Photocatalytic formaldehyde removal glass as well as preparation method and application thereof

Abstract

The invention relates to the technical field of glass, in particular to photocatalytic formaldehyde removal glass as well as a preparation method and application thereof. The provided photocatalytic formaldehyde removal glass comprises a glass substrate, a photocatalytic reaction layer which is laminated on at least one surface of the glass substrate, and a protective layer which is laminated on the photocatalytic reaction layer and deviates from the glass substrate, wherein the raw material of the photocatalytic reaction layer comprises modified nano titanium dioxide containing a doping element, and the doping element comprises any one of a nitrogen element and a transition metal element. By doping the nitrogen element or the transition metal element, the energy band structure of the nano titanium dioxide is precisely regulated and controlled, the forbidden band width is remarkably compressed, and the absorption efficiency to visible light is greatly enhanced, so that the photocatalytic activity is improved to a brand new level, harmful gases such as formaldehyde can be quickly and efficiently decomposed, and a continuous and efficient air purification function is realized; the wide application of the photocatalytic formaldehyde removal glass is facilitated.

Description

Technical Field

[0001] This application belongs to the field of glass technology, and in particular relates to a photocatalytic formaldehyde removal glass, its preparation method and application. Background Technology

[0002] With the booming development of the building decoration industry, indoor air pollution has become an increasingly prominent problem. Formaldehyde, as a major indoor pollutant, has a wide range of sources, including various types of artificial boards, adhesives, and coatings, and its release period can last from 3 to 15 years. Long-term exposure to environments with excessive formaldehyde levels can pose a serious threat to human health, potentially causing respiratory diseases, allergic reactions, and even cancer risks, especially for the elderly, children, pregnant women, and other groups with weakened immune systems.

[0003] Currently available formaldehyde removal methods have many shortcomings. Physical adsorption methods, such as using activated carbon, can adsorb a certain amount of formaldehyde, but their adsorption capacity is limited and they are prone to saturation. Once saturated, the adsorbed formaldehyde may be released again, causing secondary pollution. Moreover, frequent replacement of activated carbon increases the cost and hassle of use. Chemical formaldehyde removers decompose formaldehyde through chemical reactions, but some chemical agents have a pungent odor, corrode indoor items, and their formaldehyde removal effect is not long-lasting, with the efficiency decreasing significantly over time.

[0004] Ordinary architectural glass only provides basic lighting and heat insulation, and cannot purify indoor formaldehyde pollution. While traditional photocatalytic formaldehyde removal technology has some effect, it heavily relies on strong ultraviolet light excitation. However, in indoor environments, especially in poorly lit areas, the intensity of ultraviolet light is limited, resulting in extremely low formaldehyde removal efficiency for traditional photocatalysts, failing to meet practical needs. Therefore, there is an urgent need to develop a glass product capable of efficiently decomposing formaldehyde under various lighting conditions. Summary of the Invention

[0005] The purpose of this application is to provide a photocatalytic formaldehyde removal glass, its preparation method and application, which aims to solve the problem that the existing traditional photocatalytic formaldehyde removal technology cannot efficiently decompose formaldehyde in indoor visible light or even weak light environments.

[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides a photocatalytic formaldehyde removal glass, comprising: a glass substrate, a photocatalytic reaction layer stacked on at least one surface of the glass substrate, and a protective layer stacked on the photocatalytic reaction layer away from the glass substrate; wherein the raw material of the photocatalytic reaction layer includes modified nano-titanium dioxide containing doped elements, wherein the doped elements include any one of nitrogen and transition metal elements.

[0008] In some embodiments, the transition metal element includes at least one selected from Ag, Cu, Fe, Zn, Ni, V, Pt, and Au.

[0009] In some embodiments, the particle size of nano-titanium dioxide is 5-10 nm.

[0010] In some embodiments, the specific surface area of ​​the nano-titanium dioxide particles is 100-220 m². 2 / g.

[0011] In some embodiments, the thickness of the photocatalytic reaction layer is 50-200 nm.

[0012] In some embodiments, the protective layer comprises the following raw materials in parts by weight:

[0013] 8-15 parts of organosilane coupling agent;

[0014] 35-50 parts of acrylate monomers;

[0015] 35-55 parts of nano-silica.

[0016] In some embodiments, the thickness of the protective layer is 5-20 μm.

[0017] In some embodiments, the glass matrix is ​​float glass, and the raw materials for float glass include a mixture of cerium oxide and zinc oxide at a mass percentage of 0.5 wt% to 2 wt%.

[0018] Secondly, this application provides a method for preparing the above-mentioned photocatalytic formaldehyde removal glass, comprising the following steps:

[0019] Provide glass substrate,

[0020] A sol containing uniformly dispersed doped nano-titanium dioxide is provided. A glass substrate is immersed in the sol, and a dip-coating method is used. After drying, the substrate is calcined to prepare a photocatalytic reaction layer on at least one surface of the glass substrate.

