Preparation method and application of S-type heterostructure material with plasma resonance effect

Abstract

The invention discloses a preparation method and application of an S-type heterostructure material with a plasma resonance effect, and the preparation method comprises the following steps: grinding a precursor material, calcining, collecting solid powder, carrying out reflux purification in deionized water, and collecting white powder; dispersing the white powder in a hydrazine hydrate solution, carrying out solvothermal reaction to obtain a faint yellow solution, repeatedly dissolving and precipitating by respectively using acidic and alkaline reagents, washing and drying to obtain a faint yellow solid product; uniformly grinding the faint yellow solid product, calcining the faint yellow solid product in an atmosphere furnace, and cooling to obtain orange solid powder; and adding the orange solid powder into an organic solvent of a precursor containing a tungsten source, and centrifuging, washing and drying after the solvothermal reaction is finished to obtain the S-type heterostructure material with the plasma resonance effect. The S-type heterostructure material with the plasma resonance effect has relatively high efficiency for simulating separation and removal of uranium species in post-treatment wastewater and shows relatively good anti-radiation stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tungsten-containing catalysts, and more particularly relates to a preparation method and application of an S-type heterostructure material with plasmonic resonance effect. BACKGROUND

[0002] Nuclear industrial activities such as uranium mining, decommissioning of nuclear facilities, spent fuel processing, etc. will inevitably produce a large amount of radioactive uranium-containing organic wastewater, which poses a great threat to the environment and human health. The photocatalytic technology for converting the environmentally mobile U(VI) from wastewater into relatively insoluble U(IV) solid products is currently an important strategy. In order to improve the efficiency of photocatalytic uranium reduction, coupling two (or more) semiconductors (one as a photoreduction agent and the other as a photo-oxidation agent) to change the internal photophysical process of the photocatalyst to achieve spatial separation of electron-hole pairs is a promising candidate: the S scheme heterostructure has a relatively negative conduction band edge (ECB) position, resulting in a stronger chemical potential relative to the U(VI) / U(IV) conversion potential, thereby facilitating wastewater uranium removal. However, the photo-oxidation agent is usually only used to regulate the charge carrier transfer path in the traditional heterostructure, and does not directly participate in the reduction reaction, so the uranium reduction only depends on the low electron concentration generated by the photo-reduction agent, which limits the U(VI) reduction efficiency. SUMMARY

[0003] An object of the present application is to solve at least the above problems and / or defects, and to provide at least the advantages to be described later.

[0004] In order to achieve these objects and other advantages according to the present application, a preparation method of an S-type heterostructure material with plasmonic resonance effect is provided, comprising the following steps: Step one, grinding the precursor material directly containing or capable of directly preparing triazine ring and heptazine ring, and transferring it to an alumina crucible and calcining in an atmosphere furnace, collecting the obtained solid powder and purifying it in deionized water, and then collecting the white powder; Step two, dispersing the obtained white powder in a hydrazine hydrate solution, then transferring it to a reaction kettle to obtain a light yellow solution by solvothermal reaction, repeatedly dissolving and precipitating with acidic and alkaline reagents respectively, and then washing and drying to obtain a light yellow solid product; Step three, grinding the obtained light yellow solid product uniformly and placing it in an atmosphere furnace for calcination, and obtaining an orange solid powder after natural cooling; Step four, adding the obtained orange solid powder to an organic solvent containing a tungsten source precursor, transferring it to a polytetrafluoroethylene reaction kettle, and performing solvothermal reaction, and then obtaining the S-type heterostructure material with plasmonic resonance effect after centrifugation, washing and drying.

[0005] Preferably, in step 1, the precursor materials include but are not limited to one or more of urea, melem, melamine, cyanamide, dicyandiamide, thiourea, oxalic acid diamide, and dithiooxamide; and the tools required for grinding are not limited to mortar, ball mill, and manual mixing.

