A method for preparing cubic phase zirconia nanopowder based on complexation confinement effect

Abstract

This invention provides a method for preparing cubic phase zirconia nanoparticles based on the complexation confinement effect. Step 1 involves weighing ZrOCl2·8H2O, YCl3, and (C6H) 10 O5) n Step 1: Add deionized water to a beaker and stir until completely dissolved to obtain a mixed solution; Step 2: Weigh EDTA-2Na·2H2O into a beaker, add deionized water, and stir until completely dissolved; Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1, heat and stir in a water bath to obtain a zirconia precursor solution; Step 4: After centrifuging and washing the zirconia precursor solution, dry it in an oven and grind it to obtain zirconia precursor powder; Step 5: Place the zirconia precursor powder in a muffle furnace and calcine it at high temperature in air to obtain cubic phase nano-zirconia powder. This method is simple and easy to implement, and can be easily scaled up for industrial production. The product has high purity and can be used in SOFC and oxygen sensors, etc.

Description

Technical Field

[0001] This invention belongs to the field of ceramic materials technology, specifically relating to a method for preparing cubic phase nano-zirconia powder based on the complexation confinement effect. Background Technology

[0002] Nanoceramic powders are substances with nanoscale dimensions, falling between solids and molecules. Nanoparticle materials possess extremely small particle sizes, large specific surface areas, and high chemical properties, which can significantly reduce the sintering temperature of materials and save energy. Nanoscale powders are beneficial for improving the density and mechanical properties of ceramic materials. Furthermore, due to their small particle size, they possess unique properties not found in larger particles. Currently, there are many types of nanoceramic powders, with cubic zirconia powder being one example.

[0003] Cubic zirconia is a high-temperature stable phase, existing stably above 2370 °C. Its crystal structure exhibits high symmetry, with oxygen atoms forming a face-centered cubic lattice and zirconium atoms located in interstitial positions. Cubic zirconia possesses excellent ionic conductivity, particularly at high temperatures, allowing oxygen ions to move relatively freely within the lattice. This characteristic makes it valuable for applications in solid oxide fuel cells (SOFCs) and oxygen sensors. In SOFCs, cubic zirconia acts as an electrolyte, conducting oxygen ions and facilitating charge transfer within the battery, thereby converting chemical energy into electrical energy. With this significant advantage, cubic zirconia has become a high-performance ceramic powder material with immense development potential in the new energy field.

[0004] Chinese patent "A Method for Preparing High-Purity Zirconia" (Application No.: 202310989111.9, Authorization No.: CN116903033B, Publication Date: 2025.11.14) discloses a method for preparing high-purity zirconium oxide. This method involves adjusting the final concentration state of an acidic zirconium oxychloride solution under the action of an oxidant, as well as the cooling process after concentration and evaporation; then, crystallization is achieved through a two-stage concentration-evaporation method; finally, hafnium-free zirconium oxide is obtained by calcination. This method requires the addition of hydrochloric acid to adjust the acidity during the preparation of zirconium oxide. Hydrochloric acid is regulated, difficult to obtain, and poses certain dangers. Furthermore, the product contains a large amount of residual chloride ions, which cannot be effectively removed. Summary of the Invention

[0005] content This invention addresses the shortcomings of existing technologies for preparing cubic phase nano-zirconia powder by proposing a simple, easily controllable method for preparing cubic phase nano-zirconia powder materials that allows for controlled particle size growth at high temperatures.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing cubic phase zirconia nanoparticles based on the complexation confinement effect is implemented according to the following steps: Step 1, weigh out ZrOCl2·8H2O, YCl3 and (C6H 10 O5) n Add deionized water to a beaker and stir until completely dissolved to obtain a mixed solution; Step 2: Weigh EDTA-2Na·2H2O into a beaker and add deionized water, stirring until completely dissolved; Step 3: Add the solution obtained in step 2 to the solution obtained in step 1, heat and stir in a water bath, and the resulting milky white suspension is the zirconium oxide precursor solution. Step 4: After centrifuging and washing the obtained zirconia precursor solution, place it in an oven, dry it, and then grind it to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at high temperature in air to obtain cubic phase nano-zirconia powder.

[0007] Further, in step 1, the ZrOCl2·8H2O and deionized water are prepared into a 1 mol / L solution, and the molar ratio of ZrOCl2·8H2O to YCl3 is 92:8, (C6H 10 O5) n The mass ratio of ZrOCl2·8H2O to ZrOCl2·8H2O is 1~3:10. The stirring process is carried out using a magnetic stirrer for 10~20 min.

