SnSe piezoelectric catalyst and preparation method and application thereof
By synergistically regulating pH and hydrothermal temperature, a SnSe piezoelectric catalyst with mixed-valence structure and nanorod morphology was prepared, solving the problems of structural inhomogeneity and polarization field shielding in existing SnSe materials during nucleation and growth, and achieving highly efficient degradation of organic pollutants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-03
AI Technical Summary
Existing SnSe piezoelectric catalysts are highly sensitive to the chemical environment during the nucleation and growth process, which is difficult to precisely control. This results in the piezoelectric polarization field being easily shielded, leading to low electron-hole separation efficiency and making it difficult to meet the high-efficiency degradation requirements of various pollutants in complex wastewater systems.
By precisely adjusting pH and synergistically controlling hydrothermal temperature, mixed-valence structures and nanorod morphologies of SnSe were constructed, optimizing the local electronic structure, suppressing the polarization field shielding effect, and improving lattice polarization capability and mechanical energy transfer efficiency.
It significantly enhances the piezoelectric polarization capability and carrier separation efficiency of SnSe materials, achieving efficient degradation of organic pollutants, especially maintaining stable catalytic performance under complex wastewater conditions, simplifying the preparation process and making it suitable for large-scale production.
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Figure CN121775832A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrocatalytic materials technology, specifically to a SnSe piezoelectric catalyst, its preparation method, and its application. Background Technology
[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
[0003] Wastewater from the dye, pharmaceutical, and chemical industries is complex in composition, containing large amounts of structurally stable and recalcitrant organic pollutants such as methylene blue, posing a serious threat to the aquatic environment. Piezoelectric catalysis, a novel pollutant treatment method developed in recent years, uses mechanical stimulation such as ultrasound and stirring to generate a built-in polarization field in piezoelectric materials, driving electron-hole separation and in-situ generation of reactive oxygen species (ROS). This method does not rely on a light source and has a natural advantage in complex wastewater systems.
[0004] Tin selenide (SnSe), a two-dimensional semiconductor material, is considered an ideal piezoelectric catalytic material due to its non-centrosymmetric crystal structure, which combines piezoelectric properties with chemical stability. However, the piezoelectric catalytic performance of SnSe materials prepared by existing hydrothermal methods is often unsatisfactory. The nucleation and growth process of SnSe is highly sensitive to the chemical environment. 2+ To Sn 4+ The oxidation process is uncontrollable, and the crystal growth direction is difficult to precisely adjust. The resulting products are usually granular or short rod-shaped structures, lacking the high aspect ratio and porous structure that are conducive to enhancing polarization. In addition, the formed SnSe often has a high concentration of free carriers, and its internal piezoelectric polarization field is easily shielded, reducing the electron-hole separation efficiency. This results in a limited variety of active oxygen species and insufficient reactivity, making it difficult to meet the high-efficiency degradation requirements of various pollutants in complex wastewater systems. Summary of the Invention
[0005] To overcome the above problems, the present invention provides a SnSe piezoelectric catalyst, its preparation method and application.
[0006] To achieve the above technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a SnSe piezoelectric catalyst, comprising the following steps: Selenium powder was dispersed in deionized water, and NaBH4 powder was added to obtain a selenium source precursor solution. Sodium ascorbate was dispersed in deionized water, and anhydrous SnCl2 powder was added to obtain a tin source precursor solution. Selenium source precursor solution was added to the tin source precursor solution to obtain a mixed solution. The pH of the mixed solution was adjusted to 2-7, and then the mixed solution was subjected to a hydrothermal reaction. After filtration and drying, the SnSe piezoelectric catalyst was obtained.
