CN1861700A - Preparation process of zirconium oxide base composite nano powder - Google Patents

Abstract

The invention relates to a method to produce the composite zirconia nano powder. It is to make the ZrO2-HfO2-Y2O3-Sc2O3 nano powder in the alcohol-water solution by the method of sol-gel. The invention controls the addition of the metal ion and the PEG 6000 and adjusts the pH by adding the ammonia the process includes the sol-gel, the de-ionized water washing, the absolute ethyl alcohol filtration, drying and calcinations. The average particle diameter is 15nm.

Description

The preparation method of zirconium oxide base composite nano powder

Technical field

The present invention relates to a kind of preparation method of zirconium oxide base composite nano powder, belong to technical field of inorganic nonmetallic materials.

Background technology

Zirconium white is a kind of important stupalith that is widely used, and has many good physics, chemical property.The stable cubic phase zircite (YSZ) of doped yttrium oxide has good oxygen conduction, it has been widely used in Solid Oxide Fuel Cell, oxygen permeable film and the oxygen sensor as a kind of comparatively ideal solid electrolyte (ionophore of also expressing one's gratification) material.When the crystal grain of solid electrolyte material is little during to nano-scale, because small-size effect, quantum effect, high interface volume ratio effect, great changes will take place to make its mechanical property, electrical properties, can change the performance of material largely.Therefore, the refinement of solid electrolyte material crystal grain is significant to improving the new Application Areas of fast-ionic conductor performance and exploitation.At ZrO ₂Middle doping HfO ₂Can improve the chemical stability and the thermal shock resistance of material; Sc ₂O ₃Adding can make ZrO ₂Specific conductivity be further enhanced.Therefore people adopt the doping of multiple metal oxide, i.e. Y ₂O ₃, HfO ₂, Sc ₂O ₃Adulterated ZrO ₂Composite solid electrolyte is as novel oxygen ion conductor material.

In order to obtain nanocrystalline ZrO ₂The based solid electrolyte material at first needs to prepare uniform component distribution, particle is tiny, size distribution is even, the Zirconia composite nano powder of favorable dispersity.At present, the ZrO that has reported ₂The nano powder preparation method is mainly physical method and chemical process.Physical method comprises high-temperature spray pyrolysis method, spraying inductively coupled plasma method and freeze-drying etc.; Chemical process comprises hydrolysis method, the precipitator method, hydrothermal method, microemulsion method etc.Physical method requires harsh to technology and material, investment is big, though and all there is advantage separately in some chemical preparation process, also exist weak point, as hydrolysis method, adopt alkoxide to make raw material, the alkoxide raw material costliness, as if carrying out suitability for industrialized production, benefit is low; The powder particle good dispersity that microemulsion method makes, the little and narrowly distributing of granularity, but production process is complicated, and cost is also higher.Therefore, study and explore that other technologies are fairly simple, the relative cheap processing method of cost prepares ZrO ₂Composite nano powder has very big realistic meaning.

Summary of the invention

The preparation method who the purpose of this invention is to provide a kind of new zirconium oxide base composite nano powder.The present invention mainly adopts sol-gel method to prepare nano-powder.

A kind of zirconium oxide base composite nano powder preparation method of the present invention is characterized in that having following preparation process and step:

A. make metal ion Zr in required ratio ⁴⁺, Hf ⁴⁺, Y ³⁺, Sc ³⁺Total concn is the alcohol-water solution of 0.5～2.0mol/L; Alcohol-the water weight ratio of alcohol-water solution is 5: 1～7: 1, and the polyoxyethylene glycol (PEG 6000) of 0.5～2.0wt% of adding alcohol-water solution total amount is as dispersion agent;

B. the solution for preparing is placed water bath with thermostatic control slowly to be heated to 70～90 ℃, carry out mechanical stirring simultaneously; With reaction soln insulation, continue 10～60 minutes, to make pH value be 12～13 to dropping ammonia therein, it is temperature-resistant to continue the maintenance water bath with thermostatic control, and stirs 30～60 minutes, takes out colloidal sol subsequently;

C. with above-mentioned colloidal sol with the deionized water repetitive scrubbing to there not being Cl ^-Till; Available AgNO ₃Detect Cl ^-Disperse dehydrated alcohol suction filtration 2～3 times of the material after the dispersion then with ultrasonic wave;

D. ageing is carried out drying more than 12 hours then behind the suction filtration, and drying temperature is 80 ℃, and be 24 hours time of drying; Calcine then, calcining temperature is 600～800 ℃, and calcination time is 1～3 hour; Powder after the calcining promptly obtains zirconium oxide base composite nano powder behind naturally cooling.

