Semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 and preparation method and application thereof
A Na1.97Al1.82Ti6.15O16 semiconductor photocatalyst was prepared by electrospinning, which solved the problems of high energy consumption and low catalytic performance caused by high-temperature solid-phase synthesis. This method enables the preparation of a high-efficiency photocatalyst with low energy consumption for the degradation of alkaline organic dyes.
Patent Information
- Application Number
- CN202310142563.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-21
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2043-02-21
AI Technical Summary
The existing methods for preparing Na1.97Al1.82Ti6.15O16 materials require high-temperature solid-phase synthesis, which results in high energy consumption, harsh experimental conditions, and low catalytic performance.
A Na1.97Al1.82Ti6.15O16 semiconductor photocatalyst was prepared by electrospinning. Nanofiber membranes were prepared by mixing sodium, aluminum, titanium, polyvinylpyrrolidone and solvent, followed by heat treatment at a low temperature to obtain nanowire photocatalysts.
A high-purity nanowire-shaped Na1.97Al1.82Ti6.15O16 photocatalyst was prepared with low energy consumption. It has a high specific surface area and good photocatalytic activity, and can effectively degrade basic organic dyes such as methylene blue and rose red B.
Smart Images
Figure CN116809048B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photocatalyst materials technology, specifically to the semiconductor photocatalyst Na. 1.97 Al 1.82 Ti 6.15 O 16 Its preparation methods and applications. Background Technology
[0002] In recent years, with the continuous increase in population, human exploitation of Earth's resources has also intensified, leading to a shortage of these resources. Oil and coal are the most prominent examples, making energy a major challenge that humanity must face. This has also spurred increased research into clean energy sources such as solar energy. In the process of addressing these challenges, photocatalysis technology has been discovered as a crucial approach to solving global energy problems and the current severe environmental issues. Therefore, based on this discovery, scholars from various countries are focusing on developing photocatalysts that can effectively utilize solar energy without causing secondary pollution. At this point, semiconductor photocatalysts have attracted significant attention from researchers.
[0003] In 1990, Toraya, H. et al. published Na in the journal J. Mater. Res. 1.97 Al 1.82 Ti 6.15 O 16 The structural parameters of the new crystal Na were included in the Inorganic Crystal Structure Database (ICCD) in 1997. 1.97 Al 1.82 Ti 6.15 O 16 The structural parameters of are given by: The lattice constant is: α = 90°, β = 107.59°, γ = 90°, V = 280, space group C2 / m(12). In 1998, Sadykhov, G. et al. synthesized the homogeneous material Na2Al2Ti6O using a high-temperature solid-state method. 16 Using Na₂CO₃, Al₂O₃, and TiO₂ as raw materials, pure powder was obtained by calcination at 1200℃ for 3 hours. Currently, for Na… 1.97 Al 1.82 Ti 6.15 O 16 In terms of material synthesis methods, high-temperature solid-state synthesis requires high temperatures, consumes a large amount of energy, and has harsh experimental conditions; meanwhile, Na prepared by traditional high-temperature solid-state synthesis methods... 1.97 Al 1.82 Ti 6.15 O 16The material has a large microscopic size and a small specific surface area, so its catalytic performance is not high when it is used as a photocatalyst, resulting in a lack of research on this material. Summary of the Invention
[0004] To address the shortcomings of the existing technology, this invention provides a semiconductor photocatalyst, Na. 1.97 Al 1.82 Ti 6.15 O 16 This study aims to address the deficiencies in existing technologies regarding Na, its preparation methods, and applications. 1.97 Al 1.82 Ti 6.15 O 16 To address the technical shortcomings of traditional material preparation methods, such as high preparation temperatures, high synthesis energy consumption, and stringent experimental conditions, this paper proposes a method for preparing Na using electrospinning. 1.97 Al 1.82 Ti 6.15 O 16 A new method, and the resulting Na 1.97 Al 1.82 Ti 6.15 O 16 Semiconductor photocatalysts are used as semiconductor photodegradation catalysts for alkaline organic dyes.
[0005] To achieve the above objectives, the technical solution of the present invention is as follows:
[0006] A semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 The preparation method includes the following steps:
[0007] (1) Preparation of nanofiber membrane: Sodium source, aluminum source, titanium source, polyvinylpyrrolidone, co-solvent, acetic acid and ethanol are mixed evenly and prepared into a mixture. The mixture is electrospun to obtain nanofiber membrane. Polyvinylpyrrolidone is used as surfactant, and co-solvent, acetic acid and ethanol are used together as solvent to fully dissolve the raw materials.
