Method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method
A dopamine-coated titanium dioxide photocatalyst was prepared by hydrothermal method, and a core-shell structure was constructed. This solved the problem that TiO2 could not effectively utilize visible light in the car cabin, and achieved efficient purification of VOCs, especially significant degradation of formaldehyde.
Patent Information
- Application Number
- CN202511811437.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-05-12
AI Technical Summary
Existing TiO2 photocatalysts cannot effectively utilize the visible light band in automotive cabins, and have poor adsorption capacity for low-concentration, neutral VOCs molecules, with a high recombination rate of photogenerated carriers, making it difficult to meet purification requirements.
Dopamine-coated titanium dioxide photocatalysts were prepared by hydrothermal method, and a polydopamine-titanium dioxide core-shell structure was constructed. The visible light sensitization properties of polydopamine and catechol/amino functional groups were utilized to promote the separation and migration of photogenerated charges, thereby achieving the coupling of adsorption enrichment and photocatalytic degradation.
It broadens the spectral response range of the photocatalyst, enhances its adsorption capacity for VOCs, improves photon efficiency and purification efficiency, significantly improves degradation efficiency, and is low in cost and environmentally friendly.
Smart Images
Figure CN122006808A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of catalyst preparation technology, specifically to a method for preparing dopamine-coated titanium dioxide photocatalysts based on a hydrothermal method. Background Technology
[0002] With the development of the automotive industry and the increasing demands of consumers for driving and riding experiences, the air quality inside the car cabin has become a key indicator for measuring vehicle quality and safety. New car interior materials, such as plastics, leather, and adhesives used in dashboards, seats, headliners, and carpets, continuously release various volatile organic compounds (VOCs), with formaldehyde, acetaldehyde, benzene, toluene, and xylene being the most typical. These VOCs accumulate easily in the confined environment of a car cabin, especially at high temperatures, where their release rate accelerates significantly. Long-term exposure to such a mixed environment of VOCs poses a potential threat to the health of drivers and passengers. Therefore, efficiently removing various VOCs from car cabins, especially formaldehyde which is difficult to degrade naturally, is a core problem that urgently needs to be solved in the field of automotive air purification.
[0003] Currently, purification technologies for VOCs in automotive cabins mainly include activated carbon adsorption, ozone oxidation, and photocatalytic oxidation. Activated carbon adsorption is the most widely used, but it only adsorbs and enriches pollutants rather than completely eliminating them, and has inherent drawbacks such as easy saturation, the need for frequent replacement, and the potential for desorption and secondary pollution at elevated temperatures. While ozone oxidation can decompose organic matter, excessive ozone itself is a harmful pollutant that irritates the human respiratory tract. In contrast, photocatalytic oxidation technology can use ultraviolet or visible light to drive the reaction at room temperature, completely mineralizing various VOCs into harmless CO2 and H2O, making it the most promising radical solution. Among numerous photocatalysts, titanium dioxide (TiO2) has been widely studied due to its high activity, non-toxicity, stability, and low cost.
[0004] However, TiO2's wide bandgap makes it ineffective in utilizing the visible light band, and it exhibits poor adsorption capacity for low-concentration, neutral VOCs molecules, along with a high recombination rate of photogenerated carriers, making it difficult to meet the practical application requirements of automotive cabins. Therefore, a catalyst that can effectively improve purification efficiency is urgently needed. Summary of the Invention
[0005] To address the aforementioned technical problems, this application is proposed. Embodiments of this application provide a method for preparing a dopamine-coated titanium dioxide photocatalyst based on a hydrothermal method.
[0006] This application provides a method for preparing dopamine-coated titanium dioxide photocatalyst based on a hydrothermal method, comprising: dispersing titanium dioxide powder in deionized water and ultrasonically treating it to obtain a uniform titanium dioxide suspension; dissolving a buffer in deionized water to prepare a buffer solution, or directly using an alkaline solution, to adjust the pH value of the titanium dioxide suspension to 7.5~10.0; adding dopamine hydrochloride to the pH-adjusted titanium dioxide suspension and stirring until dopamine is fully dispersed to obtain a mixed precursor solution; transferring the mixed precursor solution to a hydrothermal reactor for reaction; after the reaction is completed, naturally cooling to room temperature, collecting the reaction product, and centrifuging, washing, and drying it to obtain a polydopamine-coated titanium dioxide photocatalyst.
