A self-floating triazine-based polymer nanosheet photocatalyst, its preparation method and application

Abstract

This invention relates to the field of powder photocatalyst technology, specifically disclosing a self-floating triazine-based polymer nanosheet photocatalyst, its preparation method, and its application. The preparation method involves using melamine and 4,4'-biphenyl dicarboxylic acid to prepare a supramolecular precursor, which is then calcined and placed in a mixed solution of acetone and ethanol for prolonged light irradiation to obtain Pt nanoparticle-supported self-floating triazine-based polymer. This polymer can stably float on water and possesses oxygen adsorption capabilities, allowing it to adsorb oxygen from the air and participate in the photocatalytic H2O2 production reaction. This eliminates the need for additional catalytic material deposition on a buoyancy medium, solving the problem that most existing powder photocatalysts require additional catalytic material deposition on a buoyancy medium to achieve stable floating on water. Furthermore, the preparation method provided by this invention is simple and has broad market prospects.

Description

Technical Field

[0001] This invention relates to the field of powder photocatalyst technology, specifically a self-floating triazine-based polymer nanosheet photocatalyst, its preparation method, and its application. Background Technology

[0002] Photocatalysis, as a highly efficient, safe, and environmentally friendly purification technology, generally relies on the redox capabilities of photocatalysts under sunlight to purify pollutants, synthesize substances, and transform them. For example, hydrogen peroxide (H₂O₂) is an important inorganic chemical product widely used in pulp bleaching, organic synthesis, environmental remediation, disinfection, fuel cells, and military applications due to its green and clean characteristics, with an annual demand of approximately 4 million tons. Typically, hydrogen peroxide is prepared via anthraquinone processes, which consume significant amounts of energy and generate substantial chemical waste. Therefore, using photocatalysts to produce H₂O₂ through the photocatalytic reaction of water and O₂ under sunlight is a clean and safe preparation method with great potential compared to other H₂O₂ preparation methods.

[0003] Currently, most reported photocatalysts exist in the form of micro or nanoparticles, which limits their widespread application in real-world water treatment systems. Small-sized powders are also difficult to recycle, and their metal leakage risks endanger the environment. Furthermore, due to the limited penetration depth of light, the activity of suspended photocatalysts located far from the water surface is significantly reduced. To address these issues, floating photocatalysts are generally used to mitigate the significant reduction in activity. Floating photocatalysts are placed closer to the water surface, allowing them to receive more sunlight, thus greatly improving light utilization. However, most reported floating photocatalysts involve depositing the catalytic material on a buoyancy medium.

[0004] Therefore, the existing technical solutions mentioned above have the following drawbacks: Existing powdered photocatalysts usually require additional deposition of the catalytic material on a buoyancy medium in order to stably float on the water surface and thus improve the utilization rate of light. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a self-floating triazine-based polymer nanosheet photocatalyst, in order to solve the problem mentioned in the background art that most existing powder photocatalysts require additional deposition of the catalytic material on a buoyancy medium to float stably on the water surface.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] A method for preparing a self-floating triazine-based polymer nanosheet photocatalyst includes the following steps:

[0008] 1) Melamine and 4,4'-biphenyl dicarboxylic acid were stirred in water in a certain proportion, and then freeze-dried to obtain a white solid, which served as a supramolecular precursor;

[0009] 2) Calcine the white solid obtained in step 1), and after cooling to room temperature, a dark brown solid is obtained, which is a self-floating triazine polymer that can stably float on the water surface.

[0010] 3) The dark brown solid obtained in step 2) and the chloroplatinic acid solution were placed in a mixed solution of acetone and ethanol and irradiated for a long time to obtain a light brown solid. The light brown solid was then washed and dried to obtain a self-floating triazine-based polymer nanosheet photocatalyst, namely, a self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles.

[0011] This invention provides a novel method for preparing a self-floating triazine-based polymer nanosheet photocatalyst. The Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst prepared using this method floats well in water, remaining stable even under simulated natural environments such as oscillation and stirring. Furthermore, it possesses oxygen adsorption capabilities, enabling it to adsorb oxygen from the air and participate in the photocatalytic H₂O₂ production reaction.

[0012] Preferably, the molar ratio of melamine to 4,4'-biphenyl dicarboxylic acid in step 1) is 0.8-1.2:1-2, and the mass-volume ratio of 4,4'-biphenyl dicarboxylic acid to water is 0.005-0.01:1 g / ml.