[0008] (2) Semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 Preparation: The nanofiber membrane from step (1) was heat-treated at 700-800℃ for 2-6 hours, then washed with water until neutral to obtain the semiconductor photocatalyst Na. 1.97 Al 1.82 Ti 6.15 O 16 .
[0009] Preferably, in step (1), the sodium source is selected from sodium acetate trihydrate, sodium carbonate or sodium sulfate, the aluminum source is selected from aluminum nitrate nonahydrate, aluminum oxide or aluminum sulfate, and the titanium source is selected from tetrabutyl titanate, titanium dioxide or titanium sulfate.
[0010] Preferably, in step (1), the molar ratio of sodium, aluminum, and titanium in the sodium source, aluminum source, and titanium source is (0.5-1):(0.5-1):(2-3); and the mass ratio of polyvinylpyrrolidone to titanium source is (1-2):(0.5-1).
[0011] The co-solvent is selected from N,N'-dimethylformamide or N,N'-diethylformamide, and the volume ratio of co-solvent, acetic acid and ethanol is (1-3):(1-2):(6-8).
[0012] Preferably, in step (1), the molar ratio of sodium, aluminum, and titanium in the sodium source, aluminum source, and titanium source is 1:1:2.
[0013] Preferably, the electrospinning conditions in step (1) are as follows: the nanofiber membrane is prepared under the following conditions: the negative voltage of the spinning voltage is -1kV, the positive voltage is 18kV, the temperature is 40-60℃, and the feed rate is 1.5-2mL / h.
[0014] Preferably, in step (2), the nanofiber membrane from step (1) is heat-treated at 700°C for 2 hours.
[0015] This invention also protects the Na semiconductor photocatalyst prepared by the aforementioned method. 1.97 Al 1.82 Ti 6.15 O 16 The semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 It is in the form of nanowires.
[0016] This invention also protects the semiconductor photocatalyst Na. 1.97 Al 1.82 Ti 6.15 O 16 Application in the preparation of alkaline organic dye semiconductor photodegradation catalysts.
[0017] Preferably, the basic organic dye is methylene blue dye or rose red B.
[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0019] 1. This invention discloses a semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O16 This invention presents a novel preparation method for Na, a semiconductor photocatalyst that is simple, operates at a low reaction temperature, and yields higher purity Na. 1.97 Al 1.82 Ti 6.15 O 16 The prepared semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 As a direct bandgap semiconductor, the bandgap energy Eg is around 3.3 eV. The nanowires are small and uniform in size, have a high specific surface area, high purity, good crystallinity, and good photocatalytic activity. They can be used as photocatalysts to catalyze the degradation of thiazide dyes (such as methylene blue dye or rose red B), and the degradation efficiency is high. Attached Figure Description
[0020] Figure 1 Na prepared in Example 1 1.97 Al 1.82 Ti 6.15 O 16 XRD pattern of semiconductor photocatalyst;
[0021] Figure 2 Na prepared in Example 1 1.97 Al 1.82 Ti 6.15 O 16 SEM image of a semiconductor photocatalyst;
[0022] Figure 3 Thermogravimetric curve of the nanofiber membrane in Example 1;
[0023] Figure 4 The Na prepared in Examples 1, 4, and 5 1.97 Al 1.82 Ti 6.15 O 16 XRD pattern of semiconductor photocatalyst;
[0024] Figure 5 Na prepared in Example 1 1.97 Al 1.82 Ti 6.15 O 16 SEM image of a semiconductor photocatalyst;
[0025] Figure 6 Na prepared in Example 4 1.97 Al 1.82 Ti 6.15 O 16 SEM image of a semiconductor photocatalyst;
[0026] Figure 7 Na prepared in Example 1 1.97 Al 1.82 Ti 6.15 O 16 UV-Vis diffuse reflectance spectrum of semiconductor photocatalyst;
[0027] Figure 8 Na prepared in Example 1 1.97 Al 1.82 Ti 6.15 O 16 Real-time degradation diagram of the semiconductor photocatalyst for the dye methylene blue;
[0028] Figure 9 Na prepared in Example 4 1.97 Al 1.82 Ti 6.15 O 16 Real-time degradation diagram of the semiconductor photocatalyst for the dye methylene blue;
[0029] Figure 10 Na prepared in Example 5 1.97 Al 1.82 Ti 6.15 O 16 Real-time degradation diagram of the semiconductor photocatalyst for the dye methylene blue;
[0030] Figure 11 The Na prepared in Examples 1, 4, and 5 1.97 Al 1.82 Ti 6.15 O 16 C / C0 ratio diagram of semiconductor photocatalysts degrading the dye methylene blue;
[0031] Figure 12 The Na prepared in Examples 1, 4, and 5 1.97 Al 1.82 Ti 6.15 O 16 Rate graph of degradation of the dye methylene blue by semiconductor photocatalyst;
[0032] Figure 13 Na prepared using Example 1 1.97 Al 1.82 Ti 6.15 O 16 Color changes of the dye at different times during the photocatalytic degradation of methylene blue using a semiconductor photocatalyst. Detailed Implementation
[0033] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.