[0007] This invention precisely regulates the precursor hydrolysis behavior and Sn through pH adjustment. 2+ / Sn 4+ By achieving redox equilibrium, a stable mixed-valence system was constructed that optimizes the local electronic structure and suppresses the polarization shielding effect. Simultaneously, hydrothermal temperature-driven lattice reconstruction and anisotropic crystal growth were induced, resulting in nanorod morphologies with high aspect ratios and porous surfaces. This morphology significantly increased the specific surface area, improved the exposure of active sites, and enhanced mechanical energy transfer efficiency, effectively overcoming the problems of structural disorder, insufficient aspect ratio, and limited active surface area in existing SnSe catalysts. In other words, through the synergistic regulation of pH and hydrothermal temperature, the nucleation, growth, valence state evolution, and defect structure of SnSe materials were synergistically controlled. Furthermore, Sn inside SnSe was also achieved through pH control. 2+ / Sn 4+ The stable construction of mixed valence states improves the local electronic structure and enhances lattice polarization. Valence state modulation reduces the generation of unproductive free carriers in the material, significantly suppresses the shielding effect of the piezoelectric polarization field, and thus significantly improves the charge separation efficiency under ultrasonic driving.
[0008] In one or more embodiments, the molar ratio of selenium powder to anhydrous SnCl2 powder is 1 to 1.1:1.
[0009] Preferably, the molar ratio of selenium powder to NaBH4 powder is 1:4 to 6. An excess of NaBH4 powder is added to ensure complete reduction of selenium to HSe. - Preferably, the molar ratio of anhydrous SnCl2 powder to sodium ascorbate is 1:2-4. Excess sodium ascorbate is added to inhibit Sn... 2+ Oxidation by air.
[0010] In one or more embodiments, the pH of the mixed solution is adjusted to 4. Under this condition, optimal piezoelectric properties are obtained, and pH has a significant impact on the nucleation, growth, and valence state formation of SnSe. At pH = 4, the hydrolysis behavior of the precursor and Sn... 2+ / Sn 4+ When the redox balance and lattice reconstruction process reach their optimal state, it is beneficial to form nanorod morphologies with high aspect ratio, porous surface and mixed valence structure, thereby enhancing the piezoelectric polarization ability and piezoelectric catalytic performance of the material.
[0011] In one or more embodiments, the temperature of the hydrothermal reaction is 180–220°C.
[0012] Preferably, the hydrothermal reaction temperature is 200℃. Under this condition, the optimal piezoelectric performance can be obtained. The hydrothermal reaction temperature is crucial to the crystal growth and structure formation of SnSe. Temperature directly determines the crystallinity, phase purity, and aspect ratio of the nanorods by precisely controlling the nucleation and growth kinetics of SnSe. The suitable thermal environment of 200℃ ensures the formation of a highly intact orthorhombic phase structure, thereby maximizing the strain-induced spontaneous polarization electric field generated by the material under pressure. This optimized morphology and crystal structure effectively reduces defect trapping of charge during migration, improves the efficiency of mechanical energy to electrical energy conversion and the separation rate of charge carriers, and thus fundamentally enhances the piezoelectric catalytic activity of SnSe. That is, when the temperature is 200℃, SnSe nanorods with uniform structure and excellent performance can be obtained. If the temperature is too low, the reaction kinetics are limited, resulting in slow crystal nucleation and growth rates. The product has low crystallinity and is accompanied by a large number of structural defects, making it impossible to form a complete lattice required to generate a strong spontaneous polarization potential. If the temperature is too high, it may cause excessive coarsening of the crystal, or even lead to the transformation of SnSe into a non-piezoelectric phase (such as SnSe2), which will destroy the original crystal symmetry and cause a significant decrease in the piezoelectric charge generation efficiency.
[0013] In one or more embodiments, the hydrothermal reaction time is 20–24 h.
[0014] Preferably, the hydrothermal reaction time is 24 hours. Under these conditions, the optimal piezoelectric properties can be obtained.
[0015] In one or more embodiments, the drying is carried out in a vacuum drying process at a temperature of 60–80°C for 10–12 hours.
[0016] Secondly, the present invention provides a SnSe piezoelectric catalyst prepared by the aforementioned preparation method.
[0017] Preferably, the SnSe piezoelectric catalyst has a nanorod morphology.
[0018] Preferably, the length of the nanorods is 300-600 nanometers and the diameter of the nanorods is 40-70 nanometers.
[0019] Thirdly, the present invention provides the application of the SnSe piezoelectric catalyst in the piezoelectric catalytic treatment of organic wastewater.