[0013] Preferably, the stirring reaction time in step 1) is 5-7 hours.

[0014] Preferably, the calcination temperature in step 2) is 350-450℃, the calcination time is 2-3h, and the heating rate is 4-6℃ / min.

[0015] Preferably, the mass-to-volume ratio of the dark brown solid to chloroplatinic acid in step 3) is 0.07-0.09:1 g / ml, the volume ratio of acetone to ethanol is 1-3:1, and the illumination time is 10-14 h.

[0016] Another objective of this invention is to provide a self-floating triazine-based polymer nanosheet photocatalyst prepared by the above-described preparation method.

[0017] Another objective of this invention is to provide an application of the above-mentioned method for preparing self-floating triazine-based polymer nanosheet photocatalysts in the preparation of other types of powder photocatalysts, and the application of the photocatalyst prepared by this method as a novel self-floating triazine-based polymer nanosheet photocatalyst in the photocatalytic production of hydrogen peroxide (H2O2). Of course, this photocatalyst can also be applied to other catalytic scenarios as needed, which will not be elaborated here. It not only floats stably on the water surface, but also remains stable on the water surface even when simulated by oscillation and stirring, eliminating the need to deposit the catalytic material on a buoyancy medium, thus greatly improving the utilization rate of light.

[0018] Compared with the prior art, the beneficial effects of the embodiments of the present invention are:

[0019] The method for preparing a self-floating triazine-based polymer nanosheet photocatalyst provided in this invention involves using melamine and 4,4'-biphenyl dicarboxylic acid to prepare a supramolecular precursor, which is then calcined and placed in a mixed solution of acetone and ethanol for prolonged illumination to obtain a Pt nanoparticle-supported self-floating triazine-based polymer. This method can improve the photocatalytic H2O2 production capacity while maintaining the self-floating effect. Furthermore, the preparation method provided in this invention is simple. The composite photocatalyst prepared by this method can stably float on the water surface and has oxygen adsorption capacity, enabling it to adsorb oxygen from the air to participate in the photocatalytic H2O2 production reaction. This eliminates the need to separately deposit the catalyst material on a buoyancy medium, solving the problem that most existing powder photocatalysts require separate deposition on a buoyancy medium to achieve stable floating on water. The preparation method of this invention not only yields a powder photocatalyst that can stably float on the water surface, but also shows that the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst exhibits a 7-fold increase in photocatalytic H2O2 production activity compared to the unsupported Pt. Meanwhile, this preparation method can also be used to prepare other types of photocatalysts that require self-floating effects, and has broad market prospects. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

[0021] Figure 1 The images shown are high-resolution transmission electron microscope (HRTEM) images of the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles obtained in Example 1 of this invention and the lattice stripe pattern of Pt. Figure (a) is a high-resolution transmission electron microscope image, and Figure (b) is the lattice stripe pattern of Pt.

[0022] Figure 2The X-ray diffraction (XRD) patterns of the self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles obtained in Example 1 of this invention and the self-floating triazine-based polymer photocatalyst without Pt nanoparticles in Comparative Example 1 are shown.

[0023] Figure 3 The Fourier transform infrared (FT-IR) spectra of the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles obtained in Example 1 of this invention and the self-floating triazine-based polymer photocatalyst without Pt nanoparticles in Comparative Example 1 are shown.

[0024] Figure 4 The carbon NMR spectra of the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst obtained in Example 1 of this invention and the self-floating triazine-based polymer photocatalyst without Pt nanoparticle support in Comparative Example 1 are shown.

[0025] Figure 5 The images show the C1s X-ray photoelectron spectra of the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles obtained in Example 1 of this invention and the self-floating triazine-based polymer photocatalyst without Pt nanoparticles in Comparative Example 1.

[0026] Figure 6 The N1s spectra of the X-ray photoelectron spectroscopy of the self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles obtained in Example 1 of this invention and the self-floating triazine-based polymer photocatalyst without Pt nanoparticles in Comparative Example 1 are shown.

[0027] Figure 7 The O1s spectra of the X-ray photoelectron spectroscopy of the self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles obtained in Example 1 of this invention and the self-floating triazine-based polymer photocatalyst without Pt nanoparticles in Comparative Example 1 are shown.

