Co2SnO4 / Ba 0.5 Sr 0.5 Preparation method of TiO3 catalyst and its application in piezoelectric photocatalytic hydrogen production

Abstract

The present invention belongs to the application of piezoelectric photocatalytic hydrogen production field, specifically to Co2SnO4 / Ba 0.5 Sr 0.5 Preparation method of TiO3 catalyst and its application in piezoelectric photocatalytic hydrogen production. 0.5 Sr 0.5 TiO3, and then synthesize the precursor CoSn(OH)6 by hydrothermal method, calcined to prepare the co-catalyst Co2SnO4, and finally ultrasonic stirring and solution evaporation method were used to fully mix the two components to obtain Co2SnO4 / Ba 0.5 Sr 0.5 TiO3 composite catalyst. The composite catalyst prepared by the present invention has excellent light absorption ability and abundant reaction active sites. The catalyst is applied to piezoelectric photocatalytic hydrogen production. Under the synergistic effect of light and ultrasound, it shows stability and excellent H2 production capacity, further expanding the Ba 0.5 Sr 0.5 Application of TiO3 in piezoelectric photocatalytic hydrogen production.

Description

Technical Field

[0001] The present invention belongs to the field of piezoelectric photocatalysis, and specifically relates to a Co2SnO4 / Ba 0.5 Sr 0.5 TiO3 composite catalyst, preparation method thereof and application of piezoelectric photocatalysis in producing H2. Background Art

[0002] With the deterioration of the environment and the increasing demand for energy, the development of renewable, clean energy has become a top priority. Hydrogen energy, as the most promising alternative to fossil fuels, has received widespread attention. In recent years, the conversion of solar energy into hydrogen energy has been studied worldwide due to its green and sustainable characteristics. Photocatalysts, as the core of the photocatalytic system, determine the efficiency of converting solar energy into hydrogen energy. Therefore, the rational design of photocatalysts is crucial to improving hydrogen production performance. When the development of photocatalysis encountered a bottleneck, researchers began to study the coupling of light field and physical field catalysis to improve efficiency and explore deeper photocatalytic mechanisms. Pressure fields, represented by ultrasound, have become the most widely studied physical fields due to their ease of application. This field is used to accelerate catalysis and is commonly known as piezoelectric catalysis.

[0003] As a lead-free ABO3 type material, barium strontium titanate (BST) is an important perovskite material with good piezoelectricity and high structural stability. Therefore, it is very important to study the piezoelectric catalytic effect of BST solid solution. Regarding the application of barium strontium titanate in the field of photocatalysis, patent CN106964338A discloses a WO3 / Ba 0.5 Sr 0.5 Preparation method and application of TiO3. Ba(OH)2·8H2O, Sr(OH)2 and TiO2 are used as raw materials, and Ba is obtained by microwave reaction, cooling, washing, centrifugation, drying and grinding. 0.5 Sr 0.5 TiO3. After mixing WO3 and titanate, add them to deionized water, ultrasonically disperse them, heat them at 100℃ for 30-40min, filter them, dry the precipitate at 120℃ for 8h, grind the obtained powder and calcine it at 700-750℃ for 1h to obtain WO3 / Ba 0.5 Sr 0.5 TiO3 composite photocatalysts have improved photocatalytic performance, but the preparation process is complicated, the raw materials are difficult to obtain, the price is expensive, the operation is difficult, and the risk factor is high. Summary of the Invention

[0004] The purpose of the present invention is to prepare a Co2SnO4 / Ba 0.5 Sr 0.5TiO3 composite catalysts are used in piezoelectric photocatalytic H2 production, showing higher photocatalytic activity than pure substances. This further broadens the application of barium strontium titanate in the field of piezoelectric photocatalytic hydrogen production.

