A WS2 pseudocapacitive interface material and its preparation method and application

Abstract

The present invention belongs to the technical field of electrode materials and heavy metal wastewater treatment, and discloses a WS2 pseudocapacitor interface material, its preparation method and application. The preparation method comprises the following steps: uniformly dispersing sodium tungstate, thiourea, hydroxylamine hydrochloride and a surfactant in deionized water to obtain a mixed solution; heating the mixed solution to 160-200°C for hydrothermal reaction, separating, washing and drying the reaction product to obtain a WS2 pseudocapacitor interface material. The preparation method of the present invention is simple, the reaction conditions are mild and the cost is low. The obtained WS2 pseudocapacitor interface material can be used for capacitor adsorption to remove heavy metal ions, and has a great effect on Cr 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions can reach over 90%. Compared with conventional methods, it has the advantages of high energy efficiency, environmental friendliness and no pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrode materials and heavy metal wastewater treatment, and specifically relates to a WS2 pseudocapacitive interface material and a preparation method and application thereof. Background Art

[0002] Copper, lead, zinc, cadmium, mercury, and chromium are the most common and toxic heavy metal contaminants in wastewater. They have been listed by the World Health Organization as chemical pollutants of public concern. They persist stably in aquatic environments and are not easily degraded naturally. Heavy metal contaminants enter water ecosystems and accumulate through the food chain, causing acute or chronic toxicity to aquatic life and humans, and in the most dangerous cases, even death. Therefore, the efficient removal of heavy metals from wastewater is crucial for the sustainable and healthy development of the heavy metals industry and for environmental protection.

[0003] In recent years, researchers at home and abroad have explored and optimized a variety of heavy metal ion removal methods, including adsorption, chemical precipitation, ion exchange, and membrane separation technologies, to remove various heavy metal pollutants. While these methods have demonstrated considerable heavy metal removal efficiency, their respective limitations remain significant. Chemical precipitation removes heavy metals by forming insoluble precipitates, but the process also produces large amounts of sludge, which can easily cause secondary environmental pollution. Ion exchange utilizes exchangers to capture heavy metals, but the exchangers' oxidative sensitivity limits their stability and lifespan, and the frequent regeneration required significantly increases operating and running costs. Membrane separation, leveraging the separation properties of membrane materials, can effectively retain heavy metal ions in water. However, membranes are easily clogged by pollutants or other impurities in wastewater, resulting in decreased membrane performance and shortened service life, which in turn affects effluent quality. Adsorption utilizes the high specific surface area or specialized functional groups of materials to adsorb heavy metals, but the difficulty of recovering and regenerating adsorbents and their limited efficiency have limited their widespread adoption in practical applications. Therefore, developing a technology that can efficiently, environmentally friendly, cost-effectively, and selectively remove heavy metal ions from water is crucial for sustainable environmental development.

[0004] Capacitive deionization (CDI) is a new electrochemical water treatment technology that is environmentally friendly, pollution-free, energy-efficient, and has great potential for development. It has attracted increasing attention from researchers in recent years. Electrochemical methods utilize redox reactions on the electrode surface to reduce heavy metal ions in water to more stable, less toxic forms, or directly reduce metal ions to elemental metals on the electrode surface, achieving efficient removal of metal ions from the aqueous phase. Therefore, CDI removal is a more effective method for removing ions from solutions. The principle of CDI is similar to that of a double-layer capacitor. By applying a certain voltage between two electrodes to create an electric field, anions and cations in the solution migrate to the corresponding electrodes under the influence of the electric field, ultimately adsorbing or precipitating on the electrode surfaces, thereby reducing the ion concentration in the solution. When the electrode surfaces reach saturation with ions, the two electrodes are reversed, and the adsorbed ions are released into the solution due to the loss of the electric field, leading to ion enrichment in the solution and regeneration of the electrodes. Electrodes are a crucial component of CDI systems and are crucial to their effectiveness. Commonly used electrodes are carbon-based electrodes. Carbon-based electrode materials, such as activated carbon, have rich pore structures and good adsorption properties. They mainly capture charged ions through the Coulomb force at the double-layer interface. However, most carbon-based materials have reached a development bottleneck due to their weak conductivity, weak capacitive adsorption capacity, and low selectivity. The development of new electrode materials has become a development need.