[0008] Furthermore, in step 2, the molar ratio of EDTA-2Na·2H2O to ZrOCl2·8H2O is 1.5~2:1, and the stirring process is carried out using a magnetic stirrer for 10~20 min.

[0009] Furthermore, the conditions for the water bath in step 3 are as follows: water bath temperature 60~70 ℃, water bath duration 0.5~1h; the stirring process is carried out using a magnetic stirrer, and the stirring time is 30~60 min.

[0010] Furthermore, in step 4, the centrifugation washing is performed by first washing with ultrapure water 3 times, and then washing with anhydrous ethanol 3 times. The centrifugation speed is 6000~8000 r / min, and the centrifugation time is 5~10 min.

[0011] Furthermore, in step 4, the oven drying temperature is 60~70 ℃, and the drying time is 6~12 h.

[0012] Furthermore, in step 5, the high-temperature calcination temperature is 800 ℃, and the holding time is 1~2 h.

[0013] The cubic phase zirconia nanopowder was prepared according to the above-mentioned method for preparing cubic phase zirconia nanopowder based on the complexation confinement effect.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a method for preparing cubic phase nano-zirconia powder based on the complexation confinement effect. In the preparation of nano-scale yttrium-stabilized zirconia precursors, the particle growth process is precisely controlled through the dual effects of "spatial confinement + complexation regulation," ultimately optimizing the particle size uniformity and dispersibility of the precursor. First, (C6H... 10 O5) n Construct an initial confined system to lock in the spatial range of metal ions. (C6H) 10 O5) n The molecule first undergoes a complexation reaction with zirconium and yttrium ions in the system, and the resulting complex products construct a "finite reaction microspace" within the reaction system; simultaneously, (C6H 10 O5) n The long-chain molecular structures intertwine to form a network-like "molecular network" structure. This "molecular network" firmly confines the EDTA complex containing metal ions within tiny regions of the "mesh," achieving initial "territorial control" of the metal ions in space and directly restricting their free diffusion range, laying the spatial foundation for subsequent homogeneous reactions. Subsequently, EDTA-2Na·2H2O mediates complexation substitution, doubly fixing the ion state and proportion. When the system is heated, EDTA-2Na·2H2O undergoes a "complexation substitution reaction": it replaces the previously (C6H... 10 O5) n Complexation with zirconium and yttrium ions, in (C6H 10 O5) n At the initial positions defined by the "molecular network," it recombines with zirconium and yttrium ions to form stable five-membered ring chelate (EDTA-2Zr, EDTA-2Y) complex precursors. This process acts like a "molecular shackle" to prevent the aggregation of individual ions while ensuring that the two ions are uniformly dispersed in a predetermined ratio. Simultaneously, the EDTA-metal ion chelate molecules are relatively large and can intercalate into (C6H... 10 O5) n "Molecular network" pores, and through carboxyl groups, amino groups and (C6H) 10 O5) n The hydroxyl groups form hydrogen bonds, firmly confining the ions within a microspace, further enhancing the spatial confinement effect; in addition, the strong chelating effect of EDTA can reduce the concentration of free metal ions and inhibit Zr. 4+ The hydrolysis reaction broadened the pH window for the reaction.

[0015] 2. In the subsequent water bath heating and high-temperature calcination stages, the "(C6H" formed in the early stage... 10 O5) n The dual confinement system of "molecular network + EDTA complex precursor" continues to play a crucial role, strictly confining the complexed zirconium and yttrium ions within a tiny space, preventing their diffusion over a wide area. This completely avoids the problem of particle size enlargement caused by collisions and fusion during particle growth. Ultimately, the particles can only complete crystallization and growth in an orderly manner within the limited tiny space, successfully preparing cubic phase zirconium oxide nanoparticles with uniform particle size and excellent dispersibility. This invention uses EDTA-2Na·2H2O and (C6H 10 O5) n It is odorless and the reagent is safe, which aligns with the national advocacy of green technology innovation.

