Oxidized starch / zirconium halide perovskite nanocomposite tanning agent and its preparation method and application

Abstract

The present invention discloses an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, its preparation method, and application, belonging to the technical field of leather tanning agents. The preparation method disclosed in the present invention uses oxidized starch / zirconium halide perovskite, which is a nanocrystal composed of zirconium metal ions, cesium metal ions, chloride ions, or bromide ions, with oxidized starch, oleic acid, and oleylamine as ligands. The zirconium ions and oxidized starch can play a tanning role, and the ligands can also act as self-masking agents to inhibit the hydrolysis of zirconium, slowing down the phenomenon of surface over-tanning. This improves the thickening rate of tanned crust leather while achieving zirconium tanning, and imparts a comfortable feel to the crust leather.

Description

Technical Field

[0001] The present invention belongs to the technical field of leather tanning agents, and in particular relates to an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, a preparation method thereof, and an application thereof. Background Art

[0002] The leather industry is a vital livelihood industry closely linked to agriculture, rural areas, and farmers, and a traditional pillar of the light industry with international competitive advantages. Tanning is the most critical process in leathermaking, transforming raw hides into leather. Chrome tanning is the most important and widely used tanning method in leather manufacturing, imparting excellent finished leather properties to crust leather and currently holding an absolute dominant position in the leather industry. However, in traditional chrome tanning processes, the absorption rate of chrome tanning agents is typically only around 70%, resulting in the production of highly concentrated chromium-containing wastewater. This not only increases environmental pollution and wastewater treatment costs, but also results in significant resource waste. Compared to traditional chrome-tanned leather, the production process of chrome-free leather is cleaner and more environmentally friendly. Therefore, promoting green development in the leather industry requires chrome-free tanning. Zirconium tanning agents offer similar tanning effects to chrome tanning agents and are considered an ideal alternative. Zirconium-tanned leather has a firm grain, good filling properties, and excellent abrasion resistance. However, the leather is rigid, and the strong hydrolysis and polymerization of zirconium salts causes them to deposit unevenly on the leather surface, resulting in surface over-tanning, which limits the application of zirconium tanning agents. Starch is a natural, widely available, renewable polysaccharide biomass. Modified with functional groups such as aldehydes and carboxyls, it can form strong crosslinks with hide collagen, providing certain tanning properties. However, starch-based tanning agents alone do not provide sufficient crosslinking with hide collagen, necessitating their use in conjunction with metal salts. Summary of the Invention

[0003] The purpose of the present invention is to provide an oxidized starch / zirconium halide perovskite nanocomposite tanning agent and its preparation method and application, so as to solve the technical problem of surface over-tanning when using zirconium tanning agent.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention discloses a method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, comprising the following steps:

[0006] A zirconium-based metal salt, a cesium-based metal salt, and an acidic organic solvent are mixed and placed in a water bath container for heating reaction to obtain a product; oleic acid and oleylamine ligands are added to the product for reaction to obtain a zirconium halide perovskite precursor solution after the reaction is completed;

[0007] Adding corn starch, sodium periodate and an acidic solution to a zirconium halide perovskite precursor solution, heating the mixture for reaction, and then post-treating the obtained product to obtain oxidized starch / zirconium halide perovskite;

[0008] The oxidized starch / zirconium halide perovskite is compounded with a zirconium salt tanning agent to obtain an oxidized starch / zirconium halide perovskite nanocomposite tanning agent.

[0009] Furthermore, the temperature for the heating reaction in the water bath container is 30-60° C., and the time is 30-90 min; magnetic stirring is used during the heating reaction in the water bath container; and the time for adding oleic acid and oleylamine ligands to the product to react is 10-50 min.

[0010] Furthermore, the zirconium-based metal salt is one of zirconium chloride or zirconium bromide; the cesium-based metal salt is cesium chloride or cesium bromide; the acidic organic solvent is obtained by mixing an acidic solute and a solvent; the solvent is hexadecene or octadecene; the acidic solute is one of formic acid and lactic acid; and the pH of the acidic organic solvent is 1 to 3.

[0011] Furthermore, the mass volume ratio of the zirconium-based metal salt, the cesium-based metal salt, the solvent and the acidic solute is 2g:1g:(2-6)mL:(40-60)mL.

[0012] Furthermore, the mass volume ratio of the zirconium-based metal salt, oleic acid and oleylamine is 1 g:2 mL:(6-12 mL).

[0013] Furthermore, when preparing oxidized starch / zirconium halide perovskite, the heating reaction temperature is 38~45°C and the time is 30~90 min; magnetic stirring is performed during the heating reaction, and the magnetic stirring speed is 30~800 r / min.

