Temperature and humidity responsive release nano-modified photocatalyst microcapsule and preparation method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING ZHONGOU PURUI TECH CO LTD
- Filing Date
- 2026-02-02
- Publication Date
- 2026-06-09
Smart Images
Figure CN122164320A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of environmental remediation materials technology, and relates to a temperature and humidity responsive nano-modified photocatalytic microcapsule and its preparation method. Background Technology
[0002] The treatment of volatile organic compounds (VOCs) in indoor air is a hot topic in environmental science. Photocatalytic oxidation technology has attracted much attention due to its ability to deeply mineralize organic pollutants. To improve the practicality and dispersibility of photocatalysts, the construction of micro-nano reactors using microencapsulation technology is currently a research hotspot. However, existing photocatalytic microencapsulation technologies still have limitations in practical applications. First, traditional microcapsules typically use volatile organic solvents, plant essential oils, or fragrances as core materials. While their release can mask odors to some extent, the released organic components themselves fall into the VOCs category. This not only increases the background level of total volatile organic compounds in the environment but may also interfere with high-sensitivity air monitoring sensors, making it difficult to meet the precise environmental purification requirements with stringent background cleanliness standards. In addition, such volatile core materials face the problem of core shrinkage and functional failure due to natural volatilization during long-term use, limiting the material's lifespan.
[0003] Secondly, commonly used hydrophilic photocatalysts have low adsorption capacity for nonpolar hydrophobic pollutants such as benzene and toluene, limiting gas-solid mass transfer efficiency. This makes it difficult for pollutants to effectively accumulate at catalytically active sites, thus restricting the degradation rate. Although introducing Fenton or Fenton-like reactions can improve oxidation efficiency by generating more reactive hydroxyl radicals, ferrous ions are easily oxidized and deactivated in air, while hydrogen peroxide, as a liquid oxidant, is unstable and difficult to store long-term in microcapsules. Summary of the Invention
[0004] To address the aforementioned problems, the present invention aims to provide a temperature and humidity responsive release nano-modified photocatalyst microcapsule and its preparation method. This application constructs a photocatalyst microcapsule composed of a surface-modified iron heterojunction photocatalyst, a hydrophobic eutectic solvent core material loaded with ferrous ions, and a temperature and humidity responsive crosslinked shell: the heterojunction improves the separation efficiency of photogenerated carriers and... 2+ / Fe 3+ The cyclic participation activates peroxides and generates free radical species with better oxidizing power; the core material of the hydrophobic eutectic solvent loaded with ferrous ions not only enriches hydrophobic VOCs but also stably stores Fe. 2+ It migrates to the interface when the shell swells; the temperature and humidity responsive cross-linked shell can reversibly swell / shrink with temperature and humidity and well encapsulate the core; the three work together to achieve VOC enrichment, light-iron synergistic activation and environmental adaptive regulation, which is conducive to the system exhibiting higher purification efficiency under high pollution, high light and high humidity conditions.
[0005] To achieve this objective, the present invention adopts the following technical solution:
[0006] In a first aspect, the present invention provides a method for preparing temperature and humidity responsive modified photocatalytic microcapsules, the method comprising:
[0007] S1: Urea is placed in a covered crucible, heated and calcined, cooled and ground to obtain graphitic carbon nitride powder; sodium tungstate and graphitic carbon nitride powder are mixed and dispersed in deionized water to obtain a suspension, stirred and dried to obtain a mixed solid, the mixed solid is calcined, washed with water and dried to obtain tungsten trioxide / carbon nitride heterojunction; it is dispersed in ferric chloride ethanol solution to obtain reaction solution A, stirred in the dark, centrifuged and dried to obtain iron-modified heterojunction photocatalyst;
[0008] S2: Mix L-menthol with decanoic acid and stir in a water bath until a transparent liquid phase is obtained to obtain a hydrophobic eutectic solvent; add ferrous acetylacetone to obtain reaction solution B, and stir magnetically under nitrogen protection to obtain a hydrophobic eutectic solvent core material loaded with ferrous ions;
[0009] S3: N-isopropylacrylamide, hydroxyethyl methacrylate and N,N'-methylenebisacrylamide were added to deionized water to obtain an aqueous solution. Iron-modified heterojunction photocatalyst was added to the aqueous solution. After ultrasonic dispersion, hydrophobic eutectic solvent core material loaded with ferrous ions was added. The mixture was homogenized in an ice bath to obtain Pickering emulsion.
[0010] S4: Nitrogen gas is introduced into the Pickering emulsion to remove oxygen, resulting in a deoxygenated emulsion. The deoxygenated emulsion is heated, and an initiator aqueous solution is added to obtain reaction solution C. The reaction is stirred under nitrogen protection, centrifuged, washed, and dried to obtain temperature and humidity responsive photocatalyst microcapsules.