[0005] Co2SnO4 / Ba prepared by the present invention 0.5 Sr 0.5 The preparation method of the TiO3 composite catalyst comprises the following steps:

[0006] (1)Ba 0.5 Sr 0.5 Preparation of TiO3:

[0007] TiO2, BaCO3, and SrCO3 were weighed in molar ratio and added to deionized water to stir to mix them thoroughly. The deionized water in the raw materials was then removed by solution evaporation. The raw materials were placed in an agate mortar and ground for 20 to 40 minutes. The raw materials were placed in a tube furnace and heated to 1000°C at a rate of 2°C / min and calcined for 12 hours. After the calcination was completed, the temperature was naturally cooled to room temperature and ground again. The raw materials were then placed in a tube furnace again and heated to 1100°C at a rate of 2°C / min. The raw materials were calcined for 12 hours. The white BaCO3 was obtained after natural cooling. 0.5 Sr 0.5 TiO3 (abbreviation: BST).

[0008] Furthermore, the molar ratio of TiO2, BaCO3, and SrCO3 is 2:1:1.

[0009] Ba 0.5 Sr 0.5 In the synthesis of TiO3, the raw materials are prepared by solution stirring and evaporation, in order to allow the raw materials to be more fully mixed before calcination.

[0010] (2) Preparation of Co2SnO4:

[0011] Dissolve Co(NO3)2·6H2O in deionized water and stir continuously at room temperature until dissolved to obtain solution A. Dissolve SnCl4·5H2O in deionized water and stir continuously at room temperature until dissolved to obtain solution B. Add solution A dropwise to solution B and stir at room temperature for 10 minutes to obtain solution C. Add NaOH solution dropwise to solution C and stir for 30 minutes to form a blue precipitate. Then, transfer the reaction solution to a high-pressure reactor and react at 180°C for 10 hours. The reaction solution is naturally cooled to room temperature, filtered, washed with water and ethanol in sequence, and dried at 80°C for 12 hours to obtain CoSn(OH)6. Place CoSn(OH)6 in a tube furnace and calcine at 500°C for 3 hours to obtain black Co2SnO4 (abbreviated as: CSO).

[0012] Furthermore, the molar ratio of Co(NO3)2·6H2O and SnCl4·5H2O is 2:1, and the concentration of the NaOH solution is 1 mol / L.

[0013] (3)Co2SnO4 / Ba 0.5 Sr 0.5 Preparation of TiO3 composite catalyst:

[0014] Co2SnO4 and Ba 0.5 Sr 0.5 TiO3 is dispersed in a certain amount of solvent, and after ultrasonication, stirring, filtering, washing and drying, Co2SnO4 / Ba 0.5 Sr 0.5 TiO3 composite catalyst.

[0015] Furthermore, the added mass of the Co2SnO4 is Ba 0.5 Sr 0.5 3-7% of TiO3 mass.

[0016] Furthermore, the solvent includes deionized water, the ultrasonic power is 240W, the time is 1 hour, and the stirring speed is 400 r / min, and the time is 24 hours.

[0017] The Co2SnO4 / Ba prepared by the above method 0.5 Sr 0.5 TiO3 composite catalyst is used for piezoelectric photocatalytic hydrogen production. The specific application method is: Co2SnO4 / Ba 0.5 Sr 0.5 The TiO3 composite catalyst is added to water and evenly dispersed by ultrasound, then the sacrificial agent methanol is added, followed by nitrogen, and finally piezoelectric photocatalysis is carried out to produce hydrogen under the conditions of ultrasound and light.

[0018] Furthermore, the light source of the illumination is sunlight.

[0019] Furthermore, the Co2SnO4 / Ba 0.5 Sr 0.5 The amount of TiO3 composite catalyst used in water is 1-3 mg / 18 mL, preferably 1 mg / 18 mL.

