Cobalt-doped cadmium sulfide aerogel material as well as preparation method and application thereof

Abstract

The invention provides a cobalt-doped cadmium sulfide aerogel material and a preparation method and application thereof, and belongs to the technical field of precious metal recovery, the cobalt-doped cadmium sulfide aerogel material comprises chitosan aerogel and cobalt-doped cadmium sulfide loaded on the chitosan aerogel, and the mass ratio of the chitosan aerogel to the cobalt-doped cadmium sulfide is 0.16: (0.1-0.15); the mass ratio of cobalt to cadmium sulfide in the cobalt-doped cadmium sulfide is 0.5: (2-3). According to the method, Co atoms are anchored on the surface of CdS, so that the electron density of active sites on the surface of the material is remarkably improved, the coordination adsorption capacity on gold ions is enhanced, and enrichment and reduction of the gold ions are promoted. And the three-dimensional structure material aerogel is combined, so that the contact efficiency of the material and the gold ions is remarkably improved, and efficient recovery of the gold ions is promoted. The adopted chemical reduction adsorption technology has a good recovery effect on gold in the thiosulfate gold leaching liquid, and the gold recovery rate close to 100% can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of precious metal recovery, and particularly relates to a cobalt-doped cadmium sulfide aerogel material, a preparation method thereof, and an application thereof. Background Art

[0002] With the rapid renewal and replacement of electronic products, the annual global output of electronic waste has exceeded 62 million tons, and it is expected to reach 74 million tons in 2030, with China accounting for more than 30%. The content of precious metals (such as gold, silver, and palladium) in electronic waste is extremely high, far exceeding the ore grade. However, its treatment still relies on traditional processes, resulting in double problems of resource waste and environmental pollution. Although the cyanidation method is mature, the highly toxic cyanide causes great pollution to the environment. The thiosulfate method has been widely studied due to its environmental friendliness and is expected to be applied in actual industrial production.

[0003] Currently, the methods for extracting gold ions from thiosulfate gold leaching solution mainly include: solvent extraction method, ion exchange resin adsorption method, electrolysis method, and chemical reduction method. The solvent extraction method is to use the extractant in the organic phase to coordinate with the gold complex Au(S2O3)2 3- to form a reversible complex to achieve selective separation. However, the extractant has a high cost, is sensitive to pH, and multiple extractions are required to improve the purity; the ion exchange resin adsorption method is to selectively adsorb the gold complex through the functionalized resin, and then recover the gold through the desorbing solution. However, due to the competitive adsorption between the copper ammonia complex and gold, a two-step desorption process is required; moreover, gold often contains a high copper content, thereby reducing the purity of gold. The electrolysis method is to use an inert electrode as the cathode in the electrolytic cell to reduce the gold complex to metallic gold at the cathode. However, this method has high energy consumption, and the decomposition products of thiosulfate are easy to corrode the electrode; the chemical reduction method is to add a reducing agent to directly reduce the gold complex to elemental gold. However, this method requires a large amount of reducing agent, and the by-product sulfur precipitate needs to be treated twice. Currently, the methods for extracting gold ions from thiosulfate gold leaching solution are relatively limited, and each method has certain defects.

[0004] The adsorption method is a method that can recover precious metals in the thiosulfate gold leaching solution system through physical and chemical actions. However, the adsorption capacity of traditional adsorption materials (such as activated carbon, resin) for the thiosulfate gold complex ion (Au(S2O3)2 3- ) is generally lower than 10 mg / g, and it is difficult to be used in a complex coexisting ion system (such as Cu 2+ , Zn 2+) achieve efficient selective adsorption; while existing nanomaterials (such as metal oxides and organic frameworks) have insufficient dispersion of surface active sites, resulting in limited electron transfer efficiency and slow coordination adsorption and reduction kinetics of gold ions; at the same time, traditional powdered adsorbents (such as silica gel and MOFs) have insufficient contact area with the gold leaching solution due to dense packing and low porosity, restricting the mass transfer and enrichment efficiency of gold ions. Therefore, driven by the dual factors of green metallurgy and resource recycling, it has become an urgent task to develop a gold recovery adsorption technology with high efficiency, selectivity, environmental friendliness and low energy consumption. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present application provides a cobalt-doped cadmium sulfide aerogel material, its preparation method and application, aiming to solve the technical problems of low adsorption capacity, poor selectivity and slow adsorption rate of existing gold ion adsorbents.

