Preparation method of trititanium pentoxide coating material

Abstract

The invention relates to the technical field of coating material preparation, and particularly discloses a preparation method of a trititanium pentoxide coating material, which comprises the following steps: firstly, under the protection of nitrogen, mixing a titanium tetrachloride solution with absolute ethyl alcohol and ethylene glycol organic solvent, adding citric acid and ascorbic acid additives, and heating and stirring in a water bath; secondly, H2O2 is dropwise added under the ice-water bath condition, a Ti3O5 precursor solution is generated through a reaction, and sol is formed through aging; then, precursor powder is obtained through supercritical CO2 drying; and finally, calcining in H2-Ar mixed gas and carrying out vacuum annealing to obtain the Ti3O5 coating material. The material has a mesoporous structure, the specific surface area is greater than or equal to 50m < 2 > / g, the Ti < 3 + > proportion is greater than or equal to 90%, the visible light absorptivity is greater than or equal to 85%, and the material is suitable for photocatalytic degradation, a solar cell counter electrode and an antibacterial coating; the preparation method is controllable in process, high in product purity and excellent in performance.

Description

Technical Field

[0001] The present application relates to the technical field of coating material preparation, and more specifically, to a method for preparing titanium pentoxide coating material. Background Art

[0002] Titanium pentoxide (Ti3O5) is a high refractive index material with excellent properties for visible infrared spectrum, with a melting point of 1780℃. It is widely used in the field of optical coating to deposit TiO2 thin films. There are many coating materials for TiO2 thin films, from metallic titanium to titanium oxides, including TiO, TiO2, Ti2O3, Ti3O5 and T i4 O7 and others are used. Studies have shown that when Ti3O5 is used as a coating material, it has good recyclability and stability, and the film has an excellent refractive index.

[0003] CN113213915A discloses a method for preparing a low-temperature titania pentoxide crystal coating material. The method uses a cold isostatic pressing process to press a mixed raw material into a green body and place it in a crucible. The crucible is then placed in a furnace, which is evacuated and then heated. A segmented heating process is employed, with the reaction temperature and time of each segment controlled to produce low-temperature titania pentoxide crystal particles of a predetermined specification. CN101333003B discloses a method for preparing a titania pentoxide coating material using vacuum induction heating. The method includes vacuum induction heating to produce titania pentoxide brown flakes and vacuum induction heating to produce titania pentoxide crystals.

[0004] Although the above methods can produce Ti3O5 coating materials, the resulting Ti3O5 coating materials generally suffer from low purity, low density, and low visible light absorptivity, which seriously affect the performance of sputtered films and fail to meet the requirements of the high-end optical coating industry for evaporated coating materials. Based on the above statements, this application provides a method for preparing titanium pentoxide coating materials. Summary of the Invention

[0005] In order to solve the defects of existing titanium pentoxide coating materials such as uneven particle size distribution, insufficient material purity, low density and low visible light absorption rate, the present application provides a method for preparing titanium pentoxide coating materials.

[0006] In a first aspect, the present application provides a method for preparing a titanium pentoxide coating material, which adopts the following technical solution:

[0007] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0008] S1. preparing titanium tetrachloride solution, hydrogen peroxide solution, organic solvent and additives;

[0009] S2. Under nitrogen protection, the titanium tetrachloride solution is added to the organic solvent and stirred once to obtain a mixed solution A, and the additive is added to the mixed solution A, heated in a water bath, and stirred a second time to obtain a mixed solution B;

[0010] S3. In an ice-water bath and under nitrogen protection, add the hydrogen peroxide solution dropwise to the mixed solution B, and stir after the addition is complete to obtain a titanium pentoxide precursor solution;

[0011] S4, aging the titanium pentoxide precursor solution to form a stable sol;

[0012] S5, drying the aged sol with supercritical CO2 to obtain a titanium pentoxide precursor powder;

[0013] S6. calcining the titanium pentoxide precursor powder in a H2-Ar mixed gas at a high temperature, and then annealing in a vacuum to generate a titanium pentoxide coating material.

[0014] Preferably, in step S1, the volume ratio of the titanium tetrachloride solution to the hydrogen peroxide solution is 1:1.5-2.5; the organic solvent is composed of anhydrous ethanol and ethylene glycol in a volume ratio of 2-4:1; and the additive is composed of citric acid and ascorbic acid in a mass ratio of 1:1-2, and the amount added is 1-3% of the volume of the titanium tetrachloride solution.