[0028] Figure 8 This is the Pt4f spectrum of the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles obtained in Example 1 of this invention.

[0029] Figure 9 These are images showing the water contact angles of the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst obtained in Example 1 of this invention and the unsupported Pt nanoparticle self-floating triazine-based polymer photocatalyst in Comparative Example 1.

[0030] Figure 10 These are images of the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles obtained in Example 1 of this invention, and the self-floating triazine-based polymer photocatalyst without Pt nanoparticles in Comparative Example 1, floating on the water surface.

[0031] Figure 11 The graphs show the yield of H2O2 under visible light when the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst obtained in Example 1 of this invention, the self-floating triazine-based polymer photocatalyst without Pt nanoparticle support in Comparative Example 1, and the self-floating triazine-based polymer photocatalyst without Pt nanoparticle support in Comparative Example 2 are directly added to chloroplatinic acid solution.

[0032] Figure 12 This is a graph showing the yield of H2O2 under long-term visible light for the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles obtained in Example 1 of this invention.

[0033] Figure 13 The photocurrent diagrams are of the self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles obtained in Example 1 of this invention and the self-floating triazine-based polymer photocatalyst without Pt nanoparticles in Comparative Example 1 (from the periodic current diagram, the periodic photocurrent of Pt@MBP is greater than that generated by MBP).

[0034] Figure 14 The impedance diagrams (EIS) are of the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst obtained in Example 1 of this invention and the unsupported Pt nanoparticle self-floating triazine-based polymer photocatalyst in Comparative Example 1. Detailed Implementation

[0035] To make the technical problems, technical solutions, and beneficial effects of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the following embodiments will help those skilled in the art to further understand the embodiments of this invention, but do not limit the embodiments of this invention in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the embodiments of this invention. These all fall within the protection scope of the embodiments of this invention. Unless otherwise specified, the experimental materials and reagents used in this document are all commercially available products conventionally available in this technical field.

[0036] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0037] This invention provides a method for preparing a novel self-floating triazine-based polymer nanosheet photocatalyst, specifically a method for preparing such a photocatalyst, which includes the following steps:

[0038] 1) Melamine and 4,4'-biphenyl dicarboxylic acid were stirred in water in a certain proportion, and then freeze-dried to obtain a white solid, which served as a supramolecular precursor;

[0039] 2) Calcine the white solid obtained in step 1), and after cooling to room temperature, a dark brown solid is obtained, which is a self-floating triazine polymer that can stably float on the water surface.

[0040] 3) The dark brown solid obtained in step 2) and the chloroplatinic acid solution were placed in a mixed solution of acetone and ethanol and irradiated for a long time to obtain a light brown solid. The light brown solid was then washed and dried to obtain a self-floating triazine-based polymer nanosheet photocatalyst, namely, a self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles.

[0041] Further preferably, the preparation method of the self-floating triazine-based polymer nanosheet photocatalyst includes the following steps: (1) stirring melamine and 4,4'-biphenyl dicarboxylic acid in an aqueous solution, and freeze-drying to obtain a supramolecular precursor; (2) calcining the supramolecular precursor obtained in step (1), and cooling it to room temperature to obtain a self-floating triazine-based polymer that can stably float on the water surface; (3) placing the self-floating triazine-based polymer obtained in step (2) and a chloroplatinic acid solution in a mixed solution of acetone and ethanol for long-term light irradiation, and filtering to obtain a self-floating triazine-based polymer supported on Pt nanoparticles. The composite photocatalytic material prepared by this method can stably float on the water surface and has oxygen adsorption capacity, enabling it to adsorb oxygen from the air and participate in the photocatalytic H2O2 production reaction.

[0042] In another preferred embodiment of the present invention, in the preparation method of the self-floating triazine-based polymer nanosheet photocatalyst, the molar ratio of melamine to 4,4'-biphenyl dicarboxylic acid in step 1) is 0.8-1.2:1-2, and the mass-volume ratio of 4,4'-biphenyl dicarboxylic acid to water is 0.005-0.01:1 g / ml.

[0043] In another preferred embodiment of the present invention, the molar ratio of melamine to 4,4'-biphenyl dicarboxylic acid in step 1) is 1:1.5, and the mass-volume ratio of 4,4'-biphenyl dicarboxylic acid to water is 0.007:1 g / ml.

[0044] More preferably, the stirring reaction time in step 1) is 5-7 hours.