[0006] In the first aspect, an embodiment of the present application provides a cobalt-doped cadmium sulfide aerogel material, including a chitosan aerogel and cobalt-doped cadmium sulfide loaded on the chitosan aerogel, and the mass ratio of the chitosan aerogel to the cobalt-doped cadmium sulfide is 0.16:(0.1~0.15); the mass ratio of cobalt to cadmium sulfide in the cobalt-doped cadmium sulfide is 0.5:(2~3).

[0007] In the technical solution of the embodiment of the present application, chitosan is a good three-dimensional structure material, which can provide adsorption sites for gold ions and is beneficial to the adsorption of gold ions; the abundant sulfur vacancies and defects on the surface of CdS can serve as adsorption sites for gold ions, and gold ions can be enriched through chemical bonding or electrostatic interaction; Co can increase the electron density of the surface active sites of the material, enhance the coordination adsorption ability of gold ions, and promote the enrichment and reduction of gold ions.

[0008] In the second aspect, an embodiment of the present application provides a preparation method of a cobalt-doped cadmium sulfide aerogel material, including the following steps: Disperse Cd(NO3)2·4H2O, a sulfur source and Co(NO3)2·6H2O in deionized water to obtain a mixed solution; Add the chitosan aerogel to the mixed solution and carry out a hydrothermal reaction to obtain the cobalt-doped cadmium sulfide aerogel material.

[0009] In the technical solution of the embodiment of the present application, the hydrothermal method can accurately control the reaction conditions, so that the chitosan aerogel has a porous structure, and at the same time, the material can be evenly distributed on the surface of the chitosan aerogel (CS).

[0010] The sulfur vacancies or defects existing on the surface of CdS can serve as the anchoring points of Co. Under hydrothermal conditions, Co can be adsorbed by CdS to the sulfur vacancies to achieve anchoring, and Co atom-doped CdS can be obtained.

[0011] In some embodiments, the sulfur source is thiourea; the molar ratio of Cd(NO3)2·4H2O, the sulfur source, and Co(NO3)2·6H2O is (1.5~3):(4.5~9):0.5.

[0012] In some embodiments, the method for preparing the chitosan aerogel includes the following steps: mixing and stirring an acetic acid solution, chitosan powder, and glutaraldehyde to obtain a gel, dividing the gel, and freeze-drying to obtain the chitosan aerogel.

[0013] In the technical solution of the embodiment of the present application, acetic acid can promote the dissolution of chitosan, disperse the chitosan powder in water to form a uniform precursor solution, and glutaraldehyde, as a chemical cross-linking agent, forms a three-dimensional network structure of the generated chitosan gel through a Schiff reaction.

[0014] In some embodiments, the concentration of the acetic acid solution is 2%~2.5%, the volume ratio of the acetic acid solution to glutaraldehyde is 20:(0.5~2), and the addition amount of chitosan powder in every 20 mL of the acetic acid solution is 0.3~0.4 g.

[0015] In some embodiments, the freeze-drying conditions are: the temperature is -60~-70 °C, and vacuum drying is carried out for 12~24 h.

[0016] In some embodiments, the hydrothermal reaction conditions are: the temperature is 160~180 °C, and the reaction time is 18~20 h.