[0015] Preferably, the concentration of the titanium tetrachloride solution in step S1 is 1.0 mol / L, and the mass fraction of the hydrogen peroxide solution is 30%.

[0016] Preferably, the volume ratio of the titanium tetrachloride solution to the organic solvent in step S2 is 1:4-6; the primary stirring parameters are: speed 300-500 r / min, time 10-20 min; the secondary stirring parameters are: speed 400-500 r / min, time 50-70 min; and the water bath temperature is 35-45°C.

[0017] Preferably, in step S3, the temperature of the ice water bath is 0-5° C., the dripping speed of the hydrogen peroxide solution is 1-3 mL / s, the stirring speed is 300-500 r / min, and the stirring time is 1.5-2.5 h.

[0018] Preferably, the aging temperature in step S4 is 40-60° C., and the aging time is 22-26 hours.

[0019] Preferably, the supercritical CO2 drying parameters in step S5 are: temperature 35-45°C, vacuum degree 8-12 MPa, and time 10-15 h.

[0020] Preferably, the specific operation steps of step S6 are as follows: first, heat to 850-950°C at a rate of 3-5°C / min, keep warm in H2-Ar mixed gas for 2-4h, wherein H2 accounts for 5-10% by volume, and then heat for 10 -4 -10 -2 Vacuum annealing at 650-750°C for 0.5-1.5h.

[0021] In a second aspect, the present application provides a titanium pentoxide coating material prepared by the above-mentioned method for preparing the titanium pentoxide coating material.

[0022] Preferably, the titanium pentoxide coating material has a mesoporous structure with a specific surface area of ​​≥50m 2 / g, XPS detection of Ti 3+ The proportion is ≥90%, and the light absorption rate in the visible light region of 400-800nm ​​is ≥85%.

[0023] In a third aspect, the present application provides the use of the above-mentioned titanium pentoxide coating material in photocatalytic degradation of organic pollutants, solar cell counter electrodes or antibacterial coatings.

[0024] In summary, this application has the following beneficial effects:

[0025] By precisely selecting and proportioning titanium tetrachloride solution, hydrogen peroxide solution, organic solvent, and additives, an ideal reaction system foundation is provided for subsequent reactions. Titanium tetrachloride, as a titanium source, and a reasonable volume ratio with hydrogen peroxide ensure the efficient redox reaction and avoid side reactions caused by excess or insufficient amounts. The organic solvent consists of anhydrous ethanol and ethylene glycol. This combination not only improves the stability of the solution but also promotes the uniform dispersion of the reactants. The synergistic effect of the additives citric acid and ascorbic acid can effectively regulate the reaction rate and the crystal morphology of the product, thus providing a guarantee for the preparation of a high-purity, high-performance titanium pentoxide precursor solution.

[0026] Under nitrogen protection, the titanium tetrachloride solution is added to the organic solvent and stirred once, ensuring thorough mixing of the titanium tetrachloride and the organic solvent, avoiding precipitation or unevenness caused by localized excessive concentration. The subsequent addition of additives and a second stirring further promotes the integration of the additives into the reaction system, making the reaction system more uniform and stable. This process not only improves reaction efficiency but also provides a uniform reaction medium for subsequent reactions, helping to form a high-quality titanium pentoxide precursor solution.

[0027] Low temperature and slow addition effectively control the reaction rate, avoiding local overheating and byproduct formation caused by vigorous reactions. Furthermore, nitrogen protection prevents atmospheric oxygen and moisture from interfering with the reaction, ensuring the purity of the reaction. The resulting titanium pentoxide precursor solution possesses a uniform chemical composition and a stable colloidal structure, laying the foundation for subsequent sol formation.

[0028] The aging process of the titanium pentoxide precursor solution causes the colloidal particles in the precursor solution to gradually aggregate and grow, forming a stable sol structure. Appropriate aging temperature and time not only improve the uniformity and stability of the sol, but also promote chemical bonding between the particles and reduce particle agglomeration, thereby providing an ideal precursor material for the subsequent drying and calcination processes. The aged sol exhibits improved coating properties and film-forming properties, facilitating the preparation of uniform, dense titanium pentoxide films.