Nanocrystalline ZrO of the present invention ₂-HfO ₂-Y ₂O ₃-Sc ₂O ₃The preparation method of composite granule adopts chemical liquid phase reaction to prepare nano-powder.When solution heats at first in alcohol-water solution, part ZrOCl ₂, HfOCl ₂Directly and H ₂O reacts, and generates Zr (OH) ₄NH ₂O and Hf (OH) ₄NH ₂The leucosol of O, Y (NO ₃) ₃And ScCl ₃In alcohol-water solution heat-processed, do not produce precipitation.Question response carry out relatively fully after, toward wherein adding ammoniacal liquor, control pH value of solution value about 12, the ZrOCl that does not react completely ₂And HfOCl ₂React with ammoniacal liquor once more.Simultaneously, Y (OH) ₃And Sc (OH) ₃Leucosol generates, and is dispersed in Zr (OH) ₄NH ₂O and Hf (OH) ₄NH ₂O sol particle surface forms a kind of " parcel " structure, like this when powder is calcined, and Y ₂O ₃And Sc ₂O ₃Can penetrate into ZrO equably ₂, HfO ₂In the crystal grain.Four kinds of metal oxides keep homogeneity on microscopic dimensions, can accelerate the reaction sintering process of material, thereby sintering temperature is reduced significantly, and sintering time also can significantly reduce simultaneously.ZrO as solid electrolyte ₂And HfO ₂Must be the stabilizing zirconia of fluorite structure, add Y ₂O ₃, ScO ₃Played function of stabilizer, they can stop ZrO ₂And HfO ₂Phase transformation during cooling, thus ZrO formed ₂-HfO ₂-Y ₂O ₃-Sc ₂O ₃Single cubic phase sosoloid.

In preparation process, if concentration of metal ions is too high, then after the primary sedimentation particle formed, the mutual collision opportunity of primary sedimentation particle was very big, and these particles collide owing to cloth youth motion and be coalescent, form offspring.The offspring that forms equally also has very big chance to collide mutually and coalescent, forms bigger particle, precipitation particles is reunited become greatly, influenced final powder granularity.But concentration of metal ions is low excessively, and obviously the output of nano-powder can be too low, and is economical inadequately for mass preparation.When metal ion in alcohol-water solution hydrolysis reaction takes place,, can reduce the reunion of precipitation particles, also help improving the dispersiveness of precipitation particles because the surface tension of alcohol-water solution is littler than water.Along with alcohol-water ratio increases, the particle size reduction of precipitation particles, the dispersed raising.When alcohol-water ratio during more than or equal to 7: 1, the particle diameter of gained powder no longer includes obvious change.In addition, the adding of an amount of polyoxyethylene glycol (PEG6000) the dispersion agent dispersiveness that also helps reducing the reunion of precipitation particles and improve precipitation particles.Experiment showed, that comparatively suitable alcohol-water ratio is 5: 1～7: 1, the metal ion total concn is 0.5～2.0mol/L, and the add-on of PEG6000 dispersion agent is the 0.5-2.0wt% of alcohol-water solution total amount.

After the colloidal sol that takes out is used the deionized water repetitive scrubbing,, very easily cause the generation of " hard aggregation " body because there are a large amount of activity hydroxies in the precipitate particles surface.Therefore, remove Cl at distilled water wash ^-After, little with surface tension again, the dehydrated alcohol that dehydration is strong carries out suction filtration to throw out, can remove large quantity of moisture of gel water absorption, and the alcoholic acid surface tension is littler than water, in the drying process, owing to the effect of capillary force causes the factor of particle aggregation to weaken greatly.On the other hand, in the ethanol volatilization process, be difficult between the particle producing hydrogen bonding, eliminate the purpose of reuniting thereby reach.