[0020] The beneficial effects of the present invention are:

[0021] (1) The present invention prepares Ba by a simple calcination method 0.5 Sr 0.5 TiO3 has the advantages of simple preparation method, safe preparation process, low preparation cost and low preparation difficulty. By adding the co-catalyst Co2SnO4, the main catalyst Ba 0.5 Sr0.5 The light absorption capacity of TiO3 greatly improves the 0.5 Sr 0.5 Piezoelectric photocatalytic properties of TiO3.

[0022] (2) Preparation of Co2SnO4 / Ba by ultrasonic stirring and solution evaporation 0.5 Sr 0.5 TiO3 composite catalyst, the composite method is simple, fast and efficient, green and pollution-free, making Co2SnO4 and Ba 0.5 Sr 0.5 TiO3 is fully and uniformly contacted and compounded.

[0023] (3) The addition of co-catalyst Co2SnO4, compared with the main catalyst Ba 0.5 Sr 0.5 TiO3, Co2SnO4 / Ba 0.5 Sr 0.5 The TiO3 composite catalyst exhibits a smaller charge transfer resistance, which improves the performance of piezoelectric photocatalysis. 0.5 Sr 0.5 The TiO3 composite catalyst showed a relatively greater photoresponse.

[0024] (4)Ba 0.5 Sr 0.5 There is charge transfer between TiO3 and Co2SnO, Co2SnO4 / Ba 0.5 Sr 0.5 The peak intensity of photoluminescence of TiO3 composite catalyst showed the lowest, which indicated that Ba 0.5 Sr 0.5 The charge transfer between TiO3 and Co2SnO effectively inhibits charge recombination, which is beneficial to improving the utilization rate of photogenerated carriers and enhancing the piezoelectric photocatalytic hydrogen production activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The Co2SnO4 / Ba synthesized in Example 1 0.5 Sr 0.5 Scanning electron microscope image of TiO3 composite catalyst;

[0026] Figure 2 Co2SnO4, Ba 0.5 Sr 0.5 XRD pattern of TiO3 catalyst;

[0027] Figure 3 The Co2SnO4 / Ba synthesized in Example 1-5 0.5 Sr 0.5XRD pattern of TiO3 composite catalyst;

[0028] Figure 4 The catalyst synthesized in Example 1-5 and Ba 0.5 Sr 0.5 H2 production performance diagram of TiO3 under piezoelectric light conditions;

[0029] Figure 5 The catalyst synthesized in Example 1-5 and Ba 0.5 Sr 0.5 Performance diagram of TiO3 producing H2 under piezoelectric action only;

[0030] Figure 6 The catalyst synthesized in Example 1-5 and Ba 0.5 Sr 0.5 Performance diagram of TiO3 producing H2 under light alone;

[0031] Figure 7 This is a performance diagram of H2 production under piezoelectric photocatalytic conditions under the conditions of Comparative Examples 8-9;

[0032] Figure 8 is a performance diagram of H2 production under piezoelectric photocatalytic conditions under the conditions of Example 1 and Examples 6-8;

[0033] Figure 9 Co2SnO4 / Ba 0.5 Sr 0.5 EDS elemental mapping of TiO3 composite catalyst.

[0034] Figure 10 Yes 0.5 Sr 0.5 TiO3 and Co2SnO4 / Ba prepared in Example 1 0.5 Sr 0.5 Electrochemical LSV diagram of TiO3 composite catalyst.

[0035] Figure 11 Yes 0.5 Sr 0.5 TiO3 and Co2SnO4 / Ba prepared in Example 1 0.5 Sr 0.5 Electrochemical EIS diagram of TiO3 composite catalyst.

[0036] Figure 12 Yes 0.5 Sr 0.5 TiO3 and Co2SnO4 / Ba prepared in Example 1 0.5 Sr 0.5 Electrochemical PL diagram of TiO3 composite catalyst. DETAILED DESCRIPTION

[0037] The present invention is not limited to the following specific embodiments. A person skilled in the art may implement the present invention in a variety of other specific embodiments based on the disclosure of the present invention. Any simple changes or modifications made to the design structure and concept of the present invention fall within the scope of protection of the present invention. It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other unless they conflict. The H2 production efficiency is calculated according to the following formula:

[0038]

[0039] R: H2 production rate, unit: μmol / (g·h),

[0040] V: Hydrogen volume, unit: μL,

[0041] m: catalyst mass, unit: g,

[0042] t: reaction time, unit: h.

