Hydrothermal synthesis method of modified zirconium dioxide and organic alkali modified zirconium dioxide

Abstract

The invention belongs to the technical field of material chemistry, and relates to a hydrothermal synthesis method of modified zirconium dioxide and organic alkali modified zirconium dioxide. The stability of metal ions in an organic solution is improved by adopting a complexing agent, the pH value of the solution is controlled by taking organic alkali as a mechanism regulator, zirconium-containing precursor powder without hard agglomeration is obtained, the self-catalysis effect of the complexing agent is utilized, the reaction rate is accelerated, the reaction temperature and the energy consumption are reduced, and the nano powder is finally obtained through calcination. According to the preparation method, the particle shape and size are easy to control, the dispersion uniformity is improved, and the nano zirconium oxide with high specific surface area and high thermal stability is obtained. Hydroxyl and amido functional groups are endowed to the surface of zirconium oxide and can form hydrogen bonds with oxygen atoms in water molecules, so that the interaction between substances and water is enhanced, water can form a stable liquid film on the surface of the substances, the hydrophilicity of zirconium oxide is optimized, alkaline charged ions are provided for the surface of zirconium oxide powder, and the surface of the zirconium oxide powder is improved. The electrical property of the diaphragm can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of material chemistry, and relates to a method for hydrothermally synthesizing modified zirconia and organo-base modified zirconia. Background Art

[0002] As the core material in an alkaline water electrolyzer for hydrogen production, diaphragms often use polyphenylene sulfide (PPS) cloth and organic-inorganic composite membranes as the diaphragm materials for separating the cathode and anode chambers. Among them, the organic-inorganic composite membrane has become a hot spot for commercial use and research due to its good gas barrier property and low ion migration resistance.

[0003] Zirconia (ZrO 2 ) has characteristics such as high specific surface area, hydrophilicity, and high temperature alkali solution corrosion resistance, and is often used as one of the main fillers in the synthesis process of organic-inorganic composite membranes. During the preparation of the composite diaphragm, it can effectively inhibit the formation of macropores, enhance the mechanical strength and pore connectivity, and at the same time improve the thermal stability and electrolyte wettability during the use of the composite diaphragm. According to literature reports (International Journal of Energy Research, 2020, 44(3): 1875-1885), adding ZrO 2 to a polysulfone / N-methylpyrrolidone solution. Because zirconia is considered a material with excellent mechanical properties, outstanding thermal stability, good corrosion resistance, good chemical stability, and proton conductivity, it can effectively improve the overall permeability, mechanical properties, and conductivity of the composite membrane.

[0004] At present, the industrial preparation methods of zirconia mainly include ammonia complex co-precipitation method and hydrothermal method. The ammonia complex co-precipitation method uses ammonia water as a precipitant, and soluble zirconium salts such as ZrOCl 2 react with the precipitant in solution to carry out a co-precipitation reaction to obtain a hydroxide precipitate with uniform element distribution, and then the hydroxide precursor is subjected to high-temperature calcination to obtain an oxide with a large specific surface area; the hydrothermal method is to crystallize the amorphous hydroxide powder after the co-precipitation reaction under high temperature and high pressure conditions to obtain a hydroxide powder with high crystallinity, and then perform high-temperature calcination to obtain the oxide product. However, both the hydrothermal method and the co-precipitation method have problems such as poor dispersion of the powder, agglomeration phenomenon, and low sintering activity, making it difficult to improve the mechanical properties and electrical energy of the hydrogen diaphragm. At present, industrially, surfactants are mainly doped or certain cations are added as stabilizers during the synthesis process. While maintaining the original crystal form, it can change the internal structure of the powder and effectively prevent particle agglomeration. However, the powders synthesized by these methods do not have hydrophilic groups on their surfaces, and cannot improve the electrical properties of the hydrogen diaphragm, which greatly restricts the application of zirconia powder in the preparation of hydrogen diaphragms.