Embodiment

After now specific embodiments of the invention being described in.

Embodiment 1

Nanometer ZrO in the present embodiment ₂-HfO ₂-Y ₂O ₃-Sc ₂O ₃The preparation process and the step of powder are as follows:

(1), with ZrOCl ₂8H ₂O, HfOCl ₂8H ₂O, Y (NO ₃) ₃6H ₂O and Sc ₂O ₃80: 10: 8 in molar ratio: 12 ratio weighing; With ZrOCl ₂8H ₂O, HfOCl ₂8H ₂O and Y (NO ₃) ₃6H ₂O is dissolved in the alcohol-water solution, Sc ₂O ₃Also be mixed in the above-mentioned mixed solution after being dissolved in hydrochloric acid, be mixed with metal ion Zr ⁴⁺, Hf ⁴⁺, Y ³⁺, Sc ³⁺Total concn is the solution of 0.5mol/L; The alcohol of alcohol-water solution-water weight ratio example is 5: 1; And the PEG 6000 of adding alcohol-water solution total amount 1wt% is as dispersion agent.

(2), place water bath with thermostatic control slowly to be heated to 80 ℃ the solution for preparing, stir simultaneously; With reaction soln insulation, continue after 30 minutes, to make pH value be 12 to dropping ammonia therein, it is constant to continue 80 ℃ of maintenance water bath with thermostatic control temperature, and stirs after 30 minutes and take out colloidal sol.

(3), with above-mentioned colloidal sol with the deionized water repetitive scrubbing to there not being Cl ^-Till; Available AgNO ₃Detect Cl ^-Disperse dehydrated alcohol suction filtration 3 times of the material after the dispersion then with ultrasonic wave.

(4), ageing 12 hours behind the suction filtration, carry out drying, calcining again; Drying temperature is 80 ℃, and be 24 hours time of drying; Calcining temperature is 700 ℃, and calcination time is 2 hours; Powder after the calcining promptly obtains zirconium oxide base composite nano powder, i.e. ZrO behind naturally cooling ₂-HfO ₂-Y ₂O ₃-Sc ₂O ₃Nano-powder.

The nano-powder of present embodiment preparation, through the transmission electron microscope observation analysis, the result shows the favorable dispersity of powder, powder granularity average out to 15nm; Show ZrO through the X-ray diffraction analytical results ₂-HfO ₂-Y ₂O ₃-Sc ₂O ₃Composite granule is a single cube of phase.

Claims (1)

1. the preparation method of a zirconium oxide base composite nano powder is characterized in that having following preparation process and step:

A. make metal ion Zr in required ratio ⁴⁺, Hf ⁴⁺, Y ³⁺, Sc ³⁺Total concn is the alcohol-water solution of 0.5～2.0mol/L; Alcohol-the water weight ratio of alcohol-water solution is 5: 1～7: 1, and the polyoxyethylene glycol (PEG 6000) of 0.5～2.0wt% of adding alcohol-water solution total amount is as dispersion agent;

B. the solution for preparing is placed water bath with thermostatic control slowly to be heated to 70～90 ℃, carry out mechanical stirring simultaneously; With reaction soln insulation, continue 10～60 minutes, to make pH value be 12～13 to dropping ammonia therein, it is temperature-resistant to continue the maintenance water bath with thermostatic control, and stirs 30～60 minutes, takes out colloidal sol subsequently;

C. with above-mentioned colloidal sol with the deionized water repetitive scrubbing to there not being Cl ^-Till; Available AgNO ₃Detect Cl ^-Disperse dehydrated alcohol suction filtration 2～3 times of the material after the dispersion then with ultrasonic wave;

D. ageing is carried out drying more than 12 hours then behind the suction filtration, and drying temperature is 80 ℃, and be 24 hours time of drying; Calcine then, calcining temperature is 600～800 ℃, and calcination time is 1～3 hour; Powder after the calcining promptly obtains zirconium oxide base composite nano powder behind naturally cooling.