[0005] WS2 has a typical layered structure similar to graphite. The structure of WS2 is a sandwich-like layered structure, with strong covalent bonds within the layers (SWS) and weak van der Waals forces between the layers, making it easy to peel off the layers. Using WS2 as the host material, guest atoms or molecules can be inserted between the host layers through insertion reactions to form intercalation compounds. Since the layers of WS2 layered compounds are bound by weak van der Waals forces, it allows the introduction of foreign ions, atoms or molecules between the layers. These characteristics have led to extensive research on the application of WS2 as an electrode material. For example, patent CN108039289 A discloses a method for preparing WS2 nanomaterials with a macroporous network structure. Tungsten hexachloride (WCl6) and thioacetamide (CH3CSNH2) are used as raw materials. By adding carbon cloth for hydrothermal reaction, WS2-carbon paper nanomaterials are obtained. It can be applied in photocatalysis, wastewater treatment, lithium-ion batteries, biosensors and other fields. Patent CN 105664836 A discloses a method for preparing WS2 / WO3 hollow microspheres. Using tungsten chloride and thioacetamide as raw materials, a WS2 / WO3 precursor is prepared via a hydrothermal method. The resulting WS2 / WO3 hollow microspheres are then heat treated at high temperatures. The resulting product can rapidly and thoroughly adsorb dyes such as rhodamine B, methyl orange, and methylene blue, and can be used for dyeing wastewater treatment. However, the sulfur active sites of the WS2 obtained by this preparation method are difficult to control, and the method does not disclose its ability to selectively remove heavy metal ions by capacitive adsorption. Summary of the Invention

[0006] In view of the shortcomings and deficiencies of the above-mentioned prior art, the primary purpose of the present invention is to provide a method for preparing a WS2 pseudocapacitive interface material.

[0007] Another object of the present invention is to provide a WS2 pseudocapacitive interface material prepared by the above method.

[0008] Another object of the present invention is to provide an application of the above-mentioned WS2 pseudocapacitive interface material in capacitive adsorption and removal of heavy metal ions.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] A method for preparing a WS2 pseudocapacitive interface material comprises the following steps:

[0011] Sodium tungstate, thiourea, hydroxylamine hydrochloride and a surfactant are uniformly dispersed in deionized water to obtain a mixed solution; the mixed solution is heated to 160-200° C. for a hydrothermal reaction; and the reaction product is separated, washed and dried to obtain a WS2 pseudocapacitive interface material.

[0012] Furthermore, the molar ratio of the sodium tungstate, thiourea and hydroxylamine hydrochloride is 0.5-0.6:2:1.

[0013] Furthermore, the amount of deionized water added is 5 to 10 times the total mass of sodium tungstate, thiourea and hydroxylamine hydrochloride.

[0014] Furthermore, the surfactant is CTAB (cetyltrimethylammonium bromide), and the amount of CTAB added is 0.5% to 2% of the mass of the mixed solution.

[0015] The present invention can improve the morphology and dispersed particle size of the WS2 pseudocapacitive interface material generated during the hydrothermal reaction by adding the cationic surfactant CTAB, increase its specific surface area, and enhance the adsorption performance; on the other hand, more soft Lewis base sites S can be formed through the interaction between anions and cations. 2- The groups are exposed on the surface, and through the above two effects, the capacitive adsorption and removal performance of the obtained WS2 pseudocapacitive interface material for heavy metal ions is significantly improved.

[0016] Furthermore, the pH value is adjusted to 5-7 before the hydrothermal reaction.

[0017] Furthermore, the hydrothermal reaction time is 12 to 48 hours.

[0018] Furthermore, the separation refers to filtering and separating the solid phase product; the washing refers to washing with deionized water and anhydrous ethanol; and the drying refers to drying at a temperature of 50 to 70° C. for 8 to 12 hours.

[0019] The above preparation method involves the following reaction:

[0020] Na2WO4+4CH4N2S+4H2O——4CO2+Na2WS4+8NH3,

[0021] Na2WS4+2NH2OH·HCl——WS2+N2+2H2O+2H2S+2NaCl.

[0022] A WS2 pseudocapacitive interface material is prepared by the above method.

[0023] The above-mentioned WS2 pseudocapacitive interface material is used in the capacitive adsorption and removal of heavy metal ions. The application method is: using the WS2 pseudocapacitive interface material as the negative electrode of the capacitive deionization device and the activated carbon material as the positive electrode, and then removing the heavy metal ions by capacitive adsorption.

[0024] Furthermore, the voltage of the capacitor adsorption is 0.1 to 5 V; and the heavy metal ions include at least one of Cr, Cd, Pb, Ni, Co, and Cu heavy metal ions.

