Self-cleaning anti-ultraviolet protective film layer and preparation method thereof, photovoltaic glass and photovoltaic module

Abstract

The invention relates to a self-cleaning anti-ultraviolet protective film layer, a preparation method thereof, photovoltaic glass and a photovoltaic module. According to the self-cleaning anti-ultraviolet protective film layer, the organic polymer is adopted as a matrix, the ultraviolet absorption material is added, the ultraviolet absorption material adopts nanofibers containing TiO2 and is doped with Cr < 3 + > ions, the absorption capacity of the nanofibers in the ultraviolet band can be improved, damage of ultraviolet rays to internal materials of the photovoltaic module can be reduced, a photocatalytic reaction can be generated, and the self-cleaning anti-ultraviolet protective film layer is formed. Hydroxyl free radicals and superoxide anions with strong oxidizing property are generated, organic pollutants such as oil stains on the surface of the photovoltaic glass are degraded, and self-cleaning is achieved. The ultraviolet absorbing material is applied to the self-cleaning anti-ultraviolet protective film layer in the form of nanofibers, the agglomeration problem of traditional particles in the coating can be reduced, and uneven photocatalytic reaction caused by particle agglomeration is avoided.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and in particular to a self-cleaning UV-protective film and its preparation method, photovoltaic glass, and photovoltaic modules. Background Technology

[0002] Photovoltaic modules typically use high-transmittance ultra-clear tempered glass as the encapsulation material. In real-world environments, dust, stains, animal feces, and other contaminants adhere to the surface of the photovoltaic glass. Cleaning this glass primarily relies on manual or mechanical cleaning, which consumes significant manpower and resources, resulting in high maintenance costs. Furthermore, photovoltaic glass cannot block ultraviolet (UV) radiation from sunlight. The polymer materials within the photovoltaic module (such as the backsheet and encapsulant film) are prone to aging and even failure under the combined effects of strong UV radiation, high temperatures, and high humidity, thus impacting the module's lifespan. Summary of the Invention

[0003] Therefore, it is necessary to provide a self-cleaning UV-resistant protective film layer and its preparation method, a photovoltaic glass having the above-mentioned self-cleaning UV-resistant protective film layer, and a photovoltaic module having the above-mentioned photovoltaic glass, so as to solve the problems of high cleaning cost and inability to block ultraviolet rays in photovoltaic glass.

[0004] The first aspect of the present invention is to provide a self-cleaning UV-protective film layer, the solution of which is as follows:

[0005] A self-cleaning UV-protective film, characterized in that it comprises an organic polymer and a UV-absorbing material, wherein the UV-absorbing material is mixed with the organic polymer, and the UV-absorbing material comprises nanofibers and Cr doped in the nanofibers. 3+ The nanofibers contain TiO2 ions.

[0006] In one embodiment, the nanofibers also include SiO2, with a molar ratio of SiO2 to TiO2 of 1:3.5~5.

[0007] In one embodiment, the nanofibers have a diameter of 50 nm to 100 nm.

[0008] In one embodiment, the nanofibers are 50 μm to 100 μm long.

[0009] In one embodiment, the aspect ratio of the nanofiber is 500 to 1000:1.

[0010] In one embodiment, the Cr in the nanofibers 3+ The mass fraction of ions is 0.5% to 10%.

[0011] In one embodiment, the organic polymer is in the amount of 1 to 10 parts by weight, and the ultraviolet absorbing material is in the amount of 20 parts by weight.

[0012] In one embodiment, the organic polymer is selected from at least one of polydimethylsiloxane, polyurethane, and polyheptadecyltrimethoxysilane.

[0013] In one embodiment, the self-cleaning UV-protective film layer also contains a silane coupling agent.

[0014] A second aspect of the present invention is to provide a method for preparing the self-cleaning UV-protective film layer described above, the method being as follows:

[0015] A method for preparing a self-cleaning UV-protective film, characterized by comprising the following steps:

[0016] A titanium source, a chromium source, and a dispersant are dispersed in a first solvent to form a precursor solution;

[0017] The precursor solution was electrospinned to obtain an ultraviolet absorbing material.

[0018] The ultraviolet absorbing material is dispersed in a second solvent, the organic polymer is added, and the mixture is stirred to obtain a slurry;

[0019] The slurry is coated onto a substrate and dried to obtain the self-cleaning UV-protective film.

[0020] In one embodiment, a silicon source is further added to the precursor solution, and the molar ratio of the silicon source to the titanium source is 1:3.5~5.

