Titanium dioxide-based catalysts and their preparation methods

Abstract

This invention discloses a titanium dioxide-based catalyst and its preparation method. The catalyst of this invention comprises porous titanium dioxide and an active metal component supported on titanium dioxide, wherein the active metal component includes at least one of Pt, Cu, and Ag. (1) Tetrabutyl titanate is mixed uniformly in an organic solvent to obtain mixture 1; a surfactant and a pore-forming agent are mixed uniformly in water to obtain mixture 2; (2) Mix mixture 1 and mixture 2 are mixed, separated into solid and liquid, washed, acid-treated, dried, and calcined once to obtain porous titanium dioxide; (3) Porous titanium dioxide and a weak organic base are dispersed in water, a solution containing an active metal component precursor is added, the reaction is carried out, washed, dried, and calcined a second time to obtain the titanium dioxide-based catalyst. The catalyst prepared by this invention through a specific preparation process has good catalytic effect and can effectively reduce COD in wastewater when used in wastewater treatment.

Description

Technical Field

[0001] This invention relates to the technical field of catalysts, and more specifically, to titanium dioxide-based catalysts and their preparation methods. Background Technology

[0002] The core of photocatalysis technology is semiconductor materials. The energy bands of a semiconductor consist of the conduction band (CB), valence band (VB), and band gap. When a semiconductor is excited by light, electrons undergo transitions, generating reducing electrons in the CB and leaving an equal number of oxidizing holes in the VB. Some of the generated electron-hole pairs recombine and dissipate energy in the form of heat or light emission, while the rest undergo redox reactions with the target material adsorbed on the surface.

[0003] Metal oxides are the most well-known materials in photocatalysis, and the application of two-dimensional metal oxides is an effective way to achieve high-performance photocatalysts. Among them, TiO2 photocatalysts are the most widely used. Under light irradiation, electrons (e) in TiO2... - This excitation creates a hole (h) in the valence band. + ), and react with O2 / H2O on its surface to generate OH / O2. - The OH / O2 - TiO2 has extremely strong oxidizing properties, capable of oxidizing and decomposing various organic compounds, and the free radicals it releases have good reducing effects, capable of reducing metals. However, the catalytic effect of existing TiO2 photocatalysts still needs further improvement. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention proposes a titanium dioxide-based catalyst and its preparation method. Through a specific preparation process, this invention prepares a titanium dioxide-based catalyst supported on an active metal component. This catalyst exhibits good catalytic performance and, when used in wastewater treatment, can effectively reduce COD in wastewater.

[0005] One objective of this invention is to provide a titanium dioxide-based catalyst, which comprises porous titanium dioxide and an active metal component supported on titanium dioxide, wherein the active metal component comprises at least one of Pt, Cu, and Ag.

[0006] The mass ratio of the porous titanium dioxide to the active metal component is 100:0.2-1;

[0007] Preferably, the specific surface area of ​​the porous titanium dioxide is 260-310 g / m². 2 .

[0008] In the catalyst of the present invention, it has been found that when Pt, Cu or Ag, Cu in the catalyst are in a specific ratio, there is a good synergistic effect, which can further improve the catalytic effect of the catalyst. Preferably, the mass ratio of Cu to Pt is 1:4-5; or the mass ratio of Cu to Ag is 1:7-8.

[0009] A second objective of this invention is to provide a method for preparing a titanium dioxide-based catalyst, comprising the following steps:

[0010] (1) Tetrabutyl titanate was mixed evenly in an organic solvent to obtain mixture 1; surfactant and porogen were mixed evenly in water to obtain mixture 2;

[0011] (2) Under stirring conditions, mixture 1 is added dropwise to mixture 2, solid-liquid separation is performed, and the product is washed. The washed product is then immersed in acid solution for treatment, dried, and calcined once to obtain porous titanium dioxide.

[0012] (3) Disperse porous titanium dioxide and organic weak base evenly in water, then add a solution containing active metal component precursor, react, wash, dry, and calcine twice to obtain the titanium dioxide-based catalyst.