[0014] Furthermore, the mass ratio of the zirconium-based metal salt, corn starch and sodium periodate is (2-6): (1-2): (2-3); the amount of the acidic solution added is until the pH of the solution is 2-3;

[0015] The post-treatment includes centrifugation, washing and drying; the centrifugation time is 8 to 40 minutes; the washing is performed 1 to 4 times with a non-polar solvent; the non-polar washing solvent is chloroform or n-hexane.

[0016] Furthermore, the mass ratio of the oxidized starch / zirconium halide perovskite to the zirconium salt tanning agent is 1:2 to 2:1; the zirconium salt tanning agent is zirconium sulfate, zirconium chloride or zirconium oxychloride;

[0017] The compounding is achieved by grinding and ball milling for 30 to 240 minutes.

[0018] The invention also discloses an oxidized starch / zirconium halide perovskite nano-composite tanning agent prepared by the above preparation method.

[0019] The present invention also discloses the use of the above-mentioned oxidized starch / zirconium halide perovskite nanocomposite tanning agent in leather tanning, comprising the following steps:

[0020] Add acid hide and water in a mass ratio of 1:1~1:3 into a rotating drum, then add 8%~10% of the mass of the acid hide and 10% acetic acid solution, adjust the bath liquid to pH 1.0~3.5 for the first time, and rotate for 60 min; add 3%~15% of the mass of the acid hide oxidized starch / zirconium halide perovskite nanocomposite tanning agent to the bath liquid, and rotate for 3~10 h; then adjust the bath liquid pH to 5.5~9.0 for the second time with 10% sodium bicarbonate solution, and rotate for 45 min; heat to 35~40℃, rotate for 3 h, let stand for 12 h, rotate for another 60 min, and wash with water.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The invention discloses a method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent. The oxidized starch / zirconium halide perovskite used is a nanocrystal composed of zirconium metal ions, cesium metal ions, chloride ions or bromide ions with oxidized starch, oleic acid and oleylamine as ligands. The zirconium ions and oxidized starch can play a tanning role. In addition, the ligands can act as self-masking agents to inhibit the hydrolysis of zirconium and slow down the over-tanning phenomenon on the surface. On the basis of achieving zirconium tanned leather, the thickening rate of the tanned crust leather is increased and the crust leather is given a comfortable feel.

[0023] Furthermore, the method disclosed in the present invention adopts a one-pot method to prepare oxidized starch / zirconium halide perovskite nano-composite tanning agent, which is simple to operate and easy to repeat. When applied to leather tanning, it can give the raw leather excellent thermal stability, comfortable feel, good filling properties, etc., which is conducive to promoting the green process of the leather making industry.

[0024] The present invention also discloses an oxidized starch / zirconium halide perovskite nanocomposite tanning agent prepared by the above-mentioned preparation method. In the present invention, the oxidized starch / zirconium halide perovskite and the metal salt tanning agent can achieve efficient synergistic tanning; the presence of the metal salt tanning agent can not only play a tanning role, but also inhibit the hydrolysis of the perovskite, maintain the perovskite nanocrystalline structure, and enable the tanning agent to better penetrate into the leather fibers, thereby further improving the leather performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a comparison chart of the shrinkage temperature and thickening rate of the crust leather after tanning with zirconium sulfate tanning, using the oxidized starch / zirconium halide perovskite nanocomposite tanning agent in Example 2 for sheepskin tanning. DETAILED DESCRIPTION

[0026] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0027] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0028] All features, such as values, amounts, contents, and concentrations, described herein as numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0029] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0030] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0031] The present invention provides a method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, comprising the following steps:

[0032] Step 1: Prepare a zirconium halide perovskite precursor solution: add a zirconium-based metal salt and a cesium-based metal salt to a flask containing an acidic organic solvent, heat in a water bath at 30-60°C, stir magnetically, and react for 30-90 minutes to obtain a uniform and transparent solution, then add oleic acid and oleylamine ligands, react for 10-50 minutes, and obtain a white turbid zirconium halide perovskite precursor solution;

[0033] Step 2: Preparation of oxidized starch / zirconium halide perovskite: Add corn starch, sodium periodate, and a small amount of acidic solution to the precursor solution of step 1, heat in a water bath at 38-45°C, and stir magnetically. After reacting for 30-90 minutes, stop heating and stirring, cool the product, and centrifuge for 8-40 minutes. Take the bottom precipitate, wash it with a non-polar solvent for 1-4 times, and dry it at room temperature to obtain oxidized starch / zirconium halide perovskite.