[0006] Preferably, in the step 1, the equipment used for calcination includes but is not limited to a muffle furnace, a vertical atmosphere furnace, and a microwave sintering furnace; the heating rate of the equipment is 3-10°C / min, the reaction temperature is 200-600°C, the holding time is 1-48h, and the calcination atmosphere includes but is not limited to air, oxygen, nitrogen, argon, and an inert mixed gas; and the reflux time is 0.5-48h.

[0007] Preferably, the amount ratio of the precursor material in step 1 to the hydrazine hydrate solution in step 2 is 0.1~50g:1~100mL, and the volume concentration of the hydrazine hydrate solution is 30%~99%; the equipment for the solvent thermal reaction includes but is not limited to one of a vacuum drying oven, a forced air drying oven, and a muffle furnace; the solvent thermal reaction temperature is 80~300℃, and the reaction time is 5~48h.

[0008] Preferably, in step 2, the acidic and alkaline reagents include but are not limited to hydrochloric acid, nitric acid, sulfuric acid, acetic acid, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, and ammonia water; and the reagents required for washing include but are not limited to water, methanol, ethanol, tetrahydrofuran, and N-methylpyrrolidone.

[0009] Preferably, in step three, the equipment used for calcination includes but is not limited to a muffle furnace, a vertical atmosphere furnace, and a microwave sintering furnace; the required atmosphere includes but is not limited to air, oxygen, nitrogen, argon, and an inert gas mixture; the heating rate of the equipment is 3-10°C / min, the reaction temperature is 300-800°C, and the holding time is 0.5-5h.

[0010] Preferably, in step 4, the precursor containing the tungsten source includes but is not limited to one or more of sodium tungstate, potassium tungstate, sodium phosphotungstate, tungsten hexachloride, tungsten pentachloride, tungsten tetrachloride, and tungsten dichloride; the organic solvent includes but is not limited to one or more of methanol, ethanol, tetrahydrofuran, and N-methylpyrrolidone, and the ratio of the precursor containing the tungsten source to the organic solvent is 10-1000 mg:10-200 mL; the equipment for the solvent thermal reaction includes but is not limited to a vacuum drying oven, a forced air drying oven, a muffle furnace, etc.; the solvent thermal reaction temperature is 100-250° C., and the reaction time is 3-48 h; the reagents required for washing include but are not limited to one or more of water, methanol, ethanol, tetrahydrofuran, and N-methylpyrrolidone.

[0011] Preferably, in the steps 1 to 4, the drying of the products at each stage includes but is not limited to natural air drying, freeze drying, supercritical drying, constant temperature heating, and variable temperature heating drying.

[0012] Preferably, in the steps 1 to 4, taking out or separating the products at each stage includes but is not limited to using centrifugation, washing, suction filtration, and filtration.

[0013] The invention discloses an application of an S-type heterostructure material with a plasma resonance effect. The S-type heterostructure material with a plasma resonance effect is used as a catalyst for catalytically separating and removing uranium in post-treatment wastewater.

[0014] In order to improve the removal rate of U(VI) in wastewater by the S-type heterostructure material with plasmon resonance effect, the orange solid powder obtained in step 3 was dispersed in deionized water, 2-5 mg / mL graphene oxide dispersion was added, and ultrasonic dispersion was performed at 40 kHz for 10-30 min to obtain a mixed suspension; 3-aminopropyltriethoxysilane was added to the mixed suspension, and the mixture was heated to 70-80°C in a water bath, stirred for 3-6 h, centrifuged and washed, and vacuum dried at 50°C to obtain graphene oxide (GO)-modified C3N5 powder; wherein the amount ratio of orange solid powder, deionized water, graphene oxide dispersion, and 3-aminopropyltriethoxysilane was 20-100 mg:30-100 mL:1-10 mL:20-60 μL; In step 4, the resulting graphene oxide-modified C3N5 powder is added to an organic solvent (ethanol) containing a tungsten source (tungsten hexachloride) precursor. Tetrabutyl titanate and acetylacetone are then added. Premixing is performed under 60kHz ultrasonication for 5-20 minutes. The mixture is then transferred to a polytetrafluoroethylene reactor for a solvothermal reaction. After the reaction is complete, the mixture is centrifuged, washed, and dried to obtain an S-shaped heterostructure material exhibiting a plasmon resonance effect. The ratio of the tungsten source precursor (tungsten hexachloride), organic solvent (ethanol), tetrabutyl titanate, and acetylacetone is 10-1000 mg: 10-200 mL: 10-20 mg: 0.5-1 mL.