[0016] 3. The synthesis process of this invention mainly uses inexpensive and readily available inorganic salts, hydroxypropyl starch, and EDTA-2Na·2H2O, resulting in low cost, environmentally friendly and safe reagents, a simple and easy-to-implement process with excellent reproducibility, and ease of large-scale industrial production. The method of this invention features a simple and easy synthesis process, low synthesis temperature, good reproducibility, and high purity of the synthesized product, making it suitable for applications in SOFCs and oxygen sensors, with broad application prospects. Attached Figure Description

[0017] Figure 1 This is a flowchart of a method for preparing cubic phase nano-zirconia powder based on the complexation confinement effect according to the present invention; Figure 2 Macroscopic images of the zirconia precursor solution, centrifuged zirconia precursor, dried and ground zirconia precursor powder, and cubic phase nano-zirconia powder prepared in Example 3 of this invention. Figure 3 This is a simulation diagram of the theoretical calculation of the complexation effect of the present invention; Figure 4 This is a reaction mechanism diagram of the complexation confinement effect of the present invention; Figure 5 The X-ray diffraction patterns of cubic phase nano-zirconia powders prepared in Examples 1-5 of this invention are shown below. Figure 6 X-ray diffraction pattern of cubic phase nano-zirconia powder prepared in Example 3 of the present invention and its re-firing at 1200℃; Figure 7 These are scanning electron microscope (SEM) images of the cubic phase nano-zirconia powders prepared in Examples 1-5 of this invention. Figure 8 This is a particle size distribution diagram of the cubic phase nano-zirconia powder prepared in Example 3 of the present invention; Figure 9The nitrogen adsorption-desorption curve and pore size distribution of the cubic phase nano-zirconia powder prepared in Example 3 of this invention are obtained by BET test. Figure 10 The diagram shows the electrical conductivity of the cubic phase nano-zirconia powder prepared in Example 3 of this invention at different temperatures. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention provides a method for preparing cubic phase zirconia nanoparticles based on the complexation confinement effect, such as... Figure 1 As shown in the flowchart, the specific operation steps are as follows: Step 1: Weigh out 14.97 g ZrOCl2·8H2O, 2.43 g YCl3, and 1.61~4.83 g (C6H 10 O5) n Add 50 mL of deionized water to a beaker and stir continuously with a magnetic stirrer for 10-20 min to obtain a mixed solution. Step 2: Weigh 25.68~33.24 g of EDTA-2Na·2H2O into a beaker and add 50 mL of deionized water. Stir continuously for 10~20 min using a magnetic stirrer.

[0020] Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1. During this process, place the solution in a water bath and heat it at 60-70 ℃ for 0.5-1 h. Use a magnetic stirrer to continuously stir for 30-60 min. The resulting milky white suspension is the zirconium oxide precursor solution. Step 4: The obtained zirconia precursor solution is centrifuged and washed. First, it is washed 3 times with ultrapure water, and then 3 times with anhydrous ethanol. The centrifugation speed is 6000~8000 r / min and the centrifugation time is 5~10 min. Finally, it is placed in an oven at 60~70 ℃ and dried for 6~12 h. After drying, it is ground to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at high temperature in air. The temperature is increased to 800 ℃ at a heating rate of 2~4 ℃ / min and held for 1~2 h to obtain cubic phase nano-zirconia powder.

[0021] Theoretical calculations and simulations were performed on the complexation effect used in this invention (e.g.) Figure 3 As shown in the figure, the results indicate that in the dual system of "spatial confinement + complexation regulation", EDTA-2Na·2H2O acts as the core complexing component with Zr. 4+ Y 3+ When this reaction occurs, the binding energy of the system decreases significantly. Based on the thermodynamic principle that "the lower the energy, the more stable the structure," it can be proven that EDTA-2Na·2H2O will form stable coordination bonds with two metal ions through the amino (-NH2) and carboxyl (-COOH) sites in the molecular structure, constructing a five-membered chelate ring and generating EDTA-Zr and EDTA-Y complex precursors. This process is equivalent to "setting shackles" for the ions, on the one hand replacing hydroxypropyl starch (C6H2O)... 10 O5) n The initial complexation connection between (C6H) and metal ions, in (C6H) 10 O5) n Zr is re-fixed within the microspace defined by the "molecular network". 4+ With Y 3+ The relative positions of the particles prevent single ions from detaching from the complex and aggregating independently, thus avoiding abnormal local particle growth. On the other hand, it ensures that the two ions are uniformly dispersed in the system according to the preset parameters, and the complex precursor itself forms a local independent reaction region, further enhancing the spatial confinement effect. This lays a key foundation for the orderly crystallization and growth of particles within the confined space during the subsequent water bath heating and high-temperature calcination stages, ultimately preparing cubic phase nano-zirconia powder with uniform particle size and excellent dispersibility.