[0034] Step 3. Preparation of oxidized starch / zirconium halide perovskite nanocomposite tanning agent: Compound the oxidized starch / zirconium halide perovskite in step 2 with the zirconium salt tanning agent, and obtain an oxidized starch / zirconium halide perovskite nanocomposite tanning agent after 30 to 240 minutes of compounding with the aid of grinding and ball milling.

[0035] The present invention also discloses the use of the above-mentioned oxidized starch / zirconium halide perovskite nanocomposite tanning agent in leather tanning, comprising the following steps:

[0036] Add acid hide and water in a mass ratio of 1:1~1:3 into a rotating drum, then add 8%~10% of the mass of the acid hide and 10% acetic acid solution, adjust the bath solution to pH 1.0~3.5 for the first time, and rotate for 60 min; add 3%~15% of the mass of the acid hide to the bath solution oxidized starch / zirconium halide perovskite nanocomposite tanning agent, and rotate for 3~10 h; then adjust the bath solution pH to 5.5~9.0 for the second time with 10% sodium bicarbonate solution, and rotate for 45 min; heat to 35~40℃, rotate for 3 h, let it stand overnight, rotate for 60 min the next day, and wash with water.

[0037] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0038] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0039] Example 1

[0040] A method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent comprises the following steps:

[0041] 800 mg of zirconium bromide and 400 mg of cesium bromide were added to a flask containing formic acid and hexadecene, heated in a water bath at 30°C with magnetic stirring, and reacted for 30 min to obtain a homogeneous and transparent solution. Oleic acid and oleylamine ligands were then added and reacted for 20 min to obtain a white turbid zirconium halide perovskite precursor solution. The mass volume ratio of zirconium bromide, cesium bromide, formic acid, hexadecene, oleic acid, and oleylamine was 2 g:1 g:2 mL:30 mL:4 mL:12 mL.

[0042] 400 mg corn starch, 800 mg sodium periodate and a small amount of dilute hydrochloric acid with a pH of 2 were added to the zirconium halide perovskite precursor solution, heated in a water bath at 38°C with magnetic stirring, and reacted for 30 minutes. The heating and stirring were then stopped, and the product was cooled and centrifuged for 15 minutes. The bottom precipitate was collected and washed twice with n-hexane and dried at room temperature to obtain oxidized starch / zirconium halide perovskite.

[0043] Oxidized starch / zirconium halide perovskite is compounded with zirconium chloride and ground for 30 minutes to obtain an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, wherein the mass ratio of oxidized starch / zirconium halide perovskite to zirconium salt tanning agent is 1:1.

[0044] Example 2

[0045] A method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent comprises the following steps:

[0046] 600 mg of zirconium chloride and 300 mg of cesium chloride were added to a flask containing formic acid and octadecene, heated in a water bath at 45°C with magnetic stirring, and reacted for 30 min to obtain a homogeneous and transparent solution. Oleic acid and oleylamine ligands were then added and reacted for 60 min to obtain a white turbid zirconium halide perovskite precursor solution. The mass volume ratio of zirconium chloride, cesium chloride, formic acid, octadecene, oleic acid, and oleylamine was 2 g:1 g:4 mL:60 mL:4 mL:16 mL.

[0047] 200 mg of corn starch, 300 mg of sodium periodate and a small amount of dilute hydrochloric acid with a pH of 2 were added to the zirconium halide perovskite precursor solution, heated in a water bath at 40°C and magnetically stirred, and reacted for 60 minutes. The heating and stirring were then stopped, and the product was cooled and centrifuged for 20 minutes. The bottom precipitate was collected and washed with chloroform three times, and dried at room temperature to obtain oxidized starch / zirconium halide perovskite.

[0048] Oxidized starch / zirconium halide perovskite is compounded with zirconium chloride and ground for 30 minutes to obtain an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, wherein the mass ratio of the oxidized starch / zirconium halide perovskite to the zirconium salt tanning agent is 2:1.

[0049] Example 3

[0050] A method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent comprises the following steps:

[0051] 400 mg of zirconium chloride and 200 mg of cesium chloride were added to a flask containing lactic acid and hexadecene, heated in a water bath at 60°C with magnetic stirring, and reacted for 90 min to obtain a homogeneous and transparent solution. Oleic acid and oleylamine ligands were then added and reacted for 40 min to obtain a white turbid zirconium halide perovskite precursor solution. The mass volume ratio of zirconium chloride, cesium chloride, formic acid, hexadecene, oleic acid, and oleylamine was 2 g:1 g:6 mL:90 mL:4 mL:20 mL.