[0015] The present invention has at least the following beneficial effects: the S-type heterostructure material with plasma resonance effect prepared by the present invention has high efficiency in simulating the separation and removal of uranium species in post-treatment wastewater and exhibits good radiation resistance stability.

[0016] Taking into account the complex environmental conditions of radioactive uranium-containing organic wastewater (e.g., its acidity, radioactivity, and multiple competing cations), this invention prepares an S-type heterostructure material with a plasmon resonance effect for efficient uranium removal from such wastewater. Experimental results demonstrate that the U(VI) removal rate of the plasmon S-type heterojunction photocatalyst can reach approximately 96% in 40 minutes. Even after irradiation (up to 100 kGy) or repeated use, the sample maintains high selectivity and catalytic activity. The present invention uses graphene oxide to modify the orange solid powder (C3N5) obtained by calcination, and finally uses solvent thermal reaction to hydrolyze tetrabutyl titanate to generate titanium dioxide. The generated titanium dioxide is coated on graphene oxide, C3N5 / WO 3-x The surface of the S-type heterostructure material improves the removal ability of U(VI) in wastewater. The modification and incorporation of GO and titanium dioxide optimizes the energy level gradient, constructs an electron directional transfer chain (C3N5→GO→TiO2→U(VI)), improves the electron migration rate, and oxygen-deficient tungsten oxide (WO 3-x ) and graphene oxide (rGO) achieve full spectrum capture from 400 to 1100 nm, and hot electron injection increases the carrier concentration, thereby synergistically improving the reduction and removal ability of S-type heterostructure materials for U(VI) in wastewater; at the same time, GO has an interfacial barrier effect on the material, enhancing the material's stability and resistance to ion interference.

[0017] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a scanning electron microscope image of the S-shaped heterostructure material with plasmon resonance effect prepared in Example 1; Figure 2 This is a transmission electron microscope image of the S-shaped heterostructure material with plasmon resonance effect prepared in Example 1; Figure 3 The X-ray photoelectric spectrum of the N element of the S-type heterostructure material with plasma resonance effect prepared in Example 1; Figure 4 The X-ray photoelectric spectrum of the W element in the S-type heterostructure material with plasmon resonance effect prepared in Example 1; Figure 5 The uranium removal rate of the S-type heterostructure material with plasma resonance effect prepared in Examples 1 to 6 under light irradiation; Figure 6 This is the uranium removal kinetic curve of the S-type heterostructure material with plasma resonance effect prepared in Example 3; Figure 7 The uranium removal rates of the S-type heterostructure material with plasma resonance effect prepared in Example 3 after different γ irradiation conditions. DETAILED DESCRIPTION

[0019] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0020] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof. Example 1 A method for preparing an S-shaped heterostructure material having a plasma resonance effect comprises the following steps: Step 1: Grind 20 g of urea precursor material, transfer it to an alumina crucible, and calcine it in a nitrogen atmosphere furnace at a heating rate of 5°C / min, a reaction temperature of 500°C, and a holding time of 5 h. The obtained solid powder was refluxed in deionized water for purification and then a white powder was collected; Step 2: Disperse the obtained white powder in 50 mL of 80% hydrazine hydrate solution, and then transfer it to a reactor to obtain a light yellow solution by solvent thermal reaction. The solvent thermal reaction temperature is 150 ° C. and the reaction time is 30 h. After repeatedly dissolving and precipitating the reactants with sulfuric acid and potassium hydroxide, respectively, a light yellow solid product is obtained after washing and drying; Step 3: Grind the obtained light yellow solid product evenly and calcine it in a nitrogen atmosphere furnace at a heating rate of 5°C / min, a reaction temperature of 400°C, and a holding time of 3 hours. After natural cooling, an orange solid powder is obtained; Step 4: Add the obtained orange solid powder to 600 mL of deionized water solution containing 50 mg of sodium tungstate, and transfer it to a polytetrafluoroethylene reactor for solvothermal reaction. The solvothermal reaction temperature is 200°C and the reaction time is 10 hours. After the reaction is completed, centrifugation, washing, and drying are performed to obtain an S-type heterostructure material with a plasma resonance effect.