[0021] The raw materials for the protective layer are provided, and the raw materials for the protective layer are uniformly coated on the surface of the photocatalytic reaction layer away from the glass substrate. The protective layer is then prepared by ultraviolet light curing treatment, and photocatalytic formaldehyde removal glass is obtained.

[0022] In some embodiments, the coating speed in the dip coating method is 1-5 cm / min.

[0023] In some embodiments, the drying temperature is 120-150°C and the time is 1-2 hours.

[0024] In some embodiments, the calcination temperature is 450-550°C and the time is 2-3 hours.

[0025] In some embodiments, the ultraviolet wavelength of the ultraviolet light used in the ultraviolet curing process is 365 nm.

[0026] Thirdly, this application provides an application of the above-mentioned photocatalytic formaldehyde removal glass in building doors, windows or curtain walls.

[0027] The photocatalytic formaldehyde-removing glass provided in the first aspect of this application constructs a three-in-one functional system through a layered structure of a glass matrix, a modified nano-titanium dioxide photocatalytic reaction layer containing doped elements, and a protective layer. In the photocatalytic reaction layer, the band structure of the nano-titanium dioxide is precisely controlled by doping with nitrogen or transition metal elements, significantly compressing the band gap and greatly enhancing the absorption efficiency of visible light, thereby elevating the photocatalytic activity to a new level. This allows for the rapid and efficient decomposition of harmful gases such as formaldehyde, achieving continuous and efficient air purification. The protective layer tightly covers the surface of the photocatalytic reaction layer, forming a robust protective barrier. This barrier effectively resists external dust and moisture erosion, while also resisting mechanical friction wear during daily use, fundamentally eliminating the risk of the photocatalytic reaction layer peeling off and preventing activity decay, thus significantly extending the glass's lifespan and ensuring long-term stable operation. The three-layer structure undergoes special processing to achieve a tight molecular-level bond, possessing excellent overall stability. While fully preserving the high light transmittance of glass, it is endowed with a long-lasting formaldehyde removal and purification function, which can be flexibly adapted to diverse application scenarios such as building doors and windows, furniture panels, and interior partitions to meet the air purification needs of different spaces.

[0028] In the preparation method provided in the second aspect of this application, during the process of immersing the glass substrate in the modified nano-titanium dioxide sol, the photocatalytic layer can be uniformly and densely covered on the glass surface, effectively ensuring the consistency of product performance. The photocatalytic reaction layer is constructed using the dip-coating method. Based on the dip-coating technology, the thickness of the photocatalytic layer can be precisely controlled by precisely adjusting the dip-coating speed of the glass substrate. Subsequent drying and calcination treatments can not only remove residual organic impurities in the sol but also promote the crystal transformation of nano-titanium dioxide, forming a highly active anatase phase. At the same time, high-temperature treatment can significantly enhance the bonding force between the photocatalytic layer and the glass substrate, avoiding coating peeling during use. Furthermore, the protective layer is prepared by ultraviolet light curing. This process has a fast curing speed and high production efficiency, enabling the protective layer raw materials to complete cross-linking and curing in a short time, forming a stable three-dimensional network structure. The overall preparation process is simple to operate and highly controllable, without relying on complex and precision equipment. It has good adaptability to industrial mass production. The prepared photocatalytic formaldehyde removal glass has tight bonding between each functional layer, and the product performance is stable and reliable. It not only has high photocatalytic efficiency but also a long service life, which can fully meet the diverse needs of practical application scenarios.

[0029] The application of the photocatalytic formaldehyde-removing glass provided in the third aspect of this application has advantages such as high photocatalytic efficiency and long service life. The photocatalytic formaldehyde-removing glass can continuously carry out photocatalytic reactions using natural light (visible light and ultraviolet light) without the need for additional energy, achieving "passive" formaldehyde removal, which is energy-saving and efficient. At the same time, it can degrade formaldehyde in indoor and outdoor air in real time, continuously improve indoor air quality, and reduce the harm of formaldehyde to human health. As a component of doors, windows or curtain walls, it can perform structural functions (lighting, windproofing, and heat insulation) while adding air purification functions, eliminating the need for additional air purification equipment, saving space and costs, and facilitating its widespread application. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a graph showing the relationship between light intensity and formaldehyde removal efficiency provided in the embodiments of this application. Detailed Implementation

[0032] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0034] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0035] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0036] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0037] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass in the embodiments of this application can be a well-known unit of mass in the chemical industry, such as μg, mg, g, or kg.

[0038] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0039] The first aspect of this application provides a photocatalytic formaldehyde removal glass, comprising: a glass substrate, a photocatalytic reaction layer stacked on at least one surface of the glass substrate, and a protective layer stacked on the photocatalytic reaction layer away from the glass substrate; wherein the raw material of the photocatalytic reaction layer includes modified nano-titanium dioxide containing doped elements, wherein the doped elements include any one of nitrogen and transition metal elements.

