Tin-doped two-dimensional organic-inorganic hybrid perovskite catalysts, preparation and use thereof
By using tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst Sn0.05(C5H10F2N)2PbI4 in synergy with an ultrasonic field, the problems of photogenerated electron-hole recombination and poor stability in the photocatalytic decomposition of hydroiodic acid were solved, and a highly efficient photocatalytic hydrogen production effect was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHEAST UNIV
- Filing Date
- 2026-04-13
- Publication Date
- 2026-07-07
AI Technical Summary
Existing photocatalytic materials for decomposing hydroiodic acid suffer from problems such as easy recombination of photogenerated electrons and holes, low quantum efficiency, and poor chemical stability, especially being prone to corrosion and deactivation in acidic environments.
A tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst, Sn0.05(C5H10F2N)2PbI4, was used in conjunction with an ultrasonic field. The catalyst promoted charge separation through a built-in electric field and achieved self-repair through a dissolution-recrystallization mechanism, thereby improving catalytic stability.
It effectively promotes the separation of photogenerated carriers, improves the catalytic hydrogen production rate and long-term stability, and the synthesis method is simple and sustainable.
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Figure CN122344154A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalyst technology, specifically relating to a tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst and its synthesis method, as well as the application of the catalyst in the photocatalytic decomposition of hydroiodic acid to produce hydrogen. Background Technology
[0002] With the continued growth of global energy demand and the acceleration of the low-carbon transition, developing green and efficient hydrogen production technologies has become an important research direction in the field of energy science. Among various hydrogen production pathways, photocatalytic decomposition of hydroiodic acid (HI) is considered a highly promising solar-powered hydrogen production method due to its relatively simple reaction pathway and theoretically low energy consumption. However, traditional photocatalytic systems generally face two major bottlenecks in practical applications: first, photogenerated electrons and holes recombine easily, leading to low quantum efficiency; second, most photocatalytic materials have poor chemical stability in strongly acidic reaction media and are prone to corrosion and deactivation. Therefore, designing and constructing novel photocatalytic materials that can effectively promote charge separation and exhibit good chemical stability in acidic environments is key to overcoming the bottleneck in photocatalytic hydrogen production efficiency.
[0003] Ferroelectric materials, due to their inherent spontaneous polarization effect, can form a stable built-in electric field within the material, effectively driving photogenerated electrons and holes to migrate in opposite directions and significantly inhibiting their recombination. Therefore, they have attracted widespread attention in the field of photocatalysis. However, traditional inorganic ferroelectric materials (such as barium titanate-based materials) typically have wide band gaps, primarily responding to ultraviolet light, with extremely low utilization of visible light, which dominates the solar spectrum. Furthermore, their structural tuning is difficult, limiting further improvements in photocatalytic performance. In contrast, organic-inorganic hybrid perovskite materials combine the structural tunability of organic components with the excellent photoelectric properties of inorganic components, exhibiting significant advantages such as tunable band gaps, high light absorption coefficients, and mild preparation conditions.
[0004] In a mother liquor environment, perovskite materials may achieve surface self-repair through a dissolution-recrystallization mechanism, thereby alleviating photocorrosion problems. Simultaneously, coupling with external physical fields, such as ultrasonic fields, can utilize the resulting acoustic flow and piezoelectric effects to improve interfacial mass transfer and charge transfer dynamics, providing a new approach for achieving efficient photo-acoustic coupled catalysis.
[0005] However, current research on the effects of elemental doping on the light absorption and photocatalytic hydrogen production of two-dimensional organic-inorganic hybrid perovskites, especially on photo-acoustic synergistic catalysis, is insufficient. Therefore, developing two-dimensional hybrid perovskite materials with suitable band structures, high stability, and excellent catalytic performance through elemental doping is of significant research importance and application value. Summary of the Invention
[0006] The present invention aims to provide a tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst with ferroelectric properties, its synthesis method, and its application in photocatalytic hydrogen production, so as to solve the shortcomings of existing photocatalytic materials in terms of light absorption range, charge separation efficiency and catalytic stability.
[0007] The technical solution of this invention is: a tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst, wherein the catalyst is Sn. 2+ Doped with the chemical formula Sn 0.05 (C5H 10 Two-dimensional organic-inorganic hybrid perovskite material of F2N)2PbI4.
[0008] A method for synthesizing a tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst includes the following steps: (1) Dissolve 4,4-difluoropiperidine in hydroiodic acid to obtain a mixture; (2) Add lead iodide, stannous iodide and hypophosphorous acid to the mixture, heat and stir until the solution is clear to obtain the precursor solution; (3) The precursor solution was filtered and cooled to crystallize under stirring to obtain a purple-red solid; (4) The purplish-red solid is dried and ground to obtain the catalyst powder.
[0009] The heating temperature in step (2) is 75-85 ℃.
