Preparation method of fly ash-based photocatalyst, photocatalyst and application

Abstract

The invention discloses a preparation method of a fly ash-based photocatalyst, the photocatalyst and application, and relates to the technical field of fly ash treatment. The preparation method of the fly ash-based photocatalyst comprises the following steps: adding fly ash and bismuth nitrate pentahydrate into distilled water, and uniformly stirring to obtain a first solution; the mass fraction ratio of the fly ash to the bismuth nitrate pentahydrate is 1.1-1.2; adding a buffer solution into the first solution, and uniformly stirring to obtain a second solution; the pH value of the second solution is 5-7; and reacting the second solution at the reaction temperature of 160-180 DEG C for at least 24 hours, cooling, carrying out suction filtration, washing and drying to obtain the fly ash-based photocatalyst. The fly ash-based photocatalyst is prepared by taking the fly ash as a raw material, harmless treatment of the fly ash is realized, the harmlessness of the fly ash to the environment is reduced, pollutants in organic wastewater can be degraded by utilizing the fly ash-based photocatalyst, the purpose of treating wastes with wastes is realized, and resource utilization of the fly ash is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of fly ash treatment, and in particular to a method for preparing a fly ash-based photocatalyst, a photocatalyst and applications. Background Art

[0002] With the acceleration of urbanization, the problem of domestic waste disposal has become increasingly prominent. Incineration, as an effective way of waste disposal, can significantly reduce the volume and weight of waste, but it also produces a large amount of fly ash. Fly ash contains a large amount of pollutants such as heavy metals and dioxins, as well as a large amount of soluble chloride salts. If not properly handled, it will threaten the natural environment and human safety.

[0003] At present, the main methods for treating fly ash include solidification, stabilization and landfill. Solidification and stabilization technologies fix harmful substances in fly ash by adding solidifying agents such as cement and chelating agents to reduce its environmental risks, but these methods have high processing costs and are difficult to achieve resource utilization of fly ash. Although the landfill method is simple, it has long-term environmental risks and does not utilize the valuable components in fly ash, which is also difficult to achieve resource utilization of fly ash. Summary of the invention

[0004] The purpose of the present application is to provide a method for preparing a fly ash-based photocatalyst, a photocatalyst and an application thereof, so as to solve the problem that fly ash cannot be utilized as a resource.

[0005] The technical solution adopted by this application to solve its technical problem is:

[0006] In a first aspect, a method for preparing a fly ash-based photocatalyst is provided, comprising:

[0007] S1. Add fly ash and bismuth nitrate pentahydrate into distilled water and stir evenly to obtain a first solution; the mass fraction ratio of the fly ash to the bismuth nitrate pentahydrate is 1.1 to 1.2;

[0008] S2, adding the buffer solution to the first solution, stirring evenly to obtain a second solution; the pH value of the second solution is 5-7;

[0009] S3. Allow the second solution to react at a reaction temperature of 160-180° C. for at least 24 hours, then cool, filter, wash and dry to obtain a fly ash-based photocatalyst.

[0010] Furthermore, the reaction temperature is 160-170°C.

[0011] Furthermore, the reaction temperature is 160°C.

[0012] Furthermore, the mass fraction ratio of the fly ash to the bismuth nitrate pentahydrate is 1.1, and the pH value of the second solution is 5.

[0013] Furthermore, the buffer solution includes at least one of a sodium hydroxide solution and a nitric acid solution.

[0014] Furthermore, the stirring method is magnetic stirring.

[0015] Furthermore, the fly ash is fly ash generated by incineration of domestic waste.

[0016] In a second aspect, a photocatalyst is provided, wherein the photocatalyst is prepared by the method for preparing the fly ash-based photocatalyst.

[0017] In a third aspect, a method for preparing a fly ash-based photocatalyst is provided for using the photocatalyst in the degradation of rhodamine B.

[0018] Beneficial effects of this application:

[0019] 1. The present application uses fly ash as raw material to prepare fly ash-based photocatalyst, which not only achieves harmless treatment of fly ash and reduces its harmfulness to the environment, but also utilizes fly ash-based photocatalyst to degrade pollutants in organic wastewater, achieving the purpose of treating waste with waste and achieving resource utilization of fly ash.

[0020] 2. The fly ash-based photocatalyst prepared in the present application has a high photocatalytic activity. Under the irradiation of a simulated sunlight xenon lamp, 0.1 g of the fly ash-based photocatalyst is dispersed in 100 mL of a 10 mg / L Rhodamine B solution. After 120 minutes of illumination, the degradation rate of Rhodamine B reaches 81.35% to 99.67%.

[0021] 3. The fly ash-based photocatalyst prepared in this application has a simple preparation method, low raw material cost, few required equipment and low energy consumption. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are clearly and completely described below.

