Preparation method and application of long afterglow photocatalyst based on precious metal nanoparticle and aluminosilicate compound
By doping activated ions Pr3+ and supported nano precious metals in the aluminosilicate complex, a long afterglow photocatalyst can efficiently degrade organic pollutants in the dark environment was prepared, which solved the problems of low catalytic efficiency and competition in the prior art and achieved efficient afterglow photocatalysis.
Patent Information
- Application Number
- CN202510261862.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-06
- Publication Date
- 2025-06-13
AI Technical Summary
The existing photocatalysts have low efficiency in degrading organic pollutants in dark environments, and there is competition between the catalytic process and the long afterglow luminescence process, resulting in a reduced catalytic efficiency.
The aluminosilicate composite supported by precious metal nanoparticles is used as a long afterglow photocatalyst. By doping activated ions Pr3+ and supported nano precious metals in the matrix material, the afterglow luminescence intensity and degradation efficiency of the material are improved.
In the dark environment, the degradation efficiency of organic pollutants in the water is significantly improved, the afterglow luminescence time is extended, and the competition problem between the catalytic process and the long afterglow luminescence process is solved.
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Figure CN120132845A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of catalytic technology, and particularly relates to a preparation method and application of a long afterglow photocatalyst based on a noble metal nanoparticle and aluminosilicate composite. Background Art
[0002] Photocatalytic technology has shown remarkable potential in the treatment of organic pollutants in wastewater and sewage. This technology uses specific photocatalysts to generate free radicals with strong oxidation ability, usually hydroxyl radicals (·OH), under ultraviolet or visible light irradiation. These free radicals can efficiently oxidize and decompose organic pollutants, converting them into harmless substances such as H 2 O and CO 2 . Defect engineering, doping strategies, surface modification, and heterostructure construction are widely used to improve the performance of photocatalysts. Although these photocatalysts exhibit very excellent degradation performance, their activity highly depends on continuous light irradiation. This means that the actual application scenarios are restricted by day-night alternation, energy consumption, technical challenges, and equipment environmental factors.
[0003] Photocatalytic technology based on long afterglow phosphors ingeniously solves the above challenges. Long afterglow phosphors achieve continuous luminescence through their internal trap levels. The key characteristic of this material is its ability to store photolysis energy and release the stored energy in a dark environment to support continuous catalytic processes. However, the main challenge faced by this technology is the significant competition between the catalytic process and the long afterglow luminescence process. For example, both the catalytic and luminescence processes require the consumption of carriers. When these processes occur simultaneously, the carriers may be distributed between the two. This results in a decrease in catalytic efficiency or a weakening of the long afterglow luminescence intensity. This competition not only restricts the catalytic efficiency but also limits the development of long afterglow photocatalytic technology in practical applications. Therefore, optimizing the utilization efficiency of photo-generated carriers is the key challenge for the further development of long afterglow photocatalysts. Summary of the Invention
[0004] Aiming at the above deficiencies, the purpose of the present invention is to provide a noble metal nanoparticle-loaded ultraviolet long afterglow matrix material Ag / Ca 2 Al 2 SiO 7 :Pr 3+ (Ag / CASO:Pr 3+ ) that can produce afterglow light capable of degrading organic pollutants in water in a dark environment. When noble metal nanoparticles are loaded, the afterglow luminescence of the ultraviolet long afterglow material will be improved, and the degradation efficiency of pollutants will be increased.
[0005] The technical solution adopted by the present invention is as follows:
[0006] A preparation method of a long afterglow photocatalyst based on a noble metal nanoparticle and aluminosilicate composite, comprising the following steps:
[0007] 1) Accurately weigh 0.0001 g, 0.0002 g, 0.0003 g, 0.0004 g, 0.0005 g or 0.0006 g of noble metal salt compounds, and dissolve them separately in 100 mL of deionized water;
[0008] 2) Add 0.5 g of aluminosilicate long afterglow photocatalyst to the solution, under the irradiation of a 300 W xenon lamp, continuously stir the suspension for 15 minutes, collect the precipitate by centrifugation, wash it 3 times with deionized water, and dry the product at 60 °C for 12 hours to finally obtain a long afterglow photocatalyst based on a noble metal nanoparticle and aluminosilicate composite.
[0009] Preferably, in the above preparation method, the noble metal is Ag, Au, Pt or Cu.
[0010] More preferably, in the above preparation method, the noble metal salt compound is AgNO 3 、AuCl 3 、PtCl 4 or CuCl 2 .