[0013] The method for preparing the titanium dioxide-based catalyst according to the present invention preferably includes the following steps:

[0014] In step (1), the organic solvent is selected from alcohol solvents, preferably from at least one of ethanol and isopropanol; and / or,

[0015] The surfactant is selected from at least one of sodium hexadecylbenzenesulfonate, sodium octadecylbenzenesulfonate, and sodium dodecylbenzenesulfonate; and / or,

[0016] The pore-forming agent is selected from at least one of hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride.

[0017] In the preparation method of the titanium dioxide-based catalyst of the present invention, preferably,

[0018] In step (1),

[0019] The mass-to-volume ratio of the tetrabutyl titanate to the organic solvent is 100g:250-400mL; and / or,

[0020] The mass ratio of tetrabutyl titanate to surfactant is 100:5-8; and / or,

[0021] The mass ratio of tetrabutyl titanate to porogen is 100:1-3.

[0022] In the preparation method of the titanium dioxide-based catalyst of the present invention, preferably,

[0023] In step (2),

[0024] The solid-liquid separation method is centrifugation; and / or,

[0025] Wash 1-3 times; wash with water; and / or,

[0026] The acid solution is selected from hydrochloric acid solution, preferably with a concentration of 0.1-0.5 mol / L; the acid treatment time is 5-10 minutes.

[0027] In the preparation method of the titanium dioxide-based catalyst of the present invention, preferably,

[0028] In step (2),

[0029] The drying temperature is 60-80℃;

[0030] The drying time is 1-3 hours;

[0031] During the first calcination, in a mixed atmosphere of argon and hydrogen, the temperature is gradually increased from 60-80 degrees Celsius to 250 degrees Celsius for 15-25 minutes; then increased to 350 degrees Celsius for 45-60 minutes; and finally increased to 450 degrees Celsius for 45-60 minutes. The preferred temperature gradient is 5-15 degrees Celsius per minute. The preferred volume ratio of argon to hydrogen in the mixed atmosphere is 10:1-3.

[0032] In the preparation method of the titanium dioxide-based catalyst of the present invention, preferably,

[0033] In step (3),

[0034] Organic weak bases are selected from ammonium carbonate; and / or,

[0035] The active metal component precursor is selected from at least one of copper nitrate, copper chloride, chloroplatinic acid, and silver nitrate.

[0036] In the preparation method of the titanium dioxide-based catalyst of the present invention, preferably,

[0037] In step (3),

[0038] The concentration of porous titanium dioxide in water is 20-25 g / L;

[0039] The mass ratio of porous titanium dioxide to the metal component in the active metal component precursor is 100:0.2-1;

[0040] The molar ratio of organic base to active metal component precursor is 1:1-1.2.

[0041] In the preparation method of the titanium dioxide-based catalyst of the present invention, preferably,

[0042] In step (3),

[0043] The reaction time is 30-60 minutes; and / or,

[0044] The drying temperature is 40-60℃; the drying time is 1-2 hours; and / or,

[0045] The secondary roasting temperature is 200-300 degrees Celsius, and the roasting time is 0.8-1.5 hours. The roasting atmosphere is a mixture of argon and hydrogen. Preferably, the volume ratio of argon to hydrogen during the secondary roasting is 100:5-10.

[0046] In the preparation of porous titanium dioxide, this invention also introduces an acid treatment and a calcination step under a special atmosphere, which can further optimize the surface defects / vacancies of titanium dioxide; it is beneficial to the subsequent loading of active metals and further improves the catalytic effect of the catalyst.

[0047] A third objective of this invention is to provide an application of the titanium dioxide-based catalyst described in one objective of this invention or the titanium dioxide-based catalyst prepared by the method described in any one of the second objectives of this invention in wastewater treatment.

[0048] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0049] Compared with the prior art, the present invention has at least the following advantages:

[0050] The catalyst of this invention has a large specific surface area, which is beneficial to improving the efficiency of wastewater treatment.