[0023] The present invention provides a method for preparing a fly ash-based photocatalyst, comprising the following steps:

[0024] S1. Add fly ash and bismuth nitrate pentahydrate into distilled water and stir evenly to obtain a first solution; the mass fraction ratio of fly ash to bismuth nitrate pentahydrate is 1.1 to 1.2. Exemplarily, the mass fraction ratio of fly ash to bismuth nitrate pentahydrate is 1.1, the stirring method is magnetic stirring, and the fly ash is fly ash produced by the incineration of domestic waste. In order to facilitate the dissolution of fly ash in distilled water, the mass fraction ratio of distilled water to fly ash is 25 to 60.

[0025] S2. Add the buffer solution to the first solution and stir to obtain a second solution; the pH value of the second solution is 5 to 7. Exemplarily, the pH value of the second solution is 5, and the buffer solution includes at least one of a sodium hydroxide solution and a nitric acid solution. For example, the concentration of the sodium hydroxide solution may be 1.6 mol / L, and the concentration of the nitric acid solution may be 2 mol / L.

[0026] S3, reacting the second solution at a reaction temperature of 160-180° C. for at least 24 hours, then cooling, filtering, washing and drying to obtain a fly ash-based photocatalyst. Exemplarily, the reaction temperature is 160-170° C. For example, the reaction temperature is 160° C. The role of the reaction time is to allow the second solution to fully undergo a hydrothermal reaction.

[0027] An embodiment of the present application provides a photocatalyst, which is prepared by a method for preparing a fly ash-based photocatalyst and has high photocatalytic activity.

[0028] The embodiment of the present application also provides an application of a photocatalyst prepared by a fly ash-based photocatalyst preparation method in the degradation of Rhodamine B. The photocatalyst has a high degradation rate for Rhodamine B.

[0029] Embodiment 1:

[0030] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0031] S2. Continue to magnetically stir the first solution, and drop a 2 mol / L HNO3 solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 5, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0032] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 160° C. to react for 24 hours. After the reaction is completed, cool and filter, and repeatedly wash with distilled water, and dry at 80° C. for 8 hours to obtain a fly ash-based photocatalyst.

[0033] Embodiment 2:

[0034] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0035] S2. Continue to magnetically stir the first solution, and drop a 2 mol / L HNO3 solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 6, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0036] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 160° C. to react for 24 hours. After the reaction is completed, cool and filter, and repeatedly wash with distilled water, and dry at 80° C. for 8 hours to obtain a fly ash-based photocatalyst.

[0037] Embodiment 3:

[0038] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0039] S2. Continue to magnetically stir the first solution, and drop a 1.6 mol / L NaOH solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 7, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0040] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 160° C. to react for 24 hours. After the reaction is completed, cool and filter, and repeatedly wash with distilled water, and dry at 80° C. for 8 hours to obtain a fly ash-based photocatalyst.

[0041] Embodiment 4:

[0042] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0043] S2. Continue to magnetically stir the first solution, and drop a 2 mol / L HNO3 solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 5, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0044] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 180°C for reaction for 24 hours. After the reaction is completed, cool and filter, wash repeatedly with distilled water, and dry at 80°C for 8 hours to obtain a fly ash-based photocatalyst.

[0045] Embodiment 5:

[0046] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0047] S2. Continue to magnetically stir the first solution, and drop a 2 mol / L HNO3 solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 6, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0048] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 180°C for reaction for 24 hours. After the reaction is completed, cool and filter, wash repeatedly with distilled water, and dry at 80°C for 8 hours to obtain a fly ash-based photocatalyst.

[0049] Embodiment 6:

[0050] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0051] S2. Continue to magnetically stir the first solution, and drop a 1.6 mol / L NaOH solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 7, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0052] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 180°C for reaction for 24 hours. After the reaction is completed, cool and filter, wash repeatedly with distilled water, and dry at 80°C for 8 hours to obtain a fly ash-based photocatalyst.

[0053] Comparative Example 1:

[0054] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0055] S2. Continue to magnetically stir the first solution, and drop a 2 mol / L HNO3 solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 6, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0056] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 160° C. to react for 24 hours. After the reaction is completed, cool and filter, and repeatedly wash with distilled water, and dry at 80° C. for 8 hours to obtain a fly ash-based photocatalyst.

[0057] Comparative Example 2:

[0058] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0059] S2. Continue to magnetically stir the first solution, and drop a 2 mol / L HNO3 solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 6, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0060] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 160° C. to react for 24 hours. After the reaction is completed, cool and filter, and repeatedly wash with distilled water, and dry at 80° C. for 8 hours to obtain a fly ash-based photocatalyst.

[0061] Comparative Example 3:

[0062] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0063] S2. Continue to magnetically stir the first solution, and drop a 2 mol / L HNO3 solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 6, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0064] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 160° C. to react for 24 hours. After the reaction is completed, cool and filter, and repeatedly wash with distilled water, and dry at 80° C. for 8 hours to obtain a fly ash-based photocatalyst.

[0065] Comparative Example 4:

[0066] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0067] S2. Continue to magnetically stir the first solution, and drop a 1.6 mol / L NaOH solution into the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 7, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0068] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 140°C for reaction for 24 hours. After the reaction is completed, cool and filter, wash repeatedly with distilled water, and dry at 80°C for 8 hours to obtain a fly ash-based photocatalyst.