[0011] Preferably, in the above preparation method, the preparation method of the aluminosilicate long afterglow photocatalyst comprises the following steps:
[0012] 1) Put calcium compound, alumina, silica and activator oxide powder into an agate mortar and grind to mix them evenly to obtain a mixture;
[0013] 2) Place the mixture obtained in step 1) in a corundum crucible and then put it into a muffle furnace for high-temperature sintering, and cool to room temperature;
[0014] 3) Grind the solid sample obtained in step 2) in an agate mortar to obtain the target product.
[0015] Preferably, in the above preparation method of the aluminosilicate long afterglow photocatalyst, in step 1), the activator oxide is praseodymium oxide.
[0016] More preferably, in the above preparation method of the aluminosilicate long afterglow photocatalyst, the chemical general formula of the aluminosilicate long afterglow photocatalyst is Ca 2(1-x) Al 2 SiO 7 , where x is the molar percentage content of the doped activator Pr 3+ in Ca ions, and 0 ≤ x ≤ 0.1.
[0017] Preferably, in the preparation method of the above-mentioned aluminosilicate long-afterglow photocatalyst, in step 1), the calcium-containing compound is calcium carbonate or calcium oxide.
[0018] Preferably, in the preparation method of the above-mentioned aluminosilicate long-afterglow photocatalyst, in step 1), the grinding time is 30 - 60 min.
[0019] Preferably, in the preparation method of the above-mentioned aluminosilicate long-afterglow photocatalyst, in step 2), the conditions for high-temperature sintering are: the atmosphere is an air atmosphere, the temperature is 1300 °C, the heating rate is 3 - 5 °C / min, and the time is 6 h.
[0020] Preferably, in the preparation method of the above-mentioned aluminosilicate long-afterglow photocatalyst, in step 3), the grinding time is 5 - 10 min.
[0021] Application of the long-afterglow photocatalyst based on noble metal nanoparticles and aluminosilicate composite prepared by the preparation method described in any one of the above in degrading pollutants in a dark environment.
[0022] Preferably, the pollutants are rhodamine B, tetracycline hydrochloride or ciprofloxacin.
[0023] The beneficial effects of the present invention are: The present invention uses aluminosilicate as the matrix material, which has stable physical and chemical properties, simple preparation process, high temperature resistance, is environmentally friendly, and can meet the requirements of large-scale industrial production. When doped with the activator ion Pr 3+ and then introduced, it can produce ultraviolet afterglow. After loading noble metal nanoparticles, the afterglow luminescence intensity of the material can be improved and the afterglow luminescence time can be extended. And this material can be used as a light source of a long-afterglow photocatalyst to degrade pollutants in water in a dark environment. Description of the Drawings
[0024] Figure 1 XRD pattern of the Ag-loaded long-afterglow photocatalyst Ag / CASO:0.01Pr prepared in Example 1 3+
[0025] Figure 2 a and Figure 2 b are TEM images of different sizes of CASO:0.01Pr prepared in Example 1 3+ Figure 2 c and Figure 2 d are TEM images of different sizes of Ag / CASO:0.01Pr 3+ Figure 2 e is the TEM (HRTEM) spectrum of high-resolution Ag / CASO:0.01Pr 3+ Figure 2 f is the diffraction image of Ag Figure 2 g and 2h are the EDS spectra of CASO:Pr 3+ and Ag / CASO:Pr 3+ respectively.
[0026] Figure 3 Figure 1 is the afterglow decay curve of the Ag-loaded long afterglow photocatalyst Ag / CASO:0.01Pr 3+ in Example 1.
[0027] Figure 4 Figure 2 is the degradation curve of rhodamine B (RhB) by the Ag-loaded long afterglow photocatalyst Ag / CASO:0.01Pr 3+ in Example 1.
[0028] Figure 5 Figure 3 is the degradation curve of tetracycline hydrochloride (TC) by the Ag-loaded long afterglow photocatalyst Ag / CASO:0.01Pr 3+ in Example 2.