[0051] This invention prepares a titanium dioxide-based catalyst supported on an active metal component through a specific preparation process. This catalyst has good catalytic effect and can effectively reduce COD in wastewater when used in wastewater treatment. Detailed Implementation

[0052] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0053] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0054] Example 1

[0055] A method for preparing a titanium dioxide-based catalyst includes the following steps:

[0056] (1) Mix 100g of tetrabutyl titanate in 250mL of ethanol to obtain mixture 1; mix sodium hexadecylbenzenesulfonate (5g) and hexadecyltrimethylammonium bromide (2g) in (100mL) of water to obtain mixture 2;

[0057] (2) Under stirring conditions, add mixture 1 dropwise to mixture 2, centrifuge, wash twice with water, immerse the washed product in hydrochloric acid solution (0.3 mol / L) for 8 minutes, and dry at 70°C for 2 hours. Gradually increase the temperature from 70°C to 250°C for 20 minutes; continue to increase the temperature to 350°C for 50 minutes; continue to increase the temperature to 450°C for 55 minutes; the temperature gradient is 8°C / minute; the calcination atmosphere is a mixture of hydrogen and argon, and the volume ratio of argon to hydrogen in the mixture is 10:2. After one calcination, porous titanium dioxide is obtained.

[0058] (3) The porous titanium dioxide and ammonium carbonate prepared above are evenly dispersed in water, and the concentration of porous titanium dioxide in water is 23 g / L; then chloroplatinic acid solution is added, wherein the mass ratio of porous titanium dioxide to the metal component in chloroplatinic acid solution is 100:0.5; the molar ratio of ammonium carbonate to active metal component precursor is 1:1, the reaction is carried out at room temperature for 50 minutes, washed once with water, dried at 50°C for 2 hours, and calcined twice in a mixed atmosphere of argon and hydrogen (the volume ratio of argon and hydrogen is 100:7) at 200°C for 1 hour; the titanium dioxide-based catalyst is obtained.

[0059] The titanium dioxide-based catalyst prepared by the above method comprises porous titanium dioxide and Pt supported on titanium dioxide, wherein the mass ratio of porous titanium dioxide to Pt is 100:0.5; and the specific surface area of ​​the porous titanium dioxide is 280 g / m². 2 .

[0060] Example 2

[0061] A method for preparing a titanium dioxide-based catalyst includes the following steps:

[0062] (1) Mix 100g of tetrabutyl titanate in 300mL of isopropanol to obtain mixture 1; mix sodium octadecylbenzenesulfonate (7g) and hexadecyltrimethylammonium chloride (3g) in (100mL) of water to obtain mixture 2;

[0063] (2) Under stirring conditions, add mixture 1 dropwise to mixture 2, centrifuge, wash twice with water, immerse the washed product in hydrochloric acid solution (0.4 mol / L) for 10 minutes, and dry at 60°C for 3 hours. Gradually increase the temperature from 60°C to 250°C for 25 minutes; continue to increase the temperature to 350°C for 50 minutes; continue to increase the temperature to 450°C for 45 minutes; the temperature gradient is 10°C / minute; the calcination atmosphere is a mixture of hydrogen and argon, and the volume ratio of argon to hydrogen in the mixture is 10:1. After one calcination, porous titanium dioxide is obtained.

[0064] (3) The porous titanium dioxide and ammonium carbonate prepared above are evenly dispersed in water, and the concentration of porous titanium dioxide in water is 25 g / L; then a solution of silver nitrate is added, wherein the mass ratio of porous titanium dioxide to the metal component in silver nitrate is 100:0.7; the molar ratio of organic base to active metal component precursor is 1:1.1, the reaction is carried out at room temperature for 60 minutes, washed once with water, dried at 50°C for 2 hours, and calcined a second time in a mixed atmosphere of argon and hydrogen (the volume ratio of argon and hydrogen is 100:8) at 300°C for 1 hour; the titanium dioxide-based catalyst is obtained.

[0065] The titanium dioxide-based catalyst prepared by the above method comprises porous titanium dioxide and Ag supported on titanium dioxide, with a mass ratio of porous titanium dioxide to Ag of 100:0.7; the specific surface area of ​​the porous titanium dioxide is 300 g / m². 2 .