[0022] Figure 3 This is a simulation diagram of the theoretical calculation of the complexation effect of the present invention. Figure 4 This is a reaction mechanism diagram of the complexation confinement effect of the present invention; it can be seen that (C6H 10 O5) n EDTA-2Na·2H2O can act as a confining component, complexing with zirconium and yttrium ions to construct a limited reaction microspace, thus completing the initial spatial confinement of metal ions. When EDTA-2Na·2H2O acts as a chelating agent and chelates with metal ions in a water bath, the binding energy decreases. Based on the thermodynamic principle that lower energy structures are more stable, it is proven that EDTA-2Na·2H2O coordinates and fixes the active ions, causing them to complex with zirconium and yttrium ions to generate complex precursors of EDTA-Zr and EDTA-Y, thus fixing the relative positions of the two metal ions. This process not only fixes the relative spatial positions of the two metal ions but also prevents individual ions from detaching from the complex and aggregating independently through strong chelation, while simultaneously ensuring the stability of Zr. 4+ With Y 3+ The particles are uniformly dispersed according to a preset pattern, providing key thermodynamic support for the orderly crystallization of the particles within a confined space during the subsequent heat treatment stage, ultimately preparing cubic phase nano-zirconia powder with uniform particle size.

[0023] Example 1

[0024] Step 1: Weigh out 14.97 g ZrOCl2·8H2O, 2.43 g YCl3, and 1.61 g (C6H 10 Add O5) to a beaker and add 50 mL of deionized water. Stir continuously for 10 min using a magnetic stirrer to obtain a mixed solution. Step 2: Weigh 25.68 g of EDTA-2Na·2H2O into a beaker and add 50 mL of deionized water. Stir continuously for 10 min using a magnetic stirrer.

[0025] Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1. During this process, place the solution in a water bath and heat it at 60°C for 0.5 h. Then, use a magnetic stirrer to continuously stir for 30 min. The resulting milky white suspension is the zirconium oxide precursor solution. Step 4: The obtained zirconia precursor solution is centrifuged and washed. First, it is washed 3 times with ultrapure water, and then 3 times with anhydrous ethanol. The centrifugation speed is 6000 r / min and the centrifugation time is 5 min. Finally, it is placed in a 60 ℃ oven to dry for 6 h. After drying, it is ground to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at high temperature in air. The temperature is increased to 800 ℃ at a heating rate of 2 ℃ / min and held for 1 h to obtain cubic phase nano-zirconia powder.

[0026] Example 2

[0027] Step 1: Weigh out 14.97 g ZrOCl2·8H2O, 2.43 g YCl3, and 2.42 g (C6H 10 O5) n Add 50 mL of deionized water to a beaker and stir continuously for 15 min using a magnetic stirrer to obtain a mixed solution. Step 2: Weigh 25.68 g of EDTA-2Na·2H2O into a beaker and add 50 mL of deionized water. Stir continuously for 15 min using a magnetic stirrer.

[0028] Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1. During this process, place the solution in a water bath and heat it at 65°C for 0.75 h. Stir continuously for 45 min using a magnetic stirrer. The resulting milky white suspension is the zirconium oxide precursor solution. Step 4: The obtained zirconia precursor solution was centrifuged and washed. It was first washed three times with ultrapure water and then three times with anhydrous ethanol. The centrifugation speed was 7000 r / min and the centrifugation time was 7.5 min. Finally, it was placed in a 65 ℃ oven to dry for 9 h. After drying, it was ground to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at high temperature in air. The temperature is increased to 800 ℃ at a heating rate of 3 ℃ / min and held for 1.5 h to obtain cubic phase nano-zirconia powder.

[0029] Example 3

[0030] Step 1: Weigh out 14.97 g ZrOCl2·8H2O, 2.43 g YCl3, and 3.22 g (C6H 10 O5) n Add 50 mL of deionized water to a beaker and stir continuously for 20 min using a magnetic stirrer to obtain a mixed solution; Step 2: Weigh 29.96 g of EDTA-2Na·2H2O into a beaker and add 50 mL of deionized water. Stir continuously for 20 min using a magnetic stirrer.