[0010] The molar ratio of 4,4-difluoropiperidine, lead iodide, and stannous iodide is 10:5:0.05-0.5.
[0011] The amount of hypophosphoric acid added in step (2) is 2%-10% of the volume of hydroiodic acid, used to prevent Sn. 2+ Ion oxidation.
[0012] It also includes using the remaining saturated hydroiodic acid solution after filtration as the mother liquor for the catalytic reaction.
[0013] The application of the tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst in photocatalytic hydrogen production.
[0014] The application includes the following steps: The catalyst powder is mixed with the catalytic reaction mother liquor and subjected to photocatalytic reaction under light conditions; or further coupled with an ultrasonic field to synergistically enhance the catalytic hydrogen production rate.
[0015] The illumination is provided by a xenon lamp.
[0016] The ultrasonic field is provided by an ultrasonic cleaner.
[0017] The beneficial effects of this invention are as follows: (1) The catalyst has a suitable band gap (about 1.96 eV) and ferroelectricity, and can form a built-in electric field under light irradiation, which can effectively promote the separation of photogenerated carriers; (2) By introducing an ultrasonic field, the synergistic effect of ferroelectric polarization and stress field is realized, further enhancing the interfacial reaction kinetics and hydrogen production rate; (3) The catalyst can achieve self-repair through a reversible dissolution-precipitation mechanism during the reaction process, thus maintaining long-term stability; (4) The synthesis method is simple and the conditions are mild. The saturated mother liquor can be recycled, which has good process sustainability. Attached Figure Description Figure 1 For Sn 0.05 (C5H 10 Comparison of PXRD test pattern and single crystal simulation pattern of F2N)2PbI4; Figure 2 For Sn 0.05 (C5H 10 UV-Vis absorption spectrum and Tauc diagram of F2N)2PbI4; Figure 3 For Sn 0.05 (C5H 10 UPS test spectrum of F2N)2PbI4; Figure 4 For Sn 0.05 (C5H 10 A schematic diagram of the band structure of F2N)2PbI4; Figure 5 For Sn 0.05 (C5H 10 HRTEM image of F2N)2PbI4; Figure 6 For Sn 0.05 (C5H 10 EDS elemental distribution map of F2N)2PbI4; Figure 7 The graphs show the catalytic hydrogen production performance of different hydroiodic acid / hypophosphoric acid ratios in Examples 1–5. Figure 8 The graph shows the cyclic stability test results for Example 6. Figure 9 This is a graph showing the long-term stability test results for Example 7; Figure 10 The graph shows a comparison of hydrogen production performance under different catalytic conditions (light, ultrasound, and photo-acoustic synergy) in Examples 3, 8, and 9. Detailed Implementation
[0018] The present invention will be further illustrated below with reference to embodiments, but should not be construed as limiting the present invention.
[0019] The first objective of this invention is to provide a method for synthesizing a tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst, comprising the following steps: S1. Raw material preparation: 4,4-difluoropiperidine, lead iodide, stannous iodide, hydroiodic acid, hypophosphite; S2. Add 4,4-difluoropiperidine to hydroiodic acid and stir until dissolved evenly to obtain a mixture; S3. Add lead iodide, stannous iodide and hypophosphorous acid to the mixture, heat to 80°C and stir until the solution turns clear and bright yellow to obtain the precursor solution; S4. Filter the precursor solution and cool it at room temperature to crystallize, obtaining a purple-red solid; S5. The purplish-red solid is dried and ground to obtain catalyst powder, and the remaining saturated solution is used as the mother liquor for the catalytic reaction.
[0020] Preferably, the molar ratio of 4,4-difluoropiperidine, lead iodide and stannous iodide is 10:5:0.25.
[0021] Preferably, the amount of hypophosphoric acid added is 2%-10% of the volume of hydroiodic acid, and its main function is to prevent the oxidation of iodide ions.
[0022] A second objective of this invention is to provide a two-dimensional organic-inorganic hybrid perovskite catalyst prepared by the above method, having the chemical formula Sn. 0.05 (C5H 10 F2N)2PbI4.
[0023] A third objective of this invention is to provide the application of the catalyst in photocatalytic hydrogen production, wherein the catalyst powder is mixed with the mother liquor of the catalytic reaction and the photocatalytic reaction is carried out under light irradiation; furthermore, an ultrasonic field can be coupled to synergistically improve the catalytic efficiency.
[0024] The illumination is provided by a xenon lamp with a photocurrent of 20 A.
[0025] The ultrasonic field is provided by an ultrasonic cleaner at a frequency of 40 kHz.
