Photo-thermal adsorbent, preparation method and application of photo-thermal adsorbent in fuel oil desulfurization
By introducing Ag nanoparticles into the porous aromatic organic framework D-PAF, a photothermal adsorbent was prepared, which solved the problem of difficulty in regeneration of adsorbents, achieved efficient adsorption and easy regeneration of thiophene sulfides, reduced energy consumption and conformed to the concept of sustainable development.
Patent Information
- Application Number
- CN202510516305.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2025-05-23
AI Technical Summary
In the existing adsorption and desulfurization technology, the strong interaction between the adsorbent and sulfide molecules makes it extremely difficult to regenerate and reuse, limiting its industrial application.
By gentle and green light reduction, Ag nanoparticles were introduced into the porous aromatic organic framework D-PAF to prepare a photothermal adsorbent. This method not only improves the regenerative properties of the adsorbent, but also enhances its adsorption effect on thiophene sulfides.
It achieves efficient adsorption and easy regeneration of thiophene sulfides, reduces energy consumption, and conforms to the concept of sustainable development.
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Figure CN120022870A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of adsorption desulfurization, and specifically to a photothermal adsorbent, a preparation method thereof, and an application thereof in fuel oil desulfurization. Background Art
[0002] Hydrodesulfurization is currently the most widely used desulfurization method in industrial applications. This method has good effects in removing sulfides such as mercaptans and thioethers, but it is difficult to remove thiophene-based sulfides. In addition, hydrodesulfurization not only needs to be carried out under extremely harsh reaction conditions such as high temperature and high pressure but also requires the use of expensive catalysts, which is obviously a great consumption of cost. With the continuous in-depth research, more and more desulfurization methods have been developed, including biological desulfurization, oxidative desulfurization, adsorption desulfurization, etc. Among them, the adsorption desulfurization technology is considered to be the future direction of fuel oil desulfurization due to its mild reaction conditions, simple equipment required, and low operating cost.
[0003] The adsorption desulfurization technology is a process technology that uses an adsorption material to selectively adsorb organic sulfur compounds from the feedstock oil through physical or chemical actions. The reaction conditions of the adsorption desulfurization technology are relatively mild and can be carried out at normal temperature and pressure. Moreover, it has the advantages of simple equipment operation, low operating cost, and the ability to selectively adsorb specific sulfides. Therefore, this technology is considered to be the future direction of fuel oil desulfurization. Currently, there are many adsorbents applied in the desulfurization field, such as molecular sieve adsorbents, activated carbon adsorbents, metal oxide adsorbents, and metal-organic framework adsorbents, etc.
[0004] Although the adsorption desulfurization technology has high selectivity for organic sulfides and relatively mild reaction conditions, due to the strong interaction between the adsorbent and sulfide molecules, it is extremely difficult to regenerate and reuse, which limits the industrial application of adsorption desulfurization. Therefore, developing a renewable adsorbent is the challenge faced by current researchers.
[0005] For the adsorption separation technology, the selection of the adsorbent is particularly important. Metal-organic frameworks (MOFs) and porous aromatic frameworks (PAFs) materials have become two of the most promising porous materials in the adsorption separation field due to their high stability, large surface area, and adjustable pore size. At the same time, the most important research content of the adsorption separation technology is to design and develop an adsorption material that is easy to recycle and regenerate.
[0006] In recent years, photothermal materials have attracted the attention of researchers due to their ability to fully absorb sunlight and convert it into thermal energy. There are three main photothermal conversion mechanisms: (1) plasma local heating; (2) non-radiative relaxation of electron-hole pairs; and (3) thermal vibration of molecules. Currently, many photothermal materials have been developed, such as carbon-based materials, organic materials, semiconductor materials, and precious metal nanomaterials.
[0007] Among them, under the irradiation of sunlight, the precious metal nanomaterials will receive incident photons to cause the free electrons on the metal surface to oscillate, thereby generating a plasma effect (SPR). When the surface plasma is confined by its own structure, a local plasma effect (LSPR) will occur. When the vibration frequency of the incident photon is the same as the oscillation frequency of the free electron, a strong resonance will occur on its surface. Heat is generated. It is worth noting that by changing the size and shape of the precious metal nanomaterial, the wavelength band of the light it receives can be adjusted. Due to this excellent photothermal ability, it is widely used in drug release, adsorption separation and other fields.