[0005] Therefore, based on this, the technical solution of the present invention is proposed. Summary of the Invention

[0006] To solve the problems existing in the prior art, the solution of the present invention is to provide a hydrothermal synthesis method of organo-base modified zirconia. In the hydrothermal synthesis method, the present invention first uses a complexing agent to improve the stability of metal ions in an organic solution, uses an organic base as an organic structure regulator to control the pH value of the solution, and obtains zirconium-containing precursor powder without hard agglomeration. By the autocatalytic action of the complexing agent, the reaction rate is accelerated, the reaction temperature and energy consumption are reduced, and finally nano-powders are obtained through a calcination process. This preparation method is easy to control the particle shape and size, increases the dispersion uniformity, obtains nano-zirconia with a high specific surface area and high thermal stability, and this method is simple to operate, the raw materials are easy to obtain, and it is conducive to industrial production. In addition, the surface chemical properties of ZrO 2 are changed by the covalent functionalization of organic base molecules, and hydroxyl and amino functional groups are imparted to the surface of zirconia. The hydroxyl and amino groups can form hydrogen bonds with the oxygen atoms in water molecules, enhancing the interaction between the substance and water, enabling water to form a stable liquid film on the surface of the substance, optimizing the hydrophilicity of zirconia and providing basic charged ions on the surface of zirconia powder, which can improve the electrical properties of the separator.

[0007] The synthesis method includes the following steps:

[0008] (1) Dissolve an alkali in a zirconium salt solution and react fully to obtain a first zirconium hydroxide gel;

[0009] (2) Mix the first zirconium hydroxide gel evenly with a sulfuric acid solution and age to obtain a zirconium precursor slurry;

[0010] (3) Mix the zirconium precursor slurry evenly with a metal inorganic salt solution, and then add a complexing agent and / or a dispersant, and mix evenly to obtain a sol-like aqueous solution containing metal ions;

[0011] (4) Add an aqueous solution containing an organic base structure regulator to the sol-like aqueous solution containing metal ions to obtain a second zirconium hydroxide gel; then heat and reflux and statically age the second zirconium hydroxide gel in sequence to obtain a third zirconium hydroxide gel;

[0012] (5) Perform a hydrothermal reaction on the third zirconium hydroxide gel, and after fully reacting, filter, wash and dry the obtained mixture in sequence to obtain a solid;

[0013] (6) High-temperature calcine the solid in an inert atmosphere and then grind it to obtain modified zirconia.

[0014] Preferably, in step (1), the alkali is one or a combination of two or more of urea, ammonia water, sodium hydroxide, and potassium hydroxide;

[0015] and / or, in step (1), the zirconium salt is Zr(NO 3 ) 4 ·5H 2 O, ZrOCl 2 ·8H 2 O, ZrO(NO 3 ) 2 ·xH 2 O, Zr(SO 4 ) 2 ·4H 2 O, ZrCl 4 , Zr(HPO 4 ) 2 , C 8 H 12 O 8 Zr, ZrO 4 C 16 H 36 , C 16 H 36 O 4 Zr, C 6 H 10 O 5 Zr, CH 2 O 7 Zr 2 or a combination of two or more thereof; the concentration of the zirconium salt solution is 0.5 - 5 mol / L;

[0016] and / or, in step (1), the molar ratio of the base to the zirconium salt is 0.2 - 0.5:1;

[0017] and / or, in step (1), the reaction temperature is 40 - 60 °C and the reaction time is 1 - 6 h.

[0018] Preferably, in step (2), the molar ratio of sulfate in the sulfuric acid solution to the zirconium salt is 0.5 - 0.6:1;

[0019] and / or, in step (2), the aging temperature is 40 - 60 °C and the aging time is 1 - 2 h.