[0026] Example 1: Catalyst Preparation 20 mL of hydroiodic acid (47%) was added to a beaker, followed by 10 mmol of 4,4-difluoropiperidine, 5 mmol of lead iodide, and 0.25 mmol of stannous iodide, and then 1 mL of hypophosphorous acid (≥50%). The mixture was heated to 80 °C and stirred vigorously until the solid was completely dissolved, yielding a clear precursor solution. The solution was filtered while hot, and the filtrate was cooled with vigorous stirring at room temperature, precipitating purple-red crystals. The crystals were collected by filtration, washed twice with anhydrous toluene, and then dried under vacuum at 80 °C for 8 hours. After grinding, a purple-red catalyst powder was obtained.
[0027] Examples 2-5: Different Sn 2+ Comparison of doping levels With 4,4-difluoropiperidine fixed at 10 mmol and lead iodide at 5 mmol, the amount of stannous iodide added was adjusted to 0.05 mmol (Example 2), 0.1 mmol (Example 3), 0.25 mmol (Example 4, same as Example 1), and 0.5 mmol (Example 5), respectively, with the remaining steps the same as in Example 1. The different Sn values were evaluated by photocatalytic hydrogen production testing. 2+ The effect of doping amount on catalyst performance is shown in the following results. Figure 7 As shown, the hydrogen production rate is highest when the tin iodide feed amount is 0.25 mmol.
[0028] Example 6: Cyclic Stability Test The photocatalytic reaction was carried out using the catalyst prepared in Example 3. Each cycle lasted 4 hours. After the reaction, the system was allowed to stand, and the gas in the system was released by ultrasound and then purged with N2 before starting the next cycle. A total of 5 cycles were performed, accumulating a total reaction time of 20 hours. The results are as follows: Figure 8 As shown, the catalyst maintains stable activity during cycling.
[0029] Example 7: Long-term stability test The catalyst from Example 3 was continuously reacted under light irradiation for 60 hours, with samples taken periodically for testing. After the reaction was completed, the mixture was allowed to stand, and then a second reaction was carried out. The results are as follows. Figure 9 As shown, the catalyst maintains high activity even after long-term operation.
[0030] Example 8: Photo-acoustic synergistic catalysis In the photocatalytic system of Example 3, an additional 40 kHz ultrasonic field was applied, while other conditions remained unchanged. The hydrogen production rate was significantly increased. Figure 10 ).
[0031] Example 9: Ultrasonic Catalysis Only In the system of Example 3, the xenon lamp was turned off, and only a 40 kHz ultrasonic field was applied for catalysis. The results are as follows: Figure 9As shown, the hydrogen production activity under ultrasound alone is much lower than that under the synergistic effect of light and sound, indicating that ultrasound mainly plays a synergistic enhancing role.
[0032] Material characterization: Test results such as PXRD, UV absorption, UPS, HRTEM, and EDS are as follows: Figure 1 As shown in Figure 6, the prepared material is confirmed to be the target compound Sn. 0.05 (C5H 10 F2N)2PbI4 has a regular crystal structure, a suitable band gap, and a uniform elemental distribution.
Claims
1. A tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst, characterized in that, The catalyst is Sn. 2+ Doped with the chemical formula Sn 0.05 (C5H 10 Two-dimensional organic-inorganic hybrid perovskite material of F2N)2PbI4.
2. The method for synthesizing the tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst according to claim 1, characterized in that, Includes the following steps: (1) Dissolve 4,4-difluoropiperidine in hydroiodic acid to obtain a mixture; (2) Add lead iodide, stannous iodide and hypophosphorous acid to the mixture, heat and stir until the solution is clear to obtain the precursor solution; (3) The precursor solution was filtered and cooled to crystallize under stirring to obtain a purple-red solid; (4) The purplish-red solid is dried and ground to obtain the catalyst powder.
3. The synthesis method according to claim 2, characterized in that, The heating temperature in step (2) is 75-85℃.
4. The synthesis method according to claim 2, characterized in that, The molar ratio of 4,4-difluoropiperidine, lead iodide, and stannous iodide is 10:5:0.05-0.
5.
5. The synthesis method according to claim 2, characterized in that, The amount of hypophosphoric acid added in step (2) is 2%-10% of the volume of hydroiodic acid, used to prevent Sn. 2+ Ion oxidation.
6. The synthesis method according to claim 2, characterized in that, It also includes using the remaining saturated hydroiodic acid solution after filtration as the mother liquor for the catalytic reaction.
7. The application of the tin-doped two-dimensional organic-inorganic hybrid perovskite catalyst according to claim 1 in photocatalytic hydrogen production.
8. The application according to claim 7, characterized in that, Includes the following steps: The catalyst powder is mixed with the catalytic reaction mother liquor and subjected to photocatalytic reaction under light conditions; or further coupled with an ultrasonic field to synergistically enhance the catalytic hydrogen production rate.
9. The application according to claim 8, characterized in that, The illumination is provided by a xenon lamp.
10. The application according to claim 8, characterized in that, The ultrasonic field is provided by an ultrasonic cleaner.