[0029] Supercritical CO2 drying can rapidly remove the solvent from the sol while avoiding the formation of pores and cracks caused by rapid solvent evaporation, resulting in a dense and uniform titanium pentoxide precursor powder. Compared to traditional drying methods, supercritical CO2 drying significantly improves the density and purity of the powder and reduces the impurity content, thus providing high-quality precursor powder for subsequent calcination and annealing processes.

[0030] The titanium pentoxide precursor powder is heated and calcined in a H2-Ar mixed gas, and then vacuum annealed. This process converts the titanium pentoxide precursor powder into high-purity titanium pentoxide crystals through high-temperature calcination. 2 The presence of can effectively reduce possible high-valence impurities, improving the purity and crystallinity of the material. Vacuum annealing further optimizes the crystal structure, eliminates internal stress, and improves the stability and optical properties of the material. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the following examples. It should be understood that the specific examples described herein are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0032] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0033] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are commercially available products unless otherwise specified.

[0034] Example 1-3 provides a method for preparing a titanium pentoxide coating material.

[0035] Example 1

[0036] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0037] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:1.5; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 2:1; and add citric acid and ascorbic acid in a mass ratio of 1:1;

[0038] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 300 r / min for 10 min to obtain a mixed solution A. Subsequently, an additive accounting for 1% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 35°C water bath and stirred at 400 r / min for 50 min to obtain a mixed solution B.

[0039] S3. In a 0°C ice-water bath under nitrogen protection, hydrogen peroxide solution was added dropwise to the mixed solution B at a rate of 1 mL / s. After the addition was completed, the stirring speed was maintained at 300 r / min and the reaction was continued for 1.5 h to finally obtain a titanium pentoxide precursor solution;

[0040] S4, placing the precursor solution in a 40°C environment and aging it for 22 hours to form a stable sol system;

[0041] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 10 hours under the conditions of controlling the temperature at 35°C and the pressure at 8 MPa to obtain a titanium pentoxide precursor powder;

[0042] S6, firstly, the titanium pentoxide precursor powder was heated to 850℃ in H2-Ar mixed gas with H2 accounting for 5% at a rate of 3℃ / min and calcined for 2h, and then -4 The titanium pentoxide coating material was finally obtained by annealing at 650°C and 0.5h.

[0043] Example 2

[0044] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0045] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 3:1; and add citric acid and ascorbic acid in a mass ratio of 1:1.5;

[0046] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0047] S3. In a 3°C ice-water bath under nitrogen protection, add hydrogen peroxide solution to the mixed solution B at a rate of 2 mL / s. After the addition is completed, maintain a stirring speed of 400 r / min and continue the reaction for 2 h to finally obtain a titanium pentoxide precursor solution;

[0048] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0049] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0050] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0051] Example 3

[0052] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0053] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2.5; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 4:1; and add citric acid and ascorbic acid in a mass ratio of 1:2;

[0054] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent at a volume ratio of 1:6, and the mixture was stirred at 500 r / min for 20 min to obtain a mixed solution A. Subsequently, an additive accounting for 3% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 45°C water bath and stirred at 500 r / min for 70 min to obtain a mixed solution B.

[0055] S3. In a 5°C ice-water bath under nitrogen protection, hydrogen peroxide solution was added dropwise to the mixed solution B at a rate of 3 mL / s. After the addition was completed, the stirring speed was maintained at 500 r / min and the reaction was continued for 2.5 h to finally obtain a titanium pentoxide precursor solution;

[0056] S4, placing the precursor solution in a 60°C environment and aging it for 26 hours to form a stable sol system;

[0057] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 15 hours under the conditions of controlling the temperature at 45°C and the pressure at 12 MPa to obtain a titanium pentoxide precursor powder;

[0058] S6, firstly, the titanium pentoxide precursor powder was heated to 950℃ in H2-Ar mixed gas with H2 accounting for 10% at a rate of 5℃ / min and calcined for 4h, and then -2 The titanium pentoxide coating material was finally obtained by annealing at 750°C and 1.5h.