[0040] The photocatalytic formaldehyde-removing glass provided in the first aspect of this application constructs a three-in-one functional system through a layered structure of a glass substrate, a modified nano-titanium dioxide photocatalytic reaction layer containing doped elements, and a protective layer. In the photocatalytic reaction layer, the band structure of the nano-titanium dioxide is precisely controlled by doping with nitrogen or transition metal elements, significantly compressing the band gap and greatly enhancing the absorption efficiency of visible light, thereby elevating the photocatalytic activity to a new level. This allows for the rapid and efficient decomposition of harmful gases such as formaldehyde, achieving continuous and efficient air purification. The protective layer tightly covers the surface of the photocatalytic reaction layer, forming a robust protective barrier. This barrier effectively resists external dust and moisture erosion, while also resisting mechanical friction wear during daily use, fundamentally eliminating the risk of the photocatalytic reaction layer peeling off and preventing activity decay, thus significantly extending the glass's service life and ensuring long-term stable operation. The three-layer structure undergoes special processing to achieve a tight molecular-level bond, possessing excellent overall stability. While fully preserving the high light transmittance of glass, it is endowed with a long-lasting formaldehyde removal and purification function, which can be flexibly adapted to diverse application scenarios such as building doors and windows, furniture panels, and interior partitions to meet the air purification needs of different spaces.

[0041] Furthermore, a photocatalytic reaction layer is stacked on at least one surface of the glass substrate, wherein the raw material of the photocatalytic reaction layer includes modified nano-titanium dioxide containing doped elements, wherein the doped elements include any one of nitrogen and transition metal elements.

[0042] The titanium dioxide layer in photocatalytic formaldehyde-removing glass can function under any lighting conditions because it has an ideal particle size of 5-10 nanometers and a particle size of 100-220 μm. 2 With an ultra-large specific surface area of ​​ / g, it provides abundant active sites; after special modification, the crystal and electronic structure are optimized, the recombination rate of photogenerated carriers is reduced, and the catalytic activity is high. It can also efficiently excite electron transitions to generate strong oxidizing free radicals even under weak light; the modification expands the photoresponse range, and can use indoor natural visible light and artificial light to excite electron transitions to start the reaction; at the same time, advanced nano-loading technology ensures that it is uniformly and firmly attached to the glass, forming a dense and stable layer, with stable performance over long-term use, and continuously exerting its formaldehyde removal function.

[0043] In some embodiments, the doping element includes nitrogen, with nitrogen atoms replacing some oxygen atoms in the titanium dioxide lattice. This doping method causes lattice distortion in nano-titanium dioxide, forming a mid-band state, which effectively extends its photoresponse range to the visible light region. This allows titanium dioxide, which originally could only produce photocatalytic reactions under ultraviolet excitation, to be activated in indoor visible light environments, greatly improving its practicality in indoor environments.

[0044] In some embodiments, the transition metal element includes at least one selected from Ag, Cu, Fe, Zn, Ni, V, Pt, and Au. The provided transition metal element serves as a dopant, uniformly distributed on the surface of titanium dioxide in elemental or ionic form. Its introduction can act as an electron-trapping center, effectively suppressing the recombination of photogenerated electron-hole pairs and further improving photocatalytic efficiency.

[0045] In some embodiments, the particle size of nano-titanium dioxide is 5-10 nm. If the particle size of nano-titanium dioxide is too large, it will lead to a decrease in specific surface area, reducing the adsorption capacity for formaldehyde and weakening the photocatalytic efficiency; it will also increase light scattering, decrease light absorption efficiency, and reduce the generation of photogenerated electron-hole pairs; the migration distance of photogenerated carriers will increase, the recombination probability will increase, and the effective carriers participating in the reaction will decrease, thus reducing photocatalytic activity. If the particle size is too small, the particle surface energy will be high, making it prone to agglomeration, losing the advantages of high dispersibility and large specific surface area, affecting photocatalytic efficiency and light propagation; it will have poor physicochemical stability, be easily affected by the environment, and be difficult to uniformly and firmly load; the preparation process will be complex, with high requirements for raw materials and equipment, increasing costs and hindering large-scale production.

[0046] In some embodiments, the specific surface area of ​​the nano-titanium dioxide particles is 100-220 m². 2 / g. The specific surface area of ​​the nano-titanium dioxide particles is limited to 100-220 m² / g. 2 This increases the surface atomic number, surface energy, and surface tension significantly. Simultaneously, this nano-titanium dioxide exhibits extremely high catalytic activity. Under visible or ultraviolet light, it can completely decompose harmful organic compounds such as formaldehyde and toluene, pollutants, odors, bacteria, and microorganisms into harmless CO2 and H2O. Testing showed that, under simulated indoor lighting conditions, its decomposition efficiency for common harmful organic compounds is more than 30% higher than that of ordinary photocatalyst-based nano-titanium dioxide.