[0021] Example 2 A method for preparing an S-shaped heterostructure material having a plasma resonance effect comprises the following steps: Step 1: Grind 10 g of thiourea precursor material, transfer it to an alumina crucible, and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 550°C, and a holding time of 6 h. The obtained solid powder is refluxed in deionized water for purification and then a white powder is collected; Step 2: Disperse the obtained white powder in 60 mL of 90% hydrazine hydrate solution, and then transfer it to a reactor to obtain a light yellow solution by solvent thermal reaction. The solvent thermal reaction temperature is 180 ° C, and the reaction time is 24 h. After repeatedly dissolving and precipitating the reactants with nitric acid and sodium hydroxide, respectively, a light yellow solid product is obtained after washing and drying; Step 3: Grind the obtained light yellow solid product evenly and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 450°C, and a holding time of 4 hours. After natural cooling, an orange solid powder is obtained; Step 4: Add the obtained orange solid powder to 70 mL of methanol solution containing 100 mg of potassium tungstate and transfer it to a polytetrafluoroethylene reactor for solvothermal reaction at a temperature of 150°C for 48 hours. After the reaction is completed, centrifuge, wash, and dry to obtain an S-type heterostructure material with a plasma resonance effect.

[0022] Example 3 A method for preparing an S-shaped heterostructure material having a plasma resonance effect comprises the following steps: Step 1: Grind 15 g of melamine precursor material, transfer it to an alumina crucible, and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 420°C, and a holding time of 12 h. The obtained solid powder is refluxed in deionized water for purification and then a white powder is collected; Step 2: Disperse the obtained white powder in 40 mL of 85% hydrazine hydrate solution, and then transfer it to a reactor to obtain a light yellow solution by solvent thermal reaction. The solvent thermal reaction temperature is 160 ° C, and the reaction time is 24 h. After repeatedly dissolving and precipitating the reactants with hydrochloric acid and sodium hydroxide, respectively, a light yellow solid product is obtained after washing and drying; Step 3: Grind the obtained light yellow solid product evenly and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 450°C, and a holding time of 2h. After natural cooling, an orange solid powder is obtained; Step 4: Add the obtained orange solid powder to 65 mL of ethanol aqueous solution containing 150 mg of tungsten hexachloride, and transfer it to a polytetrafluoroethylene reactor for solvothermal reaction at a temperature of 180°C for 24 hours. After the reaction is completed, centrifuge, wash, and dry to obtain an S-type heterostructure material with a plasma resonance effect.

[0023] Example 4 A method for preparing an S-shaped heterostructure material having a plasma resonance effect comprises the following steps: Step 1: Grind 18 g of melem precursor material, transfer it to an alumina crucible, and calcine it in an argon atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 400°C, and a holding time of 5 h. The obtained solid powder is refluxed in deionized water for purification and then a white powder is collected; Step 2: Disperse the obtained white powder in 50 mL of 90% hydrazine hydrate solution, and then transfer it to a reactor to obtain a light yellow solution through a solvothermal reaction. The solvothermal reaction temperature is 150 ° C. and the reaction time is 36 h. After repeatedly dissolving and precipitating the reactants with acetic acid and ammonia water, respectively, a light yellow solid product is obtained after washing and drying. Step 3: Grind the obtained light yellow solid product evenly and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 430°C, and a holding time of 3h. After natural cooling, an orange solid powder is obtained; Step 4: Add the obtained orange solid powder to 55 mL of ethanol solution containing 300 mg of tungsten dichloride and transfer it to a polytetrafluoroethylene reactor for solvothermal reaction at a temperature of 200°C for 10 hours. After the reaction is completed, centrifuge, wash, and dry to obtain an S-type heterostructure material with a plasma resonance effect.