[0029] Figure 6 Figure 4 is the degradation curve of norfloxacin (NTX) by the Ag-loaded long afterglow photocatalyst Ag / CASO:0.01Pr 3+ in Example 3. Detailed implementation mode
[0030] Example 1
[0031] The chemical formula composition of the long afterglow photocatalyst in this example is Ca 1.98 Al 2 SiO 7 :0.01Pr 3+ (CASO:Pr 3+ ), and the preparation method is as follows: Weigh 0.0924 g of calcium carbonate, 1.4329 g of alumina, 0.4869 g of silica, and 0.0140 g of praseodymium oxide respectively; put the weighed powders into an agate mortar and grind them clockwise for 30 min to make them evenly mixed, then transfer them to a corundum crucible, place the crucible in a high-temperature muffle furnace, under an air atmosphere, with a heating rate of 3 °C / min, heat up to 1300 °C and calcine for 6 h, and then cool to room temperature with the furnace; put the obtained solid sample in an agate mortar and grind it for 5 min to obtain CASO:Pr 3+ .
[0032] The Ag-loaded CASO:Pr 3+ phosphor (Ag / CASO:Pr 3+ ) was prepared by photoreduction deposition method. First, accurately weigh 0.0001 g, 0.0002 g, 0.0003 g, 0.0004 g, 0.0005 g, and 0.0006 g of AgNO 3The powders were separately dissolved in 100 mL of deionized water. Subsequently, 0.5 g of CASO:Pr 3+ powder was added to the solution. The suspension was continuously stirred for 15 minutes under irradiation of a 300 W xenon lamp. The precipitate was collected by centrifugation and washed three times with deionized water. The product was dried at 60 °C for 12 hours to finally obtain the Ag / CASO:Pr 3+ solid powder. According to the content of the composite silver nanoparticles, the Ag / CASO:Pr 3+ was denoted as Ag / CASO:Pr 3+ -1 to Ag / CASO:Pr 3+ -6.
[0033] Then, the phase analysis of the samples was carried out, and the obtained XRD pattern was as shown Figure 1 . Compared with the standard PDF card (JPCDS#98 - 000 - 0226), the diffraction peak positions and diffraction intensities of CASO:Pr 3+ and Ag / CASO:Pr 3+ corresponded one by one, proving the synthesis of the rare earth doped long - persistent photocatalytic material. The TEM image proved that Ag was loaded on CASO:Pr 3+ ( Figure 2 ). After irradiating CASO:Pr 3+ and Ag / CASO:Pr 3+ under a 254 nm ultraviolet lamp for 10 min and then quickly transferring them into an ultraviolet fluorescence photometer, the afterglow luminescence spectra were measured at regular intervals, and the obtained afterglow luminescence intensities were fitted. As shown Figure 3 , the afterglow luminescence intensity and time of Ag / CASO:Pr 3+ were better than those of CASO:Pr 3+ .
[0034] After irradiating CASO:0.01Pr 3+ and Ag / CASO:0.01Pr 3+ under a 254 nm ultraviolet lamp for 10 min, Rhodamine B (RhB) was degraded in the dark environment. An RhB solution (50 mL, 10 mg / L) and a photocatalyst (10 mg) were placed in a 100 mL beaker. 2 mL of the RhB solution was taken at regular intervals. The absorbance of RhB was measured with an ultraviolet - visible spectrophotometer to evaluate the photocatalytic activities of CASO:Pr 3+ and Ag / CASO:Pr 3+ . The degradation curves of RhB by CASO:Pr 3+ and Ag / CASO:Pr 3+ were as shown Figure 4 . The degradation curves of RhB by CASO:Pr 3+ and Ag / CASO:Pr 3+The maximum degradation efficiencies for RhB at 1 hour were 14% and 40% respectively.
[0035] Example 2
[0036] Put CASO:Pr 3+ and Ag / CASO:Pr 3+ under irradiation with 254 nm ultraviolet light for 10 min and then degrade tetracycline hydrochloride (TC) in a dark environment. Put the TC solution (50 mL, 10 mg / L) and the photocatalyst (10 mg) in a 100 mL beaker. Take 2 mL of the TC solution at regular intervals. Measure the absorbance of TC with a UV-visible spectrophotometer to evaluate the photocatalytic activity of CASO:Pr 3+ and Ag / CASO:Pr 3+ . The degradation curves of CASO:Pr 3+ and Ag / CASO:Pr 3+ for TC are as shown in Figure 5 . The maximum degradation efficiencies of CASO:Pr 3+ and Ag / CASO:Pr 3+ for TC at 1 hour were 7% and 15% respectively.