[0045] In another preferred embodiment of the present invention, in the preparation method of the self-floating triazine-based polymer nanosheet photocatalyst, the calcination temperature in step 2) is 350-450℃, the calcination time is 2-3h, and the heating rate is 4-6℃ / min.

[0046] In another preferred embodiment of the present invention, in the preparation method of the self-floating triazine-based polymer nanosheet photocatalyst, the calcination temperature in step 2) is 400°C, the calcination time is 2.5 h, and the heating rate is 5°C / min.

[0047] In another preferred embodiment of the present invention, in the preparation method of the self-floating triazine-based polymer nanosheet photocatalyst, the mass-to-volume ratio of the dark brown solid to chloroplatinic acid in step 3) is 0.07-0.09:1 g / ml, the volume ratio of acetone to ethanol is 1-3:1, and the irradiation time is 10-14 h.

[0048] Furthermore, in step 3), the mass-to-volume ratio of the dark brown solid to chloroplatinic acid is 0.08:1 g / ml, the volume ratio of acetone to ethanol is 2:1, and the illumination time is 12 h.

[0049] Step 3) The specific steps for obtaining the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst by washing and drying the light brown solid are as follows: the suspension in the reactor is placed in a vacuum filtration device and washed with ethanol multiple times by vacuum filtration. After drying, the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst is obtained.

[0050] As another preferred embodiment of the present invention, the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst can float stably on the water surface for a long time.

[0051] The present invention also provides a self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles prepared by the above preparation method, namely a self-floating triazine-based polymer nanosheet photocatalyst.

[0052] The composite photocatalytic material prepared by this invention can float stably on the water surface and has the ability to adsorb oxygen from the air to participate in the photocatalytic H2O2 production reaction.

[0053] This invention also provides an application of the above-described method for preparing self-floating triazine-based polymer nanosheet photocatalysts in the preparation of various photocatalysts. It is particularly suitable for preparing photocatalysts for the photocatalytic production of hydrogen peroxide (H₂O₂) in pure water.

[0054] As another preferred embodiment of the present invention, the application of the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst in the photocatalytic production of H2O2 specifically includes the following steps:

[0055] S1. Take the Pt nanoparticle-supported self-floating triazine polymer photocatalyst into a reactor, add an isopropanol aqueous solution, and stir to make the Pt nanoparticle-supported self-floating triazine polymer photocatalyst evenly dispersed in the isopropanol aqueous solution.

[0056] S2. Pass oxygen into the reactor from step S1, stir, and irradiate with a 300W xenon lamp to obtain H2O2.

[0057] In step S1, the Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst is placed in 30 ml of distilled water.

[0058] Furthermore, the illumination time in step S2 is 60 minutes.

[0059] The following specific embodiments further illustrate the technical effects of the photocatalyst prepared by the method for preparing self-floating triazine-based polymer nanosheet photocatalysts according to the present invention. In the following embodiments, the power of the xenon lamp is 300W.

[0060] Example 1

[0061] A method for preparing a self-floating triazine-based polymer nanosheet photocatalyst, specifically a method for preparing a self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles, includes the following steps:

[0062] (1) Weigh 0.36g of 4,4'-biphenyldicarboxylic acid and 0.126g of melamine, put them in a glass beaker, add 50ml of distilled water, and sonicate in an ultrasonic cleaner for 2 hours at room temperature, and then stir on an electromagnetic stirrer for 5 hours.

[0063] (2) After the stirring reaction in step (1) is completed, the reaction solution is centrifuged in a centrifuge and washed twice with water;

[0064] (3) The solid material obtained after centrifugation and washing in step (2) is dried in a vacuum freeze dryer for 12 hours to obtain a white solid.

[0065] (4) The white solid obtained in step (3) is placed in a muffle furnace for calcination treatment, specifically calcined at 400℃ for 2.5h at a heating rate of 5℃ / min. After cooling to room temperature, a dark brown solid is obtained, which is denoted as MBP.

[0066] (5) Place the dark brown solid obtained in step (4) into a reactor, add 1 ml of 0.5 wt% chloroplatinic acid, place it in a mixed solution of 20 ml acetone and 10 ml ethanol, and irradiate for 12 h to obtain a light brown solid. After cleaning and drying, the light brown solid is used to obtain a Pt nanoparticle-supported self-floating triazine-based polymer photocatalyst, denoted as Pt@MBP.