[0020] In one or more embodiments, the organic wastewater contains one or more of the following: methylene blue, tetracycline hydrochloride, carbamazepine, bisphenol A, oxytetracycline, methyl orange, rhodamine B, and acid blue.
[0021] In one or more embodiments, the SnSe piezoelectric catalyst is added to the organic wastewater to be treated and then subjected to ultrasonic treatment.
[0022] Preferably, during ultrasonic treatment, the pH value of the treatment system is 3 to 11.
[0023] Preferably, during ultrasonic treatment, the concentration of organic matter in the treatment system is 5–20 mg / L.
[0024] Preferably, during ultrasonic treatment, the concentration of SnSe piezoelectric catalyst in the treatment system is 0.3~0.5 g / L.
[0025] Preferably, the ultrasonic power during ultrasonic treatment is 30 to 120 W.
[0026] The beneficial effects of this invention are as follows: (1) In a one-step hydrothermal system, the present invention achieves synergistic regulation of SnSe material in nucleation, growth, valence state evolution and defect structure by synergistic regulation of pH and hydrothermal temperature, and successfully constructs a novel piezoelectric catalytic material with mixed valence structure and nanorod morphology, which significantly enhances the piezoelectric polarization ability, carrier separation efficiency and ROS generation ability of the material, and obtains excellent organic pollutant degradation performance.
[0027] (2) First, the high aspect ratio and porous surface of SnSe nanorods greatly increase the specific surface area and active site exposure of the material, thereby improving the efficiency of capturing and transferring mechanical energy (ultrasound). Second, Sn 2+ / Sn 4+ The construction of mixed valence states optimizes the local electronic structure of the material, enhances lattice polarization, and effectively reduces the concentration of ineffective free carriers. These two aspects work together to significantly suppress the effect of piezoelectric field shielding by free carriers, enabling the material to generate a stronger effective piezoelectric potential under ultrasonic irradiation, thereby greatly improving the piezoelectric-induced charge separation efficiency.
[0028] (3) The SnSe piezoelectric catalyst prepared in this invention exhibits rapid reaction rate, high mineralization efficiency, and stable catalytic activity in the degradation of organic pollutants through the combined effect of its mixed-valence structure and nanorod morphology. Under ultrasonic irradiation, it can efficiently generate various reactive oxygen species such as superoxide radicals, hydroxyl radicals, and hydrogen peroxide in situ without any external oxidant or light source, forming a multi-radical synergistic degradation system. This catalyst can achieve efficient degradation of organic pollutants such as methylene blue in a short time and maintain structural integrity and performance stability in multiple cycles; at the same time, it exhibits high efficiency in a wide pH range (3-11) and with multiple coexisting anions (Cl... - SO4 2- NO3 - It can maintain stable catalytic performance even under the presence of conditions such as water quality, overcoming the shortcomings of traditional catalytic materials that are sensitive to water quality, and is suitable for complex actual wastewater treatment scenarios.
[0029] (4) The synthesis process used in this invention is simple, the raw materials are readily available, and the conditions are mild, which can achieve high repeatability and large-scale production. Attached Figure Description