[0008] In summary, based on the requirements of environmental protection, the development of technology to reduce the sulfur content in fuel oil is imminent. Adsorption desulfurization technology has become one of the most competitive desulfurization methods due to its mild operating conditions and simple equipment. For adsorption desulfurization technology, how to achieve efficient regeneration of adsorbents has always been a key factor in determining adsorption desulfurization technology. The decompression desorption and heating desorption methods used in traditional industries not only have strict equipment requirements but also high energy consumption. In addition to considering the high adsorption effect on the adsorbate, the development of adsorbents must also consider the regeneration of adsorbents. The method of heating desorption in traditional industries to regenerate adsorbents will inevitably lead to a large amount of energy loss due to low heat transfer efficiency, which is not in line with the current concept of sustainable development. Therefore, it is very meaningful to develop an adsorbent that has a high adsorption effect on thiophene sulfides and is easy to regenerate. Summary of the invention
[0009] The object of the present invention is to provide a photothermal adsorbent to solve the problems raised in the above background technology.
[0010] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:
[0011] A method for preparing a photothermal adsorbent comprises the following steps:
[0012] The porous aromatic framework material (D-PAF) is activated to obtain an activated D-PAF sample;
[0013] dispersing the activated D-PAF sample in an organic solvent to obtain a dispersion;
[0014] Under dark conditions, a solution containing silver nitrate is added dropwise to the dispersion to obtain a mixed solution;
[0015] The mixed solution is irradiated with a xenon lamp with a 420-780 nm filter, and then filtered, washed and dried to obtain the photothermal adsorbent.
[0016] Preferably, the temperature of the activation treatment is 140-160°C.
[0017] Preferably, the organic solvent is anhydrous methanol; and the solution containing silver nitrate is a methanol solution of silver nitrate.
[0018] Preferably, the mass ratio of the activated D-PAF sample to silver nitrate is 100:(8-20).
[0019] Preferably, the method for preparing the porous aromatic framework material comprises the following steps:
[0020] Tetrabromotetraphenylmethane and 1,4-phenylenediboric acid are dispersed in anhydrous N,N-dimethylformamide, and then tetrakis(triphenylphosphine)palladium and potassium carbonate aqueous solution are added, and heated to react under a protective atmosphere; after the reaction is complete, the crude product is purified to obtain the porous aromatic framework material.
[0021] Preferably, the protective atmosphere is a nitrogen atmosphere.
[0022] Preferably, the heating reaction temperature is 140-160°C.
[0023] Another object of the present invention is to provide a photothermal adsorbent prepared by the above preparation method.
[0024] Another object of the present invention is to provide a use of the above-mentioned photothermal adsorbent in adsorbing pollutants.
[0025] Another object of the present invention is to provide an application of the above-mentioned photothermal adsorbent in fuel oil desulfurization.
[0026] The present invention can successfully introduce Ag nanoparticles into the porous aromatic organic framework D-PAF through a mild and green light reduction method, and the Ag nanoparticles have good dispersion in the material. In addition, the photothermal adsorbent prepared by this method has a highly efficient adsorption effect on benzothiophene (BT) molecules and good selectivity, and can be well applied to the adsorption desulfurization of fuel oil. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1These are SEM images of D-PAF and photothermal adsorbents prepared in Examples 1-3 of the present invention; in the figure, a is the SEM image of D-PAF, b is the SEM image of Ag(0)@D-PAF-1, c is the SEM image of Ag(0)@D-PAF-2, and d is the SEM image of Ag(0)@D-PAF-3.
[0028] Figure 2 These are wide-angle XRD patterns and FT-IR patterns of the D-PAF and photothermal adsorbent prepared in Examples 1-3 of the present invention; in the figure, a is a wide-angle XRD pattern, and b is a FT-IR pattern. DETAILED DESCRIPTION
[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0030] In the embodiment of the present invention, Ag nanoparticles are used as nanoheaters, PAFs materials with high stability are selected as carriers, and a type of photothermal adsorbent is designed. The LSPR effect of Ag nanoparticles under visible light is used to achieve precise control of adsorption / desorption during the desulfurization process.