[0034] Example 1
[0035] Na 1.97 Al 1.82 Ti 6.15 O 16 The preparation method of semiconductor photocatalyst includes the following steps:
[0036] (1) Preparation of nanofiber membranes: Sodium acetate trihydrate (CH3COONa·3H2O), aluminum nitrate nonahydrate (Al(NO3)3·9H2O), and tetrabutyl titanate (C 16 H 36 O4Ti), polyvinylpyrrolidone (PVP), N,N'-dimethylformamide (DMF), acetic acid, and ethanol were mixed and prepared into a solution. After stirring thoroughly for 8 hours, the mixture was prepared into a mixed solution. The resulting mixture was transferred into a spinning syringe and electrospun to obtain a nanofiber membrane.
[0037] The molar ratio of sodium, aluminum and titanium in sodium acetate trihydrate, aluminum nitrate nonahydrate and tetrabutyl titanate was 1:1:2, the amount of PVP was 1.5g, the volume ratio of DMF, acetic acid and ethanol was 3:1:6, the total volume of the mixture was 15mL, and the nanofiber membrane was prepared under the following conditions: negative voltage of -1kV, positive voltage of 18kV, temperature of 50℃ and feed rate of 1.5mL / h.
[0038] (2) Na 1.97 Al 1.82 Ti 6.15 O 16 Preparation of semiconductor photocatalyst: After peeling off the nanofiber membrane from step (1), heat-treat at 700℃ for 2 hours, then wash the resulting product with deionized water until neutral, and dry to obtain the semiconductor photocatalyst Na. 1.97 Al 1.82 Ti 6.15 O 16 .
[0039] Example 2
[0040] Na 1.97 Al 1.82 Ti 6.15 O 16 The preparation method of semiconductor photocatalyst includes the following steps:
[0041] (1) Preparation of nanofiber membrane: Sodium carbonate, aluminum oxide, titanium sulfate, polyvinylpyrrolidone (PVP), N,N'-dimethylformamide (DMF), acetic acid and ethanol were mixed and prepared into a solution. After stirring for 8 hours, the mixture was prepared into a mixed solution. The resulting mixed solution was transferred into a spinning syringe and electrospun to obtain a nanofiber membrane.
[0042] The molar ratio of sodium, aluminum and titanium in sodium carbonate, aluminum oxide and titanium sulfate is 0.5:0.5:2.5, the amount of PVP is 1.5g, the volume ratio of DMF, acetic acid and ethanol is 2:1.5:7, the total volume of the mixture is 15mL, and the nanofiber membrane is prepared under the following conditions: negative voltage of -1kV, positive voltage of 18kV, temperature of 40℃ and feed rate of 2mL / h.
[0043] (2) Na 1.97 Al 1.82 Ti 6.15 O 16 Preparation of semiconductor photocatalyst: After peeling off the nanofiber membrane from step (1), heat-treat at 750℃ for 6 hours, then wash the resulting product with deionized water until neutral, and dry to obtain the semiconductor photocatalyst Na. 1.97 Al 1.82 Ti 6.15 O 16 .
[0044] Example 3
[0045] Na 1.97 Al 1.82 Ti 6.15 O 16 The preparation method of semiconductor photocatalyst includes the following steps:
[0046] (1) Preparation of nanofiber membrane: Sodium sulfate, aluminum sulfate, titanium dioxide, polyvinylpyrrolidone (PVP), N,N'-diethylformamide, acetic acid and ethanol were mixed and prepared into a solution. After stirring for 8 hours, the mixture was prepared into a mixed solution. The resulting mixed solution was transferred into a spinning syringe and electrospun to obtain a nanofiber membrane.