[0059] Comparative Example 1

[0060] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0061] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; use anhydrous ethanol as the organic solvent; and use citric acid and ascorbic acid as the additives in a mass ratio of 1:1.5;

[0062] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0063] S3. In a 3°C ice-water bath under nitrogen protection, add hydrogen peroxide solution to the mixed solution B at a rate of 2 mL / s. After the addition is completed, maintain a stirring speed of 400 r / min and continue the reaction for 2 h to finally obtain a titanium pentoxide precursor solution;

[0064] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0065] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0066] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0067] Comparative Example 2

[0068] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0069] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and glycerol in a volume ratio of 3:1; and add citric acid and ascorbic acid in a mass ratio of 1:1.5;

[0070] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0071] S3. In a 3°C ice-water bath under nitrogen protection, add hydrogen peroxide solution to the mixed solution B at a rate of 2 mL / s. After the addition is completed, maintain a stirring speed of 400 r / min and continue the reaction for 2 h to finally obtain a titanium pentoxide precursor solution;

[0072] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0073] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0074] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0075] Comparative Example 3

[0076] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0077] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 3:1;

[0078] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent at a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 min. The mixture was then placed in a 40°C water bath and stirred at 450 r / min for 60 min to obtain a mixed solution A.

[0079] S3. In a 3°C ice-water bath under nitrogen protection, hydrogen peroxide solution was added dropwise to the mixed solution A at a rate of 2 mL / s. After the addition was completed, the stirring speed was maintained at 400 r / min and the reaction was continued for 2 h to finally obtain a titanium pentoxide precursor solution;

[0080] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0081] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0082] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0083] Comparative Example 4

[0084] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0085] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 3:1; and use citric acid as an additive;

[0086] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0087] S3. In a 3°C ice-water bath under nitrogen protection, add hydrogen peroxide solution to the mixed solution B at a rate of 2 mL / s. After the addition is completed, maintain a stirring speed of 400 r / min and continue the reaction for 2 h to finally obtain a titanium pentoxide precursor solution;

[0088] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0089] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0090] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0091] Comparative Example 5

[0092] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0093] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 3:1; and use ascorbic acid as an additive;

[0094] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0095] S3. In a 3°C ice-water bath under nitrogen protection, add hydrogen peroxide solution to the mixed solution B at a rate of 2 mL / s. After the addition is completed, maintain a stirring speed of 400 r / min and continue the reaction for 2 h to finally obtain a titanium pentoxide precursor solution;

[0096] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0097] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0098] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0099] Comparative Example 6

[0100] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0101] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 3:1; and add citric acid and ascorbic acid in a mass ratio of 1:1.5;

[0102] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0103] S3. At room temperature and under nitrogen protection, hydrogen peroxide solution was added dropwise to the mixed solution B at a rate of 2 mL / s. After the addition was completed, the stirring speed was maintained at 400 r / min and the reaction was continued for 2 h to finally obtain a titanium pentoxide precursor solution;

[0104] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0105] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0106] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0107] Comparative Example 7

[0108] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0109] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 3:1; and add citric acid and ascorbic acid in a mass ratio of 1:1.5;

[0110] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0111] S3. In a 3°C ice-water bath under nitrogen protection, add hydrogen peroxide solution to the mixed solution B at a rate of 2 mL / s. After the addition is completed, maintain a stirring speed of 400 r / min and continue the reaction for 2 h to finally obtain a titanium pentoxide precursor solution;

[0112] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0113] S5. Drying the aged sol in an oven at 80° C. for 12 h to obtain a titanium pentoxide precursor powder;

[0114] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in H2-Ar mixed gas with H2 accounting for 7.5% at a rate of 4℃ / min and calcined for 3h, and then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0115] Comparative Example 8

[0116] A method for preparing a titanium pentoxide coating material comprises the following steps:

[0117] S1. Prepare 1.0 mol / L titanium tetrachloride solution and 30% hydrogen peroxide solution in a volume ratio of 1:2; prepare an organic solvent using anhydrous ethanol and ethylene glycol in a volume ratio of 3:1; and add citric acid and ascorbic acid in a mass ratio of 1:1.5;

[0118] S2. Under nitrogen protection, the titanium tetrachloride solution was added to the organic solvent in a volume ratio of 1:4, and the mixture was stirred at 400 r / min for 15 minutes to obtain a mixed solution A. Subsequently, an additive accounting for 2% of the volume of the titanium tetrachloride solution was added, and the mixture was placed in a 40°C water bath and stirred at 450 r / min for 60 minutes to obtain a mixed solution B.