[0007] In one embodiment, the titanium dioxide powder is nano-anatase titanium dioxide.
[0008] In one embodiment, the specific surface area of the nano-anatase titanium dioxide is 50~300 m² / g.
[0009] In one embodiment, the buffer is one of tris(hydroxymethyl)aminomethane hydrochloride, phosphate, or borate.
[0010] In one embodiment, the molar ratio of the dopamine hydrochloride to the titanium dioxide powder is 1:20 to 3:1.
[0011] In one embodiment, the temperature range of the hydrothermal reactor is 120~180°C.
[0012] In one embodiment, the temperature range of the hydrothermal reactor is 140~160°C.
[0013] In one embodiment, the reaction time of the mixed precursor liquid in the hydrothermal reactor is 4 to 48 hours.
[0014] In one embodiment, the reaction time of the mixed precursor liquid in the hydrothermal reactor is 6 to 10 hours.
[0015] In one embodiment, the drying is performed using vacuum drying or freeze drying.
[0016] This application provides a method for preparing dopamine-coated titanium dioxide photocatalyst based on a hydrothermal method. The method involves dispersing titanium dioxide powder in deionized water and then ultrasonically treating it to obtain a uniform titanium dioxide suspension. A buffer solution is prepared by dissolving a buffer in deionized water, or by directly using an alkaline solution, to adjust the pH of the titanium dioxide suspension to 7.5-10.0. Dopamine hydrochloride is added to the pH-adjusted titanium dioxide suspension, and the mixture is stirred until the dopamine is fully dispersed to obtain a mixed precursor solution. The mixed precursor solution is transferred to a hydrothermal reactor for reaction. After the reaction is completed, the mixture is naturally cooled to room temperature, and the reaction product is collected. After centrifugation, washing, and drying, a polydopamine-coated titanium dioxide photocatalyst is obtained. By constructing a polydopamine-titanium dioxide core-shell structure, the coupling of "adsorption enrichment-photocatalytic degradation" is achieved, improving the purification efficiency of the catalyst for volatile organic compounds under visible light conditions in the cabin. Attached Figure Description
[0017] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.
[0018] Figure 1 This is a schematic flowchart of a method for preparing dopamine-coated titanium dioxide photocatalysts based on a hydrothermal method, provided in an exemplary embodiment of this application.
[0019] Figure 2 This is the photoluminescence spectrum of the catalyst sample in this application.
[0020] Figure 3 This is the full-spectral absorption diagram of the catalyst sample in this application. Detailed Implementation
[0021] Hereinafter, exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments of the present application. It should be understood that the present application is not limited to the exemplary embodiments described herein.
[0022] Figure 1 This is a schematic flowchart of a method for preparing dopamine-coated titanium dioxide photocatalyst based on a hydrothermal method, provided in an exemplary embodiment of this application. Figure 1 As shown, the method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method includes the following steps: Step 110: Disperse titanium dioxide powder in deionized water and sonicate it to obtain a uniform titanium dioxide suspension.
[0023] Step 120: Dissolve the buffer in deionized water to prepare a buffer solution, or directly use an alkaline solution to adjust the pH of the titanium dioxide suspension to 7.5~10.0.
[0024] The alkaline solution can be ammonia.
[0025] Step 130: Add dopamine hydrochloride to the titanium dioxide suspension after pH adjustment, and stir until dopamine is fully dispersed to obtain a mixed precursor solution.
[0026] Step 140: Transfer the mixed precursor solution to a hydrothermal reactor for reaction.
[0027] Step 150: After the reaction is completed, the product is naturally cooled to room temperature, collected, and centrifuged, washed, and dried to obtain polydopamine-coated titanium dioxide photocatalyst.