[0047] In some embodiments, the thickness of the photocatalytic reaction layer is 50-200 nm. This thickness ensures both uniform dispersion of the nano-titanium dioxide particles and maximizes their specific surface area, while avoiding an increase in the recombination rate of photogenerated carriers due to excessive thickness. If the photocatalytic reaction layer exceeds 200 nm, the nano-titanium dioxide particles may aggregate, leading to a reduction in effective catalytic active sites and an increased probability of recombination of photogenerated electron-hole pairs during migration, thus reducing the efficiency of free radical generation. Furthermore, an excessively thick photocatalytic reaction layer may affect light transmittance, weakening its absorption capacity for visible light. If the photocatalytic reaction layer is less than 50 nm, a complete and dense layer may not be formed on the glass surface, resulting in some areas not being effectively covered, preventing formaldehyde molecules from fully contacting the catalyst and reducing formaldehyde removal efficiency. Simultaneously, an excessively thin coating is susceptible to physical wear or chemical corrosion, shortening its service life.

[0048] Furthermore, a highly transparent protective layer is applied to the surface of the photocatalytic reaction layer. This layer is made of a special organic-inorganic composite polymer material through processes such as the sol-gel method. It not only effectively protects the underlying photocatalytic reaction layer from physical wear and chemical corrosion by the external environment, extending the lifespan of the photocatalytic formaldehyde removal glass, but also further improves the overall strength and toughness of the glass. Simultaneously, this protective and reinforcing layer has excellent light transmittance, ensuring that it does not affect the absorption and utilization of light by the photocatalytic reaction layer, thus guaranteeing the normal functioning of the photocatalytic formaldehyde removal process.

[0049] In some embodiments, the protective layer comprises the following raw materials in parts by weight:

[0050] 8-15 parts of organosilane coupling agent;

[0051] 35-50 parts of acrylate monomers;

[0052] 35-55 parts of nano-silica.

[0053] The organosilane coupling agent, with its amphiphilic groups, can simultaneously bind to both the photocatalytic reaction layer and the protective layer, significantly enhancing the adhesion between them and preventing the protective layer from peeling off. The acrylate monomers, after curing, form a film with excellent flexibility and abrasion resistance, resisting damage to the photocatalytic layer from daily friction and impacts. Nano-silica, as a reinforcing phase, improves the hardness and weather resistance of the protective layer, extending its service life. The synergistic effect of these three components gives the protective layer high adhesion, abrasion resistance, and weather resistance, effectively protecting the photocatalytic reaction layer from external environmental erosion and maintaining long-term stable formaldehyde removal performance.

[0054] In some embodiments, the thickness of the protective layer is 5-20 μm. A thickness of 5-20 μm allows the protective layer to form a complete and continuous protective film, effectively isolating it from external erosion and fully protecting the photocatalytic reaction layer. If the thickness is less than 5 μm, pinholes or incomplete coverage may exist, resulting in insufficient protection. This thickness range does not significantly affect light transmittance, ensuring that visible and ultraviolet light can penetrate the protective layer to reach the photocatalytic reaction layer, guaranteeing the normal progress of the photocatalytic reaction. If the thickness is too large, it may block light and reduce catalytic efficiency. Simultaneously, a thickness of 5-20 μm balances the flexibility and mechanical strength of the protective layer, avoiding increased brittleness due to excessive thickness or insufficient strength due to excessive thinness, thus extending the service life of the protective layer.

[0055] In some embodiments, the glass substrate is float glass, and the raw materials for the float glass include a mixture of cerium oxide and zinc oxide at a mass percentage of 0.5 wt%-2 wt%. The glass substrate uses high-quality float glass, with optimized raw material formulation. Adding appropriate amounts of cerium oxide, zinc oxide, and other substances with ultraviolet absorption or reflection functions allows these substances to absorb or reflect some ultraviolet rays, reducing damage to indoor items. Furthermore, they synergize with the photocatalytic reaction layer to enhance the decomposition of harmful gases. In addition, by adjusting the chemical composition of the glass substrate, its optical properties are optimized, increasing visible light transmittance to ensure sufficient indoor lighting while maintaining good thermal insulation performance, reducing heat exchange between indoors and outdoors, and decreasing energy consumption of air conditioning, heating, and other equipment.

[0056] Before loading nano-titanium dioxide onto a glass surface to form a photocatalytic reaction layer, the glass surface needs to be pretreated. The purpose is to remove stains, grease, dust, and other impurities from the glass surface, improve the cleanliness and activity of the glass surface, enhance the adhesion between the nano-titanium dioxide and the glass surface, and ensure the uniformity and firmness of the loading.

[0057] The second aspect of this application provides a method for preparing the above-mentioned photocatalytic formaldehyde removal glass, comprising the following steps:

[0058] S01. Provide a glass substrate,

[0059] S02. A sol containing uniformly dispersed doped modified nano-titanium dioxide is provided. A glass substrate is immersed in the sol, and a photocatalytic reaction layer is prepared on at least one surface of the glass substrate by dip coating, drying and calcination.

[0060] S03. Provide the raw material for the protective layer, uniformly coat the raw material for the protective layer onto the surface of the photocatalytic reaction layer away from the glass substrate, and then prepare the protective layer by ultraviolet light curing treatment to obtain photocatalytic formaldehyde removal glass.