[0017] In a third aspect, the embodiment of the present application provides an application of a cobalt-doped cadmium sulfide aerogel material, including the following steps: adding the cobalt-doped cadmium sulfide aerogel material into a thiosulfate gold leaching solution, adjusting the pH of the thiosulfate gold leaching solution to 8~12, mixing and stirring, and performing the adsorption of Au(S2O3)2 by the cobalt-doped cadmium sulfide aerogel material 3- .

[0018] In some embodiments, the concentration of Au(S2O3)2 in the thiosulfate gold leaching solution 3- is 1.25~62.5 mg / L, and the addition amount of the cobalt-doped cadmium sulfide aerogel material in the thiosulfate gold leaching solution is 0.1~0.5 g / L.

[0019] In some embodiments, the time for the cobalt-doped cadmium sulfide aerogel material to adsorb Au(S2O3)2 3- is 4~24 h.

[0020] Different from the prior art solutions, the beneficial effects of the present application include: 1. The present invention anchors Co atoms on the surface of CdS, significantly enhancing the electron density of the active sites on the material surface, strengthening the coordination adsorption ability for gold ions, and promoting the enrichment and reduction of gold ions. Combining with the three-dimensional structure material aerogel, it significantly improves the contact efficiency between the material and gold ions, and promotes the efficient recovery of gold ions. The chemical reduction adsorption technology adopted in the present invention has a good recovery effect on gold in thiosulfate leaching solution, and can achieve a gold recovery rate close to 100%.

[0021] 2. The present invention proposes a method for chemically adsorbing and reducing gold ions in a novel thiosulfate leaching solution system, realizing the efficient and simple recovery of gold ions in the actual electronic waste leaching solution. It has the characteristics of simple operation, high efficiency, and applicability to low concentrations compared with the traditional recovery process.

[0022] The above description is only an overview of the technical solution of this application. In order to be able to understand the technical means of this application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of this application more obvious and understandable, the specific embodiments of this application are specifically given below. Brief Description of the Drawings

[0023] In order to more clearly illustrate the technical solution of this application, the drawings used in this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] Figure 1 a - 1c are SEM images of the Co - CdS@CS material prepared in Example 1 of this application; Figure 1 d - 1f are SEM images of the CdS@CS material prepared in Comparative Example 1 of this application; Figure 1 g - 1i are mapping diagrams of Co - CdS.

[0025] Figure 2 is the XRD diagram of the Co - CdS@CS material prepared in Example 1 of this application.

[0026] Figure 3 is the gold recovery rate detection result diagram in Examples 3 and Comparative Examples 3 - 8 of this application.

[0027] Figure 4 is the diagram of the change of gold recovery rate with time in Examples 3 and Comparative Examples 1 - 2 of this application.

[0028] Figure 5 is the gold recovery rate detection result diagram in Examples 3 - 7 of this application.

[0029] Figure 6This is the graph of the gold recovery rate detection results in Examples 8 to 10 of this application.

[0030] Figure 7 This is the graph of the gold recovery rate detection results in Examples 11 to 16 of this application. Detailed implementation manners

[0031] The embodiments of the technical solution of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of this application more clearly, and therefore are only examples and cannot be used to limit the protection scope of this application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0033] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain this application and cannot be understood as a limitation of this application. For those not specified in the embodiments in terms of specific technology or conditions, they shall be carried out according to the technology or conditions described in the literature in this field or according to the product instructions. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchases.

[0034] I. Preparation method Example 1 A preparation method of a cobalt-doped cadmium sulfide aerogel material includes the following steps: S1: Preparation of chitosan aerogel (CS): Take 0.4 mL of acetic acid and add it to a beaker containing 19.6 mL of deionized water. Stir evenly at a rotation speed of 500 rpm, then add 0.3 g of chitosan powder and continue to stir until the powder is completely dissolved in the current solution. Then add 1.5 mL of glutaraldehyde solution and stir until the solution becomes gel-like. Then pour it into a petri dish, cut the gel into 1 cm square blocks, place them in the refrigerator and freeze for 45 min, and finally place the samples in a freeze dryer at -60°C for vacuum drying for 12 h. The obtained product is CS.