[0024] Example 5 A method for preparing an S-shaped heterostructure material having a plasma resonance effect comprises the following steps: Step 1: Grind 15 g of melamine precursor material, transfer it to an alumina crucible, and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 420°C, and a holding time of 12 h. The obtained solid powder is refluxed in deionized water for purification and then a white powder is collected; Step 2: Disperse the obtained white powder in 40 mL of 85% hydrazine hydrate solution, and then transfer it to a reactor to obtain a light yellow solution by solvent thermal reaction. The solvent thermal reaction temperature is 160 ° C, and the reaction time is 24 h. After repeatedly dissolving and precipitating the reactants with hydrochloric acid and sodium hydroxide, respectively, a light yellow solid product is obtained after washing and drying; Step 3: Grind the obtained light yellow solid product evenly and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 450°C, and a holding time of 2h. After natural cooling, an orange solid powder is obtained; 100 mg of orange solid powder was dispersed in 50 mL of deionized water, and 5 mL of 2 mg / mL graphene oxide dispersion was added. The mixture was ultrasonically dispersed at 40 kHz for 30 min to obtain a mixed suspension. 3-Aminopropyltriethoxysilane was added to the mixed suspension, and the mixture was heated to 80°C in a water bath and stirred for 6 h. The mixture was washed by centrifugation and dried in a vacuum at 50°C to obtain graphene oxide (GO)-modified C3N5 powder. Step 4: After all the orange solid powder obtained in step 3 is modified with graphene oxide according to the above method, all the products are added to 65 mL of ethanol aqueous solution containing 150 mg of tungsten hexachloride, 20 mg of tetrabutyl titanate and 0.5 mL of acetylacetone are added thereto, and ultrasonic premixing is performed at 60 kHz for 20 minutes. The mixture is transferred to a polytetrafluoroethylene reactor for a solvothermal reaction at a temperature of 180°C and a reaction time of 24 hours. After the reaction is completed, the S-type heterostructure material with a plasma resonance effect is obtained by centrifugation, washing, and drying.

[0025] Example 6 A method for preparing an S-shaped heterostructure material having a plasma resonance effect comprises the following steps: Step 1: Grind 15 g of melamine precursor material, transfer it to an alumina crucible, and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 420°C, and a holding time of 12 h. The obtained solid powder is refluxed in deionized water for purification and then a white powder is collected; Step 2: Disperse the obtained white powder in 40 mL of 85% hydrazine hydrate solution, and then transfer it to a reactor to obtain a light yellow solution by solvent thermal reaction. The solvent thermal reaction temperature is 160 ° C, and the reaction time is 24 h. After repeatedly dissolving and precipitating the reactants with hydrochloric acid and sodium hydroxide, respectively, a light yellow solid product is obtained after washing and drying; Step 3: Grind the obtained light yellow solid product evenly and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 450°C, and a holding time of 2h. After natural cooling, an orange solid powder is obtained; 100 mg of orange solid powder was dispersed in 50 mL of deionized water, and 5 mL of 2 mg / mL graphene oxide dispersion was added. The mixture was ultrasonically dispersed at 40 kHz for 30 min to obtain a mixed suspension. 3-Aminopropyltriethoxysilane was added to the mixed suspension, and the mixture was heated to 80°C in a water bath and stirred for 6 h. The mixture was washed by centrifugation and dried in a vacuum at 50°C to obtain graphene oxide (GO)-modified C3N5 powder. Step 4: After all the orange solid powder obtained in step 3 is modified with graphene oxide according to the above method, all the products are added to 65 mL of ethanol aqueous solution containing 150 mg of tungsten hexachloride, and transferred to a polytetrafluoroethylene reactor for solvothermal reaction. The solvothermal reaction temperature is 180°C and the reaction time is 24 hours. After the reaction is completed, the S-type heterostructure material with plasma resonance effect is obtained by centrifugation, washing, and drying.

