Self-cleaning photovoltaic glass and preparation method thereof

Abstract

The invention discloses a self-cleaning photovoltaic glass and a preparation method thereof, and relates to the field of photovoltaic glass. When preparing the self-cleaning photovoltaic glass, the invention comprises the following steps: acid-catalyzing and aging ethyl orthosilicate to obtain an acid-catalyzed silica sol, and alkali-catalyzing and aging polyacrylic acid as a template to obtain a hollow silica sol; the acid-catalyzed silica sol and the hollow silica sol are mixed and aged to obtain a composite silica sol; tetrabutyl titanate, urea, and lanthanum nitrate are polycondensed to obtain a nitrogen-lanthanum-doped titanium dioxide sol; the composite silica sol and the nitrogen-lanthanum-doped titanium dioxide sol are modified by a silane coupling agent to obtain a composite sol; the photovoltaic glass is impregnated and pulled with the composite silica sol and the composite sol, respectively, and dried, and finally annealed to obtain the self-cleaning photovoltaic glass. The self-cleaning photovoltaic glass prepared by the invention has excellent wear resistance, anti-reflection performance, and self-cleaning performance.

Description

Technical Field

[0001] The invention relates to the field of photovoltaic glass, in particular to self-cleaning photovoltaic glass and a preparation method thereof. Background Art

[0002] Photovoltaic glass, also known as "photoelectric glass", is a special glass that uses solar radiation to generate electricity and is equipped with a current lead-out device and cable. It is composed of glass, solar cells, film, back glass, special metal wires, etc., and is widely used in solar smart windows, solar pavilions, photovoltaic glass building roofs, photovoltaic glass curtain walls, etc.

[0003] Self-cleaning photovoltaic glass is a type of photovoltaic glass with a self-cleaning function that can reduce the adhesion of dust on the surface of photovoltaic modules, thereby improving the power generation efficiency and revenue of photovoltaic power stations. The self-cleaning property of photovoltaic glass can reduce the damage to photovoltaic glass during the cleaning process, extend the photovoltaic life, and reduce the waste of resources caused by the cleaning process, which meets the requirements of green environmental protection. With the increasing application of photovoltaic glass, self-cleaning photovoltaic glass has broad market prospects due to its self-cleaning function, anti-reflection performance and excellent film hardness. Summary of the invention

[0004] The purpose of the present invention is to provide a self-cleaning photovoltaic glass and a preparation method thereof to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A self-cleaning photovoltaic glass is prepared by preparing a composite sol from a composite silica sol and a nitrogen-lanthanum-doped titanium dioxide sol, and then impregnating and pulling the photovoltaic glass with the composite silica sol to obtain the self-cleaning photovoltaic glass.

[0007] As an optimization, the composite silica sol is prepared by composite doping of chain acid catalyzed silica sol and spherical hollow silica sol.

[0008] As an optimization, the nitrogen-lanthanum-doped titanium dioxide sol is prepared by polycondensation of tetrabutyl titanate, urea and lanthanum nitrate.

[0009] A self-cleaning photovoltaic glass comprises the following preparation steps:

[0010] (1) mixing the acid-catalyzed silica sol and the hollow silica sol in a mass ratio of 1:(4-6), and stirring at 100-200 r / min for 3-4 h at 20-30° C. to obtain a composite silica sol;

[0011] (2) Nitrogen-lanthanum-doped titanium dioxide sol, γ-aminopropyltriethoxysilane, deionized water, and anhydrous ethanol were mixed in a mass ratio of 1: (0.1-0.2): (1.5-2.5): (25-35), and stirred at 200-300 r / min for 30-40 min at 20-30° C. to obtain solution A; composite silica sol, deionized water, and anhydrous ethanol were mixed in a mass ratio of 1: (1.5-2.5): (25-3 5) mixing, adjusting the pH to 3-4 with acetic acid, adding 0.15-0.25 times the mass of the composite silica sol glycidoxypropyltrimethoxysilane, stirring at a rate of 200-300 r / min for 30-40 min at 20-30° C. to obtain solution B; mixing solution A and solution B at a volume ratio of 1:1, stirring at a rate of 60-80 r / min for 30-40 min at 20-30° C. to obtain a composite sol;

[0012] (3) The photovoltaic glass is immersed in acetone for 25 to 35 minutes, and then immersed in anhydrous ethanol for 25 to 35 minutes, washed with deionized water for 3 to 5 times, dried at 105 to 115°C for 4 to 6 hours, cooled to room temperature, impregnated with composite silica sol to form a coating, vacuum dried at 105 to 115°C for 1 to 2 hours, and cooled to room temperature; impregnated with composite sol to form a coating, vacuum dried at 105 to 115°C for 1 to 2 hours, cooled to room temperature, and annealed at 550 to 650°C for 1 to 2 hours to obtain self-cleaning photovoltaic glass.