[0011] As a preferred technical solution of the present invention, in step S1, the heating rate of urea calcination is 2-5℃ / min, for example, it can be 2.0℃ / min, 2.3℃ / min, 2.6℃ / min, 2.9℃ / min, 3.2℃ / min, 3.5℃ / min, 3.8℃ / min, 4.1℃ / min, 4.4℃ / min, 4.7℃ / min or 5.0℃ / min, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0012] In some optional embodiments, the calcination temperature of the urea is 520-560°C, for example, 520°C, 524°C, 528°C, 532°C, 536°C, 540°C, 544°C, 548°C, 552°C, 556°C or 560°C, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0013] In some optional embodiments, the calcination time of the urea is 2-4 hours, for example, it can be 2.0 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3.0 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours or 4.0 hours, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0014] In some optional embodiments, the mass ratio of sodium tungstate to graphitic carbon nitride powder in the suspension is 1:(1-5), for example, it can be 1:1.0, 1:1.4, 1:1.8, 1:2.2, 1:2.6, 1:3.0, 1:3.4, 1:3.8, 1:4.2, 1:4.6 or 1:5.0, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0015] In some optional embodiments, the total mass-to-volume ratio of the sodium tungstate and graphitic carbon nitride powder to deionized water is 1 g:(10-50) mL, for example, it can be 1 g:10 mL, 1 g:14 mL, 1 g:18 mL, 1 g:22 mL, 1 g:26 mL, 1 g:30 mL, 1 g:34 mL, 1 g:38 mL, 1 g:42 mL, 1 g:46 mL or 1 g:50 mL, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0016] In some optional embodiments, the calcination temperature of the mixed solid is 400-480°C, for example, 400°C, 408°C, 416°C, 424°C, 432°C, 440°C, 448°C, 456°C, 464°C, 472°C or 480°C, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0017] In some optional embodiments, the calcination time of the mixed solid is 1-3 hours, for example, it can be 1.0 hours, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2.0 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3.0 hours, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0018] In some optional embodiments, the concentration of the ferric chloride ethanol solution is 1-5 mg / mL, for example, it can be 1.0 mg / mL, 1.4 mg / mL, 1.8 mg / mL, 2.2 mg / mL, 2.6 mg / mL, 3.0 mg / mL, 3.4 mg / mL, 3.8 mg / mL, 4.2 mg / mL, 4.6 mg / mL or 5.0 mg / mL, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0019] In some optional embodiments, the mass ratio of ferric chloride to tungsten trioxide / carbon nitride heterojunction is (1-5):100, for example, it can be 1.0:100, 1.4:100, 1.8:100, 2.2:100, 2.6:100, 3.0:100, 3.4:100, 3.8:100, 4.2:100, 4.6:100 or 5.0:100, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0020] In some optional embodiments, the reaction solution A is stirred in the dark for 6-12 hours, for example, 6.0 hours, 6.6 hours, 7.2 hours, 7.8 hours, 8.4 hours, 9.0 hours, 9.6 hours, 10.2 hours, 10.8 hours, 11.4 hours, or 12.0 hours, but is not limited to the listed values; other unlisted values within this range are also applicable.
[0021] As a preferred technical solution of the present invention, in step S2, the molar ratio of L-menthol to decanoic acid is (1-2):1, for example, it can be 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1 or 2.0:1, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0022] In some optional embodiments, the temperature of the L-menthol and decanoic acid mixture after mixing and stirring in a water bath is 50-70°C, for example, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 62°C, 64°C, 66°C, 68°C or 70°C, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0023] In some optional embodiments, the mass ratio of ferrous acetylacetone to the hydrophobic eutectic solvent is (1-10):100, for example, it can be 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100 or 10:100, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0024] In some optional embodiments, the reaction solution B is magnetically stirred at a temperature of 50-60°C under nitrogen protection, for example, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0025] In some optional embodiments, the reaction solution B is magnetically stirred under nitrogen protection for 2-4 hours, for example, 2.0h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h or 4.0h, but is not limited to the listed values; other unlisted values within this range are also applicable.
[0026] As a preferred technical solution of the present invention, in step S3, the molar ratio of N-isopropylacrylamide to hydroxyethyl methacrylate is (5-10):1, for example, it can be 5.0:1, 5.5:1, 6.0:1, 6.5:1, 7.0:1, 7.5:1, 8.0:1, 8.5:1, 9.0:1, 9.5:1 or 10.0:1, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0027] In some optional embodiments, the total molar ratio of N,N'-methylenebisacrylamide to N-isopropylacrylamide and hydroxyethyl methacrylate is (2-5):100, for example, it can be 2.0:100, 2.3:100, 2.6:100, 2.9:100, 3.2:100, 3.5:100, 3.8:100, 4.1:100, 4.4:100, 4.7:100 or 5.0:100, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0028] In some optional embodiments, the total mass ratio of N-isopropylacrylamide and hydroxyethyl methacrylate to deionized water is 1:(10-20), for example, it can be 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0029] In some optional embodiments, the mass ratio of the surface iron-modified heterojunction photocatalyst to the hydrophobic eutectic solvent core material loaded with ferrous ions is (5-20):100, for example, it can be 5:100, 6.5:100, 8.0:100, 9.5:100, 11.0:100, 12.5:100, 14.0:100, 15.5:100, 17.0:100, 18.5:100 or 20.0:100, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0030] In some optional embodiments, the volume ratio of the ferrous ion-loaded hydrophobic eutectic solvent core to the aqueous solution is 1:(5-10), for example, it can be 1:5.0, 1:5.5, 1:6.0, 1:6.5, 1:7.0, 1:7.5, 1:8.0, 1:8.5, 1:9.0, 1:9.5 or 1:10.0, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0031] As a preferred technical solution of the present invention, in step S4, the initiator aqueous solution is added after the deoxygenated emulsion is heated to 65-70°C. For example, it can be added after heating to 65.0°C, 65.5°C, 66.0°C, 66.5°C, 67.0°C, 67.5°C, 68.0°C, 68.5°C, 69.0°C, 69.5°C, or 70.0°C, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0032] The initiator is ammonium persulfate or azobisisobutyramidine hydrochloride.
[0033] In some optional embodiments, the concentration of the initiator aqueous solution is 10-50 mg / mL, for example, it can be 10 mg / mL, 14 mg / mL, 18 mg / mL, 22 mg / mL, 26 mg / mL, 30 mg / mL, 34 mg / mL, 38 mg / mL, 42 mg / mL, 46 mg / mL or 50 mg / mL, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0034] In some optional embodiments, the total molar ratio of the initiator to N-isopropylacrylamide to hydroxyethyl methacrylate is (1-3):100, for example, it can be 1.0:100, 1.2:100, 1.4:100, 1.6:100, 1.8:100, 2.0:100, 2.2:100, 2.4:100, 2.6:100, 2.8:100 or 3.0:100, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0035] In some optional embodiments, the reaction time of the reaction solution C is 6-10 h, for example, it can be 6.0 h, 6.4 h, 6.8 h, 7.2 h, 7.6 h, 8.0 h, 8.4 h, 8.8 h, 9.2 h, 9.6 h or 10.0 h, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0036] Secondly, the present invention provides a temperature and humidity responsive nano-modified photocatalyst microcapsule.