[0031] Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1. During this process, place the solution in a water bath and heat it at 70°C for 1 hour. Then, stir continuously with a magnetic stirrer for 60 minutes. The resulting milky white suspension is the zirconium oxide precursor solution. Step 4: The obtained zirconia precursor solution is centrifuged and washed three times with ultrapure water and three times with anhydrous ethanol at a speed of 8000 r / min for 10 min. Finally, it is placed in a 70 ℃ oven to dry for 12 h. After drying, it is ground to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at high temperature in air. The temperature is increased to 800 ℃ at a heating rate of 4 ℃ / min and held for 2 h to obtain cubic phase nano-zirconia powder.

[0032] Example 4

[0033] Step 1: Weigh out 14.97 g ZrOCl2·8H2O, 2.43 g YCl3, and 4.025 g (C6H 10 O5) n Add 50 mL of deionized water to a beaker and stir continuously for 20 min using a magnetic stirrer to obtain a mixed solution; Step 2: Weigh 34.24 g of EDTA-2Na·2H2O into a beaker and add 50 mL of deionized water. Stir continuously for 20 min using a magnetic stirrer.

[0034] Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1. During this process, place the solution in a water bath and heat it at 70°C for 1 hour. Then, stir continuously with a magnetic stirrer for 60 minutes. The resulting milky white suspension is the zirconium oxide precursor solution. Step 4: The obtained zirconia precursor solution was centrifuged and washed three times with ultrapure water and three times with anhydrous ethanol. The centrifugation speed was 8000 r / min and the offline time was 10 min. Finally, it was placed in a 70 ℃ oven to dry for 12 h. After drying, it was ground to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at high temperature in air. The temperature is increased to 800 ℃ at a heating rate of 4 ℃ / min and held for 2 h to obtain cubic phase nano-zirconia powder.

[0035] Example 5

[0036] Step 1: Weigh out 14.97 g ZrOCl2·8H2O, 2.43 g YCl3, and 4.83 g (C6H 10 O5) n Add 50 mL of deionized water to a beaker and stir continuously for 20 min using a magnetic stirrer to obtain a mixed solution; Step 2: Weigh 34.24 g of EDTA-2Na·2H2O into a beaker and add 50 mL of deionized water. Stir continuously for 20 min using a magnetic stirrer.

[0037] Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1. During this process, place the solution in a water bath and heat it at 70°C for 1 hour. Then, stir continuously with a magnetic stirrer for 60 minutes. The resulting milky white suspension is the zirconium oxide precursor solution. Step 4: The obtained zirconia precursor solution is centrifuged and washed three times with ultrapure water and three times with anhydrous ethanol at a speed of 8000 r / min for 10 min. Finally, it is placed in a 70 ℃ oven to dry for 12 h. After drying, it is ground to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at high temperature in air. The temperature is increased to 800 ℃ at a heating rate of 4 ℃ / min and held for 2 h to obtain cubic phase nano-zirconia powder.

[0038] Table 1 shows the relevant parameters of the cubic phase nano-zirconia powder prepared in Examples 1-5 of this invention.

[0039] Table 1 Precursor yield (g) 8.57 9.31 9.13 9.87 8.56 Ceramic conversion rate % 43.95 48.25 45.95 44.00 44.55 Ceramic yield % 60.81 72.45 67.67 70.05 61.21 Grain size (nm) 15.9 17.0 14.9 16.0 16.5 The data shows that the precursor yield is stable and at a high level, providing a sufficient raw material base for subsequent ceramic conversion. The ceramic conversion rate and yield are excellent, demonstrating the process's efficient utilization of raw materials, effectively reducing resource waste, and meeting the needs of industrial production for cost control and efficiency improvement. Crucially, the final product grain size is controlled within the ultrafine nanoscale range of 14.9-17.0 nm, which not only achieves precise control over particle growth but also ensures uniform powder particle size and excellent dispersibility, meeting the requirements of cubic phase nano-zirconia for material microstructure and performance in fields such as SOFC and oxygen sensors.

[0040] Figure 2 Macroscopic images of (a) zirconia precursor solution, (b) centrifuged zirconia precursor, (c) dried and ground zirconia precursor powder, and (d) cubic phase nano-zirconia powder prepared in Example 3 of the present invention. Figure 2 The macroscopic images visually demonstrate the complete process and product state for preparing cubic phase nano-zirconia powder according to this invention, fully showcasing the ease of operation and high product quality of the method: From Figure 2 (a) shows that the reaction vessel process does not require complex equipment, has a low operating threshold, and is easy to scale up; Figure 2 (b) The intermediate products exhibit a uniform and fine state, reflecting the sufficiency and controllability of the complexation-confined reaction; Figure 2 (c) Figure 2 (d) The powder exhibits a loose and uniform white powder morphology, which visually demonstrates the product's excellent performance in appearance and dispersibility.