[0025] The principle of the present invention is that WS2 is a lamellar hollow sphere with a hexagonal crystal system, which has a unique SWS layered structure that can promote the insertion of ions into the interlayer space. In the WS2 layered structure, two layers of sulfur atoms are sandwiched between metal atoms, making more soft Lewis base sites S 2- The group is exposed on the surface. 2- The soft Lewis base sites have a high affinity for soft Lewis acid heavy metal ions. In addition, the central W atom of WS2 has a rich range of oxidation states (from +2 to +6) and exhibits good pseudocapacitive properties, so it can be used for capacitive adsorption and removal of heavy metal ions.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention adopts sodium tungstate, thiourea and hydroxylamine hydrochloride to hydrothermally react to obtain WS2 pseudocapacitive interface material, which has binding sites with affinity for heavy metal ions and exhibits good pseudocapacitive performance. The obtained WS2 pseudocapacitive interface material has a high capacitance to Cr at a voltage of 1.2V. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal rate of heavy metal ions can reach more than 90%.

[0028] (2) The preparation method of the WS2 pseudocapacitive interface material of the present invention is simple, the reaction conditions are mild, and the cost is low; by adding specific surfactants, the product morphology and active sites can be improved, thereby improving the capacitive adsorption and removal efficiency of heavy metal ions.

[0029] (3) Compared with conventional adsorption, chemical precipitation, ion exchange and membrane separation methods, the application method of the present invention in heavy metal removal has the advantages of high energy efficiency, environmental friendliness and pollution-free, and has better cycle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a scanning electron microscope image of the WS2 pseudocapacitive interface material prepared in Example 1;

[0031] Figure 2 This is a diagram showing the removal efficiency of heavy metal ions by the WS2 pseudocapacitive interface material prepared in Example 1. DETAILED DESCRIPTION

[0032] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0033] Example 1

[0034] A method for preparing a WS2 pseudocapacitive interface material, the specific preparation steps are as follows:

[0035] 1.6493g of sodium tungstate, 1.5224g of thiourea, 0.6949g of hydroxylamine hydrochloride, and 0.24g of the surfactant CTAB were dispersed in 30mL of deionized water. Under magnetic stirring, the pH was adjusted to 6.0 by dropwise addition of 2mol / L hydrochloric acid or aqueous ammonia to obtain a mixed solution. The mixed solution was transferred to a 50mL polytetrafluoroethylene-lined stainless steel autoclave and reacted in a digital constant-temperature oven at 180°C for 24 hours. The resulting solid phase product was separated by filtration, washed multiple times with deionized water and anhydrous ethanol, and then dried in an oven at 60°C for 10 hours to obtain the WS2 pseudocapacitive interface material.

[0036] The scanning electron microscope image of the WS2 pseudocapacitive interface material obtained in this embodiment is as follows: Figure 1 It can be seen that the WS2 pseudocapacitive interface material obtained by the present invention is composed of blocks with a particle size of less than 10 μm.

[0037] The WS2 pseudocapacitive interface material obtained in this embodiment is used in heavy metal removal. The specific application method is as follows:

[0038] The obtained WS2 / graphene electrode material was used as the negative electrode of the capacitive deionization device, and the activated carbon was used as the positive electrode of the capacitive deionization device. The capacitive adsorption of heavy metal solutions (containing Cr, Cr, Cr2, Cr3, Cr4, Cr6) with different concentrations (10ppm, 30ppm, 50ppm, 70ppm, 90ppm) under the action of 1.2V voltage was carried out. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ ) in the heavy metal ions. The solution of its capacitance adsorption was tested by ICP-OES, and the test results were as follows Figure 2 shown.

[0039] Depend on Figure 2 The results show that the WS2 pseudocapacitive interface material obtained in this embodiment has a high sensitivity to Cr with a solubility of 10ppm. 3+ 、Cd 2+ , Pb 2 + 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 94.45%, 94.92%, 90.98%, 93.67%, 89.69% and 93.61% respectively, and the solubility of Cr was 30ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 92.72%, 84.48%, 88.22%, 87.91%, 89.31% and 92.85% respectively. The solubility of Cr was 50ppm. 3+ 、Cd 2+ , Pb 2 + 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 85.52%, 78.64%, 82.60%, 79.45%, 87.57% and 92.26% respectively. The solubility of Cr was 70ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 84.20%, 67.38%, 75.67%, 74.74%, 72.61% and 86.71% respectively. The solubility of Cr was 90ppm. 3+ 、Cd 2+ , Pb 2 + 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiencies of heavy metal ions were 82.79%, 59.76%, 71.53%, 71.89%, 69.08% and 72.10% respectively.

