CN102502767A - Method for preparing lanthanum copper oxide (La2CuO4) powder by sol gel-hydrothermal method - Google Patents

Abstract

The invention relates to a method for preparing lanthanum copper oxide (La2CuO4) powder by a sol gel-hydrothermal method. The method comprises the steps that: lanthanum nitrate is dissolved in distilled water, and then, copper nitrate is added into the mixture to obtain solution B; citric acid is added into the solution B, and in addition, the pH is regulated to 2.5 to 7.0 to obtain solution D; the solution D is placed into a baking box to be baked for obtaining dried gel, the dried gel is placed in a hydrothermal kettle, then, distilled water is added into the hydrothermal kettle, the treatment is carried out for 12 to 36 hours at 160 DEG C to 240 DEG C, and the materials are cooled to the room temperature after being taken out; and the hydrothermal kettle is opened, samples are collected through centrifugal separation, then, the samples are repeatedly washed by the distilled water and acetone, and La2CuO4 powder is obtained after drying. The sol gal and hydrothermal method is adopted for preparing the La2CuO4 powder, composite oxides are directly generated by a hydrothermal method, the step capable of forming hard aggregation during product conversion through calcining in an ordinary wet chemical method is avoided, and the La2CuO4 powder synthesized by the hydrothermal method has the obvious advantages that the synthesis temperature is lower, the purity is high, the crystallization form is good, the powder particle is uniform, the particle size is small, in addition, the aggregation degree is low, and the like.

Description

Collosol and gel-Hydrothermal Preparation copper acid lanthanum (La 2CuO 4) method of powder

Technical field

The present invention relates to a kind of method for preparing copper acid lanthanum nano-powder, be specifically related to a kind of collosol and gel-Hydrothermal Preparation copper acid lanthanum (La ₂CuO ₄) method of powder.

Background technology

Perovskite-like type composite oxides La ₂CuO ₄This also is the body material of superconductor as antiferromagnetic isolator simultaneously.La ₂CuO ₄Be La _2-XM _XCuO ₄(M is Ba, Sr, Ca etc.) and La ₂CuO _{4+ δ}The parent phase structure of superconductor.First high-temperature superconductor La-Ba-Cu-O utilizes Ba partly to replace La in parent phase and obtains, and comes out one after another although after this have more the superconducting material of high transition temperature, because La ₂CuO ₄System structure and Chemical Composition are simple, and the scope of can mixing is wide, are research superconduction mechanism desirable material, thereby receive attention widely.

In addition,, can be used as catalyzer, realize Sweet natural gas efficient burning, low emission process because it has good catalytic activity and thermostability.

In addition, at aspects such as chemical sensor, catalytic cleaning of car tail gas, oxynitride catalysis elimination, catalytic organism oxidations development prospect is preferably arranged also.

The preparation La that is reported at present ₂CuO ₄Method mainly contain: solid state reaction [YANGDongsheng, WU Baimei, ZHENG Weihua, et al.THERMALCONDUCTIVITY OF EXCESS-OXYGEN-DOPEDLa ₂CuO ₄[J] .CHINESE JOURNAL OF LOW TEMPERATUREPHYSICS, 2001,23 (1): 44-47], self-propagating combustion [WANG Xiaohui, ZHOUYanchun.Preparation of La ₂CuO ₄Precursor powers by self-propagatingcombustion synthesis and their crystallization [J] .Chinese Juournal ofMaterial Research.2001; 15 (4): 387-393.]; Hydrothermal method [ZHANG Yue; ZHANG Lei, DENG Jiguang, et al.Hydrothermal fabrication andcatalytic performance of single-crystalline La _2-XSr _XCuO ₄(x=0,1) withspecific morphologies for methane oxidation [J] .Chinese Journal ofCatalysis, 2009,30 (4): 347-354.] etc.

But these methods all exist the weak point of self, and for example, solid state reaction is in order to obtain the high title product of purity; The reactant powder should be enough thin; And need at high temperature long-time roasting and repeatedly middle the grinding, this method expends time in, and more impurity phase is arranged in product; For self-propagating combustion, combustion reactions is very violent, and temperature of combustion is higher, and reaction process is fast, bad control, and product is easy to sintering, and non-equilibrium phase or metastable phase very likely occur in the product.

In order to reach the purpose of practicability, the nanometer La that necessary Development and Production cost is low, simple to operate, the cycle is short ₂CuO ₄The preparation technology of powder.

Summary of the invention

The object of the present invention is to provide and a kind ofly can reduce preparation cost, simple to operate, reaction time short, the collosol and gel of good reproducibility-Hydrothermal Preparation copper acid lanthanum (La ₂CuO ₄) method of powder, it is little that method of the present invention can be prepared particle diameter, narrow distribution range, the nanometer La that pattern is controlled ₂CuO ₄Powder.