[0041] Figure 5 These are the X-ray diffraction patterns of the cubic phase nano-zirconia powders prepared in Examples 1-5 of this invention; from Figure 5 It can be seen that the diffraction peaks of the products in each embodiment are highly matched with the standard card of cubic zirconia (c-ZrO2, PDF:49-1642), indicating that the products prepared by this method have successfully achieved precise control of the target crystal phase and have high cubic phase purity. Meanwhile, the diffraction peaks are sharp and free of obvious impurity peaks, reflecting the complete crystal structure and excellent crystallinity of the products. This fully demonstrates that the "complex confinement effect" process can stably and efficiently prepare high-purity cubic zirconia powder, providing reliable crystal phase and structural guarantees for its application in SOFC and other fields.

[0042] Figure 6The X-ray diffraction pattern of the cubic phase nano-zirconia powder prepared in Example 3 of this invention and its re-firing at 1200℃ is shown. Figure 6 As can be seen, the cubic phase nano-zirconia powder prepared by this invention exhibits excellent thermal stability: whether it is the initial product (the cubic phase nano-zirconia powder prepared in Example 3) or the sample after re-firing at 1200℃, its diffraction peaks are completely consistent with the standard card of cubic phase zirconia (c-ZrO2, PDF:49-1642), and no impurity peaks appear. Meanwhile, the diffraction peaks of the re-firing sample remain sharp and clear, indicating that the cubic phase structure of the product did not undergo a phase transformation and its crystallinity remained good after high-temperature treatment. This fully confirms that the cubic phase nano-zirconia powder prepared by this process possesses excellent high-temperature stability. This characteristic enables it to maintain a stable crystal structure and performance for a long time in fields requiring high-temperature operation, such as SOFC (service temperature 800~1000℃) and oxygen sensors (service temperature 600~800℃).

[0043] Figure 7 These are scanning electron microscope (SEM) images of the cubic phase nano-zirconia powders prepared in Examples 1-5 of this invention. Figure 8 This is a particle size distribution diagram of Example 3 of the present invention.

[0044] from Figure 7 and Figure 8 The particle size distribution of the 88 particles in Example 3 shows that the material's particle size is precisely at the nanometer level. The sample particles in each example exhibit extremely regular morphology, mostly spherical or near-spherical, with smooth surfaces and no obvious defects. The particles show good dispersion without significant agglomeration, indicating excellent particle dispersion control throughout the preparation process. The particle size distribution diagram of Example 3 shows that the 88 particles are concentrated within a narrow range, with a stable average particle size, indicating a very uniform particle size distribution. The average particle size of the material is 42.89 nm, with a deviation of only 5.39 nm, meeting the scale requirements of nanomaterials while ensuring particle uniformity. Furthermore, the material exhibits excellent dispersibility, with powder particles distributed uniformly without significant agglomeration or clumping, ensuring the full utilization of the particle's inherent properties and further enhancing the material's structural uniformity.

[0045] Table 2 shows the BET test results of the zirconia powder obtained in Example 3.

[0046] Table 2 Multi-point BET specific surface area 12.655 m² / g Total adsorption volume 0.052 cm³ / g Adsorption average pore size 16.306 nm Figure 9 The nitrogen adsorption-desorption curve and pore size distribution of the cubic phase nano-zirconia powder prepared in Example 3 of this invention are obtained by BET test.

[0047] from Figure 9The BET test results in Table 2 fully confirm that the prepared material possesses excellent dispersibility, exhibiting superior specific surface area and a rationally distributed pore structure, demonstrating outstanding structural advantages. Test data show that the material possesses a rich nanoscale pore network and ideal pore volume characteristics, indicating that no significant agglomeration occurred between particles, achieving a uniformly dispersed microstructure. This high dispersibility not only maximizes the number of surface active sites, providing ample contact and adsorption space for reactants, but also constructs unobstructed mass transfer channels, reducing interfacial resistance. This characteristic ensures the material's high efficiency in catalysis, energy, or adsorption applications and also confirms the precision of the preparation process in controlling particle morphology and microstructure, laying a solid structural foundation for the material's subsequent excellent practical application effects.