[0067] Example 2

[0068] The application of Pt nanoparticle-supported self-floating triazine-based polymer photocatalysts specifically includes the following steps:

[0069] S1. Take 0.005g of MBP obtained in Example 1 into a reactor and add 30ml of distilled water.

[0070] S2. Place the reaction flask from step S1 on a stirring table, pass O2 through for 30 minutes, and irradiate with a 300W xenon lamp for 1 hour.

[0071] S3. After exposure to light, take 1 ml of the reaction solution and filter it.

[0072] S4. Add 1 ml of the filtrate from step S3 to 1 ml of 0.4 mol / L potassium iodide solution and 1 ml of 0.1 mol / L potassium cyanide phthalate solution, shake well, and measure the absorbance using a UV-Vis spectrophotometer. Calculate the H2O2 concentration based on the absorbance.

[0073] Example 3

[0074] The application of Pt nanoparticle-supported self-floating triazine-based polymer photocatalysts specifically includes the following steps:

[0075] S1. Take 0.005g of Pt@MBP obtained in Example 1 into the reactor and add 30ml of distilled water.

[0076] S2. Place the reaction flask from step S1 on a stirring table, turn on O2 for 30 minutes, and irradiate with a 300W xenon lamp for 1 hour.

[0077] S3. After exposure to light, take 1 ml of the reaction solution and filter it.

[0078] S4. Add 1 ml of the filtrate from step S3 to 1 ml of 0.4 mol / L potassium iodide solution and 1 ml of 0.1 mol / L potassium cyanide phthalate solution, shake well, and measure the absorbance using a UV-Vis spectrophotometer. Calculate the H2O2 concentration based on the absorbance.

[0079] Specific results are as follows Figure 1-14 As shown, Pt@MBP performs significantly better than MBP.

[0080] Example 4

[0081] The application of Pt nanoparticle-supported self-floating triazine-based polymer photocatalysts specifically includes the following steps:

[0082] S1. Take 0.005 g MBP obtained in Example 1 into a reactor, add 90 μL of chloroplatinic acid solution and 30 ml of distilled water.

[0083] S2. Place the reaction flask from step S1 on a stirring table, turn on O2 for 30 minutes, and irradiate with a 300W xenon lamp for 1 hour.

[0084] S3. After exposure to light, take 1 ml of the reaction solution and filter it.

[0085] S4. Add 1 ml of the filtrate from step S3 to 1 ml of 0.4 mol / L potassium iodide solution and 1 ml of 0.1 mol / L potassium cyanide phthalate solution, shake well, and measure the absorbance using a UV-Vis spectrophotometer. Calculate the H2O2 concentration based on the absorbance.

[0086] Example 5

[0087] A method for preparing a self-floating triazine-based polymer nanosheet photocatalyst, specifically including the following steps:

[0088] 1) Melamine and 4,4'-biphenyl dicarboxylic acid were stirred in water in a certain proportion, and then freeze-dried to obtain a white solid, which served as a supramolecular precursor;

[0089] 2) Calcine the white solid obtained in step 1), and after cooling to room temperature, a dark brown solid is obtained, which is a self-floating triazine polymer that can stably float on the water surface.

[0090] 3) The dark brown solid obtained in step 2) and the chloroplatinic acid solution were placed in a mixed solution of acetone and ethanol and irradiated for a long time to obtain a light brown solid. The light brown solid was then washed and dried to obtain a self-floating triazine-based polymer nanosheet photocatalyst, namely, a self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles.

[0091] In this embodiment, the molar ratio of melamine to 4,4'-biphenyl dicarboxylic acid in step 1) is 0.8:2, and the mass-to-volume ratio of 4,4'-biphenyl dicarboxylic acid to water is 0.005:1 g / ml, with a stirring reaction time of 5 hours. In step 2), the calcination temperature is 350°C, the calcination time is 2 hours, and the heating rate is 4°C / min. In step 3), the mass-to-volume ratio of the dark brown solid to chloroplatinic acid is 0.07:1 g / ml, the volume ratio of acetone to ethanol is 1:1, and the illumination time is 10 hours.

