Photothermal catalyst, preparation method and purification equipment

Abstract

This invention discloses a photothermal catalyst, its preparation method, and purification equipment, belonging to the field of catalyst technology. The photothermal catalyst of this invention comprises the following structural formula: aα-bβOx-TiO2. In the structural formula: α includes noble metals; β includes transition metals and / or alkali metals; a includes integers greater than or equal to 0, b includes integers of 0 or greater than or equal to 1, and x is greater than or equal to 0 and less than or equal to 3; when a is 0 or 1, b is an integer greater than or equal to 2; when a is an integer greater than or equal to 2, b is 0 or greater than or equal to 2; when b is 0, x is 0. The photothermal catalyst of this invention exhibits good catalytic degradation effects on pollutants under both light and heating conditions, and also possesses good thermal stability. When applied to purification equipment, it can efficiently degrade pollutants such as grease and VOCs in cooking fumes. Furthermore, due to its good thermal stability, it can maintain a long-lasting catalytic degradation effect.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a photothermal catalyst, its preparation method, and purification equipment. Background Technology

[0002] In recent years, with the increasing demands for quality of life, kitchen air quality has become a growing concern. The grease, fumes, and volatile organic compounds (VOCs) produced during cooking not only affect the comfort of the kitchen environment but may also adversely impact the health of family members. Therefore, developing a technology that efficiently removes these pollutants is of paramount importance. Summary of the Invention

[0003] The main objective of this invention is to provide a manganese-based catalyst, its preparation method, application, and purification equipment, thereby solving the technical problem of insufficient thermal stability of manganese-based catalysts.

[0004] To achieve the above objectives, the present invention provides a photothermal catalyst comprising the following structural formula aα-bβOx-TiO2, wherein:

[0005] The α includes precious metals;

[0006] The β includes transition metals and / or alkali metals;

[0007] The a includes integers greater than or equal to 0, the b includes integers of 0 or greater than or equal to 1, and the x is greater than or equal to 0 and less than or equal to 3;

[0008] When 'a' is 0 or 1, and 'b' is an integer greater than or equal to 2,

[0009] When 'a' is an integer greater than or equal to 2, and 'b' is 0 or an integer greater than or equal to 2,

[0010] When b is 0, x is 0.

[0011] In some embodiments of the present invention, the noble metals include Pt, Au, Pd, Rh and Ru; the transition metals include Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La and W; and the alkali metals include Li, Na, K, Rb, Cs and Fr.

[0012] In some embodiments of the present invention, a equals 0, b equals 2, and 2β includes any two metallic elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr.

[0013] In some embodiments of the present invention, 2β is Mn and Ce, and the photothermal catalyst has the structural formula CeMnOx-TiO2; or, 2β is Mn and Cu, and the photothermal catalyst has the structural formula MnCuOx-TiO2; or, 2β is Ce and Cu, and the photothermal catalyst has the structural formula CeCuOx-TiO2.

[0014] In some embodiments of the present invention, a equals 1, b equals 2, 1α includes any one of the noble metal elements selected from Pt, Au, Pd, Rh and Ru, and 2β includes any two of the metal elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs and Fr.

[0015] In some embodiments of the present invention, 1α is Pt, 2β is Ce and Mn, and the photothermal catalyst has the structural formula Pt-CeMnOx-TiO2; or, 1α is Au, 2β is Ce and Mn, and the photothermal catalyst has the structural formula Au-CeMnOx-TiO2.

[0016] In some embodiments of the present invention, a equals 2, b equals 0, and 2α includes any two noble metal elements selected from pt, Au, Pd, Rh, and Ru.

[0017] In some embodiments of the present invention, 2α is Pt and Pd, and the photothermal catalyst has the structural formula PtPd-TiO2; or, 2α is Pt and Au, and the photothermal catalyst has the structural formula PtAu-TiO2.

[0018] In some embodiments of the present invention, a equals 2, b equals 2, 2α includes any two noble metal elements selected from Pt, Au, Pd, Ba, Rh, and Ru, 2β includes any two noble metal elements selected from Pt, Au, Pd, Rh, and Ru, and 1β includes any two metal elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr.

[0019] In some embodiments of the present invention, 2α is Pt and Au, 2β is Ce and Mn, and the photothermal catalyst has the structural formula PtAu-CeMnOx-TiO2.

[0020] In some embodiments of the present invention, the photothermal catalyst comprises adsorbed oxygen and bound oxygen, and the mass percentage of adsorbed oxygen is 5% to 45%, calculated with the total mass of adsorbed oxygen and bound oxygen being 100%.

[0021] The electron density of the photothermal catalyst is (2×10⁻⁶). 19 ~6×10 19 )cm -3 .