[0066] Example 3

[0067] A method for preparing a titanium dioxide-based catalyst includes the following steps:

[0068] (1) Mix 100g of tetrabutyl titanate in 250mL of ethanol (400mL) to obtain mixture 1; mix sodium hexadecylbenzenesulfonate (7g) and dodecyltrimethylammonium bromide (1g) in (100mL) of water to obtain mixture 2;

[0069] (2) Under stirring conditions, add mixture 1 dropwise to mixture 2, centrifuge, wash twice with water, immerse the washed product in hydrochloric acid solution (0.2 mol / L) for 5 minutes, and dry at 80°C for 1 hour. Gradually increase the temperature from 80°C to 250°C for 25 minutes; continue to increase the temperature to 350°C for 45 minutes; continue to increase the temperature to 450°C for 50 minutes; the temperature gradient is 15°C / minute; the calcination atmosphere is a mixture of hydrogen and argon, and the volume ratio of argon to hydrogen in the mixture is 10:3. After one calcination, porous titanium dioxide is obtained.

[0070] (3) The porous titanium dioxide and ammonium carbonate prepared above are evenly dispersed in water, and the concentration of porous titanium dioxide in water is 22 g / L; then a solution of chloroplatinic acid is added, wherein the mass ratio of porous titanium dioxide to the metal component in chloroplatinic acid is 100:1; the molar ratio of organic base to active metal component precursor is 1:1.1, the reaction is carried out at room temperature for 40 minutes, washed once with water, dried at 50°C for 2 hours, and calcined twice in a mixed atmosphere of argon and hydrogen (the volume ratio of argon and hydrogen is 100:10) at 250°C for 1.2 hours; the titanium dioxide-based catalyst is obtained.

[0071] The titanium dioxide-based catalyst prepared by the above method comprises porous titanium dioxide and Pt supported on titanium dioxide, wherein the mass ratio of the porous titanium dioxide to the active metal component is 100:1; and the specific surface area of ​​the porous titanium dioxide is 260 g / m². 2 .

[0072] Example 4

[0073] A method for preparing a titanium dioxide-based catalyst includes the following steps:

[0074] (1) Mix 100g of tetrabutyl titanate in 250mL of ethanol to obtain mixture 1; mix sodium hexadecylbenzenesulfonate (5g) and hexadecyltrimethylammonium bromide (2g) in (100mL) of water to obtain mixture 2;

[0075] (2) Under stirring conditions, add mixture 1 dropwise to mixture 2, centrifuge, wash twice with water, immerse the washed product in hydrochloric acid solution (0.3 mol / L) for 8 minutes, and dry at 70°C for 2 hours. Gradually increase the temperature from 70°C to 250°C for 20 minutes; continue to increase the temperature to 350°C for 50 minutes; continue to increase the temperature to 450°C for 55 minutes; the temperature gradient is 8°C / minute; the calcination atmosphere is a mixture of hydrogen and argon, and the volume ratio of argon to hydrogen in the mixture is 10:2. After one calcination, porous titanium dioxide is obtained.

[0076] (3) The porous titanium dioxide and ammonium carbonate prepared above are evenly dispersed in water, and the concentration of porous titanium dioxide in water is 23 g / L; then copper chloride solution is added, wherein the mass ratio of porous titanium dioxide to the metal component in copper chloride solution is 100:0.5; the molar ratio of ammonium carbonate to active metal component precursor is 1:1, the reaction is carried out at room temperature for 50 minutes, washed once with water, dried at 50°C for 2 hours, and calcined twice in a mixed atmosphere of argon and hydrogen (the volume ratio of argon and hydrogen is 100:7) at 200°C for 1 hour; the titanium dioxide-based catalyst is obtained.

[0077] The titanium dioxide-based catalyst prepared by the above method comprises porous titanium dioxide and copper supported on titanium dioxide, wherein the mass ratio of porous titanium dioxide to copper is 100:0.5.

[0078] Example 5

[0079] A method for preparing a titanium dioxide-based catalyst includes the following steps:

[0080] (1) Mix 100g of tetrabutyl titanate in 250mL of ethanol to obtain mixture 1; mix sodium hexadecylbenzenesulfonate (5g) and hexadecyltrimethylammonium bromide (2g) in (100mL) of water to obtain mixture 2;

[0081] (2) Under stirring conditions, add mixture 1 dropwise to mixture 2, centrifuge, wash twice with water, immerse the washed product in hydrochloric acid solution (0.3 mol / L) for 8 minutes, and dry at 70°C for 2 hours. Gradually increase the temperature from 70°C to 250°C for 20 minutes; continue to increase the temperature to 350°C for 50 minutes; continue to increase the temperature to 450°C for 55 minutes; the temperature gradient is 8°C / minute; the calcination atmosphere is a mixture of hydrogen and argon, and the volume ratio of argon to hydrogen in the mixture is 10:2. After one calcination, porous titanium dioxide is obtained.