[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0031] Figure 1 This is a TEM image of the SnSe-4 piezoelectric catalyst prepared in Example 1 of this invention; Figure 2 The BET diagram is shown for the SnSe-4 piezoelectric catalyst prepared in Example 1 of this invention. Figure 3 The elemental mapping spectrum of the SnSe-4 piezoelectric catalyst prepared in Example 1 of this invention; Figure 4 XPS (Sn 3d and Se 3d) images of the SnSe-4 piezoelectric catalyst prepared in Example 1 of this invention; Figure 5 The figures show the performance of SnSe piezoelectric catalysts prepared in Examples 1-6 and Comparative Examples 1-2 of this invention in the piezoelectric degradation of methylene blue under ultrasonic (US) irradiation, wherein the ultrasonic power is 60W, pH=7, methylene blue concentration is 10mg / L, and SnSe dosage is 0.4g / L. Figure 6 This is a graph showing the multiple cycle performance of the SnSe-4 piezoelectric catalyst prepared in Example 1 of this invention; Figure 7 The graph shows the performance of SnSe-4 prepared in Example 1 of this invention in the piezoelectric degradation of methylene blue at different concentrations (5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L) under ultrasonic treatment, wherein the ultrasonic power is 60 W, pH = 7, and the SnSe dosage is 0.4 g / L. Figure 8 The graph shows the piezoelectric degradation performance of SnSe-4 prepared in Example 1 of this invention under different dosages (0.3 g / L, 0.4 g / L, 0.5 g / L) at 60 W ultrasound, methylene blue concentration of 10 mg / L, and pH = 7. Figure 9 The graph shows the piezoelectric degradation performance of SnSe-4 prepared in Example 1 of this invention under ultrasonic treatment at different powers (30W, 60W, 90W, 120W) on methylene blue, wherein the methylene blue concentration is 10mg / L, the SnSe-4 dosage is 0.4g / L, and the pH is 7. Figure 10SnSe-4 prepared in Example 1 of this invention under different background substances (20 mM CO3) 2- NO3 - SO4 2- HCO3 - Cl - The performance of piezoelectric degradation of methylene blue in the control group (without background substances) is shown in the figure. The ultrasonic power is 60W, the methylene concentration is 10mg / L, the SnSe-4 dosage is 0.4g / L, and the pH is 7. Figure 11 The graph shows the piezoelectric degradation performance of SnSe-4 prepared in Example 1 of this invention at different pH values (pH=3, 5, 7, 9, 11), wherein the ultrasonic power is 60W, the methylene concentration is 10mg / L, and the SnSe-4 dosage is 0.4g / L. Figure 12 The graph shows the piezoelectric degradation performance of SnSe-4 prepared in Example 1 of this invention in the presence of different masking agents (AgNO3, CAT, p-BQL-histidine, IPA, and No quencher group without masking agent). The masking agent amounts were: AgNO3, 40 mM; IPA, 5 mL; p-BQ, 20 mM; L-histidine, 40 mM; CAT, 1 g / L; ultrasonic power 60 W; pH = 7; methylene blue concentration 10 mg / L; and SnSe dosage 0.4 g / L. Detailed Implementation
[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0033] The present invention will be further described below with reference to the embodiments.
[0034] Example 1 1) Place the rotor into a clean 100 ml beaker, add 30 ml of deionized water, place it on the magnetic stirrer, and turn on the magnetic stirrer.
[0035] 2) Add 0.2 g (0.0025 mol) of selenium powder to the beaker while stirring continuously, stir until dissolved, then add 0.5 g (0.013 mol) of NaBH4 powder and mix thoroughly to obtain NaHSe solution.
[0036] 3) In another beaker, add 30 ml of deionized water, and while stirring, add 1.4 g (0.0071 mol) of sodium ascorbate. Stir until dissolved, then add 0.476 g (0.0025 mol) of anhydrous SnCl2 powder and mix thoroughly to obtain a milky white Sn. 2+ Precursor solution.
[0037] 4) After the NaHSe solution cools to room temperature, then add Sn... 2+ Add NaHSe solution to the precursor solution and mix thoroughly to obtain a Sn-Se precursor mixed solution.
[0038] 5) Adjust the pH of the Sn-Se precursor mixture to 4 using 0.1 M nitric acid. Transfer the pH-adjusted Sn-Se precursor mixture to a 100 ml autoclave and perform a hydrothermal reaction at 200 °C for 24 hours.
[0039] 6) After the reaction is complete, the solution in the reactor is cooled and the solid and liquid are separated. The solid is washed with water three times and then washed with anhydrous ethanol three times. The solid is then dried in a vacuum oven at 70°C for 12 hours to obtain SnSe solid, which is denoted as SnSe-4.
[0040] Figure 1 This is a TEM image of the SnSe-4 piezoelectric catalyst obtained in Example 1. Figure 1 As can be seen, SnSe-4 has a nanorod structure with a length of about 300 nanometers, a diameter of 62.34 nanometers, and a lattice spacing of 0.309 nm. It belongs to the (011) crystal plane of the orthorhombic SnSe system.