[0092] Example 6

[0093] A method for preparing a self-floating triazine-based polymer nanosheet photocatalyst, specifically including the following steps:

[0094] 1) Melamine and 4,4'-biphenyl dicarboxylic acid were stirred in water in a certain proportion, and then freeze-dried to obtain a white solid, which served as a supramolecular precursor;

[0095] 2) Calcine the white solid obtained in step 1), and after cooling to room temperature, a dark brown solid is obtained, which is a self-floating triazine polymer that can stably float on the water surface.

[0096] 3) The dark brown solid obtained in step 2) and the chloroplatinic acid solution were placed in a mixed solution of acetone and ethanol and irradiated for a long time to obtain a light brown solid. The light brown solid was then washed and dried to obtain a self-floating triazine-based polymer nanosheet photocatalyst, namely, a self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles.

[0097] In this embodiment, the molar ratio of melamine to 4,4'-biphenyl dicarboxylic acid in step 1) is 1.2:1, and the mass-to-volume ratio of 4,4'-biphenyl dicarboxylic acid to water is 0.01:1 g / ml, with a stirring reaction time of 7 hours. In step 2), the calcination temperature is 450°C, the calcination time is 3 hours, and the heating rate is 6°C / min. In step 3), the mass-to-volume ratio of the dark brown solid to chloroplatinic acid is 0.09:1 g / ml, the volume ratio of acetone to ethanol is 3:1, and the illumination time is 14 hours.

[0098] Example 7

[0099] Compared with Example 5, except that the calcination was carried out at 420°C for 2 hours and the heating rate was 5°C / min, everything else was the same as Example 5.

[0100] Example 8

[0101] Compared with Example 5, except that the molar ratio of melamine to 4,4'-biphenyldicarboxylic acid is 1.1:1.6 and the mass-volume ratio of 4,4'-biphenyldicarboxylic acid to water is 0.009:1 g / ml, everything else is the same as Example 5.

[0102] Comparative Example 1

[0103] The preparation method of the self-floating triazine-based polymer photocatalyst without Pt nanoparticle loading is the same as that of Example 1, except that it is without Pt loading. The specific preparation method is as follows:

[0104] (1) Weigh 0.36g of 4,4'-biphenyldicarboxylic acid and 0.126g of melamine, put them in a glass beaker, add 50ml of distilled water, and sonicate them in an ultrasonic cleaner for 2 hours at room temperature, and then stir them on an electromagnetic stirrer for 5 hours.

[0105] (2) After the stirring reaction in step (1) is completed, the reaction solution is centrifuged in a centrifuge and washed twice with water;

[0106] (3) The solid material obtained after centrifugation and washing in step (2) is dried in a vacuum freeze dryer for 12 hours to obtain a white solid.

[0107] (4) The white solid obtained in step (3) is placed in a muffle furnace for calcination treatment, specifically calcined at 400℃ for 2.5h at a heating rate of 5℃ / min. After cooling to room temperature, a dark brown solid is obtained, which is denoted as MBP, i.e., a self-floating triazine-based polymer photocatalyst without Pt nanoparticles.

[0108] Comparative Example 2

[0109] The self-floating triazine-based polymer photocatalyst without Pt nanoparticles was directly loaded with chloroplatinic acid solution (specifically, 90 μL of chloroplatinic acid solution was added directly during the MBP irradiation process), and the resulting sample was denoted as MBP+Pt.

[0110] Performance testing

[0111] The performance of the self-floating triazine-based polymer nanosheet photocatalysts prepared in Comparative Examples 1 and 2, as well as Example 1, was tested. Specific test results are shown below. Figure 1-14 As shown. By analyzing... Figure 1-14 Analyzing the results, we can see that... Figure 1 This demonstrates that the morphology of the self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles is confirmed to be a nanosheet structure, and that Pt nanoparticles were successfully loaded. Figure 2-8 This indicates that the structure of the self-floating triazine-based polymer photocatalyst supported by Pt nanoparticles and the fact that supporting Pt did not change its structure. Figure 9-10 This indicates that the load Pt has superhydrophobic properties both before and after, enabling it to float stably on the water surface. Figure 11-12 This indicates that the photocatalytic performance is improved and stabilized after loading Pt. Figure 13-14 This indicates that the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles has a higher charge carrier separation efficiency.

[0112] Furthermore, as can be seen from the figure, the data for Comparative Example 1 without Pt loading are basically the same as those for Example 1 (see details). Figure 2-7 as well as Figure 9-10 This shows that only the effect of producing H2O2 is different.