[0052] 150 mg of corn starch, 300 mg of sodium periodate and a small amount of dilute sulfuric acid with a pH of 3 were added to the zirconium halide perovskite precursor solution, heated in a water bath at 45°C and magnetically stirred, and reacted for 90 minutes. The heating and stirring were then stopped, and the product was cooled and centrifuged for 30 minutes. The bottom precipitate was collected and washed with n-hexane four times, and dried at room temperature to obtain oxidized starch / zirconium halide perovskite.

[0053] Oxidized starch / zirconium halide perovskite is compounded with zirconium chloride and ground for 60 minutes to obtain an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, wherein the mass ratio of the oxidized starch / zirconium halide perovskite to the zirconium salt tanning agent is 1:1.

[0054] Example 4

[0055] A method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent comprises the following steps:

[0056] 400 mg of zirconium chloride and 200 mg of cesium chloride were added to a flask containing lactic acid and hexadecene, heated in a water bath at 60°C with magnetic stirring, and reacted for 90 min to obtain a homogeneous and transparent solution. Oleic acid and oleylamine ligands were then added and reacted for 40 min to obtain a white turbid zirconium halide perovskite precursor solution. The mass volume ratio of zirconium chloride, cesium chloride, hexadecene, formic acid, lactic acid, oleic acid, and oleylamine was 2 g:1 g:2 mL:40 mL:4 mL:24 mL.

[0057] 150 mg of corn starch, 300 mg of sodium periodate and a small amount of dilute sulfuric acid with a pH of 3 were added to the zirconium halide perovskite precursor solution, heated in a water bath at 38°C with magnetic stirring, and reacted for 90 minutes. The heating and stirring were then stopped, and the product was cooled and centrifuged for 30 minutes. The bottom precipitate was collected and washed with n-hexane four times, and dried at room temperature to obtain oxidized starch / zirconium halide perovskite.

[0058] Oxidized starch / zirconium halide perovskite is compounded with zirconium chloride and ground for 60 minutes to obtain an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, wherein the mass ratio of the oxidized starch / zirconium halide perovskite to the zirconium salt tanning agent is 2:1.

[0059] Application Example 1

[0060] Leather tanning is carried out using the oxidized starch / zirconium halide perovskite nanocomposite tanning agent prepared in Example 1, comprising the following steps:

[0061] Add acid leather and water in a mass ratio of 1:1 into a rotating drum, then add sodium chloride with a concentration of 9% of the acid leather mass and acetic acid solution with a concentration of 10%, adjust the bath liquid to pH 2.5 for the first time, and rotate for 60 minutes; add oxidized starch / zirconium halide perovskite nanocomposite tanning agent with a concentration of 5% of the acid leather mass to the bath liquid, and rotate for 4 hours; then adjust the bath liquid pH to 6.0 for the second time with a concentration of 10% sodium bicarbonate solution, and rotate for 45 minutes; heat to 35℃, rotate for 3 hours, let it stand overnight, rotate for 60 minutes the next day, and wash with water.

[0062] Application Example 2

[0063] Leather tanning is carried out using the oxidized starch / zirconium halide perovskite nanocomposite tanning agent prepared in Example 2, comprising the following steps:

[0064] Add acid hide and water in a mass ratio of 1:2 into a rotary drum, then add 9% sodium chloride by mass of the acid hide and 10% acetic acid solution, adjust the bath liquid to pH 3.0 for the first time, and rotate for 60 min; add 10% oxidized starch / zirconium halide perovskite nanocomposite tanning agent by mass of the acid hide to the bath liquid, and rotate for 6 h; then adjust the bath liquid pH to 7.0 for the second time with 10% sodium bicarbonate solution, and rotate for 45 min; heat to 35°C, rotate for 3 h, let stand overnight, rotate for 60 min the next day, and wash with water.

[0065] Application Example 3

[0066] Leather tanning is carried out using the oxidized starch / zirconium halide perovskite nanocomposite tanning agent prepared in Example 3, comprising the following steps:

[0067] Add acid leather and water in a mass ratio of 1:3 into a rotating drum, then add sodium chloride with a concentration of 9% of the acid leather mass and acetic acid solution with a concentration of 10%, adjust the bath liquid to pH 3.0 for the first time, and rotate for 60 minutes; add oxidized starch / zirconium halide perovskite nanocomposite tanning agent with a concentration of 15% of the acid leather mass to the bath liquid, and rotate for 10 hours; then adjust the bath liquid pH to 8.0 for the second time with a concentration of 10% sodium bicarbonate solution, and rotate for 45 minutes; heat to 40℃, rotate for 3 hours, let it stand overnight, rotate for 60 minutes the next day, and wash with water.