[0031] In the field of adsorption and separation, Ag nanoparticles have LSPR effect under visible light irradiation. Under visible light irradiation, free electrons are stimulated by the incident light and produce collective oscillations, thereby converting light energy into heat energy. At the same time, Ag nanoparticles have a weak interaction with thiophene sulfides, which can enhance their binding with S atoms and improve the adsorption effect on thiophene sulfides. In the process of continuous research, many methods for synthesizing Ag nanoparticles have been developed, such as chemical reduction method (sodium borohydride reduction method, electrochemical reduction method, thermal decomposition reduction method, etc.), biological reduction method (bacterial extraction method, plant extraction method synthesis, etc.), physical reduction method (physical steam condensation reduction method, arc discharge reduction method, photoreduction method, etc.). Compared with other methods, photoreduction method has the following advantages: (1) the synthesized Ag nanoparticles have a narrower size distribution, more uniform size, and better dispersion; (2) no highly toxic and highly reactive chemicals are required; (3) the operation is simple and the reaction conditions are relatively mild. This makes it one of the most commonly used synthesis methods.
[0032] Therefore, in the embodiment of the invention, D-PAF material with a high specific surface area is selected as a carrier, Ag nanoparticles are introduced into the porous material by a green light reduction method, and Ag nanoparticles are used as adsorption / desorption sites to synthesize photothermal adsorbents with different Ag contents. The successful synthesis of the photothermal adsorbent was demonstrated by a series of basic characterizations. And the adsorption and desulfurization effect of the photothermal adsorbent on benzothiophene (BT) molecules was studied by static adsorption experiments. The photothermal desorption effect of the optimal adsorbent under visible light was explored by dynamic penetration experiments.
[0033] Specifically, in one embodiment of the present invention, a method for preparing a photothermal adsorbent is provided, comprising the following steps:
[0034] S1. Place the porous aromatic framework material (D-PAF) in a vacuum drying oven and perform activation treatment at a temperature of 140-160 °C for 12-36 h to remove the residual solvent and moisture on the surface and in the pores of the material to obtain an activated D-PAF sample;
[0035] S2, weighing 100 mg of the activated D-PAF sample, dispersing it in 4-6 mL of anhydrous methanol, and subjecting it to ultrasonic treatment for 4-6 min to completely disperse it, thereby obtaining a dispersion;
[0036] S3. In dark conditions, add a methanol solution containing 8-20 mg of silver nitrate to the above dispersion and stir at room temperature for 3-5 h to obtain a mixed solution;
[0037] S4. Irradiate the mixed solution with a xenon lamp with a 420-780 nm filter for 0.5-1.5 h, then immediately filter and wash the mixed solution with deionized water and anhydrous methanol for several times, and then dry it in a vacuum drying oven at 50-70 °C to obtain a photothermal adsorbent named Ag(0)@D-PAF.
[0038] It should be noted that, in addition to using methanol as the solvent, other organic solvents may also be used as solvents for dispersing raw materials such as porous aromatic framework materials, and the invention is not limited thereto.
[0039] In a preferred embodiment of the present invention, the method for preparing the porous aromatic framework material comprises the following steps:
[0040] Tetrabromotetraphenylmethane and 1,4-phenylenediboric acid are dispersed in anhydrous N,N-dimethylformamide, and then tetrakis(triphenylphosphine)palladium and potassium carbonate aqueous solution are added, and heated to react at a temperature of 140-160°C under a protective atmosphere; after the reaction is complete, the crude product is filtered and washed with tetrahydrofuran, chloroform, and deionized water, and then tetrahydrofuran is added to a Soxhlet extractor to wash the crude product for further purification; finally, the porous aromatic framework material is dried in a vacuum drying oven at 50-70°C to obtain the porous aromatic framework material.
[0041] It should be noted that the above-mentioned protective atmosphere is a nitrogen atmosphere, and other inert gases can also be used as the protective atmosphere.