[0037] This application introduces a heterojunction photocatalyst modified with surface iron to perform the functions of generating photogenerated carriers and active species. Graphitic carbon nitride obtained from urea calcination provides a visible-light-responsive semiconductor substrate capable of generating electron-hole pairs under visible light irradiation. The tungsten trioxide / carbon nitride heterojunction structure formed by co-calcination with sodium tungstate enables directional migration of photogenerated electrons and holes between the two semiconductors, reducing the recombination probability of carriers and improving light energy utilization efficiency. Based on this, ferric chloride is used to modify the surface of the heterojunction, introducing iron species with variable valence states. On one hand, surface iron species can participate in electron and hole transfer under light irradiation, acting as reversible redox centers to regulate reaction pathways; on the other hand, when peroxides are generated in the system by the photocatalytic process, surface iron species can act as active centers to promote their conversion into free radical species with higher oxidizing power, thereby forming an Fe-based... 2+ / Fe 3+ A cyclic synergistic oxidation pathway. The iron-modified heterojunction photocatalyst not only improves the generation and separation efficiency of photogenerated carriers, but also pre-arranges metal centers on the surface that are conducive to the further amplification of reactive oxygen species, providing a structural basis for subsequent synergistic effects with the core iron source.
[0038] This application introduces a hydrophobic eutectic solvent core material loaded with ferrous ions to serve as a VOC enrichment and controllable ferrous ion reservoir. This application uses L-menthol and decanoic acid to form a hydrophobic eutectic solvent. A stable intermolecular network is constructed between the two through hydrogen bonds and hydrophobic interactions, allowing the hydrophobic eutectic solvent to remain liquid near room temperature and be essentially immiscible with the aqueous phase, exhibiting hydrophobicity. This property reduces the risk of secondary VOC pollution that may arise from traditional organic solvent cores. Simultaneously, its hydrophobic and organic phase properties give it high solubility and enrichment capabilities for hydrophobic or weakly polar VOCs such as benzene compounds, effectively capturing and concentrating pollutants from the surrounding environment. Furthermore, by adding ferrous acetylacetone to this hydrophobic eutectic solvent, ferrous ions are uniformly dispersed and stably exist in the hydrophobic core in the form of a complex. On the one hand, the hydrophobic environment and nitrogen protection work together to mitigate the effects of Fe... 2+ To Fe 3+ The spontaneous oxidation of iron ions helps maintain their reduced state activity over a longer timescale; on the other hand, through the swelling of the shell and changes in the interfacial environment, some Fe can be oxidized when needed. 2+ It migrates to the shell interface and participates in the free radical oxidation process in synergy with the iron-modified photocatalyst on the surface, thereby achieving the regulation of the spatial location and release rate of the iron source.
[0039] This application constructs a temperature- and humidity-responsive crosslinked polymer shell by copolymerizing N-isopropylacrylamide and hydroxyethyl methacrylate. In the aqueous phase, N-isopropylacrylamide provides temperature sensitivity, enabling the polymer to exhibit a reversible transition from a hydrophilic swelling state to a hydrophobic shrinkage state as the shell approaches its lower critical dissolution temperature. Hydroxyethyl methacrylate, through its hydroxyl and alkyl structures, regulates the overall hydrophilic / hydrophobic balance of the copolymer, enhancing the shell's water absorption and swelling capacity in high-humidity environments, while also strengthening the interfacial compatibility between the shell and the hydrophobic core, thus reducing the risk of leakage of the ferrous ion-loaded hydrophobic eutectic solvent core material during storage and use. N,N'-methylenebisacrylamide introduces three-dimensional crosslinking points between chain segments, forming a crosslinked network with a certain strength and elasticity, which facilitates reversible swelling / shrinkage of the shell without overall destruction or dissolution under temperature and humidity changes. The shell not only possesses adjustable porosity and volume change capabilities in response to temperature and humidity, but also ensures mechanical stability and effective encapsulation of core components, providing a foundation for subsequent regulation of material transport and reaction rates through environmental signals.
[0040] Using surface-modified iron-based heterojunction photocatalysts as solid emulsifiers, the photocatalyst particles, possessing both hydrophilic and oleophilic properties, are conducive to enrichment and adsorption at the oil / water interface during shear emulsification, reducing interfacial tension and thus dispersing the hydrophobic eutectic solvent core into droplets. Subsequently, polymerization of N-isopropylacrylamide, hydroxyethyl methacrylate, and N,N'-methylenebisacrylamide is initiated. The cross-linked polymer preferentially grows and solidifies at the core-aqueous phase interface, embedding the photocatalyst within the shell. Photocatalyst particles facing outwards from the microcapsule facilitate sufficient contact with light and gaseous contaminants in the environment; photocatalyst particles facing the core interface are beneficial for interaction with Fe migrating from the hydrophobic eutectic solvent. 2+ And it couples with VOC molecules enriched in the kernel.