[0021] In one embodiment, the titanium source is selected from at least one of tetrabutyl titanate, titanium tetroxide, and titanium sulfate.

[0022] In one embodiment, the chromium source is selected from at least one of chromium nitrate and chromium oxide.

[0023] In one embodiment, the dispersant is selected from at least one of polyvinylpyrrolidone and polyacrylonitrile.

[0024] In one embodiment, the first solvent is selected from at least one of methanol, ethanol, and water.

[0025] In one embodiment, during the electrospinning, the temperature is 25°C to 40°C, the humidity is 30% to 60%, the voltage is 10kV to 15kV, and the feed rate is 0.001ml / s to 0.010ml / s.

[0026] In one embodiment, the preparation method further includes the following steps:

[0027] The product obtained by electrospinning is calcined at 450℃~600℃.

[0028] A third aspect of the present invention is to provide a photovoltaic glass, the solution of which is as follows:

[0029] A photovoltaic glass includes a glass substrate and a self-cleaning UV-protective film layer as described in any of the above embodiments or a self-cleaning UV-protective film layer prepared by the preparation method described in any of the above embodiments, wherein the self-cleaning UV-protective film layer is disposed on the glass substrate.

[0030] A fourth aspect of the present invention is to provide a photovoltaic module, the solution of which is as follows:

[0031] A photovoltaic module includes a battery body and photovoltaic glass, wherein the photovoltaic glass is disposed on the battery body.

[0032] Compared with traditional solutions, the above-mentioned self-cleaning UV-protective film, its preparation method, photovoltaic glass, and photovoltaic modules have the following beneficial effects:

[0033] The aforementioned self-cleaning UV-protective film and its preparation method use an organic polymer as the matrix and add a UV-absorbing material. The UV-absorbing material consists of nanofibers containing TiO2 and doped with Cr. 3+ Ions can enhance the absorption capacity of nanofibers in the ultraviolet band, reduce the damage of ultraviolet rays to the internal materials of photovoltaic modules, and can undergo photocatalytic reactions to generate highly oxidizing hydroxyl radicals and superoxide anions, degrading organic pollutants such as oil on the surface of photovoltaic glass and achieving self-cleaning. Applying ultraviolet absorbing materials in the form of nanofibers to self-cleaning anti-ultraviolet protective films can reduce the agglomeration problem of traditional particles in coatings and avoid uneven photocatalytic reactions caused by particle agglomeration.

[0034] The aforementioned photovoltaic glass and photovoltaic modules all contain the aforementioned self-cleaning anti-ultraviolet protective film layer, and therefore all have the corresponding technical characteristics and can obtain the corresponding beneficial effects. Attached Figure Description

[0035] Figure 1 A diagram illustrating the photocatalytic mechanism by which ultraviolet-absorbing materials in a self-cleaning UV-protective film degrade organic pollutants.

[0036] Figure 2 This is a schematic diagram of the structure of a photovoltaic glass according to one embodiment;

[0037] Figure 3 This is a schematic diagram of the structure of a photovoltaic module according to one embodiment;

[0038] Figure 4The degradation rate-time relationship of the self-cleaning UV-protective film prepared in Examples 1, 2 and 3 on the photocatalytic degradation of Congo red.

[0039] Explanation of reference numerals in the attached figures:

[0040] 100. Photovoltaic glass; 110. Glass substrate; 120. Self-cleaning UV-resistant protective film layer; 10. Photovoltaic module; 200. Battery body; 300. Backsheet; 400. First encapsulant film; 500. Second encapsulant film. Detailed Implementation

[0041] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein; these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0042] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0043] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number or order of the indicated technical features.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] This invention provides a self-cleaning UV-resistant protective film that can be applied to photovoltaic glass and photovoltaic modules, achieving self-cleaning and UV protection.

[0046] One embodiment of the self-cleaning UV-protective film comprises an organic polymer and nanofibers, wherein the UV-absorbing material is mixed with the organic polymer. The nanofibers include titanium dioxide (TiO2). The nanofibers are doped with trivalent chromium ions (Cr). 3+ ).