[0035] S2: Material Preparation: Add 3 mmol of Cd(NO3)2·4H2O, 9 mmol of thiourea, and 0.5 mmol of Co(NO3)2·6H2O into the Teflon inner liner of a reaction kettle containing 60 mL of deionized water. Stir at 600 rpm for 30 min, then reduce the rotation speed to 400 rpm and add 160 mg of CS aerogel, and continue stirring for 30 min. Subsequently, place the above solution in a stainless-steel autoclave with a Teflon inner liner and react in a hydrothermal oven at 160 °C for 18 h. After the reaction is completed and cooled to room temperature, filter the obtained product, first rinse it with ethanol to remove the unreacted reagents remaining on the surface, then rinse it with deionized water, and finally place the rinsed sample in a freeze dryer at -60 °C for vacuum drying for 12 h. The obtained product is the cobalt-doped cadmium sulfide aerogel material Co-CdS@CS.

[0036] Example 2 A preparation method of a cobalt-doped cadmium sulfide aerogel material, comprising the following steps: S1: Preparation of Chitosan Aerogel (CS): Add 0.4 mL of acetic acid into a beaker containing 19.6 mL of deionized water, stir evenly at a rotation speed of 500 rpm, then add 0.3 g of chitosan powder and continue stirring until the powder is completely dissolved in the current solution, then add 1.5 mL of glutaraldehyde solution and stir until the solution becomes gel-like. Then pour it into a petri dish, cut the gel into 1 cm regular cubes, place them in the refrigerator for freezing for 45 min, and finally place the sample in a freeze dryer at -60 °C for vacuum drying for 12 h. The obtained product is CS.

[0037] S2: Material Preparation: Add 1.5 mmol of Cd(NO3)2·4H2O, 4.5 mmol of sulfur source (thiourea TU), and 0.25 mmol of Co(NO3)2·6H2O into 60 mL of ultrapure water in a mixed solution. Stir at 600 rpm for 30 min, then reduce the rotation speed to 400, add 100 mg of CS aerogel, and continue stirring for 30 min. Place the above solution in a stainless-steel autoclave with a Teflon inner liner and keep it at 160 °C for 18 hours. After cooling to room temperature, filter the obtained product, wash it with ultrapure water and ethanol, and vacuum dry it at -60 °C. The obtained product is the cobalt-doped cadmium sulfide aerogel material Co-CdS@CS.

[0038] Example 3 An application of a cobalt-doped cadmium sulfide aerogel material, comprising the following steps: S1: Preparation of simulated thiosulfate gold leaching solution: First, measure a certain volume of deionized water into a beaker, and gradually add 6 mol / L NaOH solution dropwise under magnetic stirring. Subsequently, add a certain mass of ammonium thiosulfate powder to prepare a 0.0018 mol / L ammonium thiosulfate solution. Take a certain volume of ammonium thiosulfate solution into a beaker, add chloroauric acid according to a certain ratio, and use a pH meter to detect and maintain the solution under alkaline conditions, adjusting the pH to 8 to prepare a 25 mg / L Au(S2O3)2 3- solution.

[0039] S2: Put 20 mg of Co-CdS@CS material into 100 mL of simulated thiosulfate gold leaching solution, stir at a rotation speed of 250 rpm, and conduct the adsorption experiment of Au(S2O3)2 3- test.

[0040] Example 4 The difference between Example 4 and Example 3 is that the pH of the thiosulfate gold leaching solution is adjusted to 9, and other steps are the same as those in Example 3.

[0041] Example 5 The difference between Example 5 and Example 3 is that the pH of the thiosulfate gold leaching solution is adjusted to 10, and other steps are the same as those in Example 3.

[0042] Example 6 The difference between Example 6 and Example 3 is that the pH of the thiosulfate gold leaching solution is adjusted to 11, and other steps are the same as those in Example 3.