[0020] Preferably, in step (3), the metal inorganic salt is YCl 3 ·6H 2 O, H 2 PtCl 6 ·6H 2 O, Fe(NO 3 ) 3 ·9H 2 O, CoCl 2 ·6H 2 O, MnCl 2 ·4H2 O, NiCl 2 ·6H 2 O, SnCl 2 ·2H 2 O, Ce(NO 3 ) 3 ·6H 2 O, TiOSO 4 ·8H 2 O, or a combination of two or more of them; the molar ratio of the metal ion to the zirconium ion is 0.01 - 0.2:1;

[0021] And / or, in step (3), the complexing agent is one of sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, diethylenetriaminepentaacetate, tartaric acid, sodium alginate, sodium gluconate, polyacrylic acid; the molar ratio of the complexing agent to the zirconium ion is 0.1 - 1:1;

[0022] And / or, in step (3), the dispersant is one of polyethylene glycol 200, polyethylene glycol 400, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, cetyltrimethylammonium bromide, triethylhexyl phosphate, methylpentanol; the mass fraction of the dispersant in the aqueous solution is 0.2 - 1%.

[0023] Preferably, in step (4), the organic base structure regulator is one of imidazole, 4-dimethylaminopyridine, 1-methylpiperidine, 2-aminopyrimidine, guanidine carbonate, N-methylmorpholine, tetramethylammonium hydroxide, 1,5-diazabicyclo[4.3.0]-5-nonene; the pH of the system is adjusted to 4 - 10;

[0024] And / or, in step (4), the temperature of the heating reflux is 50 - 80°C, and the time of the heating reflux is 3 - 5 h;

[0025] And / or, in step (4), the time of the static aging is 1 - 9 h.

[0026] Preferably, in step (5), the temperature of the hydrothermal reaction is 120 - 200°C, and the time of the hydrothermal reaction is 300 - 800 min;

[0027] And / or, in step (5), the temperature of the drying is 80 - 120°C, and the time of the drying is 8 - 12 h.

[0028] Preferably, in step (6), the inert atmosphere is a nitrogen atmosphere and / or an argon atmosphere;

[0029] And / or, in step (6), the process of the high-temperature calcination is as follows: heating up to 150 - 550°C at a heating rate of 2 - 5°C / min, holding for 1 - 2 h, then heating up to 800 - 1000°C at a heating rate of 1 - 4°C / min, holding for 1 - 5 h, and subsequently cooling to room temperature.

[0030] The gradient heating can enable the zirconia powder to slowly adapt to the temperature change, reducing the internal stress generated by rapid thermal expansion. The gradient heating can enable some volatile components such as moisture and organic matter residues contained in the powder to be slowly released at different temperature stages. And the slow heating is also conducive to the growth inside the crystal.

[0031] Another solution of the present invention is to provide a modified zirconia obtained by the above hydrothermal synthesis method.

[0032] The beneficial effects of the present invention are as follows:

[0033] (1) The present invention uses a complexing agent to improve the stability of metal ions in an organic solution, and plays a catalytic role in chemical reactions, accelerating the reaction rate, reducing the reaction temperature and energy consumption. The dispersant can be dissolved in an organic solvent, facilitating the mixing of zirconium and metal ions and uniformly distributing them in the solution. Then, by controlling the pH value of the solution and adding an organic base structural regulator, a zirconium-containing precursor powder without hard agglomeration is obtained, and finally, a nano-powder is obtained through a calcination process. This preparation method can more easily control the particle shape and size, obtain nano-zirconia with a high specific surface area and high thermal stability, and this method is simple to operate, the raw materials are easy to obtain, and it is conducive to industrial production.

[0034] (2) After modification with organic bases, hydroxyl and amino groups exist on the surface of the obtained zirconia, which can be used as an anion conduction medium in an alkaline aqueous solution, and the prepared anion exchange membrane has high density and high electrical properties. Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1 is the XRD pattern of the zirconia prepared in Examples 1 - 5.

[0037] Figure 2 is the FTIR pattern of the zirconia prepared in Examples 1 - 5. Detailed Embodiments

[0038] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0039] Example 1

[0040] This example provides a hydrothermal synthesis method of organo-base modified zirconia. The synthesis method includes the following steps:

[0041] (1) Pour ammonia water into 1 mol / L ZrOCl 2 ·8H 2 O solution. The molar ratio of ammonia water to zirconium oxychloride is 0.5:1. Magnetically stir in a 40°C water bath for 2 h to obtain the first zirconium hydroxide gel.