[0037] Example 3
[0038] Put CASO:Pr 3+ and Ag / CASO:Pr 3+ under irradiation with 254 nm ultraviolet light for 10 min and then degrade norfloxacin (NFX) in a dark environment. Put the NFX solution (50 mL, 10 mg / L) and the photocatalyst (10 mg) in a 100 mL beaker. Take 2 mL of the NFX solution at regular intervals. Measure the absorbance of NFX with a UV-visible spectrophotometer to evaluate the photocatalytic activity of CASO:Pr 3+ and Ag / CASO:Pr 3+ . The degradation curves of CASO:Pr 3+ and Ag / CASO:Pr 3+ for NFX are as shown in Figure 6 . The maximum degradation efficiencies of CASO:Pr 3+ and Ag / CASO:Pr 3+ for NFX at 1 hour were 2% and 20% respectively.
[0039] Example 4
[0040] Prepare Au / CASO:Pr 3+ phosphor. Replace AgNO 3 in Example 1 with AuCl 3, accurately weigh 0.0001 g, 0.0002 g, 0.0003 g, 0.0004 g, 0.0005 g, and 0.0006 g of AuCl respectively 3 , with other reaction processes and conditions remaining unchanged. The obtained noble metal long afterglow phosphor is Au / CASO:Pr 3+ .
[0041] Example 5
[0042] Prepare Pt / CASO:Pr 3+ phosphor. Replace AgNO₃ in Example 1 3 with PtCl₂ 4 , accurately weigh 0.0001 g, 0.0002 g, 0.0003 g, 0.0004 g, 0.0005 g, and 0.0006 g of PtCl₂ respectively 4 , with other reaction processes and conditions remaining unchanged. The obtained noble metal long afterglow phosphor is Pt / CASO:Pr 3+ .
[0043] Example 6
[0044] Prepare Cu / CASO:Pr 3+ phosphor. Replace AgNO₃ in Example 1 3 with CuCl₂ 2 , accurately weigh 0.0001 g, 0.0002 g, 0.0003 g, 0.0004 g, 0.0005 g, and 0.0006 g of CuCl₂ respectively 2 , with other reaction processes and conditions remaining unchanged. The obtained noble metal long afterglow phosphor is Cu / CASO:Pr 3+ .
Claims
1. A method for preparing a long afterglow photocatalyst based on a composite of noble metal nanoparticles and aluminosilicate, characterized in that: The steps include: 1) Accurately weigh 0.0001 g, 0.0002 g, 0.0003 g, 0.0004 g, 0.0005 g or 0.0006 g of the noble metal salt compound and dissolve them in 100 mL of deionized water respectively; 2) adding 0.5 g of aluminosilicate long afterglow photocatalyst to the solution, stirring the suspension for 15 minutes under irradiation with a 300 W xenon lamp, collecting the precipitate by centrifugation, washing it with deionized water for 3 times, and drying the product at 60° C. for 12 hours to finally obtain a long afterglow photocatalyst based on a composite of precious metal nanoparticles and aluminosilicate.
2. The preparation method according to claim 1, characterized in that: The noble metal is Ag, Au, Pt or Cu.
3. The preparation method according to claim 1, characterized in that: The preparation method of the aluminosilicate long afterglow photocatalyst comprises the following steps: 1) putting the calcium compound, aluminum oxide, silicon dioxide and activator oxide powder into an agate mortar and grinding them to mix them evenly to obtain a mixture; 2) placing the mixture obtained in step 1) in a corundum crucible and then placing it in a muffle furnace for high-temperature sintering, and cooling to room temperature; 3) Grinding the solid sample obtained in step 2) in an agate mortar to obtain the target product.
4. The preparation method according to claim 3, characterized in that: In step 1), the activator-containing oxide is praseodymium oxide.
5. The preparation method according to claim 4, characterized in that: The chemical formula of the aluminosilicate long afterglow photocatalyst is Ca 2(1-x) Al2SiO7, where x is the doping activator Pr 3+ The molar percentage of Ca ions is 0≤x≤0.
1.
6. The preparation method according to claim 3, characterized in that: In step 1), the calcium-containing compound is calcium carbonate or calcium oxide.
7. The preparation method according to claim 3, characterized in that: In step 1), the grinding time is 30 to 60 minutes.
8. The preparation method according to claim 3, characterized in that: In step 2), the high temperature sintering conditions are: the atmosphere is air atmosphere, the temperature is 1300° C., the heating rate is 3-5° C. / min, and the time is 6 hours.
9. The preparation method according to claim 3, characterized in that: In step 3), the grinding time is 5 to 10 minutes.
10. Use of a long afterglow photocatalyst based on a composite of noble metal nanoparticles and aluminosilicate prepared by the preparation method according to any one of claims 1 to 9 in degrading pollutants in a dark environment.