[0082] (3) The porous titanium dioxide and ammonium carbonate prepared above are evenly dispersed in water, and the concentration of porous titanium dioxide in water is 23 g / L; then copper chloride and chloroplatinic acid solution (the mass ratio of the metal ions of the two is 1:4) are added, wherein the mass ratio of porous titanium dioxide to the metal components in copper chloride and chloroplatinic acid solution is 100:0.5; the molar ratio of ammonium carbonate to the active metal component precursor is 1:1. The reaction is carried out at room temperature for 50 minutes, washed once with water, dried at 50°C for 2 hours, and calcined twice in a mixed atmosphere of argon and hydrogen (the volume ratio of argon and hydrogen is 100:7) at 200°C for 1 hour to obtain the titanium dioxide-based catalyst.

[0083] The titanium dioxide-based catalyst prepared by the above method comprises porous titanium dioxide and Cu and Pt supported on titanium dioxide, wherein the mass ratio of the porous titanium dioxide to the total active metal is 100:0.5.

[0084] Example 6

[0085] A method for preparing a titanium dioxide-based catalyst includes the following steps:

[0086] (1) Mix 100g of tetrabutyl titanate in 300mL of isopropanol to obtain mixture 1; mix sodium octadecylbenzenesulfonate (7g) and hexadecyltrimethylammonium chloride (3g) in (100mL) of water to obtain mixture 2;

[0087] (2) Under stirring conditions, add mixture 1 dropwise to mixture 2, centrifuge, wash twice with water, immerse the washed product in hydrochloric acid solution (0.4 mol / L) for 10 minutes, and dry at 60°C for 3 hours. Gradually increase the temperature from 60°C to 250°C for 25 minutes; continue to increase the temperature to 350°C for 50 minutes; continue to increase the temperature to 450°C for 45 minutes; the temperature gradient is 10°C / minute; the calcination atmosphere is a mixture of hydrogen and argon, and the volume ratio of argon to hydrogen in the mixture is 10:1. After one calcination, porous titanium dioxide is obtained.

[0088] (3) The porous titanium dioxide and ammonium carbonate prepared above are evenly dispersed in water, and the concentration of porous titanium dioxide in water is 25 g / L; then a solution of copper nitrate is added, wherein the mass ratio of porous titanium dioxide to the metal component in silver nitrate is 100:0.7; the molar ratio of organic base to active metal component precursor is 1:1.1, the reaction is carried out at room temperature for 60 minutes, washed once with water, dried at 50°C for 2 hours, and calcined twice in a mixed atmosphere of argon and hydrogen (the volume ratio of argon and hydrogen is 100:8) at 300°C for 1 hour; the titanium dioxide-based catalyst is obtained.

[0089] The titanium dioxide-based catalyst prepared by the above method comprises porous titanium dioxide and copper supported on titanium dioxide, with a mass ratio of porous titanium dioxide to copper of 100:0.7.

[0090] Example 7

[0091] A method for preparing a titanium dioxide-based catalyst includes the following steps:

[0092] (1) Mix 100g of tetrabutyl titanate in 300mL of isopropanol to obtain mixture 1; mix sodium octadecylbenzenesulfonate (7g) and hexadecyltrimethylammonium chloride (3g) in (100mL) of water to obtain mixture 2;

[0093] (2) Under stirring conditions, add mixture 1 dropwise to mixture 2, centrifuge, wash twice with water, immerse the washed product in hydrochloric acid solution (0.4 mol / L) for 10 minutes, and dry at 60°C for 3 hours. Gradually increase the temperature from 60°C to 250°C for 25 minutes, continue to increase the temperature to 350°C for 50 minutes, and continue to increase the temperature to 450°C for 45 minutes. The temperature gradient is 10°C / minute. The calcination atmosphere is a mixture of hydrogen and argon, with a volume ratio of argon to hydrogen of 10:1. After one calcination, porous titanium dioxide is obtained.