[0061] In the preparation method provided in the second aspect of this application, during the process of immersing the glass substrate in the modified nano-titanium dioxide sol, the photocatalytic layer can be uniformly and densely covered on the glass surface, effectively ensuring the consistency of product performance. The photocatalytic reaction layer is constructed using the dip-coating method. Based on the dip-coating technology, the thickness of the photocatalytic layer can be precisely controlled by precisely controlling the dip-coating speed of the glass substrate. Subsequent drying and calcination treatments can not only remove residual organic impurities in the sol, but also promote the crystal transformation of nano-titanium dioxide to form a highly active anatase phase. At the same time, high-temperature treatment can significantly enhance the bonding force between the photocatalytic layer and the glass substrate, avoiding coating peeling during use. Furthermore, the protective layer is prepared by ultraviolet light curing. This process has a fast curing speed and high production efficiency, and can complete the cross-linking and curing of the protective layer raw materials in a short time to form a stable three-dimensional network structure. The overall preparation process is simple to operate and highly controllable, without relying on complex and precision equipment. It has good adaptability to industrial mass production. The prepared photocatalytic formaldehyde removal glass has tight bonding between each functional layer, and the product performance is stable and reliable. It not only has high photocatalytic efficiency but also a long service life, which can fully meet the diverse needs of practical application scenarios.

[0062] In step S01, a glass substrate is provided.

[0063] In step S02, a sol of modified nano-titanium dioxide with uniformly dispersed doped elements is provided. A glass substrate is immersed in the sol, and a dip-coating method is used. After drying, the substrate is calcined to prepare a photocatalytic reaction layer on at least one surface of the glass substrate.

[0064] In step S03, the raw material for the protective layer is provided, and the raw material for the protective layer is uniformly coated on the surface of the photocatalytic reaction layer away from the glass substrate. Then, the protective layer is prepared by ultraviolet light curing treatment to obtain photocatalytic formaldehyde removal glass.

[0065] In step S01, a glass substrate is provided.

[0066] In some embodiments, during the float glass production process, the raw material formula is precisely controlled, with additives such as cerium oxide and zinc oxide added to the glass raw materials at a mass ratio of 0.5%-2%. During the glass melting stage, a high-temperature melting process is employed, with the melting temperature controlled at 1500-1600℃, and thorough stirring is carried out to ensure that the additives are uniformly dispersed in the molten glass. During the forming process, parameters such as drawing speed and temperature are strictly controlled to ensure the flatness and quality of the glass. Through the optimized glass matrix, in synergy with the photocatalytic reaction layer and the transparent protective and reinforcing layer, the various performance requirements of photocatalytic formaldehyde-removing glass are achieved.

[0067] In step S02, a sol of modified nano-titanium dioxide with uniformly dispersed doped elements is provided. A glass substrate is immersed in the sol, and a dip-coating method is used. After drying, the substrate is calcined to prepare a photocatalytic reaction layer on at least one surface of the glass substrate.

[0068] In some specific embodiments, the method for preparing the photocatalytic reaction layer includes:

[0069] High-quality nano-titanium dioxide raw materials with a particle size of 5-10 nanometers were selected and loaded using the sol-gel method. Titanium alkoxide and other precursors were dissolved in an organic solvent, and appropriate amounts of water and catalyst were added. A stable sol was formed through hydrolysis and condensation reactions. A surface-modified dispersant was added to the sol to ensure uniform dispersion of the nano-titanium dioxide. The glass substrate was immersed in the sol, and a dip-coating method was used, controlling the dip-coating speed and sol concentration to ensure uniform coating of the sol onto the glass surface. The coated glass was then placed in an oven to dry, removing the organic solvent and moisture, forming a preliminary nano-titanium dioxide coating. Finally, the glass was placed in a muffle furnace and calcined to allow the nano-titanium dioxide to crystallize and firmly adhere to the glass surface, forming a photocatalytic reaction layer with high catalytic activity.

[0070] In some embodiments, a titanium alkoxide (such as tetrabutyl titanate) is used as a precursor, and the ratio of the precursor to an organic solvent (such as anhydrous ethanol) is 1:5 to 1:8 (volume ratio). This ratio ensures that the precursor is fully dissolved and that the sol has a suitable viscosity during subsequent coating processes.

[0071] In some embodiments, the amount of water added is generally 2-4 times the amount of the precursor substance, and the amount of catalyst (such as glacial acetic acid) is 0.1-0.3 times the amount of the precursor substance. Water participates in the hydrolysis reaction, and its amount affects the degree of hydrolysis and the stability of the sol; the catalyst is used to regulate the reaction rate. An appropriate amount of catalyst can make the hydrolysis and polycondensation reactions proceed smoothly and avoid the reaction being too fast, which would lead to poor sol quality.