[0047] Traditional techniques involve adding pure-phase anatase TiO2 particles as UV absorbers to coatings; however, their photocatalytic ability is insufficient, their UV absorption capacity is limited, and the particles are prone to aggregation, leading to uneven chemical photocatalytic degradation of pollutants. The aforementioned self-cleaning UV-protective film layer utilizes nanofibers containing TiO2 and doped with Cr. 3 + Ions can enhance the absorption capacity of nanofibers in the ultraviolet band, reduce the damage of ultraviolet rays to the internal materials of photovoltaic modules, and can undergo photocatalytic reactions to generate highly oxidizing hydroxyl radicals and superoxide anions, degrading organic pollutants such as oil on the surface of photovoltaic glass and achieving self-cleaning. Applying ultraviolet absorbing materials in the form of nanofibers to self-cleaning anti-ultraviolet protective films can reduce the agglomeration problem of traditional particles in coatings and avoid uneven photocatalytic reactions caused by particle agglomeration.

[0048] like Figure 1 As shown, when light shines on the nanofibers in the self-cleaning UV-protective film, the nanofibers generate electrons and holes, which further react with water and oxygen in the environment to produce redox substances, thereby degrading organic pollutants. Furthermore, Cr-doped nanofibers... 3+ This can reduce the recombination rate of photogenerated electrons and holes, and improve the lifetime of photogenerated carriers.

[0049] Nanofibers can be composed of TiO2, meaning they are pure TiO2 nanofibers; they can also further include other components. For example, the nanofibers can further include silicon dioxide (SiO2), meaning they are SiO2-modified TiO2 nanofibers (SiO2@TiO2 nanofibers), which can improve the mechanical properties of the nanofibers. Furthermore, the molar ratio of SiO2 to TiO2 in the nanofibers is 1:3.5 to 5, specifically, for example, 1:3.5, 1:3.7, 1:3.9, 1:4.1, 1:4.3, 1:4.5, 1:4.7, 1:4.9, 1:5, etc.

[0050] In one example, the diameter of the nanofibers is 50nm to 100nm, specifically 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, etc.

[0051] In one example, the length of the nanofibers is 50μm to 100μm, specifically 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0052] In one example, the aspect ratio of the nanofibers is 500 to 1000:1, specifically 500:1, 600:1, 700:1, 800:1, 900:1, 1000:1, etc.

[0053] Cr 3+ Ions can be introduced by adding trivalent chromium salts to the raw materials during the nanofiber synthesis process. In one example, Cr... 3+ The mass fraction of ions is 0.5%~10%. Furthermore, Cr... 3+ The mass fraction of ions is 4%–6%. In some specific examples, Cr 3+ The mass fraction of ions is 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0054] In one example, the method for preparing the ultraviolet absorbing material includes the following steps:

[0055] Step S11: The titanium source, chromium source and dispersant are dispersed in the first solvent to form a precursor solution.

[0056] Step S12: Electrospin the precursor solution.

[0057] Optionally, the titanium source can be at least one of, but not limited to, tetrabutyl titanate, titanium tetroxide, and titanium sulfate.

[0058] Optionally, the chromium source can be, but is not limited to, at least one of chromium nitrate and chromium oxide.

[0059] The amount of chromium source added depends on the Cr content in the synthesized nanofibers. 3+ The selection is based on the mass fraction of ions, for example, Cr. 3+ The mass fraction of ions is 0.5% to 10%.

[0060] Optionally, the dispersant may be, but is not limited to, at least one of polyvinylpyrrolidone (PVP) and polyacrylonitrile (PAN).

[0061] Optionally, the first solvent may be at least one of, but not limited to, methanol, ethanol, and water.

[0062] In one example, in step S1, a silicon source is also added to the precursor solution to introduce SiO2 into the nanofibers, thereby improving their mechanical properties. The ratio of the silicon source to the titanium source is selected based on the molar ratio of SiO2 to TiO2 in the synthesized nanofibers, for example, a SiO2 to TiO2 molar ratio of 1:3.5 to 5. For example, the molar ratio of silicon source to titanium source is 1:3.5 to 5.

[0063] Optionally, the silicon source may be, but is not limited to, at least one of tetraethyl orthosilicate and methyl orthosilicate.

[0064] Furthermore, in one example, step S1 includes:

[0065] Solution A is prepared by mixing tetrabutyl titanate, chromium nitrate nonahydrate, and methanol. The dissolution of chromium nitrate can be promoted by ultrasonic treatment during the mixing of solution A. Solution B is prepared by mixing tetraethyl orthosilicate and water. Solution C is prepared by dissolving PVP in water. Then, solutions A and B are slowly added to solution C, and the mixture is stirred continuously for 10-12 hours to form a precursor solution.

[0066] It is understandable that if the nanofibers do not contain SiO2, then the above-mentioned solution B can be omitted.