[0069] Comparative Example 5:

[0070] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0071] S2. Continue to magnetically stir the first solution, and add a 1.6 mol / L NaOH solution to the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 8, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0072] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 160° C. to react for 24 hours. After the reaction is completed, cool and filter, and repeatedly wash with distilled water, and dry at 80° C. for 8 hours to obtain a fly ash-based photocatalyst.

[0073] Comparative Example 6:

[0074] S1. According to the quality score Weigh fly ash and Bi(NO)3·5H2O according to the mass fraction W 蒸馏水:飞灰 =30, distilled water was added, and magnetic stirring was performed for 15 min to obtain the first solution.

[0075] S2. Continue to magnetically stir the first solution, and add a 1.6 mol / L NaOH solution to the first solution, adjust the pH value of the solution to obtain a second solution with a pH value of 8, and then continue to magnetically stir for 1 hour before transferring the second solution to a 100 mL polytetrafluoroethylene reactor.

[0076] S3. Place the polytetrafluoroethylene reactor containing the second solution in an oven at 140°C for reaction for 24 hours. After the reaction is completed, cool and filter, wash repeatedly with distilled water, and dry at 80°C for 8 hours to obtain a fly ash-based photocatalyst.

[0077] Comparative Example 7:

[0078] Samples were taken from fly ash from the incineration of domestic waste, and experiments were conducted to degrade rhodamine B.

[0079] A xenon lamp was used to simulate sunlight to provide 13 groups of target degradation products, wherein each group of target degradation products was a 100 mL rhodamine B solution with a concentration of 10 mg / L. 0.1 g of fly ash-based photocatalyst samples were taken from the fly ash-based photocatalysts prepared in Examples 1 to 6 and Comparative Examples 1 to 6, and 0.1 g of fly ash from the incineration of domestic waste was taken from Comparative Example 7. The above 13 groups of samples were added to the 13 groups of target degradation products for photocatalytic degradation tests. The degradation rates after 120 minutes of illumination are shown in Table 1.

[0080] Table 1

[0081]

[0082] It can be seen from Table 1 that the fly ash-based photocatalysts prepared in Examples 1 to 6 have high photocatalytic activity. Under the irradiation of a simulated sunlight xenon lamp, 0.1 g of fly ash-based photocatalyst is dispersed in 100 mL of a 10 mg / L Rhodamine B solution. After 120 min of illumination, the degradation rate of Rhodamine B is as high as 81.35% to 99.67%.

[0083] The present application uses fly ash as raw material to prepare a fly ash-based photocatalyst, which not only achieves harmless treatment of fly ash and reduces its harmfulness to the environment, but also uses the fly ash-based photocatalyst to degrade pollutants in organic wastewater, achieving the purpose of treating waste with waste and achieving resource utilization of fly ash. The fly ash-based photocatalyst prepared in the present application has low raw material cost, simple preparation method and low energy consumption.

[0084] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Based on the technical essence of the present application and within the spirit and principles of the present application, any simple modification, equivalent replacement and improvement of the above embodiments shall still fall within the protection scope of the technical solution of the present application.

Claims

1. A method for preparing a fly ash-based photocatalyst, characterized in that: include: S1. Add fly ash and bismuth nitrate pentahydrate into distilled water and stir evenly to obtain a first solution; the mass fraction ratio of the fly ash to the bismuth nitrate pentahydrate is 1.1 to 1.2; S2, adding the buffer solution to the first solution, stirring evenly to obtain a second solution; the pH value of the second solution is 5-7; S3. Allow the second solution to react at a reaction temperature of 160-180° C. for at least 24 hours, then cool, filter, wash and dry to obtain a fly ash-based photocatalyst.

2. The method for preparing a fly ash-based photocatalyst according to claim 1, characterized in that: The reaction temperature is 160-170°C.

3. The method for preparing fly ash-based photocatalyst according to claim 2, characterized in that: The reaction temperature is 160°C.

4. The method for preparing the fly ash-based photocatalyst according to claim 3, characterized in that: The mass fraction ratio of the fly ash to the bismuth nitrate pentahydrate is 1.1, and the pH value of the second solution is 5.

5. The method for preparing fly ash-based photocatalyst according to claim 1, characterized in that: The buffer solution includes at least one of a sodium hydroxide solution and a nitric acid solution.

6. The method for preparing fly ash-based photocatalyst according to claim 1, characterized in that: The stirring method is magnetic stirring.

7. The method for preparing fly ash-based photocatalyst according to claim 1, characterized in that: The fly ash is fly ash generated by the incineration of domestic waste.

8. A photocatalyst, characterized in that The photocatalyst is prepared by the method for preparing a fly ash-based photocatalyst according to any one of claims 1 to 7.

9. Use of a photocatalyst prepared by the method for preparing a fly ash-based photocatalyst according to any one of claims 1 to 7 in degrading rhodamine B.

Images