[0028] This application provides a method for preparing dopamine-coated titanium dioxide photocatalyst based on a hydrothermal method. The method involves dispersing titanium dioxide powder in deionized water and then ultrasonically treating it to obtain a uniform titanium dioxide suspension. A buffer solution is prepared by dissolving a buffer in deionized water, or by directly using an alkaline solution, to adjust the pH of the titanium dioxide suspension to 7.5-10.0. Dopamine hydrochloride is added to the pH-adjusted titanium dioxide suspension, and the mixture is stirred until the dopamine is fully dispersed to obtain a mixed precursor solution. The mixed precursor solution is transferred to a hydrothermal reactor for reaction. After the reaction is completed, the mixture is naturally cooled to room temperature, and the reaction product is collected. After centrifugation, washing, and drying, a polydopamine-coated titanium dioxide photocatalyst is obtained. By constructing a polydopamine-titanium dioxide core-shell structure, the coupling of "adsorption enrichment-photocatalytic degradation" is achieved, improving the purification efficiency of the catalyst for volatile organic compounds under visible light conditions in the cabin.
[0029] In one embodiment, the titanium dioxide (TiO2) powder is nano-anatase titanium dioxide. Preferably, the specific surface area of the nano-anatase titanium dioxide is 50~300 m² / g.
[0030] Selecting nanomaterials with high specific surface area helps to provide more reaction sites.
[0031] In one embodiment, the buffer is one of tris(hydroxymethyl)aminomethane hydrochloride, phosphate, or borate.
[0032] By selecting one of tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl), phosphate, or borate as a buffer, the Tris-HCl buffer system can provide a weakly alkaline environment suitable for dopamine polymerization.
[0033] In one embodiment, the molar ratio of dopamine hydrochloride to titanium dioxide powder is 1:20 to 3:1. Preferably, the molar ratio of dopamine hydrochloride to titanium dioxide powder is 1:10 to 1:5.
[0034] By adjusting the molar ratio of dopamine hydrochloride to titanium dioxide powder, the thickness of the polydopamine coating layer on the surface of the final product can be effectively controlled.
[0035] In one embodiment, the temperature range of the hydrothermal reactor is 120~180°C. Preferably, the temperature range of the hydrothermal reactor is 140~160°C.
[0036] By selecting the temperature of the hydrothermal reactor, it is beneficial to enable dopamine to form a strong bond with the TiO2 surface while it polymerizes rapidly.
[0037] In one embodiment, the reaction time of the mixed precursor solution in the hydrothermal reactor is 4 to 48 hours. Preferably, the reaction time of the mixed precursor solution in the hydrothermal reactor is 6 to 10 hours.
[0038] By selecting the appropriate reaction time in the hydrothermal reactor, it is beneficial to achieve rapid polymerization of dopamine while simultaneously enabling it to form a strong bond with the TiO2 surface.
[0039] In one embodiment, drying is performed using vacuum drying or freeze drying.
[0040] Freeze-drying helps avoid hard agglomeration of nanomaterials during conventional drying processes, thus better maintaining their dispersibility.
[0041] This application prepares a dopamine-coated titanium dioxide photocatalyst via a hydrothermal method. Polydopamine (PDA) is used as an electron mediator to promote the separation and migration of photogenerated charges, and the unique catechol / amino functional groups of PDA enhance the adsorption capacity of various VOC molecules. By constructing a PDA-TiO2 core-shell structure, the coupling of "adsorption enrichment-photocatalytic degradation" is achieved, improving the purification efficiency of the catalyst for VOCs in the visible light environment inside the cabin. This method achieves in-situ polymerization and coating of dopamine on the TiO2 surface under hydrothermal conditions, exhibiting a broad spectral response, strong adsorption capacity, and high quantum efficiency, specifically designed for the efficient purification of volatile organic pollutants in automotive cabins. Specifically, it demonstrates the following: Expanding the visible light response range: By constructing a polydopamine (PDA) coating layer, PDA, as a natural visible light sensitizer, can effectively absorb a wide range of visible light and inject photogenerated electrons into the conduction band of TiO2 by utilizing its strong absorption characteristics of visible light. This broadens the spectral response range of the composite photocatalyst and solves the core defect of traditional TiO2, which cannot effectively utilize the main light source (visible light) in the cabin due to its wide bandgap (3.2 eV). This significantly improves the formaldehyde degradation efficiency of the catalyst under simulated in-vehicle visible light conditions.