[0043] Example 1

[0044] (1) Pour 0.56g TiO2, 0.69g BaCO3 and 0.52g SrCO3 into a beaker, then add deionized water and stir to mix them thoroughly. Then remove the deionized water in the raw materials by solution evaporation method, place them in an agate bowl, grind them for 30min, then put them in a tube furnace, heat them to 1000℃ at a rate of 2℃ / min, calcine them for 12h, after calcination, naturally cool them to room temperature, grind them again, then put them in a tube furnace, heat them to 1100℃ at a rate of 2℃ / min, calcine them for 12h, and naturally cool them to obtain white Ba 0.5 Sr 0.5 TiO3.

[0045] (2) Dissolve 4 mmol Co(NO3)2·6H2O in 30 mL of deionized water and stir continuously at room temperature until dissolved to obtain solution A. Dissolve 2 mmol SnCl4·5H2O in 20 mL of deionized water and stir continuously at room temperature until dissolved to obtain solution B. Add solution A dropwise to solution B and stir at room temperature for 10 min to obtain solution C. Add 20 mL of 1 mol / L NaOH solution dropwise to solution C and stir for 30 min to form a blue precipitate. Then, transfer the reaction solution to a 100 mL high-pressure reactor and react at 180°C for 10 h. The reaction solution is naturally cooled to room temperature, filtered, washed with water and ethanol in sequence, and dried at 80°C for 12 h to obtain CoSn(OH)6. Place CoSn(OH)6 in a tube furnace and calcine at 500°C for 3 h to obtain black Co2SnO4.

[0046] (3) will Ba 0.5 Sr 0.5 TiO3 and Co2SnO4 were dissolved in deionized water, ultrasonically dispersed for 1 hour, and then vigorously stirred and mixed for 24 hours. Then, the mixture was filtered, washed, and vacuum-dried at 60°C overnight to obtain a dark pink powdered composite catalyst, namely Co2SnO4 / Ba 0.5 Sr 0.5 TiO3 composite catalyst, in the composite catalyst, the mass of Co2SnO4 is Co2SnO4 / Ba 0.5 Sr 0.5 5% of the mass of TiO3 composite catalyst. Note as 5% Co2SnO4-Ba 0.5 Sr 0.5 TiO3.

[0047] The 5% Co2SnO4 / Ba prepared in Example 1 0.5 Sr 0.5 TiO3 composite catalyst is used for piezoelectric photocatalytic hydrogen production.

[0048] 1 mg 5% Co2SnO4-Ba 0.5 Sr 0.5 TiO₃ was mixed with 18 mL of deionized water and dispersed under ultrasound for 0.5 h to uniformly disperse the catalyst in the water. 2 mL of methanol was then added as a sacrificial agent. N₂ was then purged for 30 min. Finally, the reaction was conducted in a sealed container under ultrasound (240 W) and illumination (35 W xenon lamp simulating sunlight) for 2 h. After the experiment, 0.5 mL of gas was extracted from the tube, and the peak area was measured using a gas chromatograph. The H₂ production rate was calculated to be 4199.53 μmol / (g·h).

[0049] Example 2

[0050] Compared with Example 1, the difference is that the mass of the co-catalyst Co2SnO4 added in step (3) is Co2SnO4 / Ba 0.5 Sr 0.5 3% of the mass of the TiO3 composite catalyst. Other experimental conditions are the same as those in Example 1. 0.5 Sr 0.5 TiO3.