[0072] In some embodiments, during the hydrolysis and condensation polymerization reactions that form a stable sol, the alkoxy groups in the titanium alkoxide molecules are gradually replaced by hydroxyl groups, undergoing hydrolysis to generate intermediate products, ultimately forming titanium hydroxide. Because titanium hydroxide is unstable, it will further undergo condensation polymerization. Condensation polymerization occurs in two forms: one is the dehydration linkage between hydroxyl groups of different titanium hydroxide molecules; the other is the de-alcoholization linkage between titanium alkoxide molecules and titanium hydroxide molecules through the reaction of alkoxy groups with hydroxyl groups. As the reaction proceeds, the molecular chains grow and crosslink, forming a stable sol with a specific degree of polymerization and network structure.

[0073] In some embodiments, the specific steps of surface modification of the dispersant include: modifying the nano-titanium dioxide dispersant with a silane coupling agent. γ-methacryloyloxypropyltrimethoxysilane is dissolved in a mixed solvent of ethanol and water (volume ratio 3:1) to prepare a 0.5%-2% mass fraction solution. Nano-titanium dioxide is then added, and the mixture is stirred at 60-80°C for 2-4 hours. The alkoxy group of the silane coupling agent hydrolyzes to a silanol group, which undergoes dehydration condensation with the hydroxyl groups on the surface of the nano-titanium dioxide, grafting the coupling agent onto the particle surface. The organic functional group at the other end makes the particle surface oleophilic, improving its dispersibility in the sol and its bonding force with the glass matrix.

[0074] In some implementations, the lifting speed is generally controlled at 1-5 cm / min. If the lifting speed is too slow, the sol will accumulate on the glass surface, resulting in an excessively thick and uneven coating; if the lifting speed is too fast, the sol may not be able to adhere fully, resulting in insufficient coating thickness or flow marks.

[0075] In some embodiments, the mass percentage concentration of the sol is 5%-15%. This concentration range ensures that there is sufficient nano-titanium dioxide in the sol to form an effective photocatalytic reaction layer, while also ensuring that the sol has good flowability and coatability. If the sol concentration is too low, the resulting coating will be thin and lack sufficient photocatalytic active sites; if the concentration is too high, the sol viscosity will be too high, and problems such as agglomeration and cracking may easily occur during coating.

[0076] In some embodiments, the drying temperature is 120-150°C and the time is 1-2 hours. This can gently remove the solvent from the wet film, avoiding rapid solvent evaporation and bubble formation or cracking due to excessively high temperature or short time, or incomplete drying due to excessively low temperature or long time, which would affect subsequent calcination.

[0077] In some embodiments, the calcination temperature is 450-550°C and the time is 2-3 hours. These conditions can promote the transformation of nano-titanium dioxide from amorphous to highly active anatase phase, while removing residual organic matter and enhancing the mechanical strength and adhesion of the photocatalytic layer. If the temperature is too low or the time is too short, the crystallization will be insufficient and the activity will be inadequate; if the temperature is too high, it may lead to the transformation of the crystal form into the low-activity rutile phase. This range represents the optimal balance between crystal form and activity.

[0078] In step S03, the raw material for the protective layer is provided, and the raw material for the protective layer is uniformly coated on the surface of the photocatalytic reaction layer away from the glass substrate. Then, the protective layer is prepared by ultraviolet light curing treatment to obtain photocatalytic formaldehyde removal glass.

[0079] In some embodiments, organosilane coupling agents, acrylate monomers, nano-silica, and other raw materials are mixed in a certain proportion, and initiators and solvents are added and stirred evenly to form a mixed solution. The mixed solution is then uniformly coated onto the surface of the photocatalytic reaction layer by spin coating or spray coating. The coated glass is then placed in an ultraviolet curing device, and under ultraviolet light of a specific wavelength (365nm), the monomers in the mixed solution undergo a polymerization reaction to form an organic-inorganic composite polymer protective and reinforcing layer with a three-dimensional network structure. The ultraviolet light irradiation time and intensity are controlled to ensure complete curing and stable performance of the protective and reinforcing layer.

[0080] In some embodiments, the ultraviolet light wavelength for ultraviolet curing is 365 nm. This wavelength matches the absorption wavelength of the photoinitiator in the protective layer material (such as acrylate monomers), enabling efficient initiation of the polymerization reaction, allowing the protective layer to fully cure and ensuring its mechanical properties and stability.

[0081] The third aspect of this application provides the application of the above-described photocatalytic formaldehyde-removing glass in building doors, windows, or curtain walls.

[0082] The application of the photocatalytic formaldehyde-removing glass provided in the third aspect of this application has advantages such as high photocatalytic efficiency and long service life. The photocatalytic formaldehyde-removing glass can continuously carry out photocatalytic reactions using natural light (visible light and ultraviolet light) without the need for additional energy, achieving "passive" formaldehyde removal, which is energy-saving and efficient. At the same time, it can degrade formaldehyde in indoor and outdoor air in real time, continuously improve indoor air quality, and reduce the harm of formaldehyde to human health. As a component of doors, windows or curtain walls, it can perform structural functions (lighting, windproofing, and heat insulation) while adding air purification functions, eliminating the need for additional air purification equipment, saving space and costs, and facilitating its widespread application.