[0042] Example 1: This example provides a method for preparing a photothermal adsorbent, comprising the following steps:
[0043] S1. Place D-PAF in a vacuum drying oven and perform activation treatment at 150 °C for 24 h to obtain an activated D-PAF sample;
[0044] The preparation method of D-PAF is as follows: tetrabromotetraphenylmethane (248.04 mg, 0.39 mmol) and 1,4-phenylenediboronic acid (129.28 mg, 0.78 mmol) are dispersed in 12 mL of anhydrous N,N-dimethylformamide, nitrogen is introduced for 30 min, and then tetrakis(triphenylphosphine)palladium (50 mg, 43 mmol) and potassium carbonate aqueous solution (1.5 mL, 2M) are added, and heated at 150 °C for 24 h under a nitrogen protective atmosphere; after the reaction is complete, the crude product is filtered and washed with tetrahydrofuran, chloroform, and deionized water, and then tetrahydrofuran is added to a Soxhlet extractor to wash the crude product for 24 h for further purification; finally, it is dried in a vacuum drying oven at 50-70 °C to obtain gray-black powder D-PAF;
[0045] S2, weighing 100 mg of the activated D-PAF sample, dispersing it in 5 mL of anhydrous methanol, and subjecting it to ultrasonic treatment for 5 min to completely disperse it, thereby obtaining a dispersion;
[0046] S3. In dark conditions, a methanol solution containing 8 mg of silver nitrate was added dropwise to the above dispersion, and stirred at room temperature for 4 h to obtain a mixed solution;
[0047] S4. Irradiate the mixed solution with a xenon lamp with a 420-780 nm filter for 1 h, then immediately filter and wash it with deionized water and anhydrous methanol for several times, and then dry it in a vacuum drying oven at 60 °C to obtain a photothermal adsorbent named Ag(0)@D-PAF-1.
[0048] Example 2: This example provides a method for preparing a photothermal adsorbent, comprising the following steps:
[0049] S1. Place D-PAF in a vacuum drying oven and perform activation treatment at 150 °C for 24 h to obtain an activated D-PAF sample;
[0050] The preparation method of D-PAF is as follows: tetrabromotetraphenylmethane (248.04 mg, 0.39 mmol) and 1,4-phenylenediboronic acid (129.28 mg, 0.78 mmol) are dispersed in 12 mL of anhydrous N,N-dimethylformamide, nitrogen is introduced for 30 min, and then tetrakis(triphenylphosphine)palladium (50 mg, 43 mmol) and potassium carbonate aqueous solution (1.5 mL, 2M) are added, and heated at 150 °C for 24 h under a nitrogen protective atmosphere; after the reaction is complete, the crude product is filtered and washed with tetrahydrofuran, chloroform, and deionized water, and then tetrahydrofuran is added to a Soxhlet extractor to wash the crude product for 24 h for further purification; finally, it is dried in a vacuum drying oven at 50-70 °C to obtain gray-black powder D-PAF;
[0051] S2, weighing 100 mg of the activated D-PAF sample, dispersing it in 5 mL of anhydrous methanol, and subjecting it to ultrasonic treatment for 5 min to completely disperse it, thereby obtaining a dispersion;
[0052] S3. In dark conditions, a methanol solution containing 15 mg of silver nitrate was added dropwise to the above dispersion, and stirred at room temperature for 4 h to obtain a mixed solution;
[0053] S4. Irradiate the mixed solution with a xenon lamp with a 420-780 nm filter for 1 h, then immediately filter and wash it with deionized water and anhydrous methanol for several times, and then dry it in a vacuum drying oven at 60 °C to obtain a photothermal adsorbent named Ag(0)@D-PAF-2.