[0051] The 3% Co2SnO4-Ba prepared in Example 2 0.5 Sr 0.5 TiO3 was used for piezoelectric catalytic hydrogen production. The experimental conditions were consistent with those in Example 1, and the H2 production rate was 1672.82 μmol / (g·h).

[0052] Example 3

[0053] Compared with Example 1, the difference is that the mass of the co-catalyst Co2SnO4 added in step (3) is Co2SnO4 / Ba 0.5 Sr 0.5 4% of the mass of the TiO3 composite catalyst. Other experimental conditions are the same as those in Example 1. 0.5 Sr 0.5 TiO3.

[0054] The 4% Co2SnO4-Ba prepared in Example 3 0.5 Sr 0.5 TiO3 was used for piezoelectric catalytic hydrogen production. The experimental conditions were consistent with those in Example 1, and the H2 production rate was 1923.48 μmol / (g·h).

[0055] Example 4

[0056] Compared with Example 1, the difference is that the mass of the co-catalyst Co2SnO4 added in step (3) is Co2SnO4 / Ba 0.5 Sr 0.5 6% of the mass of the TiO3 composite catalyst. Other experimental conditions are the same as those in Example 1. 0.5 Sr 0.5 TiO3.

[0057] The 6% Co2SnO4-Ba prepared in Example 4 0.5 Sr 0.5 TiO3 was used for piezoelectric catalytic hydrogen production. The experimental conditions were consistent with those in Example 1, and the H2 production rate was 1252.80 μmol / (g·h).

[0058] Example 5

[0059] Compared with Example 1, the difference is that the mass of the co-catalyst Co2SnO4 added in step (3) is Co2SnO4 / Ba 0.5 Sr 0.5 7% of the mass of the TiO3 composite catalyst. Other experimental conditions are the same as those in Example 1. 0.5 Sr 0.5 TiO3.

[0060] The 7% Co2SnO4-Ba prepared in Example 5 0.5 Sr 0.5 TiO3 was used for piezoelectric catalytic hydrogen production. The experimental conditions were consistent with those in Example 1, and the H2 production rate was 1160.24 μmol / (g·h).

[0061] Example 6

[0062] Compared with Example 1, the catalyst is the same, except that the sacrificial agent added in the piezoelectric photocatalytic hydrogen production application is changed to ethanol. Other experimental conditions are the same as in Example 1.

[0063] According to the conditions of Example 6, the sacrificial agent was changed to ethanol, and the prepared 5% Co2SnO4-Ba 0.5 Sr 0.5 TiO3 was used for piezoelectric catalytic hydrogen production. Other experimental conditions were consistent with those in Example 1, and the H2 production rate was 991.66 μmol / (g·h).

[0064] Example 7

[0065] Compared with Example 1, the catalyst is the same, except that the sacrificial agent added in the piezoelectric photocatalytic hydrogen production application is changed to sodium sulfide-sodium sulfite solution. Other experimental conditions are the same as in Example 1.

[0066] According to the conditions of Example 7, the sacrificial agent was changed to sodium sulfide-sodium sulfite solution, and the prepared 5% Co2SnO4-Ba 0.5 Sr 0.5 TiO3 was used for piezoelectric catalytic hydrogen production. Other experimental conditions were consistent with those in Example 1, and the H2 production rate was 340.68 μmol / (g·h).

[0067] Example 8

[0068] Compared with Example 1, the catalyst is the same, except that the sacrificial agent added in the piezoelectric photocatalytic hydrogen production application is changed to lactic acid. Other experimental conditions are the same as in Example 1.

[0069] According to the conditions of Example 8, the sacrificial agent was changed to lactic acid, and the prepared 5% Co2SnO4-Ba 0.5 Sr 0.5 TiO3 was used for piezoelectric catalytic hydrogen production. Other experimental conditions were consistent with those in Example 1, and the H2 production rate was 135.26 μmol / (g·h).