[0094] (3) The porous titanium dioxide and ammonium carbonate prepared above are evenly dispersed in water, and the concentration of porous titanium dioxide in water is 25 g / L; then a solution of copper nitrate and silver nitrate is added, wherein the mass ratio of metal ions in copper nitrate and silver nitrate is 1:8, and the mass ratio of metal components in porous titanium dioxide and silver nitrate is 100:0.7; the molar ratio of organic base to active metal component precursor is 1:1.1, the reaction is carried out at room temperature for 60 minutes, washed once with water, dried at 50°C for 2 hours, and calcined a second time in a mixed atmosphere of argon and hydrogen (the volume ratio of argon and hydrogen is 100:8) at 300°C for 1 hour; the titanium dioxide-based catalyst is obtained.

[0095] The titanium dioxide-based catalyst prepared by the above method comprises porous titanium dioxide and copper and silver supported on titanium dioxide, with a mass ratio of porous titanium dioxide to total active metal of 100:0.7.

[0096] In this invention, the active metal components in the liquid after impregnation with the active metal components in the above embodiments were tested, and it was found that the content of the active metal components was very low. Therefore, in this invention, the active metal content in the catalyst is estimated based on the assumption that all the added active metal components are loaded on the support.

[0097] Comparative Example 1

[0098] It uses the same preparation method as Example 1, the only difference being that the washed product in this comparative example was not immersed in acid solution.

[0099] Comparative Example 2

[0100] It uses the same preparation method as Example 1, the only difference being that the first calcination in this comparative example is carried out under a pure argon atmosphere.

[0101] Comparative Example 3

[0102] It uses the same preparation method as Example 1, the only difference being that the first calcination in this comparative example is carried out in a pure hydrogen atmosphere.

[0103] Comparative Example 4

[0104] It uses the same preparation method as Example 1, the only difference being that in this comparative example, the first calcination is carried out in a mixed atmosphere of argon and hydrogen, with a volume ratio of argon to hydrogen of 10:5.

[0105] Comparative Example 5

[0106] It uses the same preparation method as Example 5, the only difference being that in this comparative example, copper chloride and chloroplatinic acid solutions (the mass ratio of the two metal ions is 1:1).

[0107] Comparative Example 6

[0108] It uses the same preparation method as Example 7, the only difference being that copper nitrate and silver nitrate (the mass ratio of their metal ions is 1:1) are used in this comparative example.

[0109] Comparative Example 7

[0110] It uses the same preparation method as Example 1, the only difference being that in this comparative example, during the first calcination, the temperature is directly raised to 450 degrees Celsius and heated for 125 minutes.

[0111] Comparative Example 8

[0112] It uses the same preparation method as Example 1, the only difference being that the porous titanium dioxide in this comparative example is ordinary titanium dioxide (purchased from Aladdin).

[0113] The catalysts prepared in the above examples and comparative examples were used for wastewater treatment. The catalyst activity was evaluated in a fixed-bed reactor. 200g of catalyst was loaded into a 400mL reactor containing an aerator, and 300mL of industrial wastewater with a COD of 1800mg / L was added. The mixture was reacted for 5 hours under ultraviolet light irradiation at room temperature, and the CODcr after the reaction was measured.

[0114] Table 1

[0115] sample CODcr (mg / L) Example 1 731 Example 2 928 Example 3 850 Example 4 1150 Example 5 689 Example 6 1164 Example 7 843 Comparative Example 1 861 Comparative Example 2 1035 Comparative Example 3 988 Comparative Example 4 949 Comparative Example 5 807 Comparative Example 6 902 Comparative Example 7 1206 Comparative Example 8 1202

[0116] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0117] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0118] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0119] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