[0083] The following description is based on specific embodiments.

[0084] Example 1

[0085] A photocatalytic formaldehyde-removing glass and its preparation method

[0086] Photocatalytic formaldehyde removal glass includes: a glass substrate, a photocatalytic reaction layer stacked on at least one surface of the glass substrate, and a protective layer stacked on the photocatalytic reaction layer away from the glass substrate; wherein the raw material of the photocatalytic reaction layer includes modified nano-titanium dioxide containing doped elements, wherein the doped elements include nitrogen, the nano-titanium dioxide has a particle size of 5 nm, and the specific surface area of ​​the nano-titanium dioxide particles is 120 m². 2 / g, the thickness of the photocatalytic reaction layer is 50nm, and the thickness of the protective layer is 5μm;

[0087] The protective layer comprises the following raw materials in parts by weight:

[0088] 10 parts of organosilane coupling agent;

[0089] 50 parts of acrylate monomers;

[0090] 40 parts of nano-silica.

[0091] Preparation methods include:

[0092] Provide glass substrate,

[0093] A sol containing uniformly dispersed doped modified nano-titanium dioxide is provided. The sol preparation includes: selecting high-quality nano-titanium dioxide raw material with a particle size of 5 nanometers; dissolving a titanium alkoxide precursor and urea in an organic solvent; adding appropriate amounts of water and a catalyst; and forming a stable sol through hydrolysis and condensation reactions. A surface-modified dispersant is added to the sol to ensure uniform dispersion of the nano-titanium dioxide, resulting in the addition of a nitrogen-containing organic compound such as urea.

[0094] The glass substrate was immersed in a sol and coated using a dip-coating method at a speed of 1 cm / min. After drying, it was calcined at a temperature of 120°C for 1 hour and at a temperature of 450°C for 2 hours to prepare a photocatalytic reaction layer on at least one surface of the glass substrate.

[0095] The raw materials for the protective layer are provided. After the raw materials for the protective layer are mixed evenly, they are uniformly coated on the surface of the photocatalytic reaction layer away from the glass substrate. Then, the protective layer is prepared by ultraviolet light (365nm) curing treatment, and photocatalytic formaldehyde removal glass is obtained.

[0096] Example 2

[0097] Compared with Example 1, the difference is that "the doping element includes nitrogen" is changed to "the doping element includes silver", and in the preparation method, "urea" is changed to "silver nitrate"; all other aspects are the same as in Example 1.

[0098] Example 3

[0099] Compared with Example 1, the difference is that "the particle size of nano titanium dioxide is 5nm" is changed to "the particle size of nano titanium dioxide is 10nm"; all other aspects are the same as Example 1.

[0100] Example 4

[0101] The difference compared to Example 1 is that: "The specific surface area of ​​the nano-titanium dioxide particles is 120m²". 2 " / g" should be changed to "The specific surface area of ​​the nano-titanium dioxide particles is 200m²". 2 / g”; everything else is the same as in Example 1.

[0102] Example 5

[0103] Compared with Example 1, the difference is that "the thickness of the photocatalytic reaction layer is 50nm" is changed to "the thickness of the photocatalytic reaction layer is 200nm"; all other aspects are the same as Example 1.

[0104] Comparative Example 1

[0105] Ordinary float glass.

[0106] Performance Testing and Result Analysis

[0107] Long-term use simulation tests were conducted on the photocatalytic formaldehyde-removing glass obtained in Example 1, and the formaldehyde removal efficiency was recorded after 1000 hours, 2000 hours, 3000 hours, 4000 hours, and 5000 hours of use. The data shows that after 1000 hours of use, the formaldehyde removal efficiency was 92% of the initial value; after 2000 hours, it decreased to 89% of the initial value; after 3000 hours, it remained at 86% of the initial value; after 4000 hours, it was 83% of the initial value; and after 5000 hours, it stabilized at 81% of the initial value, fully demonstrating its durability and stability.

[0108] In the thermal insulation performance test, the photocatalytic formaldehyde-removing glass obtained in Example 1 and the ordinary float glass obtained in Comparative Example 1 were placed in the same temperature difference environment (25℃ indoors, 35℃ outdoors), and the indoor surface temperature of the glass was measured every hour. Data showed that after one hour, the indoor temperature of the ordinary float glass rose to 28.5℃, while that of the photocatalytic formaldehyde-removing glass was only 27℃; after three hours, the indoor temperature of the ordinary float glass reached 29.8℃, while that of the photocatalytic formaldehyde-removing glass was 27.8℃, clearly demonstrating the superior thermal insulation performance of the glass. Regarding the impact resistance test, a falling ball impact test was conducted according to relevant standards. The ordinary float glass cracked when subjected to a 227g steel ball dropped freely from a height of 1 meter, while the photocatalytic formaldehyde-removing glass did not crack under the same conditions, only showing slight scratches, proving its significantly enhanced impact resistance.