[0013] As an optimization, the preparation method of the acid-catalyzed silica sol in step (1) is: mix tetraethyl orthosilicate, hydrochloric acid, and anhydrous ethanol in a mass ratio of 1: (0.3-0.4): (9-9.5), stir at 200-300 r / min for 3-4 hours at 20-30° C., and age for 5 days.

[0014] As an optimization, the preparation method of the hollow silica sol in step (1) is as follows: polyacrylic acid and ammonia water are mixed in a mass ratio of 1: (45-50): (740-750), stirred at 200-300 r / min for 10-20 min at 20-30° C., 0.1-0.2 times the mass of ammonia water of tetraethyl orthosilicate is added in 5 portions, stirred at 200-300 r / min for 10-14 h at 20-30° C., aged for 5 days, refluxed at 75-85° C. for 10-14 h, and cooled to room temperature.

[0015] As an optimization, the preparation method of the lanthanum nitrogen-doped titanium dioxide sol in step (1) is: mix nitric acid, urea, lanthanum nitrate, tetrabutyl titanate, deionized water, and anhydrous ethanol in a volume ratio of 1: (4.5-5.5): (0.3-0.4): (6-6.5): (35-40): (15-20), stir at 25-35°C at 60-80r / min for 2-3h, and age at 25-35°C for 45-50h.

[0016] As an optimization, the immersion and pulling process parameters of step (3) are: temperature 20-30°C, humidity 40%-60%, and pulling rate 130-150 mm / min.

[0017] As an optimization, the polyacrylic acid is polyacrylic acid with a molecular weight of 3000.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0019] When preparing the self-cleaning photovoltaic glass, the present invention comprises the following steps: acid-catalyzing and aging ethyl orthosilicate to obtain acid-catalyzed silica sol, and alkali-catalyzing and aging using polyacrylic acid as a template to obtain hollow silica sol; the acid-catalyzed silica sol and the hollow silica sol are mixed and aged to obtain composite silica sol; tetrabutyl titanate, urea and lanthanum nitrate are polycondensed to obtain nitrogen-lanthanum-doped titanium dioxide sol; the composite silica sol and the nitrogen-lanthanum-doped titanium dioxide sol are combined to obtain a composite sol; the photovoltaic glass is impregnated with the composite silica sol and the composite sol, respectively, and then pulled and dried, and finally annealed to obtain the self-cleaning photovoltaic glass.

[0020] Firstly, the hollow silica sol prepared by base catalysis with polyacrylic acid as template has a high porosity, which not only improves the transmittance of the film layer, but also improves the anti-reflection performance of the film layer; the acid-catalyzed silica sol has a chain structure, which can be used as a binder and filler to fill the gaps of part of the hollow silica sol, and form a stable structure through the connection of Si-0-Si bonds, thereby improving the wear resistance of the film layer; titanium dioxide has a good decomposition effect on organic pollutants. In the process of preparing titanium dioxide sol, nitrogen and lanthanum are introduced to prepare nitrogen-lanthanum-doped titanium dioxide sol. Nitrogen doping expands the light response range of titanium dioxide, and lanthanum doping reduces the recombination rate of photogenerated electrons and hole pairs in titanium dioxide, thereby improving the photocatalytic hydrophilicity of the film layer. The nitrogen-lanthanum doping modification can effectively improve the photocatalytic activity of titanium dioxide, improve the decomposition ability of the film layer on organic pollutants, and thus improve the self-cleaning performance.