[0068] Oxidized starch / zirconium halide perovskite has an ionic structure. Zirconium ions and oxidized starch with excellent tanning functions are introduced into the perovskite structure to make it a high-efficiency leather tanning agent. When combined with a zirconium salt tanning agent, an oxidized starch / zirconium halide perovskite nanocomposite tanning agent can be obtained, further improving the water resistance and stability of the perovskite and the tanning properties of the tanning agent.

[0069] Figure 1 This graph compares the shrinkage temperature and thickening rate of sheepskin tanned with the oxidized starch / zirconium halide perovskite nanocomposite tanning agent used in Example 2, compared to that of leather tanned with zirconium sulfate. The graph shows that the oxidized starch / zirconium halide perovskite nanocomposite tanning agent achieves the highest shrinkage temperature and the best thickening rate, demonstrating its optimal moisture and heat stability and a fuller feel.

[0070] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent, characterized in that: The following steps are involved: A zirconium-based metal salt, a cesium-based metal salt and an acidic organic solvent are mixed and placed in a water bath container for heating reaction to obtain a product; adding oleic acid and oleylamine ligand to the product to react, and obtaining a zirconium halide perovskite precursor solution after the reaction is completed; Adding corn starch, sodium periodate and an acidic solution to a zirconium halide perovskite precursor solution, heating the mixture for reaction, and then post-treating the obtained product to obtain oxidized starch / zirconium halide perovskite; The oxidized starch / zirconium halide perovskite is compounded with a zirconium salt tanning agent to obtain an oxidized starch / zirconium halide perovskite nanocomposite tanning agent.

2. The method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 1, characterized in that: The temperature for the heating reaction in the water bath container is 30-60° C., and the time is 30-90 min. Magnetic stirring is used during the heating reaction in the water bath container. The time for adding oleic acid and oleylamine ligand to the product for the reaction is 10-50 min.

3. The method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 1, characterized in that: The zirconium-based metal salt is one of zirconium chloride and zirconium bromide; the cesium-based metal salt is cesium chloride and cesium bromide; the acidic organic solvent is obtained by mixing an acidic solute and a solvent; the solvent is hexadecene or octadecene; the acidic solute is one of formic acid and lactic acid; and the pH of the acidic organic solvent is 1 to 3.

4. The method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 3, characterized in that: The mass volume ratio of the zirconium-based metal salt, the cesium-based metal salt, the solvent and the acidic solute is 2g:1g:(2-6)mL:(40-60)mL.

5. The method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 1, characterized in that: The mass volume ratio of the zirconium-based metal salt, oleic acid and oleylamine ligand is 1 g:2 mL:(6-12 mL).

6. The method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 1, characterized in that: When preparing oxidized starch / zirconium halide perovskite, the heating reaction temperature is 38-45° C., and the time is 30-90 min. Magnetic stirring is performed during the heating reaction, and the speed of the magnetic stirring is 30-800 r / min.

7. The method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 1, characterized in that: The mass ratio of the zirconium-based metal salt, corn starch and sodium periodate is (2-6): (1-2): (2-3); the amount of the acidic solution added is until the pH of the solution reaches 2-3; The post-processing includes centrifugation, washing and drying; The centrifugal treatment time is 8 to 40 minutes; the washing is performed by washing with a non-polar solvent for 1 to 4 times; the non-polar solvent is chloroform or n-hexane.

8. The method for preparing an oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 1, characterized in that: The mass ratio of the oxidized starch / zirconium halide perovskite to the zirconium salt tanning agent is 1:2 to 2:1; the zirconium salt tanning agent is zirconium sulfate, zirconium chloride or zirconium oxychloride; The compounding is achieved by grinding and ball milling for 30 to 240 minutes.

9. An oxidized starch / zirconium halide perovskite nanocomposite tanning agent, characterized in that: The method is prepared by any one of claims 1 to 8.

10. Use of the oxidized starch / zirconium halide perovskite nanocomposite tanning agent according to claim 9 in leather tanning, characterized in that: The following steps are involved: Add acid hide and water in a mass ratio of 1:1~1:3 into a rotating drum, then add 8%~10% of the mass of the acid hide and 10% acetic acid solution, adjust the bath liquid to pH 1.0~3.5 for the first time, and rotate for 60 min; add 3%~15% of the mass of the acid hide oxidized starch / zirconium halide perovskite nanocomposite tanning agent to the bath liquid, and rotate for 3~10 h; then adjust the bath liquid pH to 5.5~9.0 for the second time with 10% sodium bicarbonate solution, and rotate for 45 min; heat to 35~40℃, rotate for 3 h, let stand for 12 h, rotate for another 60 min, and wash with water.

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