[0043] Example 7 The difference between Example 7 and Example 3 is that the pH of the thiosulfate gold leaching solution is adjusted to 12, and other steps are the same as those in Example 3.

[0044] Example 8 The difference between Example 8 and Example 3 is that 10 mg of Co-CdS@CS material is put into 100 mL of simulated thiosulfate gold leaching solution, and other steps are the same as those in Example 3.

[0045] Example 9 The difference between Example 9 and Example 3 is that 30 mg of Co-CdS@CS material is put into 100 mL of simulated thiosulfate gold leaching solution, and other steps are the same as those in Example 3.

[0046] Example 10 The difference between Example 10 and Example 3 is that 50 mg of Co-CdS@CS material is put into 100 mL of simulated thiosulfate gold leaching solution, and other steps are the same as those in Example 3.

[0047] Example 11 The difference between Example 11 and Example 3 is that the Au(S2O3)2 3- The concentration of 1.25 mg / L and the other steps were the same as those in Example 3.

[0048] Example 12 The difference between Example 12 and Example 3 is that the Au(S2O3)2 in the simulated thiosulfate gold leaching solution is 3- The concentration of 6.25 mg / L and the other steps were the same as those in Example 3.

[0049] Example 13 The difference between Example 13 and Example 3 is that the Au(S2O3)2 3- The concentration of 12.5 mg / L was the same as in Example 3.

[0050] Example 14 The difference between Example 14 and Example 3 is that the Au(S2O3)2 3- The concentration of 18.75 mg / L was the same as in Example 3.

[0051] Example 15 The difference between Example 15 and Example 3 is that the Au(S2O3)2 in the simulated thiosulfate gold leaching solution is 3- The concentration of 37.5 mg / L and the other steps were the same as those in Example 3.

[0052] Example 16 The difference between Example 16 and Example 3 is that the Au(S2O3)2 3- The concentration of 62.5 mg / L and the other steps were the same as those in Example 3.

[0053] Comparative Example 1 An application of a cadmium sulfide aerogel material comprises the following steps: S1: Preparation of chitosan aerogel (CS): 0.4 mL of acetic acid was added to a beaker containing 19.6 mL of deionized water and stirred at 500 rpm. 0.3 g of chitosan powder was then added and stirred until the powder was completely dissolved in the solution. 1.5 mL of glutaraldehyde solution was then added and stirred until the solution became a gel. The solution was then poured into a Petri dish and cut into 1 cm squares and placed in a refrigerator for 45 min. The sample was then placed in a freeze dryer at −60°C and vacuum dried for 12 h. The resulting product was CS.

[0054] S2: Material Preparation: Add 3 mmol of Cd(NO3)2·4H2O and 9 mmol of thiourea into the inner liner of a Teflon reactor containing 60 mL of deionized water. After stirring at 600 rpm for 30 min, reduce the rotation speed to 400 rpm and add 160 mg of CS aerogel, then continue stirring for 30 min. Subsequently, place the above solution in a stainless-steel autoclave with a Teflon inner liner and react in a hydrothermal oven at 160 °C for 18 h. After the reaction is completed and cooled to room temperature, filter the obtained product, first rinse it with ethanol to remove the residual unreacted reagents on the surface, then rinse it with deionized water, and finally place the rinsed sample in a freeze dryer at -60 °C for vacuum drying for 12 h. The obtained product is CdS@CS.

[0055] S3: Put 20 mg of CdS@CS material into 100 mL of 25 mg / L Au(S2O3)2 3- solution, stir at a rotation speed of 250 rpm, and conduct the adsorption of Au(S2O3)2 3- test.

[0056] Comparative Example 2 An application of a cadmium sulfide aerogel material, including the following steps: Put the 20 mg of CS material into 100 mL of 25 mg / L Au(S2O3)2 3- solution, stir at a rotation speed of 250 rpm, and conduct the adsorption of Au(S2O3)2 3- test.