[0042] Enhanced adsorption and enrichment capacity for VOCs: Utilizing the abundant catechol and amino functional groups on the surface of the PDA layer, the composite material is endowed with strong adsorption capacity for low-concentration, neutral VOC molecules (such as formaldehyde and benzene compounds) in the vehicle, achieving efficient enrichment of target pollutants on the catalyst surface and providing a high local concentration environment for photocatalytic degradation reaction.
[0043] Promote photogenerated charge separation: A dense PDA-TiO2 interface constructed by hydrothermal method is established to create an efficient electron transport channel, which promotes the transfer of photogenerated electrons from PDA to the conduction band of TiO2, thereby significantly suppressing electron-hole recombination and improving photonic quantum efficiency.
[0044] Enhanced catalyst structural stability: Under high temperature and high pressure conditions, the polymerization reaction of dopamine is more intense, and its active intermediate forms stronger covalent bonds with the hydroxyl groups on the TiO2 surface, making the PDA coating layer more dense, uniform and firm.
[0045] Low preparation cost: It avoids the use of expensive precious metals such as platinum and silver. The main raw materials are titanium dioxide and dopamine hydrochloride, which makes the cost controllable and more conducive to large-scale industrial production and automotive applications. Moreover, the entire preparation process is carried out in an aqueous phase, without the use of toxic organic solvents, making it environmentally friendly and in line with the principles of green chemistry.
[0046] This application provides a detailed description of the solution through the following embodiments and comparative examples: Example 1: Step 1: Add 0.12 g TiO2 powder to the hydrothermal reactor, disperse it in 40 mL of deionized water, and sonicate at room temperature (300W) for 30 minutes to obtain a uniform and stable milky white suspension.
[0047] Step 2: Weigh 0.35 g of Tris-HCl buffer solution and add it to the above suspension under mechanical stirring.
[0048] Step 3: Add 0.075 g of dopamine hydrochloride and continue stirring for 30 minutes to ensure that dopamine is fully dispersed, thus obtaining a mixed precursor solution.
[0049] Step 4: Transfer all the mixed precursor solution into the polytetrafluoroethylene liner of a 50 mL hydrothermal reactor, seal it, and place it in a forced-air drying oven to react at 160°C for 8 hours.
[0050] Step 5: After the reaction is complete, allow the reaction vessel to cool naturally to room temperature and remove the reaction product. Wash the product three times alternately with deionized water and anhydrous ethanol by centrifugation (8000 rpm, 10 minutes each time) to thoroughly remove unreacted monomers and byproducts. Place the washed precipitate in a vacuum drying oven and dry at 60°C for 12 hours. Grind the dried block sample in an agate mortar to obtain polydopamine-coated titanium dioxide photocatalyst powder.
[0051] Example 2 (the hydrothermal reaction temperature was changed to 120°C): Step 1: Add 0.12 g TiO2 powder to the hydrothermal reactor, disperse it in 40 mL of deionized water, and sonicate at room temperature (300W) for 30 minutes to obtain a uniform and stable milky white suspension.
[0052] Step 2: Weigh 0.35 g of Tris-HCl buffer solution and add it to the above suspension under mechanical stirring.
[0053] Step 3: Add 0.075 g of dopamine hydrochloride and continue stirring for 30 minutes to ensure that dopamine is fully dispersed, thus obtaining a mixed precursor solution.
[0054] Step 4: Transfer all the mixed precursor solution into the polytetrafluoroethylene liner of a 50 mL hydrothermal reactor, seal it, and place it in a forced-air drying oven to react at 120°C for 8 hours.
[0055] Step 5: After the reaction is complete, allow the reaction vessel to cool naturally to room temperature and remove the reaction product. Wash the product three times alternately with deionized water and anhydrous ethanol by centrifugation (8000 rpm, 10 minutes each time) to thoroughly remove unreacted monomers and byproducts. Place the washed precipitate in a vacuum drying oven and dry at 60°C for 12 hours. Grind the dried block sample in an agate mortar to obtain polydopamine-coated titanium dioxide photocatalyst powder.
