂difference be more than or equal to 5.

5. the preparation method of core-shell structure particles material as claimed in claim 1, it is characterized in that, the detailed process of step 2 is as follows:

In the described suspension liquid of step one, add metal organic salt makes it dissolve completely, calcines after abundant drying, and namely finally grinding screening obtains required core-shell structure particles material;

In calcination process, metal organic salt decomposes generation metal oxide as while shell, and also generation water vapour and carbonic acid gas are as by product.

6. the preparation method of core-shell structure particles material as claimed in claim 1, it is characterized in that, the detailed process of step 2 is as follows:

In the described suspension liquid of step one, add metal nitrate and fuel makes it dissolve completely, calcine after abundant drying, namely finally grinding screening obtains required core-shell structure particles material;

Wherein, described fuel is metal acetate salt or urea, and in calcination process, metal nitrate and described fuel complete reaction generate metal oxide as while shell, also generate nitrogen, water vapour and carbonic acid gas as by product.

7. the preparation method of core-shell structure particles material as claimed in claim 5, it is characterized in that, metal nitrate and fuel are prepared burden according to stoichiometric ratio during complete reaction.

8. the oxygen carrier utilizing preparation method described in claim 1 to obtain, is characterized in that:

Described nucleome material is the α phase Al of 37 μm ~ 75 μm of particle diameters ₂o ₃particle, described interlayer material is the Rutile Type TiO of particle diameter 10nm ~ 100nm ₂nano particle; Described shell raw material is urea and cupric nitrate, and both mol ratios are 5:3.

9. the CO utilizing preparation method described in claim 1 to obtain ₂absorption agent, is characterized in that:

Described nucleome material is the α phase Al of 37 μm ~ 75 μm of particle diameters ₂o ₃particle, described interlayer material is the Rutile Type TiO of particle diameter 10nm ~ 100nm ₂nano particle; Described shell raw material is calcium acetate and nitrocalcite, and both mol ratios are 5:8.