[0048] Table 3 shows the statistical values ​​of residual chloride ion content in the zirconia powder obtained in Example 3.

[0049] Table 3 1 5.0004 92.95 2 5.0000 98.08 3 4.9998 102.82 As can be seen from Table 3, the residual chloride ion content is stable at around 100 ppm, which is far lower than the industry standard of 200 ppm and the fluctuation is small. This fully demonstrates that the process has excellent and controllable chloride ion removal effect and completely solves the pain point of excessive residual chloride ions in the existing technology.

[0050] Figure 10 The conductivity graphs of the cubic phase nano-zirconia powder (10 mm in diameter) prepared in Example 3 of this invention at different temperatures fully demonstrate the superior performance of the prepared zirconia material in core applications such as solid oxide fuel cells (SOFC) and oxygen sensors, perfectly meeting industry standards and authoritative technical requirements. Whether it's the industry standard conductivity range of 0.12-0.16 S / cm for 8YSZ electrolyte in SOFC at 1000℃ in air, or the technical specification that zirconia ceramics for oxygen sensors must maintain stable ion conduction at 300-800℃, the conductivity data of this material precisely matches these standards, with some indicators even surpassing them. It exhibits stable and efficient ion transport characteristics in the mid-to-high temperature range. This performance not only confirms the precise control of the lattice structure through the material preparation process—forming sufficient oxygen vacancy channels through reasonable doping to ensure efficient oxygen ion migration—but also reflects its advantages in key properties such as high-temperature stability and chemical inertness. It fully meets the core requirements of high-power output in SOFCs, rapid response in oxygen sensors, and long-term reliable operation, providing solid material performance support for the commercial application of these two types of devices.

[0051] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples. Other experimentally proven alternatives, such as changes to chelating agents (sucrose, fructose, glucose, tartaric acid, oxalic acid, citric acid, etc.) and dispersants (PVA, PEG, starch, etc.), not mentioned in the patent, are also protected. The scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for preparing cubic phase nano-zirconia powder based on complexation confinement effect, characterized in that, The specific steps are as follows: Step 1, weigh out ZrOCl2·8H2O, YCl3 and (C6H 10 O5) n Add deionized water to a beaker and stir until completely dissolved to obtain a mixed solution; Step 2: Weigh EDTA-2Na·2H2O into a beaker and add deionized water, stirring until completely dissolved; Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1, heat and stir in a water bath, and the resulting milky white suspension is the zirconium oxide precursor solution. The water bath temperature is 60~70 ℃ and the water bath time is 0.5~1h. The stirring process is carried out using a magnetic stirrer and the stirring time is 30~60 min. Step 4: After centrifuging and washing the obtained zirconia precursor solution, place it in an oven, dry it, and then grind it to obtain zirconia precursor powder. Step 5: Place the zirconia precursor powder obtained in Step 4 into a muffle furnace and calcine it at a high temperature of 800 °C in air for 1-2 h to obtain cubic phase nano-zirconia powder.

2. The method for preparing cubic phase nano-zirconia powder based on the complexation confinement effect according to claim 1, characterized in that, In step 1, ZrOCl2·8H2O and deionized water are prepared to form a 1 mol / L solution, with a molar ratio of ZrOCl2·8H2O to YCl3 of 92:

8. (C6H 10 O5) n The mass ratio of ZrOCl2·8H2O to ZrOCl2·8H2O is 1~3:

10. The stirring process is carried out using a magnetic stirrer for 10~20 min.

3. The method for preparing cubic phase nano-zirconia powder based on the complexation confinement effect according to claim 1, characterized in that, In step 2, the molar ratio of EDTA-2Na·2H2O to ZrOCl2·8H2O is 1.5~2:1, and the stirring process is carried out using a magnetic stirrer for 10~20 min.

4. The method for preparing cubic phase nano-zirconia powder based on the complexation confinement effect according to claim 1, characterized in that, In step 4, during centrifugation and washing, first wash with ultrapure water 3 times, then wash with anhydrous ethanol 3 times. The centrifugation speed is 6000~8000 r / min, and the centrifugation time is 5~10 min.

5. The method for preparing cubic phase nano-zirconia powder based on the complexation confinement effect according to claim 1, characterized in that, In step 4, the oven drying temperature is 60~70 ℃, and the drying time is 6~12 h.

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