[0042] (2) Pour 30 wt.% H 2 SO 4 into the first zirconium hydroxide gel. The molar ratio of sulfate radical to zirconium salt is 0.55:1. Keep magnetically stirring and aging in a 60°C water bath for 1 h to obtain a zirconium precursor slurry.

[0043] (3) Mix the zirconium precursor slurry with YCl 3 ·6H 2 O inorganic salt solution evenly, and then add polyethylene glycol 200 dispersant, and continuously stir to obtain a sol-like aqueous solution containing metal ions. The molar ratio of metal ions to zirconium ions is 0.1:1, and the mass fraction of the dispersant in the aqueous solution is 0.2%.

[0044] (4) Slowly add the imidazole aqueous solution to the sol-like aqueous solution containing metal ions at a speed of 0.5 s / drop, and continuously stir to make the pH of the solution = 8 to obtain the second zirconium hydroxide gel. Then transfer the second zirconium hydroxide gel to a reaction kettle, keep it refluxing in an 80°C water bath for 3 h, with a stirring speed of 800 rpm, and finally age for 2 h to obtain the third zirconium hydroxide gel.

[0045] (5) Transfer the third zirconium hydroxide gel to a 300 mL hydrothermal kettle, place it in an oven at 180°C for hydrothermal reaction for 12 h, then wash the obtained zirconia solid by centrifugation until neutral, and place it in a vacuum dryer at 80°C for 12 h to obtain a white powder.

[0046] (6) Heat the white powder to 200 °C at a heating rate of 5 °C / min under a nitrogen atmosphere, hold for 1 h, then heat to 800 °C at a heating rate of 3 °C / min, hold for 5 h, and then cool to room temperature in a muffle furnace to obtain the modified zirconia powder.

[0047] Example 2

[0048] This example provides a hydrothermal synthesis method of organo-base modified zirconia. The synthesis method includes the following steps:

[0049] (1) Pour urea into a 1 mol / L ZrOCl 2 ·8H 2 O solution. The molar ratio of urea to zirconium oxychloride is 0.5:1. Stir magnetically in a 50 °C water bath for 1 h to obtain the first zirconium hydroxide gel.

[0050] (2) Pour 30 wt.% H 2 SO 4 into the first zirconium hydroxide gel. The molar ratio of sulfate to zirconium salt is 0.5:1. Keep stirring and aging in a 40 °C water bath for 1.5 h to obtain the zirconium precursor slurry.

[0051] (3) Mix the zirconium precursor slurry with a YCl 3 ·6H 2 O inorganic salt solution evenly, and then add a polyacrylic acid complexing agent. Keep stirring to obtain a sol-like aqueous solution containing metal ions. The molar ratio of metal ions to zirconium ions is 0.1:1, and the molar ratio of the complexing agent to zirconium ions is 0.1:1.

[0052] (4) Slowly add the 1-methylpiperidine aqueous solution to the sol-like aqueous solution containing metal ions at a rate of 0.2 s / drop. Keep stirring to make the pH of the solution = 10 to obtain the second zirconium hydroxide gel. Then transfer the second zirconium hydroxide gel to a reaction kettle, keep it refluxing in a 60 °C water bath for 2 h, with a stirring speed of 600 rpm, and finally age for 1 h to obtain the third zirconium hydroxide gel.

[0053] (5) Transfer the third zirconium hydroxide gel to a 300 mL hydrothermal kettle, place it in an oven at 180 °C for hydrothermal reaction for 8 h, then wash the obtained zirconia solid by centrifugation until it is neutral, and dry it in a vacuum at 120 °C for 12 h to obtain a white powder.