[0109] In summary, the photocatalytic formaldehyde removal glass provided in this application embodiment has the following characteristics:

[0110] (1) High-efficiency formaldehyde removal performance: Breaking through the dependence of traditional photocatalysts on strong ultraviolet light, this photocatalytic formaldehyde-removing glass can achieve a formaldehyde removal rate of over 85% under common indoor lighting conditions. According to professional testing, under simulated indoor lighting and formaldehyde concentration conditions, after 24 hours of continuous light exposure, the formaldehyde concentration can be reduced from 0.3 mg / m³. 3 Reduced to 0.05 mg / m³ 3 The following levels are far below the national indoor formaldehyde safety limit (GB / T 18883-2022, which specifies 0.08 mg / m³). 3This provides reliable formaldehyde purification protection for indoor spaces.

[0111] (2) Long-term stable operation: The nano-titanium dioxide in the photocatalytic reaction layer is firmly supported, and the protective layer effectively blocks external interference, so that the photocatalytic formaldehyde removal glass maintains stable photocatalytic performance and is not easily degraded during long-term use. According to accelerated aging test verification, after 5000 hours of light exposure and various environmental factors in simulated actual use environment, its formaldehyde removal efficiency can still maintain more than 80% of the initial efficiency, which greatly reduces the frequency and cost of glass replacement.

[0112] (3) Multifunctional Synergy: While efficiently removing formaldehyde, the optimized design of the glass substrate gives it excellent light transmission, with a visible light transmittance of over 88%, ensuring a bright and transparent interior. Thermal insulation performance is also improved, effectively reducing heat transfer between indoors and outdoors. In winter, it reduces indoor heat loss, and in summer, it blocks outdoor heat from entering, reducing energy consumption for air conditioning and heating, thus achieving energy savings. Furthermore, the protective layer enhances the physical properties of the glass, giving it better impact and scratch resistance, improving its safety and durability.

[0113] (4) Environmentally friendly and pollution-free: The photocatalytic formaldehyde removal process only uses light energy and oxygen and moisture in the air to decompose formaldehyde into harmless carbon dioxide and water, without producing any secondary pollution. It poses no harm to the indoor environment and human health, and is in line with the green and environmentally friendly development concept.

[0114] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photocatalytic formaldehyde-removing glass, characterized in that, include: A glass substrate, a photocatalytic reaction layer stacked on at least one surface of the glass substrate, and a protective layer stacked on the photocatalytic reaction layer away from the glass substrate; wherein the raw material of the photocatalytic reaction layer includes modified nano-titanium dioxide containing doped elements, wherein the doped elements include any one of nitrogen and transition metal elements.

2. The photocatalytic formaldehyde removal glass according to claim 1, characterized in that, The transition metal element includes at least one of Ag, Cu, Fe, Zn, Ni, V, Pt, and Au.

3. The photocatalytic formaldehyde removal glass according to claim 1, characterized in that, The nano-titanium dioxide has a particle size of 5-10 nm; and / or, The specific surface area of ​​the nano-titanium dioxide particles is 100-220 m². 2 / g.

4. The photocatalytic formaldehyde removal glass according to claim 1, characterized in that, The thickness of the photocatalytic reaction layer is 50-200 nm.

5. The photocatalytic formaldehyde removal glass according to claim 1, characterized in that, The protective layer comprises the following raw materials in parts by weight: 8-15 parts of organosilane coupling agent; 35-50 parts of acrylate monomers; 35-55 parts of nano-silica.

6. The photocatalytic formaldehyde removal glass according to claim 1, characterized in that, The thickness of the protective layer is 5-20 μm.

7. The photocatalytic formaldehyde removal glass according to claim 1, characterized in that, The glass substrate is float glass, and the raw materials of the float glass include a mixture of cerium oxide and zinc oxide with a mass percentage of 0.5wt%-2wt%.

8. A method for preparing photocatalytic formaldehyde-removing glass as described in any one of claims 1-7, characterized in that, Includes the following steps: Provide glass substrate, A sol containing uniformly dispersed doped nano-titanium dioxide is provided. A glass substrate is immersed in the sol, and a photocatalytic reaction layer is prepared on at least one surface of the glass substrate by dip-coating, drying, and calcination. The raw material for the protective layer is provided, and the raw material for the protective layer is uniformly coated on the surface of the photocatalytic reaction layer away from the glass substrate. Then, the protective layer is prepared by ultraviolet light curing treatment to obtain photocatalytic formaldehyde removal glass.

9. The method for preparing photocatalytic formaldehyde-removing glass according to claim 8, characterized in that, In the aforementioned dip coating method, the dip coating speed is 1-5 cm / min; and / or, The drying temperature is 120-150℃, and the time is 1-2 hours; and / or, The calcination temperature is 450-550℃, and the time is 2-3 hours; and / or, The ultraviolet light wavelength for the ultraviolet curing treatment is 365nm.

10. The application of the photocatalytic formaldehyde-removing glass according to any one of claims 1-6 in the doors, windows or curtain walls of buildings.

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