[0067] In one example, the weight percentage of tetrabutyl titanate is 80-100 parts, more specifically 85-95 parts, such as 86 parts, 88 parts, 90 parts, 92 parts, 94 parts, etc. The weight percentage of tetraethyl orthosilicate is 15-25 parts, more specifically 17-23 parts, such as 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, etc. The weight percentage of chromium nitrate nonahydrate is 1-3 parts, more specifically 1.5-2.5 parts, such as 1.7 parts, 1.9 parts, 2 parts, 2.1 parts, 2.3 parts, etc.

[0068] Optionally, in step S12, the electrospinning temperature is 25℃~40℃. The electrospinning humidity is 30%~60%. The electrospinning voltage is 10~15kV. The electrospinning feed rate is 0.001~0.010 ml / s.

[0069] In one example, the preparation method of the ultraviolet absorbing material further includes the following steps:

[0070] Step S13: The nanofiber product obtained by electrospinning is calcined at 450~600℃.

[0071] In one example, the calcination time was 1–3 h. The heating rate during calcination was 1–10 °C / min.

[0072] In one example, electrospinning yields a membrane-like nanofiber (fiber membrane). The fiber membrane can be milled to obtain rod-shaped nanofibers (nanofiber rods) for uniform dispersion.

[0073] The organic polymer can be, but is not limited to, at least one of polydimethylsiloxane, polyurethane, and polyheptadecyltrimethoxysilane.

[0074] The organic polymer is preferably a hydrophobic polymer, such as an organosilicon polymer. Examples of organosilicon polymers include polydimethylsiloxane and polyheptadecyltrimethoxysilane. Based on chemical self-cleaning, superhydrophobic materials such as polydimethylsiloxane are used as the organic polymer component. These materials have a low surface energy, approximately 21 mN / m to 22 mN / m, which effectively increases the water contact angle of the coating, forming a lotus leaf-like self-cleaning structure. By applying a superhydrophobic and UV-resistant self-cleaning coating to the photovoltaic glass, both photocatalytic reactions degrade oil and other organic pollutants, and the lotus leaf-like self-cleaning structure removes dust and stains. The combined effect of chemical and physical self-cleaning effectively removes dirt deposited on the photovoltaic glass.

[0075] In one example, the self-cleaning UV-protective film also includes a silane coupling agent dispersed within the organic polymer. The silane coupling agent improves the compatibility between the organic polymer and the UV-absorbing material.

[0076] In one example, the organic polymer comprises 1 to 10 parts by weight, and the UV-absorbing material comprises 20 parts by weight. Further, the organic polymer comprises 1 to 3 parts by weight, and the UV-absorbing material comprises 20 parts by weight. Further still, the organic polymer comprises 1 to 2 parts by weight, and the UV-absorbing material comprises 20 parts by weight.

[0077] Furthermore, in one example, the silane coupling agent is 1 part by weight.

[0078] Optionally, the silane coupling agent may be at least one of, but not limited to, A151 (vinyltriethoxysilane), A171 (vinyltrimethoxysilane), and A172 (vinyltri(β-methoxyethoxy)silane).

[0079] Furthermore, the present invention also provides a method for preparing a self-cleaning UV-protective film layer according to any of the above examples.

[0080] One embodiment of the method for preparing a self-cleaning UV-protective film includes the following steps:

[0081] Step S21: Disperse the ultraviolet absorbing material in the second solvent, add the organic polymer, and stir to obtain a slurry.

[0082] Step S22: The slurry is coated onto the substrate and dried to obtain a self-cleaning UV-protective film.

[0083] In step S21, ultrasonic treatment can be used to promote the dispersion of the ultraviolet absorbing material in the second solvent.

[0084] In one example, the second solvent contains ethanol and water in a mass ratio of 4 to 6:1.

[0085] Furthermore, the present invention also provides a photovoltaic glass.

[0086] like Figure 2 As shown, a photovoltaic glass 100 of one embodiment includes a glass substrate 110 and a self-cleaning UV-protective film layer 120. The self-cleaning UV-protective film layer 120 is disposed on the glass substrate 110.

[0087] In one example, the thickness of the self-cleaning UV protection film is 1~3μm.

[0088] Furthermore, the present invention also provides a photovoltaic module.

[0089] like Figure 3 As shown, a photovoltaic module 10 of one embodiment includes the photovoltaic glass 100 and the battery body 200 described above. The photovoltaic glass 100 is disposed on the battery body 200.