[0070] Example 9

[0071] Compared with Example 1, the difference is that in step (3), Co2SnO4 and Ba 0.5 Sr 0.5 The TiO3 stirring compound solution was changed from deionized water to ethanol. Other experimental conditions were the same as those in Example 1.

[0072] According to the conditions of Example 9, the solution stirred in step (3) was changed from deionized water to ethanol, and the prepared 5% Co2SnO4-Ba 0.5 Sr 0.5TiO3 was used for piezoelectric catalytic hydrogen production. Other experimental conditions were consistent with those in Example 1, and the H2 production rate was 1283.59 μmol / (g·h).

[0073] Comparative Example 1

[0074] 0.56g TiO2, 0.69g BaCO3 and 0.52g SrCO3 were poured into a beaker, and then deionized water was added and stirred to mix them thoroughly. The deionized water in the raw materials was then removed by solution evaporation. The raw materials were placed in an agate bowl and ground for 30 minutes. The raw materials were then placed in a tube furnace and heated to 1000°C at a rate of 2°C / min and calcined for 12 hours. After the calcination was completed, the temperature was naturally cooled to room temperature and ground again. The raw materials were then placed in a tube furnace and heated to 1100°C at a rate of 2°C / min and calcined for 12 hours. The white BaCO3 was obtained after natural cooling. 0.5 Sr 0.5 TiO3.

[0075] The prepared Ba 0.5 Sr 0.5 TiO3 was used for piezoelectric photocatalytic hydrogen production. Other experimental conditions were consistent with those in Example 1, and the H2 production rate was 210.38 μmol / (g·h).

[0076] Comparative Example 2

[0077] 4 mmol of Co(NO₃)₂·6H₂O was dissolved in 30 mL of deionized water and stirred continuously at room temperature until dissolved, yielding Solution A. 2 mmol of SnCl₄·5H₂O was dissolved in 20 mL of deionized water and stirred continuously at room temperature until dissolved, yielding Solution B. Solution A was added dropwise to Solution B and stirred at room temperature for 10 minutes, yielding Solution C. 20 mL of 1 mol / L NaOH solution was added dropwise to Solution C and stirred for 30 minutes, resulting in the formation of a blue precipitate. The reaction solution was then transferred to a 100 mL high-pressure reactor and reacted at 180°C for 10 hours. The reaction solution was cooled to room temperature, filtered, washed sequentially with water and ethanol, and dried at 80°C for 12 hours to yield CoSn(OH)₂. The CoSn(OH)₂ was then calcined in a tube furnace at 500°C for 3 hours to obtain black Co₂SnO₄.

[0078] The prepared Co2SnO4 was used for piezoelectric photocatalytic hydrogen production. Other experimental conditions were consistent with those in Example 1, and the H2 production rate was 100.76 μmol / (g·h).

[0079] Comparative Example 3

[0080] Compared with Examples 1-5 and Comparative Example 1, the difference is that the experimental conditions for the piezoelectric photocatalytic hydrogen production experiment are changed from ultrasound (240W) and light (35W xenon lamp simulated sunlight) to ultrasound (240W). Other experimental conditions are the same as those of Examples 1-5 and Comparative Example 1. The measured H2 production rate is shown in Figure 5 .

[0081] Comparative Example 4

[0082] Compared with Examples 1-5 and Comparative Example 1, the difference is that the experimental conditions for the piezoelectric photocatalytic hydrogen production experiment are changed from ultrasound (240W) and light (35W xenon lamp simulated sunlight) to light (35W xenon lamp simulated sunlight). Other experimental conditions are the same as those of Examples 1-5 and Comparative Example 1. The measured H2 production rate is shown in Figure 6 .