[0040] Example 2

[0041] A method for preparing a WS2 pseudocapacitive interface material, the specific preparation steps are as follows:

[0042] 1.6493g of sodium tungstate, 1.5224g of thiourea, 0.6949g of hydroxylamine hydrochloride, and 0.17g of the surfactant CTAB were dispersed in 30mL of deionized water. Under magnetic stirring, the pH was adjusted to 6.0 by dropwise addition of 2mol / L hydrochloric acid or aqueous ammonia to obtain a mixed solution. The mixed solution was transferred to a 50mL polytetrafluoroethylene-lined stainless steel autoclave and reacted in a digital constant temperature oven at 160°C for 48 hours. The resulting solid phase product was separated by filtration, washed multiple times with deionized water and anhydrous ethanol, and then dried in an oven at 60°C for 10 hours to obtain the WS2 pseudocapacitive interface material.

[0043] The WS2 pseudocapacitive interface material obtained in this example is used as the negative electrode of the capacitor deionization device, and the activated carbon is used as the positive electrode of the capacitor deionization device. Under the action of a voltage of 1.2 V, the Cr with a solubility of 10 ppm is3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 92.51%, 93.47%, 91.02%, 92.37%, 90.48% and 93.17% respectively. The solubility of Cr was 30ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 90.65%, 84.27%, 87.94%, 88.21%, 88.39% and 89.85% respectively, and the solubility of Cr was 50ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 84.76%, 79.80%, 81.54%, 80.23%, 85.69% and 90.71% respectively. The solubility of Cr was 70ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 81.58%, 68.92%, 74.83%, 76.70%, 74.55% and 79.97% respectively. The solubility of Cr was 90ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiencies of heavy metal ions were 79.07%, 62.74%, 69.81%, 70.43%, 66.59% and 69.76% respectively.

[0044] Example 3

[0045] A method for preparing a WS2 pseudocapacitive interface material, the specific preparation steps are as follows:

[0046] 1.6493g of sodium tungstate, 1.5224g of thiourea, 0.6949g of hydroxylamine hydrochloride, and 0.68g of the surfactant CTAB were dispersed in 30mL of deionized water. Under magnetic stirring, the pH was adjusted to 6.0 by dropwise addition of 2mol / L hydrochloric acid or aqueous ammonia to obtain a mixed solution. The mixed solution was transferred to a 50mL polytetrafluoroethylene-lined stainless steel autoclave and reacted in a digital constant-temperature oven at 200°C for 12 hours. The resulting solid phase product was separated by filtration, washed multiple times with deionized water and anhydrous ethanol, and then dried in an oven at 60°C for 10 hours to obtain the WS2 pseudocapacitive interface material.

[0047] The WS2 pseudocapacitive interface material obtained in this example is used as the negative electrode of the capacitor deionization device, and the activated carbon is used as the positive electrode of the capacitor deionization device. Under the action of a voltage of 1.2 V, the Cr with a solubility of 10 ppm is 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 94.45%, 94.92%, 90.98%, 93.67%, 89.69% and 93.61% respectively, and the solubility of Cr was 30ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 93.89%, 87.57%, 89.17%, 89.16%, 89.29% and 90.68% respectively, and the solubility of Cr was 50ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 88.64%, 80.72%, 81.65%, 80.22%, 88.31% and 89.63% respectively. The solubility of Cr was 70ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 85.91%, 75.42%, 76.79%, 72.82%, 74.10% and 80.25% respectively. The solubility of Cr was 90ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co2+ 、Cu 2+ The removal efficiencies of heavy metal ions were 80.63%, 68.72%, 74.11%, 76.29%, 68.90% and 69.23% respectively.

[0048] Comparative Example 1

[0049] A method for preparing a WS2 pseudocapacitive interface material, compared with Example 1, does not add the surfactant CTAB, and other conditions are the same.

[0050] The WS2 pseudocapacitive interface material obtained in this comparative example is used as the negative electrode of the capacitor deionization device, and the activated carbon is used as the positive electrode of the capacitor deionization device. Under the action of 1.2V voltage, the Cr with a solubility of 10ppm is 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 41.20%, 52.65%, 73.77%, 72.00%, 61.40% and 76.44% respectively. The solubility of Cr was 30ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 26.37%, 49.00%, 64.50%, 65.21%, 45.32% and 70.73% respectively. The solubility of Cr was 50ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 8.23%, 17.17%, 29.48%, 59.06%, 23.46% and 45.44% respectively. The solubility of Cr was 70ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 5.63%, 9.68%, 26.35%, 27.72%, 10.69% and 32.53% respectively. The solubility of Cr was 90ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+The removal efficiencies of heavy metal ions were 5.26%, 5.15%, 12.66%, 19.85%, 9.38% and 31.53%, respectively.