[0021] Secondly, the composite titanium dioxide sol and the nitrogen-lanthanum-doped titanium dioxide sol are silane-modified with γ-aminopropyltriethoxysilane and glycidoxypropyltrimethoxysilane respectively and then mixed. The amino group induces the epoxy ring opening to form a stable chemical bond, so that the composite titanium dioxide sol and the nitrogen-lanthanum-doped titanium dioxide sol form a stable cross-linked network, thereby improving the wear resistance of the film layer. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] A self-cleaning photovoltaic glass comprises the following preparation steps:

[0025] (1) Tetraethyl orthosilicate, hydrochloric acid, and anhydrous ethanol were mixed in a mass ratio of 1:0.3:9, stirred at 200 r / min for 3 h at 20°C, and aged for 5 days to obtain an acid-catalyzed silica sol; polyacrylic acid and ammonia water were mixed in a mass ratio of 1:45:740, stirred at 200 r / min for 10 min at 20°C, and 0.1 times the mass of ammonia water of tetraethyl orthosilicate was added in 5 portions, stirred at 200 r / min for 10 h at 20°C, aged for 5 days, refluxed at 75°C for 10 h, and cooled to room temperature to obtain a hollow silica sol; nitric acid, urea, lanthanum nitrate, tetrabutyl titanate, deionized water, and anhydrous ethanol were mixed in a volume ratio of 1:4.5:0.3:6:35:15, stirred at 60 r / min for 2 h at 25°C, and aged at 25°C for 45 h to obtain a lanthanum nitrogen-doped titanium dioxide sol;

[0026] (2) mixing the acid-catalyzed silica sol and the hollow silica sol in a mass ratio of 1:4, and stirring at 100 r / min for 3 h at 20° C. to obtain a composite silica sol;

[0027] (3) Nitrogen lanthanum doped titanium dioxide sol, γ-aminopropyltriethoxysilane, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:0.1:1.5:25, and stirred at a rate of 200 r / min for 30 min at 20°C to obtain solution A; composite silica sol, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:1.5:25, the pH was adjusted to 3 with acetic acid, 0.15 times the mass of composite silica sol glycidoxypropyltrimethoxysilane was added, and stirred at a rate of 200 r / min for 30 min at 20°C to obtain solution B; solution A and solution B were mixed in a volume ratio of 1:1, and stirred at a rate of 60 r / min for 30 min at 20°C to obtain a composite sol;

[0028] (4) The photovoltaic glass was immersed in acetone for 25 minutes and then immersed in anhydrous ethanol for 25 minutes, washed with deionized water for 3 times, dried at 105°C for 4 hours, cooled to room temperature, impregnated with composite silica sol to form a coating, vacuum dried at 105°C for 1 hour, and cooled to room temperature; impregnated with composite sol to form a coating, vacuum dried at 105°C for 1 hour, cooled to room temperature, and annealed at 550°C for 1 hour to obtain self-cleaning photovoltaic glass.

[0029] Example 2

[0030] A self-cleaning photovoltaic glass comprises the following preparation steps:

[0031] (1) Tetraethyl orthosilicate, hydrochloric acid, and anhydrous ethanol were mixed in a mass ratio of 1:0.35:9.2, stirred at 250 r / min for 3.5 h at 25°C, and aged for 5 days to obtain an acid-catalyzed silica sol; polyacrylic acid and ammonia water were mixed in a mass ratio of 1:47:745, stirred at 250 r / min for 15 min at 25°C, and tetraethyl orthosilicate (0.15 times the mass of ammonia water) was added in 5 portions, and aged at 25 ℃, stirred at 250r / min for 12h, aged for 5 days, refluxed at 80℃ for 12h, and cooled to room temperature to obtain hollow silica sol; nitric acid, urea, lanthanum nitrate, tetrabutyl titanate, deionized water, and anhydrous ethanol were mixed at a volume ratio of 1:5:0.35:6.2:37:17, stirred at 70r / min at 30℃ for 2.5h, and aged at 30℃ for 47h to obtain lanthanum nitrogen doped titanium dioxide sol;

[0032] (2) mixing the acid-catalyzed silica sol and the hollow silica sol in a mass ratio of 1:5, and stirring at 150 r / min for 3.5 h at 25° C. to obtain a composite silica sol;