[0083] Comparative Example 5

[0084] Compared with Example 1, the difference is that Ba 0.5 Sr 0.5 TiO3 is replaced by Ba 0.2 Sr 0.8 TiO3. The amount of BaCO3 and SrCO3 was changed from 0.69g and 0.52g to 0.28g and 0.53g respectively, and Ba 0.2 Sr 0.8 TiO3, and other conditions were the same as in Example 1. The prepared composite catalyst was recorded as 5% Co2SnO4-Ba 0.2 Sr 0.8 TiO3.

[0085] The 5% Co2SnO4-Ba prepared in Comparative Example 5 0.2 Sr 0.8 The TiO3 composite catalyst was used for piezoelectric photocatalytic hydrogen production. The experimental conditions were consistent with those in Example 1, and the H2 production rate was 457.58 μmol / (g·h).

[0086] Comparative Example 6

[0087] Compared with Example 1, the difference is that Ba 0.5 Sr 0.5 TiO3 is replaced by Ba 0.8 Sr 0.2 BaTiO3 was prepared by changing the amount of BaCO3 and SrCO3 from 0.69g and 0.52g to 1.10g and 0.21g respectively. 0.8 Sr 0.2 The prepared composite catalyst is recorded as 5% Co2SnO4-Ba 0.8 Sr 0.2TiO3. Other conditions are the same as those in Example 1.

[0088] The 5% Co2SnO4-Ba prepared in Comparative Example 6 0.8 Sr 0.2 The TiO3 composite catalyst was used for piezoelectric photocatalytic hydrogen production. The experimental conditions were consistent with those in Example 1, and the H2 production rate was 535.71 μmol / (g·h).

[0089] Comparative Example 7

[0090] Compared with Example 1, the difference is that in step (2), the prepared CoSn(OH)6 is not calcined, and CoSn(OH)6 is used as the co-catalyst and the main catalyst Ba 0.5 Sr 0.5 TiO3 was stirred and compounded, and other conditions were the same as in Example 1, and recorded as 5% CoSn(OH)6-Ba 0.5 Sr 0.5 TiO3.

[0091] The 5% CoSn(OH)6-Ba prepared in Comparative Example 7 0.5 Sr 0.5 TiO3 was used for piezoelectric photocatalytic hydrogen production. Other experimental conditions were consistent with those in Example 1, and the H2 production rate was 179.92 μmol / (g·h).

[0092] Comparative Example 8

[0093] Compared with Example 1, the catalyst is the same. The difference is that in the piezoelectric photocatalytic hydrogen production application, the catalyst dosage in the piezoelectric photocatalytic hydrogen production experiment is changed from 1 mg to 0.5 mg. The other conditions are the same as those in Example 1, and the H2 production rate is 763.31 μmol / (g·h).

[0094] Comparative Example 9

[0095] Compared with Example 1, the catalyst is the same, except that in the piezoelectric photocatalytic hydrogen production application, the catalyst dosage in the piezoelectric photocatalytic hydrogen production experiment is changed from 1 mg to 2 mg. Other conditions are consistent with Example 1, and the H2 production rate is 1728.31 μmol / (g·h).

[0096] Comparative Example 10

[0097] Compared with Example 1, the difference is that the compounding method is different.

[0098] Step (1): Ba 0.5 Sr 0.5 TiO3, same as Example 1.

[0099] Step (2): Dissolve 4mmol Co(NO3)2·6H2O in 30mL deionized water and stir continuously at room temperature until dissolved to obtain solution A. Dissolve 2mmol SnCl4·5H2O in 20mL deionized water and stir continuously at room temperature until dissolved to obtain solution B. Add solution A dropwise to solution B and stir at room temperature for 10min to obtain solution C. Add 20mL 1mol / L NaOH solution dropwise to solution C and stir for 30min to form a blue precipitate. Add a certain amount of Ba 0.5 Sr 0.5 TiO3 (the mass content of Co2SnO4 in the composite is 5%), stirred for 30 minutes to mix evenly, then transferred to a hydrothermal reactor and reacted at 180°C for 10 hours. The reaction solution was naturally cooled to room temperature, filtered, washed with water and ethanol in sequence, dried at 80°C for 12 hours, placed in a tube furnace, and calcined at 500°C for 3 hours to obtain 5% Co2SnO4-Ba 0.5 Sr 0.5 TiO3.