[0054] Example 3: This example provides a method for preparing a photothermal adsorbent, comprising the following steps:
[0055] S1. Place D-PAF in a vacuum drying oven and perform activation treatment at 150 °C for 24 h to obtain an activated D-PAF sample;
[0056] Among them, the preparation method of D-PAF is as follows: Disperse tetrabromotetraphenylmethane (248.04 mg, 0.39 mmol) and 1,4-benzenediboronic acid (129.28 mg, 0.78 mmol) in 12 mL of anhydrous N,N-dimethylformamide, introduce nitrogen for 30 min, then add tetrakis(triphenylphosphine)palladium (50 mg, 43 mmol) and aqueous potassium carbonate solution (1.5 mL, 2M), and carry out a heating reaction at 150 °C for 24 h under a protective atmosphere of nitrogen; after the reaction is complete, filter and wash the crude product with tetrahydrofuran, chloroform, and deionized water respectively, then add tetrahydrofuran to a Soxhlet extractor to wash the crude product for 24 h for further purification; finally, carry out drying treatment in a vacuum drying oven at 50-70 °C to obtain a grayish-black powder D-PAF;
[0057] S2: Weigh 100 mg of the above-activated D-PAF sample and disperse it in 5 mL of anhydrous methanol, and perform ultrasonic treatment for 5 min to make it completely dispersed to obtain a dispersion;
[0058] S3: Under dark conditions, add a methanol solution containing 20 mg of silver nitrate dropwise to the above dispersion, and stir at room temperature for 4 h to obtain a mixed solution;
[0059] S4: Above the mixed solution, irradiate the mixed solution with a xenon lamp equipped with a 420-780 nm filter for 1 h, then immediately filter and wash it several times with deionized water and anhydrous methanol, and then carry out drying treatment in a vacuum drying oven at 60 °C to obtain a photothermal adsorbent named Ag(0)@D-PAF-3.
[0060] Example 4: This example provides a preparation method of a photothermal adsorbent, including the following steps:
[0061] S1: Put D-PAF into a vacuum drying oven and carry out activation treatment at 140 °C for 12 h to obtain an activated D-PAF sample;
[0062] The preparation method of D-PAF is as follows: tetrabromotetraphenylmethane (248.04 mg, 0.39 mmol) and 1,4-phenylenediboronic acid (129.28 mg, 0.78 mmol) are dispersed in 12 mL of anhydrous N,N-dimethylformamide, nitrogen is introduced for 30 min, and then tetrakis(triphenylphosphine)palladium (50 mg, 43 mmol) and potassium carbonate aqueous solution (1.5 mL, 2M) are added, and heated at 140 °C for 24 h under a nitrogen protective atmosphere; after the reaction is complete, the crude product is filtered and washed with tetrahydrofuran, chloroform, and deionized water, and then tetrahydrofuran is added to a Soxhlet extractor to wash the crude product for 24 h for further purification; finally, it is dried in a vacuum drying oven at 50 °C to obtain gray-black powder D-PAF;
[0063] S2, weighing 100 mg of the activated D-PAF sample, dispersing it in 4 mL of anhydrous methanol, and subjecting it to ultrasonic treatment for 4 min to completely disperse it, thereby obtaining a dispersion;
[0064] S3. In dark conditions, a methanol solution containing 10 mg of silver nitrate was added dropwise to the above dispersion, and stirred at room temperature for 3 h to obtain a mixed solution;
[0065] S4. Irradiate the mixed solution with a xenon lamp with a 420-780 nm filter for 0.5 h, then immediately filter and wash the mixed solution with deionized water and anhydrous methanol for several times, and then dry it in a vacuum drying oven at 50 °C to obtain a photothermal adsorbent.
[0066] Example 5: This example provides a method for preparing a photothermal adsorbent, comprising the following steps:
[0067] S1. Place D-PAF in a vacuum drying oven and perform activation treatment at 160 °C for 36 h to obtain an activated D-PAF sample;
[0068] The preparation method of D-PAF is as follows: tetrabromotetraphenylmethane (248.04 mg, 0.39 mmol) and 1,4-phenylenediboronic acid (129.28 mg, 0.78 mmol) are dispersed in 12 mL of anhydrous N,N-dimethylformamide, nitrogen is introduced for 30 min, and then tetrakis(triphenylphosphine)palladium (50 mg, 43 mmol) and potassium carbonate aqueous solution (1.5 mL, 2M) are added, and heated at 160 °C for 24 h under a nitrogen protective atmosphere; after the reaction is complete, the crude product is filtered and washed with tetrahydrofuran, chloroform, and deionized water, and then tetrahydrofuran is added to a Soxhlet extractor to wash the crude product for 24 h for further purification; finally, it is dried in a vacuum drying oven at 70 °C to obtain gray-black powder D-PAF;
[0069] S2, weighing 100 mg of the activated D-PAF sample, dispersing it in 6 mL of anhydrous methanol, and subjecting it to ultrasonic treatment for 6 min to completely disperse it, thereby obtaining a dispersion;
[0070] S3. In dark conditions, a methanol solution containing 18 mg of silver nitrate was added dropwise to the above dispersion, and stirred at room temperature for 5 h to obtain a mixed solution;
[0071] S4. Irradiate the mixed solution with a xenon lamp with a 420-780 nm filter for 1.5 h, then immediately filter and wash the mixed solution with deionized water and anhydrous methanol for several times, and then dry it in a vacuum drying oven at 70 °C to obtain a photothermal adsorbent.