[0113] Based on the above results, the beneficial effects of the embodiments of the present invention are as follows: The embodiments of the present invention, using melamine, 4,4'-biphenyl dicarboxylic acid, chloroplatinic acid, and other raw materials, through simple operations such as stirring, calcination, and light irradiation, obtain a self-floating triazine-based polymer supported on Pt nanoparticles. This can improve the photocatalytic H2O2 production capacity while ensuring the self-floating effect. Furthermore, the composite photocatalyst material prepared by this method can stably float on the water surface and has oxygen adsorption capacity, enabling it to adsorb oxygen from the air to participate in the photocatalytic H2O2 production reaction. This eliminates the need to separately deposit the catalyst material on a buoyancy medium, solving the problem that most existing powder photocatalysts require separate deposition on a buoyancy medium to achieve stable floating on water. The present invention not only obtains a powder photocatalyst that can stably float on the water surface, but also demonstrates that the photocatalytic H2O2 production activity of the self-floating triazine-based polymer photocatalyst supported on Pt nanoparticles is increased by 7 times compared to the unsupported Pt, indicating broad market prospects.

[0114] The preferred embodiments of the present invention have been described in detail above, outlining the basic principles, main features, and advantages of the invention. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the above-described embodiments. The embodiments and descriptions in the specification are merely preferred examples of the present invention and are not intended to limit the invention. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the embodiments of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. However, obvious changes or modifications derived therefrom are still within the protection scope of the embodiments of the present invention.

Claims

1. A method for preparing a self-floating triazine-based polymer nanosheet photocatalyst, characterized in that, Includes the following steps: 1) Melamine and 4,4'-biphenyl dicarboxylic acid were added to water, and the mixture was first sonicated at room temperature for a certain time, then stirred and reacted for a certain time. After freeze-drying, a white solid was obtained. 2) The white solid obtained in step 1) is calcined and cooled to obtain a dark brown solid; 3) The dark brown solid obtained in step 2) was placed in a mixed solution of acetone and ethanol and irradiated to obtain a light brown solid. After washing and drying, a self-floating triazine-based polymer nanosheet photocatalyst was obtained.

2. The method for preparing the self-floating triazine-based polymer nanosheet photocatalyst according to claim 1, characterized in that, The molar ratio of melamine to 4,4'-biphenyl dicarboxylic acid is 0.8-1.2:1-2, and the mass-volume ratio of 4,4'-biphenyl dicarboxylic acid to water is 0.005-0.01:1 g / ml.

3. The method for preparing the self-floating triazine-based polymer nanosheet photocatalyst according to claim 2, characterized in that, The molar ratio of melamine to 4,4'-biphenyl dicarboxylic acid is 1:1.5, and the mass-volume ratio of 4,4'-biphenyl dicarboxylic acid to water is 0.007:1 g / ml.

4. The method for preparing the self-floating triazine-based polymer nanosheet photocatalyst according to claim 3, characterized in that, The stirring time is 5-7 hours.

5. The method for preparing the self-floating triazine-based polymer nanosheet photocatalyst according to claim 4, characterized in that, The calcination temperature is 350-450℃, the calcination time is 2-3h, and the heating rate is 4-6℃ / min.

6. The method for preparing the self-floating triazine-based polymer nanosheet photocatalyst according to claim 5, characterized in that, The calcination temperature is 400℃, the calcination time is 2.5h, and the heating rate is 5℃ / min.

7. The method for preparing the self-floating triazine-based polymer nanosheet photocatalyst according to claim 6, characterized in that, The mass-to-volume ratio of the dark brown solid to chloroplatinic acid is 0.07-0.09:1 g / ml, the volume ratio of acetone to ethanol is 1-3:1, and the illumination time is 10-14 h.

8. The method for preparing the self-floating triazine-based polymer nanosheet photocatalyst according to claim 7, characterized in that, The mass-to-volume ratio of the dark brown solid to chloroplatinic acid was 0.08:1 g / ml, the volume ratio of acetone to ethanol was 2:1, and the illumination time was 12 h.

9. A self-floating triazine-based polymer nanosheet photocatalyst prepared by the preparation method according to any one of claims 1-8.

10. The application of the self-floating triazine-based polymer nanosheet photocatalyst according to claim 9 in the catalytic production of hydrogen peroxide.

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