[0041] This application also exhibits a synergistic enhancement effect. The hydrophobic eutectic solvent core material loaded with ferrous ions has a high solubility for hydrophobic VOCs, enabling continuous transfer of airborne pollutants to the inside of the microcapsule during its operation, transforming low-concentration diffused pollution into locally high-concentration targets for treatment, thereby improving the kinetic efficiency of the subsequent degradation process. Under external light irradiation, the heterojunction photocatalyst at the shell interface generates photogenerated electrons and holes, which participate in redox reactions with iron species. Simultaneously, under conditions of increased temperature and humidity, the shell undergoes swelling and volume changes, promoting the penetration of moisture and oxygen within the shell, as well as the Fe... 2+ Directed migration from the hydrophobic eutectic solvent core to the shell interface. When the photogenerated peroxide interacts with Fe at the interface... 2+ When in contact, Fe 2+ After being oxidized to Fe 3+ Simultaneously, it activates and decomposes peroxides to generate free radical species with stronger oxidizing power, thereby achieving a scale-up from a mild oxidant to a highly active free radical; the Fe generated during the reaction... 3+ Then, under the reduction of organic components in photogenerated electrons or hydrophobic eutectic solvents, it may be converted back into Fe. 2+ This forms a cycle based on changes in the valence state of iron ions, continuously amplifying the oxidation capacity of photobiotic species. The temperature- and humidity-sensitive behavior of the shell limits the mass transfer rate between the core and interface through a lower degree of swelling when the environmental load is low or the light intensity is weak, thus delaying the consumption of the core's iron source. When VOC concentrations are high, light intensity is strong, or humidity is high, the shell swelling and local volume changes increase mass transfer and reaction rates, which is beneficial for the system to exhibit higher purification efficiency under conditions of high pollution, high light intensity, and high humidity.
[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0043] This application constructs a tungsten trioxide / carbon nitride heterojunction photocatalyst with iron-modified surface. On one hand, it utilizes the heterojunction band structure to improve the separation efficiency of photogenerated electrons and holes and the utilization rate of visible light. On the other hand, it leverages the variable valence state of iron species on the surface to participate in electron / hole transfer and activate peroxides, generating free radicals with stronger oxidizing power. This achieves photogenerated carrier separation and Fe-based... 2+ / Fe 3+ The cyclic synergistic oxidation amplification provides a structural basis for subsequent coupling with the core iron source.
[0044] This application constructs a hydrophobic eutectic solvent using L-menthol and decanoic acid. On one hand, it acts as a liquid adsorbent with low volatility and high solubility for hydrophobic VOCs such as benzene compounds, achieving the enrichment of pollutants. On the other hand, it dissolves ferrous acetylacetone to release Fe... 2+ It is stably stored in a hydrophobic core and achieves controlled migration of ferrous ions to the shell interface during shell swelling and changes in the interfacial environment, thus participating as a controllable iron source in the interfacial free radical oxidation process.
[0045] This application constructs a temperature and humidity responsive crosslinked shell that can reversibly swell / shrink with temperature and humidity and has encapsulation capabilities by copolymerizing N-isopropylacrylamide and hydroxyethyl methacrylate and introducing N,N'-methylenebisacrylamide. On the one hand, this shell has good interfacial compatibility with the core material of the hydrophobic eutectic solvent loaded with ferrous ions, reducing core material leakage. On the other hand, through adjustable porosity and volume changes, it provides a structural basis for subsequent material transport and reaction rate regulation based on environmental signals.
[0046] This application features synergistic enhancement: the hydrophobic eutectic solvent core loaded with ferrous ions can efficiently dissolve and enrich hydrophobic VOCs, while simultaneously acting as Fe... 2+ In storage applications, the heterojunction photocatalyst at the shell interface generates peroxides under illumination, which further reacts with Fe... 2+ / Fe 3+ Under cyclic action, the free radicals are activated into highly oxidizing free radicals, improving degradation efficiency. Simultaneously, the temperature and humidity responsive shell inhibits mass transfer and iron source consumption under low load, while enhancing Fe degradation under high VOC concentrations, strong light, or high humidity. 2+ Migration and material exchange enable the system to exhibit higher purification efficiency. Attached Figure Description
[0047] Figure 1 This is a photograph of the temperature and humidity responsive photocatalyst microcapsules prepared by the method described in Example 1 of this application. Detailed Implementation
[0048] The technical solution of the present invention will be described in detail below with reference to specific embodiments. The embodiments described herein are specific implementations of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limiting the implementation of the present invention or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that employ any obvious substitutions and modifications made to the embodiments described herein.
[0049] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone further purification or processing.
[0050] Example 1
[0051] This embodiment provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule and its preparation method. The preparation method of the temperature and humidity responsive release nano-modified photocatalyst microcapsule specifically includes the following steps:
[0052] S1: Urea was placed in a covered crucible and calcined at 550°C for 3.5 h at a heating rate of 4°C / min. After cooling and grinding, graphitic carbon nitride powder was obtained. Sodium tungstate and graphitic carbon nitride powder were mixed at a mass ratio of 1:4 and dispersed in deionized water to obtain a suspension, wherein the total mass-volume ratio of sodium tungstate and graphitic carbon nitride powder to deionized water was 1 g:40 mL. After stirring and drying, a mixed solid was obtained. The mixed solid was calcined at 450°C for 2.5 h, washed with water, and dried to obtain tungsten trioxide / carbon nitride heterojunction. It was dispersed in an ethanol solution of ferric chloride with a concentration of 4 mg / mL to obtain reaction solution A, wherein the mass ratio of ferric chloride to tungsten trioxide / carbon nitride heterojunction was 4:100. The mixture was stirred in the dark for 10 h, centrifuged, and dried to obtain a heterojunction photocatalyst with iron-modified surface.
[0053] S2: L-menthol and decanoic acid were mixed at a molar ratio of 1.8:1 and stirred in a water bath at 65°C until a transparent liquid phase was obtained to obtain a hydrophobic eutectic solvent; ferrous acetylacetone was added to obtain reaction solution B, wherein the mass ratio of ferrous acetylacetone to hydrophobic eutectic solvent was 8:100. The mixture was magnetically stirred at 55°C for 3.5 h under nitrogen protection to obtain a hydrophobic eutectic solvent core material loaded with ferrous ions.