[0056] Example 3 (with the dosage of dopamine hydrochloride changed to 0.75 g): Step 1: Add 0.12 g TiO2 powder to the hydrothermal reactor, disperse it in 40 mL of deionized water, and sonicate at room temperature (300W) for 30 minutes to obtain a uniform and stable milky white suspension.
[0057] Step 2: Weigh 0.35 g of Tris-HCl buffer solution and add it to the above suspension under mechanical stirring.
[0058] Step 3: Add 0.75 g of dopamine hydrochloride and continue stirring for 30 minutes to ensure that dopamine is fully dispersed, thus obtaining a mixed precursor solution.
[0059] Step 4: Transfer all the mixed precursor solution into the polytetrafluoroethylene liner of a 50 mL hydrothermal reactor, seal it, and place it in a forced-air drying oven to react at 160°C for 8 hours.
[0060] Step 5: After the reaction is complete, allow the reaction vessel to cool naturally to room temperature and remove the reaction product. Wash the product three times alternately with deionized water and anhydrous ethanol by centrifugation (8000 rpm, 10 minutes each time) to thoroughly remove unreacted monomers and byproducts. Place the washed precipitate in a vacuum drying oven and dry at 60°C for 12 hours. Grind the dried block sample in an agate mortar to obtain polydopamine-coated titanium dioxide photocatalyst powder.
[0061] Comparative Example 1 (without hydrothermal reaction): Step 1: Disperse 0.12 g TiO2 powder in 40 mL of deionized water and sonicate at room temperature (300 W) for 30 minutes to obtain a uniform and stable milky white suspension.
[0062] Step 2: Weigh 0.35 g of Tris-HCl buffer solution and add it to the above suspension under mechanical stirring.
[0063] Step 3: Add 0.075 g of dopamine hydrochloride to the system and continue stirring for 30 minutes to ensure that dopamine is fully dispersed, thus obtaining a mixed precursor solution.
[0064] Step 4: Continue mechanically stirring the mixed precursor solution at room temperature for 24 hours.
[0065] Step 5: After the reaction is complete, allow the reaction vessel to cool naturally to room temperature and remove the reaction product. Wash the product three times alternately with deionized water and anhydrous ethanol by centrifugation (8000 rpm, 10 minutes each time) to thoroughly remove unreacted monomers and byproducts. Place the washed precipitate in a vacuum drying oven and dry at 60°C for 12 hours. Grind the dried block sample in an agate mortar to obtain polydopamine-coated titanium dioxide photocatalyst powder.
[0066] Comparative Example 2 (Dopamine-free system): Step 1: Add 0.12 g TiO2 powder to the hydrothermal reactor, disperse it in 40 mL of deionized water, and sonicate at room temperature (300W) for 30 minutes to obtain a uniform and stable milky white suspension.
[0067] Step 2: Transfer all the mixed precursor solution into the polytetrafluoroethylene liner of a 50 mL hydrothermal reactor, seal it, and place it in a forced-air drying oven to react at 160°C for 8 hours.
[0068] Step 3: After the reaction is complete, allow the reaction vessel to cool naturally to room temperature and remove the reaction product. Wash the product three times alternately with deionized water and anhydrous ethanol by centrifugation (8000 rpm, 10 minutes each time) to thoroughly remove unreacted monomers and byproducts. Place the washed precipitate in a vacuum drying oven and dry it at 60°C for 12 hours. Grind the dried block sample in an agate mortar to obtain photocatalyst powder.
[0069] The products prepared in Example 1, Comparative Examples 1 and 2 were used as samples for corresponding tests. The test methods and results are as follows: Fluorescent PL spectral performance (e.g.) Figure 2 (as shown) Fluorescence spectroscopy results showed that, compared with Comparative Examples 1 and 2, the catalyst sample of Example 1 had the lowest PL peak intensity, indicating that dopamine coating effectively suppressed photoinduced carrier recombination. The polydopamine-coated titanium dioxide photocatalyst prepared by hydrothermal method had even lower photogenerated electron recombination efficiency.