[0100] The detection method was consistent with that in Example 1. The H2 production rate was measured to be 208.75 μmol / (g·h).

[0101] Comparative Example 11

[0102] Compared with Example 1, the difference is that the compounding method is different.

[0103] Step (1): Ba 0.5 Sr 0.5 TiO3, same as Example 1.

[0104] Step (2): The preparation method of CoSn(OH)6 is the same as that of Example 1. Compared with Example 1, the difference is that in step (2) of preparing Co2SnO4, before CoSn(OH)6 is placed in a tube furnace for calcination, a certain amount of Ba 0.5 Sr 0.5 TiO3 and CoSn(OH)6 were ground and mixed uniformly (the mass content of Co2SnO4 in the composite was 5%), and then calcined in a tube furnace at 500°C for 3 hours. Other conditions were the same as in Example 1. The measured H2 production rate was 657.35 μmol / (g·h).

[0105] Although the present invention has been described in conjunction with the preferred embodiments, the present invention is not limited to the above embodiments, and it should be understood that the appended claims summarize the scope of the present invention. Under the guidance of the inventive concept, those skilled in the art should appreciate that certain changes made to the various embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

Claims

1. A Co2SnO4 / Ba 0.5 Sr 0.5 The application of TiO3 composite catalyst in piezoelectric photocatalytic H2 production is characterized by: The composite catalyst is composed of Co2SnO4 and Ba 0.5 Sr 0.5 Formation of Co2SnO4 / BaTiO3 by ultrasonic stirring and solution evaporation 0.5 Sr 0.5 TiO3 composite; Specifically: prepare Co2SnO4 and Ba respectively 0.5 Sr 0.5 TiO3 powder, Co2SnO4 and Ba 0.5 Sr 0.5 TiO3 was dispersed in deionized water, mixed, and then ultrasonicated and stirred, and then filtered, washed, and dried to obtain Co2SnO4 / Ba 0.5 Sr 0.5 TiO3 composite catalyst; the Co2SnO4 is Ba 0.5 Sr 0.5 3-7% of TiO3 mass; Co2SnO4 / Ba 0.5 Sr 0.5 TiO3 composite catalyst was added to water and dispersed evenly, then methanol was added as a sacrificial agent, and then N2 was introduced. Piezoelectric photocatalysis was carried out to produce H2 under the conditions of ultrasound and light. Co2SnO4 / Ba 0.5 Sr 0.5 The dosage of TiO3 composite catalyst in water is 1~3 mg / 18 mL.

2. The use according to claim 1, characterized in that The mass of Co2SnO4 is Ba 0.5 Sr 0.5 5% of TiO3 mass.

3. The use according to claim 2, characterized in that Ba 0.5 Sr 0.5 The preparation method of TiO3 is as follows: weigh TiO2, BaCO3 and SrCO3 in molar ratio, add deionized water and stir to mix them thoroughly, then remove the deionized water in the raw materials by solution evaporation method, grind them in an agate mortar, put them in a tube furnace for primary calcination, and after the calcination is completed, grind them again after naturally cooling to room temperature, and then put them in the tube furnace for secondary calcination again, and cool them naturally to obtain BaO3. 0.5 Sr 0.5 TiO3; the molar ratio of TiO2, BaCO3, and SrCO3 is 2:1:

1.

4. The use according to claim 3, characterized in that The primary calcination condition was 1000℃ for 12 h, and the secondary calcination condition was 1100℃ for 12 h.

5. The use according to claim 1, characterized in that The Co2SnO4 / Ba 0.5 Sr 0.5 The dosage of TiO3 composite catalyst in water is 1 mg / 18 mL.

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