[0072] Performance test: 1. The D-PAF and photothermal adsorbent prepared in the above examples 1-3 were subjected to SEM test. The results are as follows: Figure 1 shown; from Figure 1 It can be seen that the D-PAF and photothermal adsorbent prepared in Examples 1-3 all present a regular spherical structure; Figure 1 It can be seen from a, b, c, and d that the preparation method provided in the embodiment of the present invention can successfully load Ag nanoparticles in the D-PAF material. In addition, the Ag content in the above-mentioned photothermal adsorbent was quantitatively analyzed by ICP-MS test, and the results are as follows: the Ag loading amounts in Ag(0)@D-PAF-1, Ag(0)@D-PAF-2, and Ag(0)@D-PAF-3 are 3.85%, 7.88%, and 10.21% (mass percentage), respectively.
[0073] Second, the crystallinity of the D-PAF and the photothermal adsorbent prepared in the above Examples 1-3 was characterized by XRD technology. The results are as follows: Figure 2As shown in a, it can be seen from the figure that the introduction of Ag nanoparticles does not affect the structure of the D-PAF material, which shows that the preparation method provided in the embodiment of the present invention can make the Ag nanoparticles have good dispersibility in the D-PAF material.
[0074] In addition, the D-PAF and photothermal adsorbent prepared in the above Examples 1-3 were subjected to FT-IR testing. Figure 2 As shown in b, it can be seen from the figure that Ag in the photothermal adsorbent prepared in the embodiment of the present invention exists in the composite material in a single substance state, which further proves the structural stability of the composite material during the synthesis process.
[0075] 3. The photothermal performance of D-PAF and photothermal adsorbents prepared in Examples 1-3 was tested. The temperature change of the photothermal adsorbent under light was recorded by an infrared thermal imager. The results are as follows: for D-PAF material, after 10 minutes of visible light irradiation, the temperature of the sample surface increased by about 24°C. The temperature increase was caused by the heat generated by the xenon lamp itself during use; while the surface temperature of the photothermal adsorbent Ag(0)@D-PAF-3 prepared in the embodiment of the present invention increased by about 45°C within 10 minutes, and the surface temperature of Ag(0)@D-PAF-1 increased by about 30°C within 10 minutes, which shows that the photothermal performance of the material can be significantly improved by introducing Ag nanoparticles into the D-PAF material in the embodiment of the present invention.
[0076] 4. Static desulfurization experiments were conducted on the D-PAF and photothermal adsorbent prepared in Examples 1-3 in a benzothiophene (BT) solution with a concentration of 550 ppm. The results are as follows: The saturated adsorption capacity of D-PAF at room temperature is 0.17 mmol·g -1 The adsorption capacity of Ag(0)@D-PAF-1 is 0.18 mmol·g -1 The adsorption capacity of Ag(0)@D-PAF-2 is 0.25 mmol·g -1 The adsorption capacity of Ag(0)@D-PAF-3 is 0.23 mmol·g -1 The results show that Ag nanoparticles, as adsorption active sites, can promote their combination with S atoms in the thiophene ring, thereby greatly improving the adsorption and desulfurization effect of the material; however, if the loading amount of Ag nanoparticles is too much, the pores of the material will be blocked, which will reduce the adsorption performance.