[0054] (6) Heat the white powder to 150 °C at a heating rate of 4 °C / min under a nitrogen atmosphere, hold for 2 h, then heat to 800 °C at a heating rate of 3 °C / min, hold for 5 h, and then cool to room temperature in a muffle furnace to obtain the modified zirconia powder.

[0055] Example 3

[0056] This embodiment provides a hydrothermal synthesis method of organo-base modified zirconia, and the synthesis method includes the following steps:

[0057] (1) Pour ammonia water into 1 mol / L ZrOCl 2 ·8H 2 O solution. The molar ratio of ammonia water to zirconium oxychloride is 0.5:1. Magnetically stir for 1 h in a 50 °C water bath to obtain the first zirconium hydroxide gel;

[0058] (2) Pour 30 wt.% H 2 SO 4 into the first zirconium hydroxide gel. The molar ratio of sulfate radical to zirconium salt is 0.5:1. Keep magnetically stirring and aging for 2 h in a 40 °C water bath to obtain a zirconium precursor slurry;

[0059] (3) Mix the zirconium precursor slurry with YCl 3 ·6H 2 O inorganic salt solution evenly, then add polyethylene glycol 200 dispersant and polyacrylic acid complexing agent, and continuously stir to obtain a sol-like aqueous solution containing metal ions; the molar ratio of metal ions to zirconium ions is 0.1:1, the mass fraction of the dispersant in the aqueous solution is 0.2%, and the molar ratio of the complexing agent to zirconium ions is 0.2:1;

[0060] (4) Slowly add 4-dimethylaminopyridine aqueous solution to the sol-like aqueous solution containing metal ions at a speed of 0.5 s / drop, and continuously stir to make the pH of the solution = 10 to obtain the second zirconium hydroxide gel; then transfer the second zirconium hydroxide gel to a reaction kettle, keep it refluxing in an 80 °C water bath for 2 h, the stirring speed is 800 rpm, and finally age for 5 h to obtain the third zirconium hydroxide gel;

[0061] (5) Transfer the third zirconium hydroxide gel to a 300 mL hydrothermal kettle, place it in an oven at 180 °C for hydrothermal reaction for 8 h, then wash the obtained zirconia solid by centrifugation until it is neutral, and put it in a vacuum dryer at 80 °C for 8 h to obtain a white powder;

[0062] (6) Under a nitrogen atmosphere, heat the white powder to 200 °C at a heating rate of 4 °C / min, keep it warm for 2 h, then heat it to 800 °C at a heating rate of 3 °C / min, keep it warm for 8 h, and then cool it to room temperature in a muffle furnace to obtain the modified zirconia powder.

[0063] Example 4

[0064] This embodiment provides a hydrothermal synthesis method of organo-base modified zirconia, and the synthesis method includes the following steps:

[0065] (1) Pour urea into 1 mol / L ZrOCl 2 ·8H 2 O solution, with the molar ratio of urea to zirconium oxychloride being 0.5:1, and magnetically stir in a 60 °C water bath for 1 h to obtain the first zirconium hydroxide gel;

[0066] (2) Pour 20 wt.% H 2 SO 4 into the first zirconium hydroxide gel, with the molar ratio of sulfate radical to zirconium salt being 0.6:1, and keep magnetically stirring and aging in a 40 °C water bath for 2 h to obtain a zirconium precursor slurry;

[0067] (3) Mix the zirconium precursor slurry evenly with YCl 3 ·6H 2 O inorganic salt solution, then add methyl pentanol dispersant, and continuously stir to obtain a sol-like aqueous solution containing metal ions; the molar ratio of metal ions to zirconium ions is 0.1:1, and the mass fraction of the dispersant in the aqueous solution is 0.2%;

[0068] (4) Slowly add aqueous tetramethylammonium hydroxide solution to the sol-like aqueous solution containing metal ions at a rate of 0.5 s / drop, and continuously stir to make the pH of the solution = 10 to obtain the second zirconium hydroxide gel; then transfer the second zirconium hydroxide gel to a reaction kettle, keep it refluxing in an 80 °C water bath for 2 h, with a stirring speed of 800 rpm, and finally age for 3 h to obtain the third zirconium hydroxide gel;