[0054] S3: N-Isopropylacrylamide, hydroxyethyl methacrylate, and N,N'-methylenebisacrylamide were added to deionized water to obtain an aqueous solution, wherein the molar ratio of N-isopropylacrylamide to hydroxyethyl methacrylate was 8:1, the total molar ratio of N,N'-methylenebisacrylamide to N-isopropylacrylamide and hydroxyethyl methacrylate was 4:100, and the total mass ratio of N-isopropylacrylamide, hydroxyethyl methacrylate, and deionized water was 1:18; a heterojunction photocatalyst modified with iron was added to the aqueous solution, and after ultrasonic dispersion, a hydrophobic eutectic solvent core material loaded with ferrous ions was added, wherein the mass ratio of the heterojunction photocatalyst modified with iron to the hydrophobic eutectic solvent core material loaded with ferrous ions was 15:100, and the volume ratio of the hydrophobic eutectic solvent core material loaded with ferrous ions to the aqueous solution was 1:8; the mixture was homogenized in an ice bath to obtain a Pickering emulsion;
[0055] S4: Nitrogen gas was introduced into the Pickering emulsion to remove oxygen, resulting in a deoxygenated emulsion. The deoxygenated emulsion was heated to 68°C, and an aqueous solution of ammonium persulfate with a concentration of 40 mg / mL was added to obtain reaction solution C. The total molar ratio of ammonium persulfate to N-isopropylacrylamide to hydroxyethyl methacrylate was 2.5:100. The reaction was stirred for 9 hours under nitrogen protection, centrifuged, washed, and dried to obtain temperature and humidity responsive photocatalyst microcapsules. Figure 1 The image shows the prepared temperature and humidity responsive modified photocatalyst microcapsules, which are dry, free-flowing, light-colored fine powders without obvious agglomeration.
[0056] Example 2
[0057] This embodiment provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule and its preparation method. The preparation method of the temperature and humidity responsive release nano-modified photocatalyst microcapsule specifically includes the following steps:
[0058] S1: Urea was placed in a covered crucible and calcined at 520°C for 2 hours at a heating rate of 2°C / min. After cooling and grinding, graphite-phase carbon nitride powder was obtained. Sodium tungstate and graphite-phase carbon nitride powder were mixed at a mass ratio of 1:1 and dispersed in deionized water to obtain a suspension, wherein the total mass-volume ratio of sodium tungstate and graphite-phase carbon nitride powder to deionized water was 1 g:10 mL. After stirring and drying, a mixed solid was obtained. The mixed solid was calcined at 400°C for 1 hour, washed with water, and dried to obtain a tungsten trioxide / carbon nitride heterojunction. It was dispersed in an ethanol solution of ferric chloride with a concentration of 1 mg / mL to obtain reaction solution A, wherein the mass ratio of ferric chloride to tungsten trioxide / carbon nitride heterojunction was 1:100. The solution was stirred in the dark for 6 hours, centrifuged, and dried to obtain a heterojunction photocatalyst with iron-modified surface.
[0059] S2: L-menthol and decanoic acid are mixed in a molar ratio of 1:1 and stirred in a water bath at 50°C until a transparent liquid phase is obtained to obtain a hydrophobic eutectic solvent; ferrous acetylacetone is added to obtain reaction solution B, wherein the mass ratio of ferrous acetylacetone to hydrophobic eutectic solvent is 1:100, and the mixture is magnetically stirred at 60°C for 2 hours under nitrogen protection to obtain a hydrophobic eutectic solvent core material loaded with ferrous ions;
[0060] S3: N-Isopropylacrylamide, hydroxyethyl methacrylate, and N,N'-methylenebisacrylamide were added to deionized water to obtain an aqueous solution, wherein the molar ratio of N-isopropylacrylamide to hydroxyethyl methacrylate was 10:1, the total molar ratio of N,N'-methylenebisacrylamide to N-isopropylacrylamide and hydroxyethyl methacrylate was 2:100, and the total mass ratio of N-isopropylacrylamide, hydroxyethyl methacrylate, and deionized water was 1:10; a heterojunction photocatalyst modified with iron was added to the aqueous solution, and after ultrasonic dispersion, a hydrophobic eutectic solvent core material loaded with ferrous ions was added, wherein the mass ratio of the heterojunction photocatalyst modified with iron to the hydrophobic eutectic solvent core material loaded with ferrous ions was 5:100, and the volume ratio of the hydrophobic eutectic solvent core material loaded with ferrous ions to the aqueous solution was 1:5; the mixture was homogenized in an ice bath to obtain a Pickering emulsion;
[0061] S4: Nitrogen gas was introduced into the Pickering emulsion to remove oxygen, resulting in a deoxygenated emulsion. The deoxygenated emulsion was heated to 65°C, and an aqueous solution of azobisisobutyramidine hydrochloride with a concentration of 10 mg / mL was added to obtain reaction solution C. The total molar ratio of azobisisobutyramidine hydrochloride to N-isopropylacrylamide to hydroxyethyl methacrylate was 1:100. The reaction was stirred for 6 hours under nitrogen protection, centrifuged, washed, and dried to obtain temperature and humidity responsive photocatalyst microcapsules.
[0062] Example 3
[0063] This embodiment provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule and its preparation method. The preparation method of the temperature and humidity responsive release nano-modified photocatalyst microcapsule specifically includes the following steps:
[0064] S1: Urea was placed in a covered crucible and calcined at 530°C for 2.5 h at a heating rate of 3°C / min. After cooling and grinding, graphitic carbon nitride powder was obtained. Sodium tungstate and graphitic carbon nitride powder were mixed at a mass ratio of 1:2 and dispersed in deionized water to obtain a suspension, wherein the total mass-volume ratio of sodium tungstate and graphitic carbon nitride powder to deionized water was 1 g:20 mL. After stirring and drying, a mixed solid was obtained. The mixed solid was calcined at 420°C for 1.5 h, washed with water, and dried to obtain tungsten trioxide / carbon nitride heterojunction. It was dispersed in an ethanol solution of ferric chloride with a concentration of 2 mg / mL to obtain reaction solution A, wherein the mass ratio of ferric chloride to tungsten trioxide / carbon nitride heterojunction was 2:100. The solution was stirred in the dark for 8 h, centrifuged, and dried to obtain a heterojunction photocatalyst with iron-modified surface.