[0026] Example 7 A method for preparing an S-shaped heterostructure material having a plasma resonance effect comprises the following steps: Step 1: Grind 15 g of melamine precursor material, transfer it to an alumina crucible, and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 420°C, and a holding time of 12 h. The obtained solid powder is refluxed in deionized water for purification and then a white powder is collected; Step 2: Disperse the obtained white powder in 40 mL of 85% hydrazine hydrate solution, and then transfer it to a reactor to obtain a light yellow solution through a solvent thermal reaction. The solvent thermal reaction temperature is 160 ° C, and the reaction time is 24 h. After repeatedly dissolving and precipitating the reactants with hydrochloric acid and sodium hydroxide, respectively, a light yellow solid product is obtained after washing and drying; Step 3: Grind the obtained light yellow solid product evenly and calcine it in an air atmosphere furnace at a heating rate of 3°C / min, a reaction temperature of 450°C, and a holding time of 2h. After natural cooling, an orange solid powder is obtained; Step 4: Add the orange solid powder to 65 mL of ethanol aqueous solution containing 150 mg of tungsten hexachloride, add 20 mg of tetrabutyl titanate and 0.5 mL of acetylacetone, premix under 60 kHz ultrasound for 20 minutes, and transfer to a polytetrafluoroethylene reactor for solvothermal reaction at a temperature of 180°C for 24 hours. After the reaction is completed, centrifuge, wash, and dry to obtain an S-type heterostructure material with a plasma resonance effect.

[0027] Figure 1 It can be seen that the one-dimensional nanorod-shaped defective WO in Example 1 3-x Uniformly grown on the two-dimensional C3N5 polymer to form C3N5 / WO 3-x Nanohybrids.

[0028] Figure 2 It can be seen that the nanorod-shaped defective WO in Example 1 3-x Tightly combined with C3N5 polymer, it means the formation of heterogeneous structure.

[0029] Figure 3 It can be seen that the high-resolution N1s spectrum of C3N5 in Example 1 is deconvoluted into two peaks with binding energies of 398.2 eV and 400.3 eV, corresponding to the secondary C=NC group and the residual -NH2 / bridging -N=N- group, respectively.

[0030] Figure 4 It can be seen that in Example 1, the defective WO 3-x The high-resolution W4f spectrum of the deconvolution is divided into three peaks with binding energies of 33.7 eV, 35.4 eV, and 37.4 eV, corresponding to W 4+ 、W 5+ and W 6+, indicating that oxygen vacancies induce the formation of low-valence WW atomic pairs.

[0031] Figure 5 It can be seen that the S-type heterostructure materials with plasma resonance effect obtained by different preparation routes in Examples 1 to 6 have different removal rates of uranium in wastewater. Among them, the S-type heterostructure material with plasma resonance effect prepared in Example 3 has a highest removal rate of 96.1% for uranium in wastewater, and the S-type heterostructure material with plasma resonance effect prepared in Example 5 has a uranium removal rate of 98.4%. At the same time, the removal rates of Examples 6 and 7 are 96.2% and 96.7%, respectively.

[0032] Figure 6 It can be seen that the uranium removal rate of the S-type heterostructure material with plasma resonance effect prepared in Example 3 exceeds 80% in wastewater after 20 minutes, basically reaches equilibrium after 30 minutes, and exceeds 96% in 40 minutes.

[0033] Figure 7 It can be seen that the uranium removal rate of the S-type heterostructure material with plasma resonance effect prepared in Example 3 only slightly decreases under different γ irradiation doses, indicating that the material has good radiation tolerance and has application potential in medium and low-level uranium-containing wastewater.

[0034] The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be readily apparent to those skilled in the art.