[0041] Figure 2 This is the BET plot of the SnSe-4 piezoelectric catalyst obtained in Example 1, from... Figure 2 As can be seen, the specific surface area of SnSe-4 is 33.78 m² / g, which is significantly greater than that of SnSe-initial (10.8 m² / g). This is attributed to the selective H+ ionization during growth. + Etching induces a hierarchical porous structure and exposes more active surface sites.
[0042] Figure 3 This is the elemental mapping spectrum of the SnSe-4 piezoelectric catalyst prepared in Example 1, from... Figure 3 As can be seen, Sn and Se elements are uniformly distributed on the surface of SnSe, which proves the successful preparation of SnSe.
[0043] Figure 4 The image shows XPS (Sn 3d and Se 3d) plots of SnSe-4 obtained in Example 1. Figure 4As can be seen from the data, the test yielded Sn 3d. 3 / 2 and Sn 3d 5 / 2 Characteristic peaks of two types of Sn, and Se 3d 3 / 2 and Se 3d 5 / 2 Characteristic peaks of both Se types were observed. Furthermore, a distinct peak splitting phenomenon was observed in the Sn 3d spectrum, indicating mixed valence states of Sn. 2+ / Sn 4+ coexist.
[0044] Example 2 Unlike Example 1, in step 5), the pH of the Sn-Se precursor mixed solution was adjusted to 2 using 0.1 M nitric acid. The other preparation methods were the same as in Example 1, and it was referred to as SnSe-2.
[0045] Example 3 Unlike Example 1, in step 5), the pH of the Sn-Se precursor mixed solution was adjusted to 3 using 0.1 M nitric acid. The other preparation methods were the same as in Example 1, and it was denoted as SnSe-3.
[0046] Example 4 Unlike Example 1, in step 5), the pH of the Sn-Se precursor mixed solution was adjusted to 5 using 0.1 M nitric acid. The other preparation methods were the same as in Example 1, and it was denoted as SnSe-5.
[0047] Example 5 Unlike Example 1, in step 5), the pH of the Sn-Se precursor mixed solution was adjusted to 6 using 0.1 M nitric acid. The other preparation methods were the same as in Example 1, and it was referred to as SnSe-6.
[0048] Example 6 Unlike Example 1, in step 5), the pH of the Sn-Se precursor mixed solution was adjusted to 7 using 0.1 M nitric acid. The other preparation methods were the same as in Example 1, and it was referred to as SnSe-7.
[0049] Comparative Example 1 1) Place the rotor into a clean 100 ml beaker, add 30 ml of deionized water, place it on the magnetic stirrer, and turn on the magnetic stirrer.
[0050] 2) Add 0.2 g (0.0025 mol) of selenium powder to the beaker while stirring continuously, stir until dissolved, then add 0.5 g (0.013 mol) of NaBH4 powder and mix thoroughly to obtain NaHSe solution.
[0051] 3) In another beaker, add 30 ml of deionized water, and while stirring, add 1.4 g (0.0071 mol) of sodium ascorbate. Stir until dissolved, then add 0.476 g (0.0025 mol) of anhydrous SnCl2 powder and mix thoroughly to obtain a milky white Sn. 2+ Precursor solution.
[0052] 4) After the NaHSe solution cools to room temperature, then add Sn... 2+ Add NaHSe solution to the precursor solution and mix thoroughly to obtain a Sn-Se precursor mixed solution.
[0053] 5) Transfer the Sn-Se precursor mixture to a 100ml autoclave and hydrothermally react at 200℃ for 24 hours.
[0054] 6) After the reaction is complete, the solution in the reactor is cooled and the solid and liquid are separated. The solid is washed with water three times and then with anhydrous ethanol three times. The solid is then dried in a vacuum oven at 70°C for 12 hours to obtain SnSe solid, which is denoted as SnSe-initial.
[0055] Comparative Example 2 Unlike Example 1, in step 5), the pH of the Sn-Se precursor mixed solution was adjusted to 10 using 0.1 M sodium hydroxide solution. The other preparation methods were the same as in Example 1, and this was referred to as SnSe-10.
[0056] Comparative Example 3 1) Place the rotor into a clean 100 ml beaker, add 30 ml of deionized water, place it on the magnetic stirrer, and turn on the magnetic stirrer.