[0090] In one example, the self-cleaning UV protection film 120 is located on the outside of the photovoltaic glass 100, that is, on the side away from the battery body 200.

[0091] In one example, the photovoltaic module 10 also includes a backsheet 300. The cell body 200 is located between the backsheet 300 and the photovoltaic glass 100.

[0092] In one example, the photovoltaic module 10 further includes a first encapsulating film 400 and / or a second encapsulating film 500. The first encapsulating film 400 is located between the cell body 200 and the photovoltaic glass 100. The second encapsulating film 500 is located between the cell body 200 and the backsheet 300.

[0093] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the specific embodiments described below.

[0094] Example 1

[0095] This embodiment provides a self-cleaning UV-protective film and its preparation method.

[0096] The method for preparing the self-cleaning UV-protective film in this embodiment includes the following steps:

[0097] Step 1: Prepare the precursor solution. Mix tetrabutyl titanate, chromium nitrate nonahydrate, and methanol, and sonicate at 30°C until all nitrates are dissolved to obtain solution A. Mix tetraethyl orthosilicate with pure water to obtain solution B. Dissolve PVP in water to obtain solution C. Then slowly add solutions A and B to solution C and stir for 12 hours to obtain the precursor solution. The raw materials, by weight, are: 90 parts tetrabutyl titanate, 20 parts tetraethyl orthosilicate, 9 parts polyvinylpyrrolidone (molecular weight 1.3 million), and 1 part chromium nitrate nonahydrate.

[0098] Step 2, electrospinning. The precursor solution prepared in Step 1 is loaded into a syringe, and the temperature is controlled at 25℃ and the humidity at 30%. A uniform fiber membrane is spun under conditions of 13kV voltage and a push speed of 0.001ml / s. The receiver rotation speed is 40r / min, the needle specification is 20G, and the distance between the needle and the receiver is 12cm.

[0099] Step 3, high-temperature calcination. The fiber membrane prepared in step 2 is placed in a muffle furnace and heated at 500°C for 2 hours at a rate of 5°C / min.

[0100] Step 4: Place the fiber membrane prepared in step 3 into an agate mortar and grind it to form nanofiber rods.

[0101] Step 5: Prepare the slurry. Disperse 20 parts of the above-mentioned ultraviolet absorbing material ultrasonically in 80 parts of solvent, which contains ethanol and water in a mass ratio of 4:1. Add 1 part of polydimethylsiloxane and 1 part of silane coupling agent (vinyltriethoxysilane), stir and mix to obtain the slurry.

[0102] Step 6, Coating. The above slurry is sprayed onto the photovoltaic glass, and after drying, a self-cleaning UV-resistant protective film layer is obtained.

[0103] Example 2

[0104] The preparation steps in this embodiment are basically the same as those in Example 1, except that the amount of chromium nitrate nonahydrate added to the precursor solution is 2 parts when preparing the ultraviolet absorbing material.

[0105] Example 3

[0106] The preparation steps in this embodiment are basically the same as those in Example 1, except that the amount of chromium nitrate nonahydrate added to the precursor solution is 3 parts when preparing the ultraviolet absorbing material.

[0107] Example 4

[0108] The preparation steps in this embodiment are basically the same as those in Example 1, except that the amount of polydimethylsiloxane added is 5 parts when preparing the self-cleaning UV-protective film.

[0109] Example 5

[0110] The preparation steps in this embodiment are basically the same as those in Example 1, except that the amount of polydimethylsiloxane added is 10 parts when preparing the self-cleaning UV-protective film.

[0111] Comparative Example 1

[0112] The preparation steps of this comparative example are basically the same as those of Example 1, except that the amount of chromium nitrate nonahydrate added to the precursor solution is 0 parts when preparing the ultraviolet absorbing material.

[0113] The self-cleaning UV-protective films prepared in the above embodiments and comparative examples were subjected to performance tests. The test items included UV blocking rate, degradation rate of the organic pollutant Congo red, and water contact angle. The test results are shown in Table 1.

[0114] Table 1 Performance test results of the self-cleaning UV-protective film prepared in the examples

[0115]

[0116] As shown in Table 1, the self-cleaning UV-protective film has a good UV blocking rate, can effectively degrade Congo red, and the coating is superhydrophobic. A comparison between Example 1 and the comparative example shows that Cr was added to the UV-absorbing material in Example 1. 3+ Ions can significantly improve the coating's UV blocking ability and organic matter degradation ability.