[0065] S2: L-menthol and decanoic acid were mixed at a molar ratio of 1.2:1 and stirred in a water bath at 55°C until a transparent liquid phase was obtained to obtain a hydrophobic eutectic solvent; ferrous acetylacetone was added to obtain reaction solution B, wherein the mass ratio of ferrous acetylacetone to hydrophobic eutectic solvent was 5:100. The mixture was magnetically stirred at 52°C for 2.5 h under nitrogen protection to obtain a hydrophobic eutectic solvent core material loaded with ferrous ions.
[0066] S3: N-Isopropylacrylamide, hydroxyethyl methacrylate, and N,N'-methylenebisacrylamide were added to deionized water to obtain an aqueous solution, wherein the molar ratio of N-isopropylacrylamide to hydroxyethyl methacrylate was 9:1, the total molar ratio of N,N'-methylenebisacrylamide to N-isopropylacrylamide and hydroxyethyl methacrylate was 3:100, and the total mass ratio of N-isopropylacrylamide, hydroxyethyl methacrylate, and deionized water was 1:12; a heterojunction photocatalyst modified with iron surface was added to the aqueous solution, and after ultrasonic dispersion, a hydrophobic eutectic solvent core material loaded with ferrous ions was added, wherein the mass ratio of the heterojunction photocatalyst modified with iron surface to the hydrophobic eutectic solvent core material loaded with ferrous ions was 10:100, and the volume ratio of the hydrophobic eutectic solvent core material loaded with ferrous ions to the aqueous solution was 1:6; the mixture was homogenized under an ice bath to obtain a Pickering emulsion;
[0067] S4: Nitrogen gas was introduced into the Pickering emulsion to remove oxygen, resulting in a deoxygenated emulsion. The deoxygenated emulsion was heated to 69°C, and an aqueous solution of azobisisobutyramidine hydrochloride with a concentration of 20 mg / mL was added to obtain reaction solution C. The total molar ratio of azobisisobutyramidine hydrochloride to N-isopropylacrylamide to hydroxyethyl methacrylate was 1.5:100. The reaction was stirred for 7 h under nitrogen protection, centrifuged, washed, and dried to obtain temperature and humidity responsive photocatalyst microcapsules.
[0068] Example 4
[0069] This embodiment provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule and its preparation method. The preparation method of the temperature and humidity responsive release nano-modified photocatalyst microcapsule specifically includes the following steps:
[0070] S1: Urea was placed in a covered crucible and calcined at 560°C for 4 hours at a heating rate of 5°C / min. After cooling and grinding, graphite-phase carbon nitride powder was obtained. Sodium tungstate and graphite-phase carbon nitride powder were mixed at a mass ratio of 1:5 and dispersed in deionized water to obtain a suspension, wherein the total mass-volume ratio of sodium tungstate and graphite-phase carbon nitride powder to deionized water was 1 g:50 mL. After stirring and drying, a mixed solid was obtained. The mixed solid was calcined at 480°C for 3 hours, washed with water, and dried to obtain tungsten trioxide / carbon nitride heterojunction. It was dispersed in an ethanol solution of ferric chloride with a concentration of 5 mg / mL to obtain reaction solution A, wherein the mass ratio of ferric chloride to tungsten trioxide / carbon nitride heterojunction was 5:100. The solution was stirred in the dark for 12 hours, centrifuged, and dried to obtain a heterojunction photocatalyst with iron-modified surface.
[0071] S2: L-menthol and decanoic acid are mixed at a molar ratio of 2:1 and stirred in a water bath at 70°C until a transparent liquid phase is obtained to obtain a hydrophobic eutectic solvent; ferrous acetylacetone is added to obtain reaction solution B, wherein the mass ratio of ferrous acetylacetone to hydrophobic eutectic solvent is 10:100, and the mixture is magnetically stirred at 50°C for 4 hours under nitrogen protection to obtain a hydrophobic eutectic solvent core material loaded with ferrous ions;
[0072] S3: N-Isopropylacrylamide, hydroxyethyl methacrylate, and N,N'-methylenebisacrylamide were added to deionized water to obtain an aqueous solution, wherein the molar ratio of N-isopropylacrylamide to hydroxyethyl methacrylate was 5:1, the total molar ratio of N,N'-methylenebisacrylamide to N-isopropylacrylamide and hydroxyethyl methacrylate was 5:100, and the total mass ratio of N-isopropylacrylamide, hydroxyethyl methacrylate, and deionized water was 1:20; a heterojunction photocatalyst modified with iron was added to the aqueous solution, and after ultrasonic dispersion, a hydrophobic eutectic solvent core material loaded with ferrous ions was added, wherein the mass ratio of the heterojunction photocatalyst modified with iron to the hydrophobic eutectic solvent core material loaded with ferrous ions was 20:100, and the volume ratio of the hydrophobic eutectic solvent core material loaded with ferrous ions to the aqueous solution was 1:10; the mixture was homogenized in an ice bath to obtain a Pickering emulsion;
[0073] S4: Nitrogen gas was introduced into the Pickering emulsion to remove oxygen, resulting in a deoxygenated emulsion. The deoxygenated emulsion was heated to 70°C, and an aqueous solution of ammonium persulfate with a concentration of 50 mg / mL was added to obtain reaction solution C. The total molar ratio of ammonium persulfate to N-isopropylacrylamide to hydroxyethyl methacrylate was 3:100. The reaction was stirred for 10 h under nitrogen protection, centrifuged, washed, and dried to obtain temperature and humidity responsive photocatalyst microcapsules.
[0074] Comparative Example 1
[0075] This comparative example provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule. The difference from Example 1 is that in S1, the tungsten trioxide / carbon nitride heterojunction is not impregnated with ferric chloride ethanol solution, but the tungsten trioxide / carbon nitride heterojunction is used directly. Other operation steps and process parameters are exactly the same as in Example 1.
[0076] Comparative Example 2
[0077] This comparative example provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule. The difference from Example 1 is that ferrous acetylacetone is not added in S2, while the other operating steps and process parameters are exactly the same as in Example 1.