For achieving the above object, the technical scheme that the present invention adopts is:

1) with analytically pure Lanthanum trinitrate (La (NO ₃) ₃6H ₂O) be dissolved in and process the solution A that Lanthanum trinitrate concentration is 0.8mol/L～2.8mol/L in 20ml～100ml zero(ppm) water;

2) press La ³⁺: Cu ²⁺=(1～2): 1 mol ratio adds analytical pure cupric nitrate (Cu (NO in solution A ₃) ₃3H ₂O) get solution B;

3) press analytical pure Hydrocerol A (C ₆H ₈O ₇H ₂O) be (0.5～1.5) with the metallic cation summation: 1 mol ratio adds analytical pure Hydrocerol A (C in solution B ₆H ₈O ₇H ₂O), stirring at normal temperature 10min～70min obtains solution C, and using urea to regulate pH is 2.5～7.0, obtains solution D;

4) place baking oven to colloidal sol D, in 50 ℃～100 ℃ dry xerogel, xerogel is placed water heating kettle; In water heating kettle, add zero(ppm) water again; Add to water heating kettle volumetrical 1/3～2/3 place, then handle 12h～36h down, take out postcooling to room temperature at 160 ℃～240 ℃;

5) open water heating kettle, collect sample, pass through zero(ppm) water, acetone repetitive scrubbing then, obtain La after the drying through spinning ₂CuO ₄Powder.

The present invention adopts collosol and gel to combine the method for hydro-thermal to prepare La ₂CuO ₄Powder uses hydrothermal method directly to generate composite oxides, has avoided general wet chemistry method need pass through calcining and has changed into product this possibly form the step of hard aggregation, adopts hydrothermal method synthetic La ₂CuO ₄Powder, remarkable advantage such as it is lower to have a synthesis temperature, and purity is high, and crystal habit is good, and powder is even, and the little and reunion degree of granularity is low.The preparation process goes out La with Prepared by Sol Gel Method earlier ₂CuO ₄Xerogel, selecting water then for use is solvent, hydrothermal treatment consists places retort furnace to calcine after for some time again.Gained nanometer La ₂CuO ₄Size distribution is even, and pattern is controlled, and reaction time is short, good reproducibility.

Description of drawings

Fig. 1 is the prepared La of embodiment 1 ₂CuO ₄The X-ray diffraction of powder (XRD) collection of illustrative plates.

Fig. 2 is the prepared La of embodiment 1 ₂CuO ₄The transmission electron microscope of powder (SEM) figure.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is done further explain.

Embodiment 1:

1) with analytically pure Lanthanum trinitrate (La (NO ₃) ₃6H ₂O) be dissolved in and process the solution A that Lanthanum trinitrate concentration is 1.5mol/L in the 45ml zero(ppm) water;

2) press La ³⁺: Cu ²⁺=1: 1 mol ratio adds analytical pure cupric nitrate (Cu (NO in solution A ₃) ₃3H ₂O) get solution B;

3) press analytical pure Hydrocerol A (C ₆H ₈O ₇H ₂O) be that 1.2: 1 mol ratio adds analytical pure Hydrocerol A (C in solution B with the metallic cation summation ₆H ₈O ₇H ₂O), stirring at normal temperature 35min obtains solution C, and using urea to regulate pH is 4.5, obtains solution D;

4) place baking oven to colloidal sol D, in 80 ℃ dry xerogel, xerogel is placed water heating kettle, in water heating kettle, add zero(ppm) water again, add to water heating kettle volumetrical 1/3～2/3 place, then handle down 20h at 180 ℃, take out postcooling to room temperature;

5) open water heating kettle, collect sample, pass through zero(ppm) water, acetone repetitive scrubbing then, obtain La after the drying through spinning ₂CuO ₄Powder.

Can find out that by Fig. 1 product is single La ₂CuO ₄Phase can be found out that by Fig. 2 product is a spheroidal particle, is of a size of 80nm～100nm.