[0070] Light absorption properties (e.g.) Figure 3 As shown in the figure): UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) shows that the catalyst samples of Example 1 and Comparative Example 1 both have strong absorption in the visible light region of 400-700 nm, indicating that their visible light response capability is greatly enhanced. Moreover, the light absorption capability of Comparative Example 1 is slightly lower than that of Example 1, indicating that the catalyst sample coated with dopamine by hydrothermal method has a stronger visible light response capability.
[0071] Photocatalytic performance (as shown in Table 1): In a self-made photocatalytic reactor, formaldehyde vapor was introduced via bubbling, with an initial formaldehyde concentration of approximately 5-20 ppm at the catalyst inlet. A 0.1 g catalyst sample was evenly spread in a quartz tank and placed at the bottom of the reactor. A 20 W full-spectrum xenon lamp was used as the irradiation source. After the reaction stabilized, the downstream gas was adsorbed using DNPH, and the residual formaldehyde concentration in the reactor was detected by HPLC to calculate the degradation efficiency. The test results are summarized in Table 1.
[0072] Table 1. Catalytic degradation effect of catalyst samples on formaldehyde
[0073] According to the test results in Table 1, under visible light irradiation, the formaldehyde degradation efficiency of Examples 1-3 was higher than that of Comparative Examples 1 and 2, with Example 1 achieving a formaldehyde degradation efficiency of over 95%. In Comparative Example 1, the dopamine-coated sample at room temperature had a formaldehyde purification efficiency of only 70.0%, while in Comparative Example 2, the hydrothermal sample without dopamine coating had a formaldehyde purification efficiency of only 24.0%.
[0074] In addition to the methods and apparatus described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of this application described in the "Exemplary Methods" section above.
[0075] The computer program product can be written in any combination of one or more programming languages to perform the operations of the embodiments of this application. The programming languages include object-oriented programming languages such as Java and C++, as well as conventional procedural programming languages such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.
[0076] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of this application described in the "Exemplary Methods" section above.
[0077] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.
[0078] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.
[0079] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.
[0080] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.
[0081] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.
[0082] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.
Claims
1. A method for preparing dopamine-coated titanium dioxide photocatalysts based on a hydrothermal method, characterized in that, include: Titanium dioxide powder was dispersed in deionized water and then subjected to ultrasonic treatment to obtain a uniform titanium dioxide suspension. The buffer solution is prepared by dissolving the buffer in deionized water, or by directly using an alkaline solution, to adjust the pH of the titanium dioxide suspension to 7.5-10.
0. Add dopamine hydrochloride to the titanium dioxide suspension after pH adjustment, and stir until dopamine is fully dispersed to obtain a mixed precursor solution; The mixed precursor solution is transferred to a hydrothermal reactor for reaction. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The reaction products were collected and then centrifuged, washed, and dried to obtain polydopamine-coated titanium dioxide photocatalyst.
2. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 1, characterized in that, The titanium dioxide powder is nano-anatase titanium dioxide.
3. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 2, characterized in that, The specific surface area of the nano-anatase titanium dioxide is 50~300 m² / g.
4. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 1, characterized in that, The buffer is one of tris(hydroxymethyl)aminomethane hydrochloride, phosphate, or borate.
5. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 1, characterized in that, The molar ratio of dopamine hydrochloride to titanium dioxide powder is 1:20 to 3:
1.
6. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 1, characterized in that, The temperature range of the hydrothermal reactor is 120~180℃.
7. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 6, characterized in that, The temperature range of the hydrothermal reactor is 140~160℃.
8. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 1, characterized in that, The reaction time of the mixed precursor liquid in the hydrothermal reactor is 4 to 48 hours.
9. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 8, characterized in that, The reaction time of the mixed precursor liquid in the hydrothermal reactor is 6 to 10 hours.
10. The method for preparing dopamine-coated titanium dioxide photocatalyst based on hydrothermal method according to claim 1, characterized in that, The drying process employs either vacuum drying or freeze drying.