[0117] Among them, Example 2 showed the best overall performance. Compared with Examples 4 and 5, when the amount of polydimethylsiloxane added increased to more than 5 parts, although the hydrophobicity was improved, the UV blocking ability and the ability to degrade organic matter decreased significantly. Figure 4 The graph shows the degradation rate-time relationship of the self-cleaning UV-protective films prepared in Examples 1-3 above for the photocatalytic degradation of Congo red. As can be seen from the graph, with the increase of the amount of chromium nitrate nonahydrate in the precursor solution (from 1 part to 3 parts), the photocatalytic degradation effect of the self-cleaning UV-protective films on Congo red first increases and then decreases. The photocatalytic degradation effect is best when the amount of chromium nitrate nonahydrate is 2 parts, followed by 3 parts, and then 1 part.

[0118] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A self-cleaning UV-protective film, characterized in that, It comprises an organic polymer and a UV-absorbing material, wherein the UV-absorbing material is mixed with the organic polymer, and the UV-absorbing material comprises nanofibers and Cr doped in the nanofibers. 3+ The nanofibers contain TiO2 ions.

2. The self-cleaning UV-protective film layer as described in claim 1, characterized in that, The nanofibers also include SiO2, with a molar ratio of SiO2 to TiO2 of 1:3.5~5.

3. The self-cleaning UV-protective film layer as described in claim 1, characterized in that, The self-cleaning UV protection film layer meets at least one of the following characteristics (1) to (3): (1) The diameter of the nanofiber is 50 nm to 100 nm; (2) The average length of the nanofibers is 50 μm to 100 μm; (3) The aspect ratio of the nanofiber is 500~1000∶1.

4. The self-cleaning UV-protective film layer as described in any one of claims 1 to 3, characterized in that, In the nanofibers, the Cr 3+ The mass fraction of ions is 0.5% to 10%.

5. The self-cleaning UV-protective film layer as described in any one of claims 1 to 3, characterized in that, The organic polymer is present in parts by weight of 1 to 10, and the ultraviolet absorbing material is present in parts by weight of 20.

6. The self-cleaning UV-protective film layer as described in any one of claims 1 to 3, characterized in that, The organic polymer is selected from at least one of polydimethylsiloxane, polyurethane, and polyheptadecyltrimethoxysilane.

7. The self-cleaning UV-protective film layer as described in any one of claims 1 to 3, characterized in that, The self-cleaning UV-protective film also contains a silane coupling agent.

8. A method for preparing a self-cleaning UV-protective film layer according to any one of claims 1 to 7, characterized in that, Includes the following steps: A titanium source, a chromium source, and a dispersant are dispersed in a first solvent to form a precursor solution; The precursor solution was electrospinned to obtain an ultraviolet absorbing material. The ultraviolet absorbing material is dispersed in a second solvent, the organic polymer is added, and the mixture is stirred to obtain a slurry; The slurry is coated onto a substrate and dried to obtain the self-cleaning UV-protective film.

9. The preparation method according to claim 8, characterized in that, The precursor solution also contains a silicon source, and the molar ratio of the silicon source to the titanium source is 1:3.5~5.

10. The preparation method according to claim 8, characterized in that, The preparation method meets at least one of the following characteristics (1) to (4): (1) The titanium source is selected from at least one of tetrabutyl titanate, titanium tetroxide and titanium sulfate; (2) The chromium source is selected from at least one of chromium nitrate and chromium oxide; (3) The dispersant is selected from at least one of polyvinylpyrrolidone and polyacrylonitrile; (4) The first solvent is selected from at least one of methanol, ethanol and water.

11. The preparation method according to claim 8, characterized in that, In the electrospinning process, the temperature is 25℃~40℃, the humidity is 30%~60%, the voltage is 10kV~15kV, and the feed rate is 0.001ml / s~0.010ml / s.

12. The preparation method according to any one of claims 8 to 11, characterized in that, The preparation method further includes the following steps: The product obtained by electrospinning is calcined at 450℃~600℃.

13. A photovoltaic glass, characterized in that, The invention comprises a glass substrate and a self-cleaning UV-protective film layer as described in any one of claims 1 to 7 or a self-cleaning UV-protective film layer prepared by the preparation method as described in any one of claims 8 to 12, wherein the self-cleaning UV-protective film layer is disposed on the glass substrate.

14. A photovoltaic module, characterized in that, It includes a battery body and the photovoltaic glass as described in claim 13, wherein the photovoltaic glass is disposed on the battery body.

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