[0057] Comparative Example 3 The difference between Comparative Example 3 and Example 8 is that 0.05 mmol of K 3- is added to the Au(S2O3)2 + solution, and other steps are the same as those in Example 8.

[0058] Comparative Example 4 The difference between Comparative Example 4 and Example 8 is that 0.05 mmol of Ca 3- is added to the Au(S2O3)2 2+ solution, and other steps are the same as those in Example 8.

[0059] Comparative Example 5 The difference between Comparative Example 5 and Example 8 is that 0.05 mmol of Na 3- is added to the Au(S2O3)2 + solution, and other steps are the same as those in Example 8.

[0060] Comparative Example 6 The difference between Comparative Example 6 and Example 8 is that 0.05 mmol of Mg is added to the Au(S2O3)2 3- solution, and the other steps are the same as those in Example 8. 2+

[0061] Comparative Example 7 The difference between Comparative Example 7 and Example 8 is that 0.05 mmol of Al is added to the Au(S2O3)2 3- solution, and the other steps are the same as those in Example 8. 3+

[0062] Comparative Example 8 The difference between Comparative Example 8 and Example 8 is that 0.05 mmol of Fe is added to the Au(S2O3)2 3- solution, and the other steps are the same as those in Example 8. 3+

[0063] II. Testing Method Au recovery rate detection method: The concentration of Au ions in the sample is detected by atomic absorption spectrometry, and the recovery rate is calculated as follows: Recovery rate = [(gold content in the solution before reaction - gold content in the solution after reaction) / gold content in the solution before reaction] × 100%.

[0064] III. Analysis of Test Results of Each Example and Comparative Example (1) Characterization of Co-CdS@CS in Example 1 Figure 1 , it can be seen from Figure 1 that Co-doped CdS nanoparticles are uniformly loaded on the surface of chitosan aerogel. It can be seen from Figure 2 the XRD pattern of Co-CdS@CS that there are two diffraction peaks at 44.30° and 51.55°, indicating the presence of crystalline grains of face-centered structured Co, which shows that Co is doped in CdS in atomic form.

[0065] (2) The Au recovery rate of the reaction suspension after the adsorption test of Au(S2O3)2 in Example 3 and Comparative Examples 3-8 was detected, and the test results are shown in 3- . It can be seen from Figure 3 that metal cations have little effect on the recovery rate of Au ions, indicating that the Co-CdS@CS material prepared in Example 1 has good selectivity for Au ions. Figure 3

[0066] (3) The Au recovery rate of the reaction suspension after the adsorption test of Au(S2O3)2 in Example 3 and Comparative Examples 1-2 was detected, and the test results are shown in 3- ​Figure 4 It can be seen from Figure 5 that the Au adsorption effect of the Co-CdS@CS material is significantly higher than that of the CdS@CS material and the CS material, indicating that Co-doped Cd can significantly increase the electron density of the surface active sites of the material, enhance the coordination adsorption ability of gold ions, and promote the enrichment and reduction of gold ions.

[0067] (4) The Au recovery rate of the reaction suspension after the Au(S2O3)2 3- adsorption test in Examples 3 to 7 was detected, and the detection results are shown in Figure 5 It can be seen from Figure 5 that within the range of pH 8 to 12, a relatively high and uniform Au recovery rate is obtained, and the Au recovery rate is the highest at pH 8, which is 100%.

[0068] (5) The Au recovery rate of the reaction suspension after the Au(S2O3)2 3- adsorption test in Example 3 and Examples 8 to 10 was detected, and the detection results are shown in Figure 6 It can be seen from Figure 6 that when the dosage of the Co-CdS@CS material is 0.1 to 0.5 g / L, the Co-CdS@CS material has a relatively high Au recovery rate.