[0119] S3. In a 3°C ice-water bath under nitrogen protection, add hydrogen peroxide solution to the mixed solution B at a rate of 2 mL / s. After the addition is completed, maintain a stirring speed of 400 r / min and continue the reaction for 2 h to finally obtain a titanium pentoxide precursor solution;

[0120] S4, placing the precursor solution in a 50°C environment and aging it for 24 hours to form a stable sol system;

[0121] S5. Treat the aged sol with supercritical CO2 drying technology, and dry it for 12 hours under the conditions of controlling the temperature at 40°C and the pressure at 10 MPa to obtain a titanium pentoxide precursor powder;

[0122] S6, firstly, the titanium pentoxide precursor powder was heated to 900℃ in air at a rate of 4℃ / min and calcined for 3h, then -3 The titanium pentoxide coating material was finally obtained by annealing at 700℃ for 1h.

[0123] Performance Testing

[0124] Specific surface area test (nitrogen adsorption-desorption method)

[0125] 0.1g of titanium pentoxide coating material samples prepared in Examples 1-3 and Comparative Examples 1-8 were taken and vacuum degassed at 120°C for 6h to remove impurities, and then placed in a liquid nitrogen environment (-196°C) for nitrogen adsorption-desorption test. The relative pressure (P / P2) range was set to 0.05-0.30, the adsorption data was recorded, and the specific surface area was calculated using the BET equation. The curve was fitted using the instrument software to ensure that R 2 >0.99, and the final output is the accurate specific surface area value. Each sample is tested three times and the average value is taken to ensure data reliability.

[0126] Ti 3+ Proportion test (X-ray photoelectron spectroscopy, XPS)

[0127] The titanium pentoxide coating material samples prepared in Examples 1-3 and Comparative Examples 1-8 were uniformly pressed into pellets and placed in an XPS instrument. Under vacuum conditions, monochromatic Al Kα rays (1486.6 eV) were used for scanning, focusing on the Ti 2p orbital, and the Ti 2p spectrum was subjected to peak fitting using Avantage software to identify the Ti 3+ (2p 3 / 2 peak at 457.2eV) and Ti 4+ (2p 3 / 2 The peak is located at 458.6eV). Calculate Ti 3+ The ratio of the peak area to the total titanium peak area is finally obtained. 3+ Each sample was tested three times and the average value was taken to ensure data reliability.

[0128] Visible light absorbance test (UV-Vis-NIR spectroscopy)

[0129] The titanium pentoxide coating material samples prepared in Examples 1-3 and Comparative Examples 1-8 were mixed with BaSO₄ in a ratio of 1:10 and pressed into tablets. The samples were scanned using a UV-Vis spectrophotometer over a wavelength range of 400-800 nm with a 1 nm step size. Transmission / reflection spectra of the samples were measured using BaSO₄ or a blank substrate as a reference baseline. The average light absorbance within the 400-800 nm range was calculated by integration. Each sample was tested three times and the average value was calculated to ensure data reliability.

[0130] The data of the above three tests are statistically analyzed and the results are shown in Table 1.

[0131] Table 1 Performance test of titanium pentoxide coating materials

[0132] sample <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Ti 3+ Proportion (%)]]> Visible light absorption rate (%) Example 1 52.2±1.2 90.7±1.5 86.4±0.5 Example 2 55.6±0.8 94.6±0.9 88.2±0.3 Example 3 52.8±0.9 91.5±1.2 87.1±0.6 Comparative Example 1 42.7±2.1 80.2±3.2 82.1±1.8 Comparative Example 2 45.9±1.5 83.6±2.1 85.5±1.6 Comparative Example 3 50.2±1.9 77.4±1.8 75.5±1.5 Comparative Example 4 50.9±1.4 79.5±1.7 80.1±0.9 Comparative Example 5 51.1±1.0 78.5±2.3 79.8±2.4 Comparative Example 6 49.5±1.3 87.4±2.2 79.2±1.3 Comparative Example 7 51.4±0.8 71.4±1.7 82.3±0.9 Comparative Example 8 47.9±0.7 70.1±3.8 83.2±0.6