Embodiment 2:

1) with analytically pure Lanthanum trinitrate (La (NO ₃) ₃6H ₂O) be dissolved in and process the solution A that Lanthanum trinitrate concentration is 0.8mol/L in the 20ml zero(ppm) water;

2) press La ³⁺: Cu ²⁺=1.3: 1 mol ratio adds analytical pure cupric nitrate (Cu (NO in solution A ₃) ₃3H ₂O) get solution B;

3) press analytical pure Hydrocerol A (C ₆H ₈O ₇H ₂O) be that 0.5: 1 mol ratio adds analytical pure Hydrocerol A (C in solution B with the metallic cation summation ₆H ₈O ₇H ₂O), stirring at normal temperature 10min obtains solution C, and using urea to regulate pH is 2.5, obtains solution D;

4) place baking oven to colloidal sol D, in 50 ℃ dry xerogel, xerogel is placed water heating kettle, in water heating kettle, add zero(ppm) water again, add to water heating kettle volumetrical 1/3～2/3 place, then handle down 36h at 160 ℃, take out postcooling to room temperature;

5) open water heating kettle, collect sample, pass through zero(ppm) water, acetone repetitive scrubbing then, obtain La after the drying through spinning ₂CuO ₄Powder.

Embodiment 3:

1) with analytically pure Lanthanum trinitrate (La (NO ₃) ₃6H ₂O) be dissolved in and process the solution A that Lanthanum trinitrate concentration is 2mol/L in the 100ml zero(ppm) water;

2) press La ³⁺: Cu ²⁺=1.8: 1 mol ratio adds analytical pure cupric nitrate (Cu (NO in solution A ₃) ₃3H ₂O) get solution B;

3) press analytical pure Hydrocerol A (C ₆H ₈O ₇H ₂O) be that 1.5: 1 mol ratio adds analytical pure Hydrocerol A (C in solution B with the metallic cation summation ₆H ₈O ₇H ₂O), stirring at normal temperature 50min obtains solution C, and using urea to regulate pH is 7.0, obtains solution D;

4) place baking oven to colloidal sol D, in 100 ℃ dry xerogel, xerogel is placed water heating kettle, in water heating kettle, add zero(ppm) water again, add to water heating kettle volumetrical 1/3～2/3 place, then handle down 12h at 240 ℃, take out postcooling to room temperature;

5) open water heating kettle, collect sample, pass through zero(ppm) water, acetone repetitive scrubbing then, obtain La after the drying through spinning ₂CuO ₄Powder.

Embodiment 4:

1) with analytically pure Lanthanum trinitrate (La (NO ₃) ₃6H ₂O) be dissolved in and process the solution A that Lanthanum trinitrate concentration is 2.8mol/L in the 70ml zero(ppm) water;

2) press La ³⁺: Cu ²⁺=2: 1 mol ratio adds analytical pure cupric nitrate (Cu (NO in solution A ₃) ₃3H ₂O) get solution B;

3) press analytical pure Hydrocerol A (C ₆H ₈O ₇H ₂O) be that 0.8: 1 mol ratio adds analytical pure Hydrocerol A (C in solution B with the metallic cation summation ₆H ₈O ₇H ₂O), stirring at normal temperature 70min obtains solution C, and using urea to regulate pH is 5.5, obtains solution D;

4) place baking oven to colloidal sol D, in 60 ℃ dry xerogel, xerogel is placed water heating kettle, in water heating kettle, add zero(ppm) water again, add to water heating kettle volumetrical 1/3～2/3 place, then handle down 28h at 200 ℃, take out postcooling to room temperature;

5) open water heating kettle, collect sample, pass through zero(ppm) water, acetone repetitive scrubbing then, obtain La after the drying through spinning ₂CuO ₄Powder.

Claims (1)

1. collosol and gel-Hydrothermal Preparation copper acid lanthanum (La ₂CuO ₄) method of powder, its

Be characterised in that:

1) with analytically pure Lanthanum trinitrate (La (NO ₃) ₃6H ₂O) be dissolved in and process the solution A that Lanthanum trinitrate concentration is 0.8mol/L～2.8mol/L in 20ml～100ml zero(ppm) water;

2) press La ³⁺: Cu ²⁺=(1～2): 1 mol ratio adds analytical pure cupric nitrate (Cu (NO in solution A ₃) ₃3H ₂O) get solution B;

3) press analytical pure Hydrocerol A (C ₆H ₈O ₇H ₂O) be (0.5～1.5) with the metallic cation summation: 1 mol ratio adds analytical pure Hydrocerol A (C in solution B ₆H ₈O ₇H ₂O), stirring at normal temperature 10min～70min obtains solution C, and using urea to regulate pH is 2.5～7.0, obtains solution D;

4) place baking oven to colloidal sol D, in 50 ℃～100 ℃ dry xerogel, xerogel is placed water heating kettle; In water heating kettle, add zero(ppm) water again; Add to water heating kettle volumetrical 1/3～2/3 place, then handle 12h～36h down, take out postcooling to room temperature at 160 ℃～240 ℃;

5) open water heating kettle, collect sample, pass through zero(ppm) water, acetone repetitive scrubbing then, obtain La after the drying through spinning ₂CuO ₄Powder.

Images