[0047] The molar ratio of sodium, aluminum and titanium in sodium sulfate, aluminum sulfate and titanium dioxide is 0.75:0.75:3, the amount of PVP is 1.5g, the volume of DMF, acetic acid and ethanol is 3:2:8, the total volume of the mixture is 15mL, and the nanofiber membrane is prepared under the following conditions: negative voltage of -1kV, positive voltage of 18kV, temperature of 60℃ and feed rate of 1.5mL / h.
[0048] (2) Na1.97 Al 1.82 Ti 6.15 O 16 Preparation of semiconductor photocatalyst: After peeling off the nanofiber membrane from step (1), heat-treat at 800℃ for 4 hours, then wash the resulting product with deionized water until neutral, and dry to obtain the semiconductor photocatalyst Na. 1.97 Al 1.82 Ti 6.15 O 16 .
[0049] Example 4
[0050] The preparation method is the same as in Example 1, except that the heat treatment time in step (2) is replaced by 4 hours instead of 2 hours.
[0051] Example 5
[0052] The preparation method is the same as in Example 1, except that the heat treatment time in step (2) is replaced by 6 hours instead of 2 hours.
[0053] The following section studies the sample and its catalytic effect in this application. The research methods and results are shown below:
[0054] I. Sample Testing
[0055] Na was obtained in Examples 1-5 of this invention. 1.97 Al 1.82 Ti 6.15 O 16 Semiconductor photocatalysts, specifically Na prepared in Examples 1, 4, and 5. 1.97 Al 1.82 Ti 6.15 O 16 Taking semiconductor photocatalysts as an example, the results are as follows: Figure 1 and Figure 2 As shown, Figure 1 The results show that the semiconductor photocatalyst synthesized under the conditions described in Example 1 is a pure phase, and the diffraction peak positions in the XRD data perfectly match those of the standard card PDF#80-1014. Figure 2 The results show that the semiconductor photocatalyst Na synthesized under the described conditions 1.97 Al 1.82 Ti 6.15 O 16 It consists of nanowires with good crystallinity.
[0056] II. In order to determine the process conditions and specific parameters of the present invention, the inventors conducted a large number of experiments and explorations. The specific experimental results and analysis are as follows:
[0057] 1. Determine the reaction temperature
[0058] First, thermogravimetric analysis was performed on the prepared nanofiber membrane to determine the appropriate reaction temperature. Figure 3 Thermogravimetric analysis showed that the nanofiber membranes obtained by spinning no longer lost mass between 600 and 1200 °C. The precursor fiber membranes were then heat-treated at 700 °C for 2–6 h, and the XRD patterns of the resulting powders were analyzed. Figure 4 The results showed that pure-phase Na could be obtained by treating it at 700℃ for 2 hours. 1.97 Al 1.82 Ti 6.15 O 16 Material.
[0059] 2. Morphological characteristics
[0060] Figure 5 SEM image of sodium copper titanate treated at 700℃ for 2h. Figure 6 SEM images of sodium copper titanate treated at 700℃ for 4 h show that the samples prepared at different holding times at a sintering temperature of 700℃ are all pure-phase semiconductor photocatalysts. 1.97 Al 1.82 Ti 6.15 O 16 The sample exhibits good crystallinity.
[0061] 3. Ultraviolet-visible diffuse reflectance spectrum
[0062] from Figure 7 The absorption edge of the sodium aluminum titanate sample is at 369 nm, and its band gap is calculated to be 3.36 eV.
[0063] 4. Photocatalytic performance test
[0064] Figure 8-10 This is a real-time photocatalytic degradation graph of methylene blue by sodium aluminum titanate with different calcination times. The dye concentration was 10 mg / L, the catalyst mass was 50 mg, and the lamp source was a 400 W metal halide lamp. The specific operation was as follows: the weighed sodium aluminum titanate photocatalyst was baked at 80℃ and set aside for use. 50 mL of the prepared dye was measured into a quartz test tube for photocatalytic reaction using a graduated cylinder. The catalyst was added and stirred continuously for 30 min. -30 min represents the start of the dark reaction. A dye sample was taken once at -20 min to record the concentration change. 0 min represents the end of the dark reaction. After sampling and recording, the lamp was turned on. The dye concentration was measured every 10 min using a UV-Vis spectrophotometer. Figure 8-10 The results showed that the intensity of the dye absorption peak measured by the spectrophotometer decreased for different samples at different lighting times, indicating that the dye concentration decreased and that the synthesized photocatalyst effectively degraded the dye.