[0035] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing an S-type heterostructure material with a plasmon resonance effect, characterized in that: The following steps are involved: Step 1: Grind the precursor material containing or capable of directly preparing the triazine ring and the heptazine ring, transfer it to an alumina crucible, and calcine it in an atmosphere furnace. Collect the obtained solid powder and reflux it in deionized water for purification, and then collect the white powder. Step 2: Disperse the obtained white powder in a hydrazine hydrate solution, then transfer it to a reactor to obtain a light yellow solution through a solvothermal reaction, and repeatedly dissolve and precipitate it using acidic and alkaline reagents, and then wash and dry it to obtain a light yellow solid product; Step 3: Grind the obtained light yellow solid product evenly and calcine it in an atmosphere furnace, and then cool it naturally to obtain an orange solid powder; Step 4: Add the obtained orange solid powder to an organic solvent containing a tungsten source precursor, transfer it to a polytetrafluoroethylene reactor, and perform a solvent thermal reaction. After the reaction is completed, centrifuge, wash, and dry to obtain an S-type heterostructure material with a plasma resonance effect.

2. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: In the step 1, the precursor materials include but are not limited to one or more of urea, melem, melamine, cyanamide, dicyandiamide, thiourea, oxalic acid diamide, and dithiooxamide; the tools required for grinding are not limited to mortar, ball mill, and manual mixing.

3. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: In the step 1, the equipment used for calcination is not limited to a muffle furnace, a vertical atmosphere furnace, or a microwave sintering furnace; the heating rate of the equipment is 3-10°C / min, the reaction temperature is 200-600°C, the holding time is 1-48 hours, and the calcination atmosphere includes but is not limited to air, oxygen, nitrogen, argon, and an inert mixed gas; and the reflux time is 0.5-48 hours.

4. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: The ratio of the precursor material in step 1 to the hydrazine hydrate solution in step 2 is 0.1-50 g:1-100 mL, and the volume concentration of the hydrazine hydrate solution is 30%-99%. The equipment for the solvothermal reaction includes but is not limited to one of a vacuum drying oven, a forced air drying oven, and a muffle furnace. The solvothermal reaction temperature is 80-300° C., and the reaction time is 5-48 h.

5. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: In step 2, the acidic and alkaline reagents include but are not limited to hydrochloric acid, nitric acid, sulfuric acid, acetic acid, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, and ammonia water; the reagents required for washing include but are not limited to water, methanol, ethanol, tetrahydrofuran, and N-methylpyrrolidone.

6. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: In the step 3, the equipment used for calcination includes but is not limited to a muffle furnace, a vertical atmosphere furnace, and a microwave sintering furnace; the required atmosphere includes but is not limited to air, oxygen, nitrogen, argon, and an inert gas mixture; the heating rate of the equipment is 3-10°C / min, the reaction temperature is 300-800°C, and the holding time is 0.5-5h.

7. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: In step 4, the precursor containing the tungsten source includes but is not limited to one or more of sodium tungstate, potassium tungstate, sodium phosphotungstate, tungsten hexachloride, tungsten pentachloride, tungsten tetrachloride, and tungsten dichloride; the organic solvent includes but is not limited to one or more of methanol, ethanol, tetrahydrofuran, and N-methylpyrrolidone, and the ratio of the precursor containing the tungsten source to the organic solvent is 10-1000 mg:10-200 mL; the equipment for the solvent thermal reaction includes but is not limited to a vacuum drying oven, a forced air drying oven, a muffle furnace, etc.; the solvent thermal reaction temperature is 100-250° C., and the reaction time is 3-48 h; the reagents required for washing include but are not limited to one or more of water, methanol, ethanol, tetrahydrofuran, and N-methylpyrrolidone.

8. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: In the steps 1 to 4, the drying of the products at each stage includes but is not limited to natural air drying, freeze drying, supercritical drying, constant temperature heating, and variable temperature heating drying.

9. The method for preparing an S-type heterostructure material having a plasmon resonance effect according to claim 1, wherein: In the steps 1 to 4, taking out or separating the products at each stage includes but is not limited to centrifugation, washing, suction filtration, and filtration.

10. An application of an S-type heterostructure material with a plasmon resonance effect, wherein the S-type heterostructure material with a plasmon resonance effect is prepared by the method for preparing an S-type heterostructure material with a plasmon resonance effect according to any one of claims 1 to 9, characterized in that: The S-type heterostructure material with plasma resonance effect is used as a catalyst for catalytically separating and removing uranium in post-treatment wastewater.

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