[0078] Comparative Example 3
[0079] This comparative example provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule. The difference from Example 1 is that liquid paraffin is used in S2 instead of the hydrophobic eutectic solvent. Other operating steps and process parameters are exactly the same as in Example 1.
[0080] Comparative Example 4
[0081] This comparative example provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule. The difference from Example 1 is that in S3, sodium dodecyl sulfate is used instead of the surface iron-modified heterojunction photocatalyst added to the aqueous solution to obtain a Pickering emulsion before adding the surface iron-modified heterojunction photocatalyst. Other operation steps and process parameters are exactly the same as in Example 1.
[0082] Comparative Example 5
[0083] This comparative example provides a temperature and humidity responsive release nano-modified photocatalyst microcapsule. The difference from Example 1 is that hydroxyethyl methacrylate is not added in S3, while the other operating steps and process parameters are exactly the same as in Example 1.
[0084] The performance of the temperature and humidity responsive photocatalytic microcapsules of Examples 1-4 and Comparative Examples 1-5 was tested, and the specific process is as follows:
[0085] Performance Testing: Equal amounts of microcapsule samples were placed in a sealed quartz glass reactor equipped with a built-in fan and temperature and humidity control device. Quantities of formaldehyde and toluene were injected into the reactor, and the reactor was kept in darkness and static conditions for 2 hours. The pollutant concentration C1 was measured at this time, and the adsorption rate of the sample under dark conditions was calculated to verify the VOC adsorption / enrichment capacity of the microcapsule samples. Subsequently, reactions were carried out under three sets of conditions: low temperature and low humidity (5℃, 30% relative humidity), room temperature and medium humidity (25℃, 50% relative humidity), and high temperature and high humidity (40℃, 80% relative humidity), with each set of reaction times lasting 4 hours. After the reaction, samples were taken from the reactor, and the final pollutant concentration C1 was measured using gas chromatography-mass spectrometry (GC-MS). t The degradation rates of formaldehyde and toluene in the samples under different conditions were calculated.
[0086] The sample was aged at high temperature and high humidity (40℃, 80% relative humidity) for 48 hours. After the aging process, it was returned to a normal temperature and medium humidity (25℃, 50% relative humidity) environment to test its degradation rate of formaldehyde and toluene.
[0087] The test results are shown in Table 1.
[0088] Table 1: Performance test results of temperature and humidity responsive release of nano-modified photocatalytic microcapsules in Examples 1-4 and Comparative Examples 1-5
[0089]
[0090] From the test results of Example 1 and Comparative Example 1 in Table 1, it can be seen that in S1, the tungsten trioxide / carbon nitride heterojunction was not impregnated with ferric chloride ethanol solution, and the tungsten trioxide / carbon nitride heterojunction was used directly. Lacking reversible iron active centers, although a certain degree of electron-hole separation could still be achieved under illumination by the heterojunction itself, it was difficult to achieve electron-hole separation through Fe... 2+ / Fe 3+ The efficient activation of peroxides through circulation generates highly oxidizing free radicals, which limits the utilization efficiency of photogenerated carriers. As a result, the overall VOC degradation rate decreases under various temperature and humidity conditions. At the same time, due to the lack of introduction of surface iron species, the interfacial charge regulation ability is weakened, and the amplification effect on the reaction rate deteriorates under high temperature and high humidity conditions. However, its core and shell structure remain unchanged, and the adsorption / enrichment capacity and the performance retention rate after high temperature and high humidity aging are relatively stable.
[0091] From the test results of Example 1 and Comparative Example 2 in Table 1, it can be seen that in S2, without the addition of ferrous acetylacetone, the core no longer acts as a migratable Fe. 2+ In this storage system, iron species on the photocatalyst surface participate in the redox process. Although the adsorption / enrichment capacity of the hydrophobic eutectic solvent core material for VOCs remains essentially unchanged, during the illumination phase, Fe is continuously supplied from the core to the shell interface. 2+ Fe's ability to decline2+ / Fe 3+ The cycle is mainly confined to the photocatalyst surface, especially under high temperature and high humidity conditions, where both the increase in reaction rate and the final degradation rate deteriorate; at the same time, due to the lack of core Fe... 2+ As a buffer, when the surface iron is oxidized or lost during high-humidity aging, the system's regeneration capacity is weak, and its degradation performance decreases after aging.
[0092] From the test results of Example 1 and Comparative Example 3 in Table 1, it can be seen that in S2, liquid paraffin was used to replace the hydrophobic eutectic solvent. The core material, which had a hydrogen bond network and high solubility, was changed from a hydrophobic eutectic solvent core material to a relatively inert ordinary hydrophobic oil phase. This resulted in a decrease in the solubility and enrichment capacity of hydrophobic VOCs such as benzene series compounds, a decrease in adsorption rate under dark conditions, and a lower local concentration of VOCs near the interface before illumination. Simultaneously, liquid paraffin exhibited poor solubility stability and coordination environment for ferrous acetylacetone, leading to Fe... 2+ The dispersion and long-term existence of Fe in the core are not as good as in hydrophobic eutectic solvent core materials, which is beneficial to Fe. 2+ / Fe 3+ The core-interface synergy of the cycle is affected, resulting in a decrease in degradation rate under various temperature and humidity conditions; the ordinary oil phase can still play a certain role in encapsulation in terms of structure, so the performance retention rate after aging is still acceptable.