[0065] Figure 11The vertical axis represents the ratio of dye concentration C to initial dye concentration C0 at any given time, and the horizontal axis represents time. Negative values indicate that the dark reaction stirring time is 30 minutes, and the experiment starts at time 0. Figure 11 It can be seen that sodium aluminum titanate has a certain adsorption effect on dye during the 30-minute dark reaction stage. After the lamp is turned on, the C / CO ratio of samples with different calcination times shows different decreasing trends, indicating that the catalytic performance of samples with different calcination times varies.
[0066] Figure 12 The degradation rate graphs of different samples at the moment the lamp was turned on are shown. After pseudo-first-order dynamic fitting, the slope obtained represents the rate of dye degradation, indicating that the sample calcined for 2 hours after the lamp was turned on has the best photocatalytic effect.
[0067] Figure 13 The color change of methylene blue at different times during photocatalytic degradation was investigated. The results showed that as time progressed, the color of the dye changed from dark blue to colorless at different times, indicating that the dye was completely degraded.
[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 Its application as a photocatalyst for the catalytic degradation of methylene blue dye or rose red B is characterized by... Semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 Prepare according to the following steps: (1) Preparation of nanofiber membrane: Sodium source, aluminum source, titanium source, polyvinylpyrrolidone, co-solvent, acetic acid and ethanol are mixed evenly and prepared into a mixture. The mixture is electrospun to obtain nanofiber membrane. (2) Semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 Preparation: The nanofiber membrane from step (1) was heat-treated at 700-800℃ for 2-6 hours, then washed with water until neutral to obtain the semiconductor photocatalyst Na. 1.97 Al 1.82 Ti 6.15 O 16 ; The co-solvent is N,N'-dimethylformamide or N,N'-diethylformamide.
2. The semiconductor photocatalyst Na according to claim 1 1.97 Al 1.82 Ti 6.15 O 16 Its application as a photocatalyst for the catalytic degradation of methylene blue dye or rose red B is characterized by... In step (1), the sodium source is selected from sodium acetate trihydrate, sodium carbonate or sodium sulfate, the aluminum source is selected from aluminum nitrate nonahydrate, aluminum oxide or aluminum sulfate, and the titanium source is selected from tetrabutyl titanate, titanium dioxide or titanium sulfate.
3. The semiconductor photocatalyst Na according to claim 1 1.97 Al 1.82 Ti 6.15 O 16 Its application as a photocatalyst for the catalytic degradation of methylene blue dye or rose red B is characterized by... In step (1), the molar ratio of sodium, aluminum, and titanium in the sodium source, aluminum source, and titanium source is (0.5-1):(0.5-1):(2-3); the mass ratio of polyvinylpyrrolidone to titanium source is (1-2):(0.5-1). The volume ratio of the co-solvent, acetic acid, and ethanol is (1-3):(1-2):(6-8).
4. The semiconductor photocatalyst Na according to claim 3 1.97 Al 1.82 Ti 6.15 O 16 Its application as a photocatalyst for the catalytic degradation of methylene blue dye or rose red B is characterized by... In step (1), the molar ratio of sodium, aluminum, and titanium in the sodium source, aluminum source, and titanium source is 1:1:
2.
5. The semiconductor photocatalyst Na according to claim 1 1.97 Al 1.82 Ti 6.15 O 16 Its application as a photocatalyst for the catalytic degradation of methylene blue dye or rose red B is characterized by... The electrospinning conditions in step (1) are as follows: the nanofiber membrane is prepared under the following conditions: the negative voltage of the spinning voltage is -1 kV, the positive voltage is 18 kV, the temperature is 40-60 ℃, and the propulsion rate is 1.5-2 mL / h.
6. The semiconductor photocatalyst Na according to claim 1 1.97 Al 1.82 Ti 6.15 O 16 Its application as a photocatalyst for the catalytic degradation of methylene blue dye or rose red B is characterized by... In step (2), the nanofiber membrane from step (1) is heat-treated at 700 °C for 2 h.
7. The semiconductor photocatalyst Na according to claim 1 1.97 Al 1.82 Ti 6.15 O 16 Its application as a photocatalyst for the catalytic degradation of methylene blue dye or rose red B is characterized by... The semiconductor photocatalyst Na 1.97 Al 1.82 Ti 6.15 O 16 It is in the form of nanowires.
Citation Information
Patent Citations
Production of fibrous or filmy substance of titanate having hollandite type structure
JP1990074527A