[0069] (5) Transfer the third zirconium hydroxide gel to a 300 mL hydrothermal kettle, place it in an oven at 160 °C for hydrothermal reaction for 8 h, then wash the obtained zirconia solid by centrifugation until it is neutral, and place it in a 100 °C vacuum dryer for 12 h to obtain a white powder;

[0070] (6) Under a nitrogen atmosphere, heat the white powder to 250 °C at a heating rate of 4 °C / min, keep it for 2 h, then heat it to 900 °C at a heating rate of 3 °C / min, keep it for 12 h, and then cool it to room temperature in a muffle furnace to obtain the modified zirconia powder.

[0071] Example 5

[0072] This example provides a hydrothermal synthesis method for organo-base modified zirconia, and the synthesis method includes the following steps:

[0073] (1) Pour ammonia water into 1 mol / L ZrOCl 2 ·8H 2 O solution, with the molar ratio of ammonia water to zirconium oxychloride being 0.5:1, and magnetically stir in a 50 °C water bath for 1.5 h to obtain the first zirconium hydroxide gel;

[0074] (2) Pour 20 wt.% of H 2 SO 4 into the first zirconium hydroxide gel, with the molar ratio of sulfate radical to zirconium salt being 0.5:1. Keep it magnetically stirred and aged in a 40°C water bath for 2 h to obtain a zirconium precursor slurry;

[0075] (3) Mix the zirconium precursor slurry uniformly with an inorganic salt solution of YCl 3 ·6H 2 O, and then add polyethylene glycol 200 dispersant. Continuously stir to obtain a sol-like aqueous solution containing metal ions; the molar ratio of metal ions to zirconium ions is 0.1:1, and the mass fraction of the dispersant in the aqueous solution is 0.2%;

[0076] (4) Slowly add an aqueous solution of 1,5-diazabicyclo[4.3.0]-5-nonene (DBN) to the sol-like aqueous solution containing metal ions at a rate of 0.5 s / drop, and continuously stir to make the pH of the solution = 10 to obtain a second zirconium hydroxide gel; then transfer the second zirconium hydroxide gel to a reaction kettle, keep it refluxed in an 80°C water bath for 2 h, with a stirring speed of 800 rpm, and finally age for 5 h to obtain a third zirconium hydroxide gel;

[0077] (5) Transfer the third zirconium hydroxide gel to a 300 mL hydrothermal kettle, place it in an oven at 180°C for hydrothermal reaction for 12 h, then wash the obtained zirconia solid by centrifugation until it is neutral, and place it in a vacuum dryer at 120°C for 12 h to obtain a white powder;

[0078] (6) Under a nitrogen atmosphere, heat the white powder to 200°C at a heating rate of 4°C / min, keep it for 1 h, then heat it to 800°C at a heating rate of 3°C / min, keep it for 12 h, and then cool it to room temperature in a muffle furnace to obtain a modified zirconia powder.

[0079] Comparative Example 1

[0080] (1) Pour ammonia water into 1 mol / L ZrOCl 2 ·8H 2 O, with the molar ratio of ammonia water to zirconium oxychloride being 0.5:1. Magnetically stir in a 40°C water bath for 2 h to obtain a first zirconium hydroxide gel;

[0081] (2) Then pour 30 wt.% H 2 SO 4 into the first zirconium hydroxide gel, with the molar ratio of sulfate radical to zirconium salt being 0.55:1. Keep it magnetically stirred and aged in a 60°C water bath for 1 h to obtain a zirconium precursor slurry;

[0082] (3) Add polyethylene glycol 200 to the zirconium precursor slurry. The mass fraction of the dispersant in the aqueous solution is 0.2%, and continuously stir to obtain the second zirconium hydroxide gel;

[0083] (4) Transfer the second zirconium hydroxide gel to a reaction kettle, maintain reflux in a water bath at 80 °C for 3 h, and the stirring speed is 800 rpm to obtain the third zirconium hydroxide gel;