[0057] 2) Add 0.2 g (0.0025 mol) of selenium powder to the beaker while stirring continuously, stir until dissolved, then add 0.5 g (0.013 mol) of NaBH4 powder and mix thoroughly to obtain NaHSe solution.
[0058] 3) In another beaker, add 30 ml of deionized water, and while stirring, add 1.4 g (0.0071 mol) of sodium ascorbate. Stir until dissolved, then add 0.476 g (0.0025 mol) of anhydrous SnCl2 powder and mix thoroughly to obtain a milky white Sn. 2+ Precursor solution.
[0059] 4) After the NaHSe solution cools to room temperature, then add Sn... 2+ Add NaHSe solution to the precursor solution and mix thoroughly to obtain a Sn-Se precursor mixed solution.
[0060] 5) Adjust the pH of the Sn-Se precursor mixture to 4 using 0.1 M nitric acid, and let the pH-adjusted Sn-Se precursor mixture stand at room temperature for 24 hours.
[0061] 6) After the reaction is complete, the solution is separated into solid and liquid. The solid is washed three times with water and then three times with anhydrous ethanol. The solid is then dried in a vacuum oven at 70°C for 12 hours to obtain SnSe solid, denoted as SnSe-4-normal T.
[0062] Comparative Example 4 1) Place the rotor into a clean 100 ml beaker, add 30 ml of deionized water, place it on the magnetic stirrer, and turn on the magnetic stirrer.
[0063] 2) Add 0.2 g (0.0025 mol) of selenium powder to the beaker while stirring continuously, stir until dissolved, then add 0.5 g (0.013 mol) of NaBH4 powder and mix thoroughly to obtain NaHSe solution.
[0064] 3) In another beaker, add 30 ml of deionized water, and while stirring, add 1.4 g (0.0071 mol) of sodium ascorbate. Stir until dissolved, then add 0.476 g (0.0025 mol) of anhydrous SnCl2 powder and mix thoroughly to obtain a milky white Sn. 2+ Precursor solution.
[0065] 4) After the NaHSe solution cools to room temperature, then add Sn... 2+ Add NaHSe solution to the precursor solution and mix thoroughly to obtain a Sn-Se precursor mixed solution.
[0066] 5) Let the Sn-Se precursor mixture stand at room temperature for 24 hours.
[0067] 6) After the reaction is complete, the solution is separated into solid and liquid. The solid is washed three times with water and then three times with anhydrous ethanol. The solid is then dried in a vacuum oven at 70°C for 12 hours to obtain SnSe solid, denoted as SnSe-initial-normalT.
[0068] Piezoelectric degradation performance test The SnSe synthesized according to the above synthesis method was used to conduct a piezoelectric degradation effect test on organic pollutants, represented by methylene blue.
[0069] The specific operating steps and methods are described below: Add an appropriate amount of SnSe to a beaker containing a methylene blue solution of a certain concentration. Use an ultrasonic generator with a certain power to induce the piezoelectric degradation effect of SnSe, causing it to degrade the methylene blue. The reaction time is 15 minutes. Before turning on the ultrasonic generator, the beaker containing the methylene blue solution with the added SnSe should be placed in the dark and left to stand for 120 minutes to eliminate any potential influence of SnSe adsorption on the experiment.
[0070] Starting from the start of the ultrasonic generator, a certain amount of solution was collected from the beaker at 1, 2, 3, 4, 5, 6, 9, 12, and 15 minutes. After passing through a 0.22 μm membrane, the effect of SnSe piezoelectric degradation of organic pollutants was tested using ultraviolet-high performance liquid chromatography.
[0071] The piezoelectric degradation performance of SnSe was tested using methylene blue as the degradation target. Figure 5 This indicates that different pH conditions affect the piezoelectric properties of the final material, with SnSe-4 prepared in Example 1 showing the best degradation effect. Comparing Example 1 with Comparative Example 3 shows that hydrothermal temperature affects the piezoelectric properties of the final material. Comparing Example 1 with Comparative Example 4 shows that the SnSe-4 prepared in Example 1 achieves the best degradation effect through the synergistic regulation of pH and hydrothermal temperature.