[0077] In addition, the D-PAF and photothermal adsorbent prepared in Examples 1-3 were exposed to visible light (420-780 nm) to investigate the desorption performance of the materials under light. The results are as follows: The desorption amount of D-PAF under light was only 0.02 mmol·g -1(This is due to the heat of the xenon lamp itself); the desorption amount of Ag(0)@D-PAF-1 under light irradiation reaches 0.05mmol·g -1 The desorption rate was 23%; the desorption amount of Ag(0)@D-PAF-2 under light irradiation reached 0.09 mmol·g -1 The desorption rate was 39%; the desorption amount of Ag(0)@D-PAF-3 under light irradiation reached 0.11 mmol·g -1 , the desorption rate is 48%. The results show that after the introduction of Ag nanoparticles, the photothermal performance of the material can be significantly improved due to its LSPR effect under light. Therefore, during the adsorption process, Ag nanoparticles can be used as adsorption sites to achieve efficient adsorption of BT molecules, and during the desorption process, Ag nanoparticles can be used as nano heaters to precisely heat the adsorption sites, achieve efficient desorption of BT molecules, and achieve precise regulation of the adsorption desulfurization process.
[0078] 5. The photothermal adsorbent Ag(0)@D-PAF-2 prepared in Example 2 was placed in BT model oil containing 15% toluene by volume for competitive adsorption experiment. The results are as follows: In the presence of 15% toluene, the saturated adsorption capacity of Ag(0)@D-PAF-2 can also reach 0.17 mmol·g -1 , indicating that the photothermal adsorbent has good selectivity.
[0079] In addition, the photothermal adsorbent prepared in the above embodiment was loaded into a simulated fixed bed. Under visible light irradiation, the desorption rate of the photothermal adsorbent was significantly improved and the desorption time was greatly shortened. The results show that the photothermal adsorbent prepared in the embodiment of the present invention can be used in industrial applications, and in a fixed bed, compared with the traditional solvent desorption method, the photothermal desorption method provided by the embodiment of the present invention has a faster desorption rate and a shorter desorption time.
[0080] In summary, the embodiment of the present invention can successfully introduce Ag nanoparticles into the porous aromatic organic framework D-PAF through a mild and green light reduction method, and the Ag nanoparticles have good dispersion in the material. In addition, the photothermal adsorbent prepared by this method has a highly efficient adsorption effect on BT molecules and good selectivity, and can be well applied to the adsorption desulfurization of fuel oil.
[0081] Based on the above-mentioned ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above-mentioned description. The technical scope of the present invention is not limited to the contents of the specification.
Claims
1. A method for preparing a photothermal adsorbent, characterized in that: The following steps are involved: The porous aromatic framework material is activated to obtain an activated D-PAF sample; dispersing the activated D-PAF sample in an organic solvent to obtain a dispersion; Under dark conditions, a solution containing silver nitrate is added dropwise to the dispersion to obtain a mixed solution; The mixed solution is irradiated with a xenon lamp with a 420-780 nm filter, and then filtered, washed and dried to obtain the photothermal adsorbent.
2. The method for preparing the photothermal adsorbent according to claim 1, characterized in that: The activation treatment temperature is 140-160°C.
3. The method for preparing the photothermal adsorbent according to claim 1, characterized in that: The organic solvent is anhydrous methanol; the solution containing silver nitrate is a methanol solution of silver nitrate.
4. The method for preparing a photothermal adsorbent according to claim 1, characterized in that: The mass ratio of the activated D-PAF sample to silver nitrate is 100:(8-20).
5. The method for preparing a photothermal adsorbent according to any one of claims 1 to 4, characterized in that: The preparation method of the porous aromatic framework material comprises the following steps: Tetrabromotetraphenylmethane and 1,4-phenylenediboric acid are dispersed in anhydrous N,N-dimethylformamide, and then tetrakis(triphenylphosphine)palladium and potassium carbonate aqueous solution are added, and heated to react under a protective atmosphere; after the reaction is complete, the crude product is purified to obtain the porous aromatic framework material.
6. The method for preparing the photothermal adsorbent according to claim 5, characterized in that: The protective atmosphere was nitrogen.
7. The method for preparing a photothermal adsorbent according to claim 5, characterized in that: The heating temperature of the reaction is 140-160°C.
8. A photothermal adsorbent prepared by the preparation method according to any one of claims 1 to 7.
9. Use of the photothermal adsorbent as claimed in claim 8 in adsorbing pollutants.
10. Use of the photothermal adsorbent as claimed in claim 8 in desulfurization of fuel oil.