[0084] (5) Transfer the third zirconium hydroxide gel to a 300 mL hydrothermal kettle, place it in an oven at 180 °C for hydrothermal reaction for 12 h, then centrifuge and wash the zirconia solid obtained by hydrothermal treatment until it is neutral, and place it in a vacuum dryer at 80 °C for 12 h to obtain a white powder;

[0085] (6) Under a nitrogen atmosphere, heat the white powder to 200 °C at a heating rate of 5 °C / min, hold for 1 h, then heat to 800 °C at a heating rate of 3 °C / min, hold for 6 h, and then cool the muffle furnace to room temperature to obtain zirconia powder.

[0086] Verification example

[0087] (I) Preparation of a composite separator

[0088] (1) At room temperature, disperse 10 g of polysulfone (PSF) and 40 g of the zirconia powder obtained in Examples 1-5 and Comparative Example 1 in 50 g of N-methyl-2-pyrrolidone (NMP), and perform high-speed stirring through a ball mill to obtain a uniform and stable casting solution.

[0089] (2) Knife-coat the obtained casting solution on a clean glass plate, and then slowly immerse it in deionized water at room temperature to complete phase inversion. Immerse the above-obtained membrane in deionized water for 24 h to fully remove the residual solvent in the membrane, and finally prepare a polysulfone-ZrO 2 Composite separator with a membrane thickness of 500 μm.

[0090] The test results are shown in Tables 1 and 2.

[0091] Table 1

[0092] Group Average particle size <![CDATA[Specific surface area (m 2 / g)]]> Example 1 27.1 281.4 Example 2 28.3 223.9 Example 3 29.2 291.1 Example 4 21.1 287.2 Example 5 26.1 229.3 Comparative Example 1 40.4 101.5

[0093] Table 2

[0094] Group <![CDATA[Sheet resistance (Ω·cm 2 )]]> <![CDATA[Current density at 2.1 V (A·m -2 )]]> Example 1 0.25 6400 Example 2 0.26 6200 Example 3 0.23 6500 Example 4 0.24 6800 Example 5 0.22 7200 Comparative Example 1 0.44 4200

[0095] As can be seen from Tables 1 and 2: For the samples prepared in this example, the average particle size obtained is 20-30 nm, and the specific surface area is 200-300 m 2Zirconia powder of / g. The composite separator prepared in the example has a smaller surface resistance and a larger current density under the same voltage condition compared with the composite separator prepared in the comparative example.

[0096] (2) XRD and FTIR Characterization

[0097] Figure 1 Figure 1 is the XRD pattern of zirconia prepared in Examples 1-5. Figure 2 Figure 2 is the FTIR pattern of zirconia prepared in Examples 1-5.

[0098] From Figure 1 and Figure 2 it can be seen that the nano-zirconia powder prepared by the hydrothermal method has good crystallization performance, and the crystal form of zirconia is tetragonal. FTIR characterization proves the formation of amino groups after the modification of zirconia powder with organic bases.

[0099] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A hydrothermal synthesis method for organic base modified zirconium dioxide, characterized in that: The synthesis method comprises the following steps: (1) dissolving alkali in a zirconium salt solution and reacting the solution sufficiently to obtain a first zirconium hydroxide gel; (2) uniformly mixing the first zirconium hydroxide gel and the sulfuric acid solution, and aging to obtain a zirconium precursor slurry; (3) mixing the zirconium precursor slurry and the metal inorganic salt solution uniformly, adding a complexing agent and / or a dispersant, and mixing uniformly to obtain a sol-like aqueous solution containing metal ions; (4) adding an aqueous solution containing an organic base structure regulator to the sol-like aqueous solution containing metal ions to obtain a second zirconium hydroxide gel; and then heating the second zirconium hydroxide gel to reflux and standing for aging to obtain a third zirconium hydroxide gel; (5) subjecting the third zirconium hydroxide gel to a hydrothermal reaction, and after sufficient reaction, filtering, washing and drying the obtained mixed solution in sequence to obtain a solid; (6) The solid is calcined at a high temperature under an inert atmosphere and then ground to obtain modified zirconium dioxide.