[0051] Comparative Example 2

[0052] A method for preparing a WS2 pseudocapacitive interface material, compared with Example 1, wherein an equal amount of non-ionic surfactant AEO-10 is used instead of CTAB, and other conditions are the same.

[0053] The WS2 pseudocapacitive interface material obtained in this comparative example is used as the negative electrode of the capacitor deionization device, and the activated carbon is used as the positive electrode of the capacitor deionization device. Under the action of 1.2V voltage, the Cr with a solubility of 10ppm is 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 53.23%, 60.88%, 84.37%, 74.47%, 79.13% and 93.49% respectively. The solubility of Cr was 30ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 42.48%, 59.26%, 74.13%, 74.97%, 68.14% and 90.81% respectively. The solubility of Cr was 50ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 23.89%, 43.10%, 53.35%, 70.99%, 48.04% and 85.44% respectively. The solubility of Cr was 70ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions was 11.03%, 19.43%, 39.21%, 35.85%, 27.77% and 73.33% respectively. The solubility of Cr was 90ppm. 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+The removal efficiencies of heavy metal ions were 10.37%, 17.20%, 32.56%, 29.66%, 17.20% and 40.66%, respectively.

[0054] By comparing the results of Comparative Examples 1 to 2 with Example 1, it can be seen that when no surfactant is added during the hydrothermal reaction or a non-ionic surfactant is used instead of CTAB, the capacitance adsorption and removal efficiency of the obtained WS2 pseudocapacitive interface material for heavy metal ions is significantly reduced. The reason is that the addition of surfactant can improve the morphology and dispersed particle size of the WS2 pseudocapacitive interface material generated during the hydrothermal reaction, increase its specific surface area, and enhance the adsorption performance; and the use of the specific cationic surfactant CTAB of the present invention can also make more soft Lewis base sites S through the interaction of anions and cations. 2- The groups are exposed on the surface, which increases the affinity for soft Lewis acid heavy metal ions, thereby further significantly improving the capacitive adsorption and removal performance of heavy metal ions.

[0055] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. Application of a WS2 pseudocapacitive interface material in capacitive adsorption and removal of heavy metal ions, characterized in that: The application method comprises: using the WS2 pseudocapacitive interface material as the negative electrode of a capacitive deionization device and the activated carbon material as the positive electrode, and then removing heavy metal ions by capacitive adsorption; the voltage of the capacitive adsorption is 0.1 to 5V; and the heavy metal ions include at least one of Cr, Cd, Pb, Ni, Co, and Cu heavy metal ions; The preparation method of the WS2 pseudocapacitive interface material comprises the following preparation steps: Sodium tungstate, thiourea, hydroxylamine hydrochloride and a surfactant are uniformly dispersed in deionized water to obtain a mixed solution; the mixed solution is heated to 160-200°C for a hydrothermal reaction, and the reaction product is separated, washed and dried to obtain a WS2 pseudocapacitive interface material; The surfactant is CTAB, and the amount of CTAB added is 0.5% to 2% of the mass of the mixed solution.

2. The use of a WS2 pseudocapacitive interface material according to claim 1 in capacitive adsorption removal of heavy metal ions, characterized in that: The molar ratio of the sodium tungstate, thiourea and hydroxylamine hydrochloride is 0.5-0.6:2:

1.

3. The use of a WS2 pseudocapacitive interface material according to claim 1 in capacitive adsorption removal of heavy metal ions, characterized in that: The amount of deionized water added is 5 to 10 times the total mass of sodium tungstate, thiourea and hydroxylamine hydrochloride.

4. The use of a WS2 pseudocapacitive interface material according to claim 1 in capacitive adsorption removal of heavy metal ions, characterized in that: The pH value is adjusted to 5-7 before the hydrothermal reaction.

5. The use of a WS2 pseudocapacitive interface material according to claim 1 in capacitive adsorption removal of heavy metal ions, characterized in that: The hydrothermal reaction time is 12 to 48 hours.

6. The use of a WS2 pseudocapacitive interface material according to claim 1 in capacitive adsorption removal of heavy metal ions, characterized in that: The separation refers to filtering and separating the solid phase product; the washing refers to washing with deionized water and anhydrous ethanol; and the drying refers to drying at a temperature of 50-70° C. for 8-12 hours.

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