[0033] (3) Nitrogen lanthanum doped titanium dioxide sol, γ-aminopropyltriethoxysilane, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:0.15:2:30, and stirred at a rate of 250 r / min for 35 min at 25°C to obtain solution A; composite silica sol, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:2:30, the pH was adjusted to 3.5 with acetic acid, and 0.2 times the mass of composite silica sol glycidoxypropyltrimethoxysilane was added, and stirred at a rate of 250 r / min for 35 min at 25°C to obtain solution B; solution A and solution B were mixed in a volume ratio of 1:1, and stirred at a rate of 70 r / min for 35 min at 25°C to obtain a composite sol;

[0034] (4) The photovoltaic glass was immersed in acetone for 30 minutes and then immersed in anhydrous ethanol for 30 minutes. The glass was washed with deionized water for 4 times, dried at 110°C for 5 hours, cooled to room temperature, impregnated with composite silica sol to form a coating, vacuum dried at 110°C for 1.5 hours, and cooled to room temperature; the coating was impregnated with composite sol to form a coating, vacuum dried at 110°C for 1.5 hours, cooled to room temperature, and annealed at 600°C for 1.5 hours to obtain self-cleaning photovoltaic glass.

[0035] Example 3

[0036] A self-cleaning photovoltaic glass comprises the following preparation steps:

[0037] (1) Tetraethyl orthosilicate, hydrochloric acid, and anhydrous ethanol were mixed in a mass ratio of 1:0.4:9.5, stirred at 300 r / min for 4 h at 30°C, and aged for 5 days to obtain an acid-catalyzed silica sol; polyacrylic acid and ammonia water were mixed in a mass ratio of 1:50:750, stirred at 300 r / min for 20 min at 30°C, and tetraethyl orthosilicate (0.2 times the mass of ammonia water) was added in 5 portions, and then stirred at 30°C. The mixture was stirred at 300 r / min for 14 h, aged for 5 days, refluxed at 85°C for 14 h, and cooled to room temperature to obtain hollow silica sol; nitric acid, urea, lanthanum nitrate, tetrabutyl titanate, deionized water, and anhydrous ethanol were mixed at a volume ratio of 1:5.5:0.4:6.5:40:20, stirred at 80 r / min for 3 h at 35°C, and aged at 35°C for 50 h to obtain lanthanum nitrogen doped titanium dioxide sol;

[0038] (2) mixing the acid-catalyzed silica sol and the hollow silica sol in a mass ratio of 1:6, and stirring at 200 r / min at 30° C. for 4 h to obtain a composite silica sol;

[0039] (3) Nitrogen lanthanum doped titanium dioxide sol, γ-aminopropyltriethoxysilane, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:0.2:2.5:35, and stirred at 30°C at a rate of 300 r / min for 40 min to obtain solution A; composite silica sol, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:2.5:35, the pH was adjusted to 4 with acetic acid, 0.25 times the mass of composite silica sol glycidoxypropyltrimethoxysilane was added, and stirred at 300 r / min for 40 min at 30°C to obtain solution B; solution A and solution B were mixed in a volume ratio of 1:1, and stirred at 80 r / min for 40 min at 30°C to obtain a composite sol;

[0040] (4) The photovoltaic glass was immersed in acetone for 35 minutes and then immersed in anhydrous ethanol for 35 minutes. The glass was washed with deionized water for 5 times, dried at 115°C for 6 hours, cooled to room temperature, impregnated with composite silica sol to form a coating, vacuum dried at 115°C for 2 hours, and cooled to room temperature; the coating was impregnated with composite sol to form a coating, vacuum dried at 115°C for 2 hours, cooled to room temperature, and annealed at 650°C for 2 hours to obtain self-cleaning photovoltaic glass.