2. The hydrothermal synthesis method of organic base modified zirconium dioxide according to claim 1, characterized in that: In step (1), the base is one or a combination of two or more of urea, ammonia water, sodium hydroxide and potassium hydroxide; And / or, in step (1), the zirconium salt is Zr(NO3)4·5H2O, ZrOCl2·8H2O, ZrO(NO3)2·xH2O, Zr(SO4)2·4H2O, ZrCl4, Zr(HPO4)2, C8H 12 O8Zr、ZrO4C 16 H 36 , C 16 H 36 O4Zr、C6H 10 O5Zr, CH2O7Zr2 or a combination of two or more thereof; the concentration of the zirconium salt solution is 0.5-5 mol / L; And / or, in step (1), the molar ratio of the base to the zirconium salt is 0.2 to 0.5:1; And / or, in step (1), the reaction temperature is 40-60° C., and the reaction time is 1-6 hours.

3. The hydrothermal synthesis method of organic base modified zirconium dioxide according to claim 1, characterized in that: In step (2), the molar ratio of sulfate to zirconium salt in the sulfuric acid solution is 0.5-0.6:1; And / or, in step (2), the aging temperature is 40-60° C., and the aging time is 1-2 hours.

4. The hydrothermal synthesis method of organic base modified zirconium dioxide according to claim 1, characterized in that: In step (3), the metal inorganic salt is one or a combination of two or more of YCl3·6H2O, H2PtCl6·6H2O, Fe(NO3)3·9H2O, CoCl2·6H2O, MnCl2·4H2O, NiCl2·6H2O, SnCl2·2H2O, Ce(NO3)3·6H2O, TiOSO4·8H2O; the molar ratio of metal ions to zirconium ions is 0.01 to 0.2:1; And / or, in step (3), the complexing agent is one of sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, diethylenetriamine pentacarboxylate, tartaric acid, sodium alginate, sodium gluconate, and polyacrylic acid; the molar ratio of the complexing agent to the zirconium ion is 0.1 to 1:1; And / or, in step (3), the dispersant is one of polyethylene glycol 200, polyethylene glycol 400, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide, triethylhexyl phosphoric acid, and methylpentanol; and the mass fraction of the dispersant in the aqueous solution is 0.2-1%.

5. The hydrothermal synthesis method of organic base modified zirconium dioxide according to claim 1, characterized in that: In step (4), the organic base structure regulator is one of imidazole, 4-dimethylaminopyridine, 1-methylpiperidine, 2-aminopyrimidine, guanidine carbonate, N-methylmorpholine, tetramethylammonium hydroxide, and 1,5-diazabicyclo[4.3.0]-5-nonene; the pH of the system is adjusted to 4-10; And / or, in step (4), the heating reflux temperature is 50 to 80° C., and the heating reflux time is 3 to 5 hours; And / or, in step (4), the static aging time is 1 to 9 hours.

6. The hydrothermal synthesis method of organic base modified zirconium dioxide according to claim 1, characterized in that: In step (5), the temperature of the hydrothermal reaction is 120 to 200° C., and the time of the hydrothermal reaction is 300 to 800 min; And / or, in step (5), the drying temperature is 80-120° C., and the drying time is 8-12 hours.

7. The hydrothermal synthesis method of organic base modified zirconium dioxide according to claim 1, characterized in that: In step (6), the inert atmosphere is a nitrogen atmosphere and / or an argon atmosphere; And / or, in step (6), the high temperature calcination process is: heating to 150-550°C at a heating rate of 2-5°C / min, keeping warm for 1-2h, then heating to 800-1000°C at a heating rate of 1-4°C / min, keeping warm for 1-5h, and then cooling to room temperature.

8. Modified zirconium dioxide obtained by the hydrothermal synthesis method according to any one of claims 1 to 7.

Images