Claims

1. Use of a titanium dioxide-based catalyst in sewage treatment, characterized in that: the titanium dioxide-based catalyst comprises porous titanium dioxide and an active metal component supported on the titanium dioxide, the active metal component comprising Cu and Ag; the mass ratio of Cu to Ag is 1:7-8; the mass ratio of the porous titanium dioxide to the active metal component is 100:0.7-1; a preparation method of the titanium dioxide-based catalyst comprises the following steps: (1) uniformly mixing tetrabutyl titanate in an organic solvent to obtain a mixed solution 1; uniformly mixing a surfactant and a porogen in water to obtain a mixed solution 2; (2) under stirring, dropping the mixed solution 1 into the mixed solution 2, performing solid-liquid separation, washing, immersing the washed product in an acid solution for treatment, drying, and performing primary calcination to obtain the porous titanium dioxide; the acid solution is selected from a hydrochloric acid solution; the concentration of the hydrochloric acid solution is 0.1-0.5 mol / L; the acid solution treatment time is 5-10 minutes; during the primary calcination, under a mixed gas atmosphere of argon and hydrogen, the temperature is gradually increased from 60-80 degrees Celsius, heated to 250 degrees Celsius for 15-25 minutes, then continuously heated to 350 degrees Celsius for 45-60 minutes, and then continuously heated to 450 degrees Celsius for 45-60 minutes; the temperature increasing gradient is 5-15 degrees Celsius per minute; in the mixed gas atmosphere, the volume ratio of argon to hydrogen is 10:2-3; (3) uniformly dispersing the porous titanium dioxide and an organic weak base in water, then adding a solution containing an active metal component precursor, reacting, washing, drying, and performing secondary calcination to obtain the titanium dioxide-based catalyst; the titanium dioxide-based catalyst is used for removing COD in sewage.

2. Use of the titanium dioxide-based catalyst in sewage treatment according to claim 1, characterized in that, in step (1), the organic solvent is selected from at least one of ethanol and isopropanol; and / or, the surfactant is selected from at least one of sodium hexadecyl benzene sulfonate, sodium octadecyl benzene sulfonate, and sodium dodecyl benzene sulfonate; and / or, the porogen is selected from at least one of cetyltrimethylammonium bromide and cetyltrimethylammonium chloride.

3. Use of the titanium dioxide-based catalyst according to claim 1 in the treatment of sewage, characterized in that, comprises the following steps: in step (1), the mass-to-volume ratio of the tetrabutyl titanate to the organic solvent is 100 g:250-400 mL; and / or, the mass ratio of the tetrabutyl titanate to the surfactant is 100:5-8; and / or, the mass ratio of the tetrabutyl titanate to the porogen is 100:1-3.

4. Use of the titanium dioxide-based catalyst in sewage treatment according to claim 1, characterized in that, in step (2), the solid-liquid separation mode is centrifugal separation; and / or, the washing frequency is 1-3 times; and the washing is performed with water.

5. Use of the titanium dioxide-based catalyst in sewage treatment according to claim 1, characterized in that, in step (2), the drying temperature is 60-80 degrees Celsius; and the drying treatment time is 1-3 hours.

6. Use of the titanium dioxide-based catalyst in sewage treatment according to claim 1, characterized in that, in step (3), the organic weak base is selected from ammonium carbonate; and / or, The active metal component precursor is selected from at least one of copper nitrate, copper chloride and silver nitrate.

7. Use of the titanium dioxide-based catalyst according to claim 1 in the treatment of sewage, characterized by the fact that, The method comprises the following steps: In step (3), The concentration of the porous titanium dioxide in water is 20-25 g / L; The mass ratio of the porous titanium dioxide to the metal component in the active metal component precursor is 100:0.2-1; The molar ratio of the organic weak base to the active metal component precursor is 1:1-1.

2.

8. The application of the titanium dioxide-based catalyst in sewage treatment according to claim 1, characterized in that, In step (3), The reaction time is 30-60 minutes; The drying temperature is 40-60°C; the drying time is 1-2 hours; The secondary calcination temperature is 200-300°C, the calcination time is 0.8-1.5 hours; and the calcination atmosphere is a mixed atmosphere of argon and hydrogen.

9. The application of the titanium dioxide-based catalyst in sewage treatment according to claim 8, characterized in that, In the secondary calcination, the volume ratio of argon to hydrogen is 100:5-10.