[0041] Comparative Example 1

[0042] A self-cleaning photovoltaic glass comprises the following preparation steps:

[0043] (1) Tetraethyl orthosilicate, hydrochloric acid and anhydrous ethanol were mixed in a mass ratio of 1:0.35:9.2, stirred at 250 r / min for 3.5 h at 25°C, and aged for 5 days to obtain an acid-catalyzed silica sol; polyacrylic acid and ammonia water were mixed in a mass ratio of 1:47:745, stirred at 250 r / min for 15 min at 25°C, tetraethyl orthosilicate with a mass of 0.15 times that of ammonia water was added in 5 portions, stirred at 250 r / min for 12 h at 25°C, aged for 5 days, refluxed at 80°C for 12 h, and cooled to room temperature to obtain a hollow silica sol; nitric acid, tetrabutyl titanate, deionized water and anhydrous ethanol were mixed in a volume ratio of 1:6.2:37:17, stirred at 70 r / min for 2.5 h at 30°C, and aged at 30°C for 47 h to obtain a titanium dioxide sol;

[0044] (2) mixing the acid-catalyzed silica sol and the hollow silica sol in a mass ratio of 1:5, and stirring at 150 r / min for 3.5 h at 25° C. to obtain a composite silica sol;

[0045] (3) Titanium dioxide sol, γ-aminopropyltriethoxysilane, deionized water, and anhydrous ethanol were mixed in a mass ratio of 1:0.15:2:30, and stirred at a rate of 250 r / min for 35 min at 25°C to obtain solution A; composite silica sol, deionized water, and anhydrous ethanol were mixed in a mass ratio of 1:2:30, the pH was adjusted to 3.5 with acetic acid, and 0.2 times the mass of composite silica sol glycidoxypropyltrimethoxysilane was added, and stirred at a rate of 250 r / min for 35 min at 25°C to obtain solution B; solution A and solution B were mixed in a volume ratio of 1:1, and stirred at a rate of 70 r / min for 35 min at 25°C to obtain a composite sol;

[0046] (4) The photovoltaic glass was immersed in acetone for 30 minutes and then immersed in anhydrous ethanol for 30 minutes. The glass was washed with deionized water for 4 times, dried at 110°C for 5 hours, cooled to room temperature, impregnated with composite silica sol to form a coating, vacuum dried at 110°C for 1.5 hours, and cooled to room temperature; the coating was impregnated with composite sol to form a coating, vacuum dried at 110°C for 1.5 hours, cooled to room temperature, and annealed at 600°C for 1.5 hours to obtain self-cleaning photovoltaic glass.

[0047] Comparative Example 2

[0048] A self-cleaning photovoltaic glass, comprising the following preparation steps:

[0049] (1) polyacrylic acid and ammonia water were mixed in a mass ratio of 1:47:745, stirred at 250 r / min for 15 min at 25°C, 0.15 times the mass of ammonia water of tetraethyl orthosilicate was added in 5 portions, stirred at 250 r / min for 12 h at 25°C, aged for 5 days, refluxed at 80°C for 12 h, and cooled to room temperature to obtain hollow silica sol; nitric acid, urea, lanthanum nitrate, tetrabutyl titanate, deionized water, and anhydrous ethanol were mixed in a volume ratio of 1:5:0.35:6.2:37:17, stirred at 70 r / min for 2.5 h at 30°C, and aged at 30°C for 47 h to obtain lanthanum nitrogen doped titanium dioxide sol;

[0050] (2) Nitrogen lanthanum doped titanium dioxide sol, γ-aminopropyltriethoxysilane, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:0.15:2:30, and stirred at a rate of 250 r / min for 35 min at 25°C to obtain solution A; hollow silica sol, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:2:30, the pH was adjusted to 3.5 with acetic acid, and 0.2 times the mass of hollow silica sol was added with glycidoxypropyltrimethoxysilane, and stirred at a rate of 250 r / min for 35 min at 25°C to obtain solution B; solution A and solution B were mixed in a volume ratio of 1:1, and stirred at a rate of 70 r / min for 35 min at 25°C to obtain a composite sol;

[0051] (3) The photovoltaic glass was immersed in acetone for 30 minutes and then immersed in anhydrous ethanol for 30 minutes, washed with deionized water for 4 times, dried at 110°C for 5 hours, cooled to room temperature, impregnated with composite silica sol to form a coating, vacuum dried at 110°C for 1.5 hours, and cooled to room temperature; impregnated with composite sol to form a coating, vacuum dried at 110°C for 1.5 hours, cooled to room temperature, and annealed at 600°C for 1.5 hours to obtain self-cleaning photovoltaic glass.