[0093] From the test results of Example 1 and Comparative Example 4 in Table 1, it can be seen that in S3, when sodium dodecyl sulfate was used to replace the surface iron-modified heterojunction photocatalyst in the aqueous solution to obtain a Pickering emulsion, and then the surface iron-modified heterojunction photocatalyst was added, the photocatalyst was mainly dispersed in the aqueous phase and was difficult to spontaneously enrich at the oil / water interface, thus lacking the function of constructing a reaction band at the interface. Under this structure, there is a longer mass transfer path between the photogenerated carrier generation site and the VOC-enriched core interface, and the Fe migrated from the core... 2+ It is also more difficult to fully contact the photocatalyst active sites, resulting in a reduction in the interfacial reaction area and light utilization efficiency, and a decrease in VOC degradation rate under various conditions. At the same time, the residue of small molecule surfactants makes the shell more easily wetted by water. During long-term high temperature and high humidity aging, the risk of loss of core components and iron species through water migration increases, resulting in a decrease in degradation performance after aging.
[0094] As can be seen from the test results of Example 1 and Comparative Example 5 in Table 1, in S3, when no hydroxyethyl methacrylate is added and the shell is composed only of N-isopropylacrylamide and N,N'-methylenebisacrylamide, although the temperature-sensitive swelling / shrinkage characteristics are still retained, the overall hydrophilic / oleophilic balance of the shell is shifted, the interfacial compatibility between the shell and the hydrophobic eutectic solvent core material decreases, and it is easier to form interfacial voids or micro-defects, resulting in a decrease in core filling and encapsulation efficiency and a decrease in VOC adsorption rate during the dark adsorption stage. Under light conditions, the single shell has limited ability to respond to humidity changes, and the swelling behavior of the shell under high temperature and high humidity is difficult to balance controllable opening and structural stability, resulting in a decrease in the removal rate improvement under high temperature and high humidity. After aging, due to the insufficient resistance of the shell to swelling damage and leakage, some hydrophobic eutectic solvent core material and iron source migrate outward, resulting in a decrease in degradation performance after aging.
[0095] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.
Claims
1. A method for preparing temperature and humidity responsive nano-modified photocatalyst microcapsules, characterized in that, The preparation method includes: S1: Urea is placed in a covered crucible, heated and calcined, cooled and ground to obtain graphitic carbon nitride powder; sodium tungstate and graphitic carbon nitride powder are mixed and dispersed in deionized water to obtain a suspension, stirred and dried to obtain a mixed solid, the mixed solid is calcined, washed with water and dried to obtain tungsten trioxide / carbon nitride heterojunction; it is dispersed in ferric chloride ethanol solution to obtain reaction solution A, stirred in the dark, centrifuged and dried to obtain iron-modified heterojunction photocatalyst; S2: Mix L-menthol with decanoic acid and stir in a water bath until a transparent liquid phase is obtained to obtain a hydrophobic eutectic solvent; add ferrous acetylacetone to obtain reaction solution B, and stir magnetically under nitrogen protection to obtain a hydrophobic eutectic solvent core material loaded with ferrous ions; S3: N-isopropylacrylamide, hydroxyethyl methacrylate and N,N'-methylenebisacrylamide were added to deionized water to obtain an aqueous solution. Iron-modified heterojunction photocatalyst was added to the aqueous solution. After ultrasonic dispersion, hydrophobic eutectic solvent core material loaded with ferrous ions was added. The mixture was homogenized in an ice bath to obtain Pickering emulsion. S4: Nitrogen gas is introduced into the Pickering emulsion to remove oxygen, resulting in a deoxygenated emulsion. The deoxygenated emulsion is heated, and an initiator aqueous solution is added to obtain reaction solution C. The reaction is stirred under nitrogen protection, centrifuged, washed, and dried to obtain temperature and humidity responsive photocatalyst microcapsules.
2. The method for preparing a temperature and humidity responsive release nano-modified photocatalyst microcapsule according to claim 1, characterized in that, In S1: The mass ratio of sodium tungstate to graphitic carbon nitride powder in the suspension is 1:(1-5); The total mass-to-volume ratio of sodium tungstate and graphitic carbon nitride powder to deionized water is 1 g:(10-50) mL.
3. The method for preparing a temperature and humidity responsive photocatalyst microcapsule according to claim 1, characterized in that, In S1: The concentration of the ferric chloride ethanol solution is 1-5 mg / mL; The mass ratio of ferric chloride to tungsten trioxide / carbon nitride heterojunction is (1-5):
100.
4. The method for preparing a temperature and humidity responsive photocatalyst microcapsule according to claim 1, characterized in that, In S2: The molar ratio of L-menthol to decanoic acid is (1-2):1; The temperature of the L-menthol and decanoic acid mixture after mixing in a water bath is 50-70℃.
5. The method for preparing a temperature and humidity responsive release nano-modified photocatalyst microcapsule according to claim 1, characterized in that, In S2: The mass ratio of ferrous acetylacetone to the hydrophobic eutectic solvent is (1-10):
100.
6. The method for preparing a temperature and humidity responsive photocatalyst microcapsule according to claim 1, characterized in that, In S3: The molar ratio of N-isopropylacrylamide to hydroxyethyl methacrylate is (5-10):1; The total molar ratio of N,N'-methylenebisacrylamide to N-isopropylacrylamide and hydroxyethyl methacrylate is (2-5):100; The total mass ratio of N-isopropylacrylamide and hydroxyethyl methacrylate to deionized water is 1:(10-20).
7. The method for preparing a temperature and humidity responsive release nano-modified photocatalyst microcapsule according to claim 1, characterized in that, In S3: The mass ratio of the surface iron-modified heterojunction photocatalyst to the hydrophobic eutectic solvent core material loaded with ferrous ions is (5-20):
100.
8. The method for preparing a temperature and humidity responsive release nano-modified photocatalyst microcapsule according to claim 1, characterized in that, In S3: The volume ratio of the hydrophobic eutectic solvent core material loaded with ferrous ions to the aqueous solution is 1:(5-10).
9. The method for preparing a temperature and humidity responsive release nano-modified photocatalyst microcapsule according to claim 1, characterized in that, In S4: The total molar ratio of the initiator to N-isopropylacrylamide to hydroxyethyl methacrylate is (1-3):
100.
10. A temperature and humidity responsive photocatalyst microcapsule prepared by the preparation method according to any one of claims 1-9.