[0072] The stability of SnSe-4 was further investigated. Figure 6 This indicates that the degradation effect of SnSe-4 is stable after multiple cycles.
[0073] The degradation performance of SnSe-4 under different methylene blue substrate concentrations, different catalyst dosages, different ultrasonic powers, different background substances, and different pH values was also investigated. See details below. Figure 7-11 It can be seen that SnSe-4 achieves excellent degradation effects under different methylene blue substrate concentrations, different catalyst dosages, different ultrasonic powers, different background substances, and different pH values.
[0074] Figure 12 The graph shows the piezoelectric degradation performance of SnSe-4 prepared in Example 1 of this invention under different masking agents (AgNO3, CAT, p-BQL-histidine, IPA, and No quencher group without masking agent). AgNO3 is the e - The masking agent, IPA is • OH masking agent, P-BQ is O2 •- The masking agent, L-histidine is 1 CAT is a masking agent for O2 and for H2O2. For example... Figure 10 As shown, e- / h + It is a core prerequisite for the formation of bioactive species. IPA and L-histidine only weakly inhibit degradation, indicating that... • OH and 1 O2 has a minor effect; p-BQ reduces degradation efficiency, indicating that O2 •- It makes a certain contribution; the degradation efficiency of CAT (1 g / L) after removing H2O2 is 72.74%, which confirms that H2O2 can be generated in situ in the system.
[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a SnSe piezoelectric catalyst, characterized in that, Includes the following steps: Selenium powder was dispersed in deionized water, and NaBH4 powder was added to obtain a selenium source precursor solution. Sodium ascorbate was dispersed in deionized water, and anhydrous SnCl2 powder was added to obtain a tin source precursor solution. Selenium source precursor solution was added to the tin source precursor solution to obtain a mixed solution. The pH of the mixed solution was adjusted to 2-7, and then the mixed solution was subjected to a hydrothermal reaction. After filtration and drying, the SnSe piezoelectric catalyst was obtained.
2. The preparation method according to claim 1, characterized in that, The molar ratio of selenium powder to anhydrous SnCl2 powder is 1~1.1:1; Preferably, the molar ratio of selenium powder to NaBH4 powder is 1:4 to 6; Preferably, the molar ratio of anhydrous SnCl2 powder to sodium ascorbate is 1:2 to 4.
3. The preparation method according to claim 1, characterized in that, Adjust the pH of the mixed solution to 4.
4. The preparation method according to claim 1, characterized in that, The hydrothermal reaction temperature is 180–220 ℃; Preferably, the hydrothermal reaction temperature is 200℃.
5. The preparation method according to claim 1, characterized in that, The hydrothermal reaction time is 20–24 h; Preferably, the hydrothermal reaction time is 24 h.
6. The preparation method according to claim 1, characterized in that, The drying is carried out in a vacuum, at a temperature of 60–80°C, for a time of 10–12 hours.
7. A SnSe piezoelectric catalyst, characterized in that: By claim 1 6. Prepared by any of the preparation methods described above; Preferably, the SnSe piezoelectric catalyst has a nanorod morphology; Preferably, the length of the nanorods is 300-600 nanometers and the diameter of the nanorods is 40-70 nanometers.
8. The application of the SnSe piezoelectric catalyst according to claim 7 in the piezoelectric catalytic treatment of organic wastewater.
9. The application as described in claim 8, characterized in that, The organic wastewater contains one or more of the following: methylene blue, tetracycline hydrochloride, carbamazepine, bisphenol A, oxytetracycline, methyl orange, rhodamine B, and acid blue.
10. The application as described in claim 8, characterized in that, The SnSe piezoelectric catalyst was added to the organic wastewater to be treated and then subjected to ultrasonic treatment. Preferably, during ultrasonic treatment, the pH value of the treatment system is 3 to 11; Preferably, during ultrasonic treatment, the concentration of organic matter in the treatment system is 5–20 mg / L; Preferably, during ultrasonic treatment, the concentration of SnSe piezoelectric catalyst in the treatment system is 0.3~0.5 g / L; Preferably, the ultrasonic power during ultrasonic treatment is 30 to 120 W.