[0052] Comparative Example 3

[0053] A self-cleaning photovoltaic glass comprises the following preparation steps:

[0054] (1) Tetraethyl orthosilicate, hydrochloric acid, and anhydrous ethanol were mixed in a mass ratio of 1:0.35:9.2, stirred at 250 r / min for 3.5 h at 25°C, and aged for 5 days to obtain an acid-catalyzed silica sol; polyacrylic acid and ammonia water were mixed in a mass ratio of 1:47:745, stirred at 250 r / min for 15 min at 25°C, and tetraethyl orthosilicate (0.15 times the mass of ammonia water) was added in 5 portions, and aged at 25 ℃, stirred at 250r / min for 12h, aged for 5 days, refluxed at 80℃ for 12h, and cooled to room temperature to obtain hollow silica sol; nitric acid, urea, lanthanum nitrate, tetrabutyl titanate, deionized water, and anhydrous ethanol were mixed at a volume ratio of 1:5:0.35:6.2:37:17, stirred at 70r / min at 30℃ for 2.5h, and aged at 30℃ for 47h to obtain lanthanum nitrogen doped titanium dioxide sol;

[0055] (2) mixing the acid-catalyzed silica sol and the hollow silica sol in a mass ratio of 1:5, and stirring at 150 r / min for 3.5 h at 25° C. to obtain a composite silica sol;

[0056] (3) The photovoltaic glass was immersed in acetone for 30 minutes and then immersed in anhydrous ethanol for 30 minutes, washed with deionized water for 4 times, dried at 110°C for 5 hours, cooled to room temperature, impregnated with composite silica sol for pulling out the coating, vacuum dried at 110°C for 1.5 hours, and cooled to room temperature; the composite sol of nitrogen-lanthanum-doped titanium dioxide and silicon dioxide was impregnated with the coating, vacuum dried at 110°C for 1.5 hours, cooled to room temperature, and annealed at 600°C for 1.5 hours to obtain self-cleaning photovoltaic glass.

[0057] Test Example 1

[0058] Self-cleaning performance:

[0059] (1) Contact angle test: Self-cleaning photovoltaic glass with a size of 100 mm × 100 mm was taken and the static contact angle of water was tested using an SL200A contact angle meter after irradiation with ultraviolet light for 6 hours. The results are shown in Table 1.

[0060] (2) Methylene blue degradation test: The composite sol and 10 mg / L methylene blue were mixed at a mass ratio of 1:2000, irradiated under ultraviolet light for 2 h, and the absorbance was measured using a Shimadzu UV-2600 ultraviolet spectrophotometer to calculate the degradation rate of methylene blue. The results are shown in Table 1.

[0061] Table 1

[0062] Static contact angle Degradation rate Static contact angle Degradation rate Example 1 1.23 90％ Comparative Example 1 10.27 0％ Example 2 1.12 92％ Comparative Example 2 1.31 90％ Example 3 1.19 90％ Comparative Example 3 1.22 89％

[0063] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the static contact angles of Examples 1, 2, and 3 are significantly greater than the static contact angle of Comparative Example 1, indicating that lanthanum doping reduces the recombination rate of photogenerated electrons and hole pairs in titanium dioxide and improves the photocatalytic hydrophilicity of the film layer.

[0064] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the degradation rates of Examples 1, 2, and 3 are significantly greater than the degradation rate of Comparative Example 1, indicating that nitrogen doping expands the light response range of titanium dioxide, and lanthanum doping reduces the recombination rate of photogenerated electrons and hole pairs in titanium dioxide. The nitrogen-lanthanum doping modification can effectively improve the photocatalytic activity of titanium dioxide, improve the ability of the film layer to decompose organic pollutants, and thus improve the self-cleaning performance.

[0065] Test Example 2

[0066] Hardness: The sample was prepared according to GB / T 43083-2023 standard, the sample size was 300 mm × 300 mm, and the hardness of the self-cleaning photovoltaic glass film layer was tested using a QHQ-A pencil hardness scratch tester. The results are shown in Table 2.

[0067] Table 2

[0068]

[0069]

[0070] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 2, it can be found that the hardness of Examples 1, 2, and 3 is significantly improved compared with Comparative Example 2, indicating that the acid-catalyzed silica sol has a chain structure and can be used as a binder and filler to fill the voids of part of the hollow silica sol, forming a stable structure through the connection of Si-0-Si bonds, thereby improving the wear resistance of the film layer.