[0133] According to the results of Table 1, it can be seen that compared with Comparative Examples 1-2, Examples 1-3 and ethylene glycol mixed organic solvents are more conducive to forming high specific surface area and high Ti than single ethanol or ethanol and glycerol mixed organic solvents. 3+ The reason is that the stabilizing dispersing effect of ethylene glycol will reduce particle agglomeration and promote the formation of uniform sol; compared with comparative examples 3-5, it can be seen that the addition of citric acid and ascorbic acid additives or the addition of one of the additives alone will lead to Ti 3+ The proportion and light absorption rate dropped significantly because the two additives synergistically regulated the reduction reaction and inhibited the high-priced titanium Ti 4+ Compared with Comparative Example 6, it can be seen that the addition of H2O2 at room temperature will cause local overheating and microcracks in the material, resulting in a decrease in light absorption rate; Compared with Comparative Example 7, it can be seen that the porosity is too high due to oven drying, Ti 3+ The percentage dropped sharply, proving the key role of supercritical CO2 drying in structural protection; compared with Example 8, it can be seen that calcination in air induces oxidation to generate Ti4O7 impurity phase, Ti 3+ The proportion is only 70.1%, and the performance is significantly deteriorated. In general, the preparation method of titanium pentoxide coating material in this application achieves the controllable preparation of high-purity, high-performance Ti3O5 coating material by optimizing solvent combination, additives, low-temperature reaction, supercritical CO2 drying and reductive calcination, and the performance is significantly better than traditional methods.

[0134] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing a titanium pentoxide coating material, characterized in that: The preparation method comprises the following steps: S1. preparing titanium tetrachloride solution, hydrogen peroxide solution, organic solvent and additives; S2. Under nitrogen protection, the titanium tetrachloride solution is added to the organic solvent and stirred once to obtain a mixed solution A, and the additive is added to the mixed solution A, heated in a water bath, and stirred a second time to obtain a mixed solution B; S3. In an ice-water bath and under nitrogen protection, add the hydrogen peroxide solution dropwise to the mixed solution B, and stir after the addition is complete to obtain a titanium pentoxide precursor solution; S4, aging the titanium pentoxide precursor solution to form a stable sol; S5, drying the aged sol with supercritical CO2 to obtain a titanium pentoxide precursor powder; S6. calcining the titanium pentoxide precursor powder in a H2-Ar mixed gas at a high temperature, and then annealing in a vacuum to generate a titanium pentoxide coating material.

2. The method for preparing a titanium pentoxide coating material according to claim 1, wherein: In step S1, the volume ratio of the titanium tetrachloride solution to the hydrogen peroxide solution is 1:1.5-2.5; the organic solvent is composed of anhydrous ethanol and ethylene glycol in a volume ratio of 2-4:1; and the additive is composed of citric acid and ascorbic acid in a mass ratio of 1:1-2, and the amount of the additive is 1-3% of the volume of the titanium tetrachloride solution.

3. The method for preparing a titanium pentoxide coating material according to claim 1, wherein: In step S2, the volume ratio of the titanium tetrachloride solution to the organic solvent is 1:4-6; the primary stirring parameters are: speed 300-500 r / min, time 10-20 min; the secondary stirring parameters are: speed 400-500 r / min, time 50-70 min; and the water bath temperature is 35-45°C.

4. The method for preparing a titanium pentoxide coating material according to claim 1, wherein: In step S3, the temperature of the ice-water bath is 0-5° C., the hydrogen peroxide solution is added at a rate of 1-3 mL / s, the stirring speed is 300-500 r / min, and the stirring time is 1.5-2.5 h.

5. The method for preparing a titanium pentoxide coating material according to claim 1, wherein: In step S4, the aging temperature is 40-60° C., and the aging time is 22-26 hours.

6. The method for preparing a titanium pentoxide coating material according to claim 1, wherein: The supercritical CO2 drying parameters in step S5 are: temperature 35-45°C, vacuum degree 8-12 MPa, and time 10-15 h.

7. The method for preparing a titanium pentoxide coating material according to claim 1, wherein: The specific operation steps of step S6 are as follows: first, heat to 850-950℃ at a rate of 3-5℃ / min, keep warm in H2-Ar mixed gas for 2-4h, wherein H2 accounts for 5-10% by volume, and then heat in 10 -4 -10 -2 Vacuum annealing at 650-750°C for 0.5-1.5h.

8. A titanium pentoxide coating material, characterized in that: The titanium pentoxide coating material is prepared by the preparation method of the titanium pentoxide coating material according to any one of claims 1 to 7.

9. The titanium pentoxide coating material according to claim 8, characterized in that: The titanium pentoxide coating material has a mesoporous structure and a specific surface area of ​​50 m 2 / g, XPS detection of Ti 3+ The proportion is ≥90%, and the light absorption rate in the visible light region of 400-800nm ​​is ≥85%.

10. Use of the titanium pentoxide coating material according to claim 8 or 9 in photocatalytic degradation of organic pollutants, solar cell counter electrodes or antibacterial coatings.