[0069] (6) The Au recovery rate of the reaction suspension after the Au(S2O3)2 3- adsorption test in Examples 11 to 16 was detected, and the detection results are shown in Figure 7 It can be seen from Figure 7 that when the concentration of Au(S2O3)2 3- is 1.25 to 62.5 mg / L, the Co-CdS@CS material has a relatively high Au recovery rate.

[0070] It should be noted that this application is not limited to the above embodiments. The above embodiments are only examples, and embodiments with the same structure and the same function and effect as the technical idea within the technical scope of this application are included in the technical scope of this application. In addition, within the scope of not departing from the gist of this application, various deformations that can be thought of by those skilled in the art are applied to the embodiments, and other embodiments constructed by combining some constituent elements of the embodiments are also included in the scope of this application.

Claims

1. A cobalt-doped cadmium sulfide aerogel material, characterized in that, It includes chitosan aerogel and cadmium sulfide doped with cobalt supported on the chitosan aerogel, and the mass ratio of the chitosan aerogel to the cadmium sulfide doped with cobalt is 0.16:(0.1 - 0.15); the mass ratio of cobalt to cadmium sulfide in the cadmium sulfide doped with cobalt is 0.5:(2 - 3).

2. The preparation method of the cobalt-doped cadmium sulfide aerogel material according to claim 1, characterized in that, It includes the following steps: Disperse Cd(NO3)2·4H2O, a sulfur source and Co(NO3)2·6H2O in deionized water to obtain a mixed solution; Add chitosan aerogel to the mixed solution and carry out a hydrothermal reaction to obtain a cadmium sulfide aerogel material doped with cobalt.

3. The preparation method of the cobalt-doped cadmium sulfide aerogel material according to claim 2, wherein, The sulfur source is thiourea; the molar ratio of Cd(NO3)2·4H2O, the sulfur source and Co(NO3)2·6H2O is (1.5 - 3):(4.5 - 9):0.

5.

4. The preparation method of the cobalt-doped cadmium sulfide aerogel material according to claim 2, characterized in that, The preparation method of the chitosan aerogel includes the following steps: mix and stir an acetic acid solution, chitosan powder and glutaraldehyde to obtain a gel, divide the gel and freeze-dry it to obtain chitosan aerogel.

5. The preparation method of the cobalt-doped cadmium sulfide aerogel material according to claim 4, characterized in that, The concentration of the acetic acid solution is 2% - 2.5%, the volume ratio of the acetic acid solution to glutaraldehyde is 20:(0.5 - 2), and the addition amount of chitosan powder in every 20 mL of acetic acid solution is 0.3 - 0.4 g.

6. The preparation method of the cobalt-doped cadmium sulfide aerogel material according to claim 4, characterized in that, The freeze-drying conditions are: the temperature is -60~-70 °C, and vacuum drying is carried out for 12 - 24 h.

7. The preparation method of the cobalt-doped cadmium sulfide aerogel material according to claim 2, characterized in that, The hydrothermal reaction conditions are: the temperature is 160~180 °C, and the reaction time is 18 - 20 h.

8. Use of the cobalt-doped cadmium sulfide aerogel material as described in claim 1, characterized in that, The method includes the following steps: adding the cobalt-doped cadmium sulfide aerogel material into a thiosulfate gold leaching solution, adjusting the pH of the thiosulfate gold leaching solution to 8-12, mixing and stirring, and performing the adsorption of Au(S2O3)2 by the cobalt-doped cadmium sulfide aerogel material 3- .

9. Use of the cobalt-doped cadmium sulfide aerogel material according to claim 8, characterized in that, Au(S2O3)2 in the thiosulfate gold leaching solution 3- The concentration is 1.25 - 62.5 mg / L, and the addition amount of cobalt-doped cadmium sulfide aerogel material in the thiosulfate gold leaching solution is 0.1 - 0.5 g / L.

10. Use of the cobalt-doped cadmium sulfide aerogel material according to claim 8, characterized in that, The cobalt-doped cadmium sulfide aerogel material adsorbs Au(S2O3)2 3- for 4 to 24 h.

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