[0071] Test Example 3

[0072] Wear resistance: Take a self-cleaning photovoltaic glass with a specification of 100mm×100mm, use 120-grit sandpaper, sandpaper weight 350g, stroke length 200mm, reciprocate rub 40 strokes, and use SL200A contact angle meter to test the static contact angle of water before and after friction after ultraviolet light irradiation for 6 hours. The results are shown in Table 3.

[0073] Table 3

[0074]

[0075] From the comparison of the experimental data of Examples 1, 2, 3 and Comparative Example 3 in Table 3, it can be found that the static contact angle changes of Examples 1, 2, 3 are significantly increased compared with Comparative Example 3, indicating that the composite titanium dioxide sol and the nitrogen-lanthanum-doped titanium dioxide sol are silane-modified with γ-aminopropyltriethoxysilane and glycidoxypropyltrimethoxysilane respectively and then mixed, and the amino group induces the epoxy group to open the ring to form a stable chemical bond, so that the composite titanium dioxide sol and the nitrogen-lanthanum-doped titanium dioxide sol form a stable cross-linked network, thereby improving the wear resistance of the film layer.

[0076] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing self-cleaning photovoltaic glass, characterized in that: The method comprises the following preparation steps: (1) mixing the acid-catalyzed silica sol and the hollow silica sol in a mass ratio of 1:(4-6), stirring at 100-200 r / min for 3-4 h at 20-30°C to obtain a composite silica sol; (2) Mix lanthanum nitrogen-doped titanium dioxide sol, γ-aminopropyltriethoxysilane, deionized water, and anhydrous ethanol in a mass ratio of 1: (0.1-0.2): (1.5-2.5): (25-35), and stir at 200-300 r / min for 30-40 min at 20-30 °C to obtain solution A; mix composite silica sol, deionized water, and anhydrous ethanol in a mass ratio of 1: (1.5-2.5): (25-3 5) mixing, adjusting the pH to 3-4 with acetic acid, adding 0.15-0.25 times the mass of the composite silica sol of glycidoxypropyltrimethoxysilane, stirring at a rate of 200-300 r / min for 30-40 min at 20-30° C. to obtain solution B; mixing solution A and solution B at a volume ratio of 1:1, stirring at a rate of 60-80 r / min for 30-40 min at 20-30° C. to obtain a composite sol; (3) The photovoltaic glass was immersed in acetone for 25-35 min, then immersed in anhydrous ethanol for 25-35 min, washed with deionized water for 3-5 times, dried at 105-115 °C for 4-6 h, cooled to room temperature, impregnated with composite silica sol for coating, vacuum dried at 105-115 °C for 1-2 h, cooled to room temperature; impregnated with composite sol for coating, vacuum dried at 105-115 °C for 1-2 h, cooled to room temperature, and annealed at 550-650 °C for 1-2 h to obtain self-cleaning photovoltaic glass.

2. The method for preparing a self-cleaning photovoltaic glass according to claim 1, characterized in that: The preparation method of the acid-catalyzed silica sol in step (1) is as follows: ethyl orthosilicate, hydrochloric acid and anhydrous ethanol are mixed in a mass ratio of 1: (0.3-0.4): (9-9.5), stirred at 200-300 r / min for 3-4 hours at 20-30° C., and aged for 5 days.

3. The method for preparing a self-cleaning photovoltaic glass according to claim 1, characterized in that: The preparation method of the nitrogen-lanthanum-doped titanium dioxide sol in step (2) is as follows: nitric acid, urea, lanthanum nitrate, tetrabutyl titanate, deionized water, and anhydrous ethanol are mixed in a volume ratio of 1: (4.5-5.5): (0.3-0.4): (6-6.5): (35-40): (15-20), stirred at 25-35° C. at 60-80 r / min for 2-3 h, and aged at 25-35° C. for 45-50 h.

4. The method for preparing a self-cleaning photovoltaic glass according to claim 1, characterized in that: The immersion and pulling process parameters of step (3) are: temperature 20-30°C, humidity 40%-60%, and pulling rate 130-150 mm / min.

5. A self-cleaning photovoltaic glass prepared according to the method for preparing the self-cleaning photovoltaic glass according to any one of claims 1 to 4.

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