[0022] And / or, the TiO2 mass percentage in the photothermal catalyst is below 90%;

[0023] And / or, the starting point of the photothermal catalyst under no-light conditions is 100°C;

[0024] And / or, the catalytic temperature starting point of the photothermal catalyst under light irradiation is 90°C;

[0025] And / or, the morphology of TiO2 in the photothermal catalyst includes at least one of the following: plate-like, tubular, and spherical.

[0026] And / or, the particle size of TiO2 in the photothermal catalyst is 10 nm to 10 μm.

[0027] In some embodiments of the present invention, the mass percentage of TiO2 in the photothermal catalyst is less than 90%, and the mass percentage of TiO2 in the photothermal catalyst is 20%.

[0028] The present invention also provides a method for preparing the photothermal catalyst as described above, including method one, method two or method three;

[0029] The first method includes the following steps:

[0030] A metal nitrate solution is obtained by dissolving nitrates corresponding to at least two metal elements, and nitric acid is added to the metal nitrate solution to prepare solution A1, wherein the metal elements include transition metals and / or alkali metals;

[0031] Solution B1 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol;

[0032] Solution B1 and solution A1 were mixed and stirred to obtain gel C1;

[0033] The photothermal catalyst was obtained by calcining the gel C1.

[0034] The second method includes the following steps:

[0035] Dissolve nitrates corresponding to at least two metal elements to obtain a metal nitrate solution, and add nitric acid to the metal nitrate solution to obtain solution A2, wherein the metal elements include transition metals and / or alkali metals;

[0036] Solution B2 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol;

[0037] At least one noble metal salt is added to solution B2, and solution A2 is added. The mixture is stirred to obtain gel C2.

[0038] The photothermal catalyst was obtained by calcining the gel C2.

[0039] Method 3 includes the following steps:

[0040] Solution A3 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol;

[0041] Nitric acid was poured into solution A3 and stirred, and then two or more noble metal salts were added and stirred to obtain gel B3.

[0042] The photothermal catalyst was obtained by calcining the gel B3.

[0043] In some embodiments of the present invention, in method one,

[0044] The calcination temperature is 600℃-800℃;

[0045] And / or, the concentration of the nitric acid is 68% to 99%.

[0046] In some embodiments of the present invention, in the second method,

[0047] The calcination temperature is 300℃-500℃;

[0048] And / or, the concentration of the nitric acid is 68% to 99%;

[0049] And / or, the noble metal salt includes chloroplatinic acid, ammonium tetrachloroaurate, palladium chloride, rhodium acetate, ruthenium acetate, or silver nitrate.

[0050] In some embodiments of the present invention, in method three,

[0051] The calcination temperature is 300℃-500℃;

[0052] And / or, the concentration of the nitric acid is 68% to 99%;

[0053] And / or, the noble metal salt includes chloroplatinic acid, ammonium tetrachloroaurate, palladium chloride, rhodium acetate, ruthenium acetate, or silver nitrate.

[0054] The present invention also provides a purification device, the purification device comprising a catalytic coating, the catalytic coating comprising the photothermal catalyst as described above.

[0055] The beneficial effects that this invention can achieve are:

[0056] The photothermal catalyst provided by this invention has the structural formula aα-bβOx-TiO2, which contains a thermocatalytic component aα-bβOx and a photocatalytic component TiO2, combining photocatalytic and thermocatalytic functions. It can effectively degrade oils, fumes and volatile organic compounds (VOCs) under both light and no light conditions.

[0057] The photocatalytic principle of the photothermal catalyst of this invention is based on the photocatalytic component TiO2. When TiO2 is exposed to light, it can absorb light energy to generate electron-hole pairs, thereby catalyzing the oxidation reaction in the air and decomposing organic matter into harmless substances. With the above-mentioned photocatalytic performance, the photothermal catalyst of this invention can use light energy to decompose pollutants in the air into harmless substances, achieving efficient removal of oil fumes and VOCs.

[0058] The thermocatalytic principle of the photothermal catalyst of this invention is based on the thermocatalytic component aα-bβOx, wherein the aα part contains noble metals and the bβOx part contains oxides of transition metals and / or alkali metals. Both have good redox properties and can chemically react with organic matter in grease, fumes, and VOCs at relatively low temperatures to degrade them into water and carbon dioxide, thereby further improving the purification efficiency and the performance stability of the catalyst.

[0059] Furthermore, in the photothermal catalyst of the present invention, the aα portion of the thermocatalytic component is a complex of two or more noble metal elements, or the bβOx portion is a metal oxide obtained by a complex of two or more transition metals and / or alkali metals, so that the catalyst forms a mixed valence state, which not only can obtain different catalytic performances, but also provides stable oxygen vacancies and enhances the thermal stability of the catalyst. In particular, the bβOx portion being a complex of two or more metals can also prevent the agglomeration of noble metals at high temperatures, further improving the photocatalytic performance and thermal stability of the catalyst.

[0060] The photothermal catalyst of this invention is applied to purification equipment, which is then used in the cooking field. The synergistic effect of the photocatalytic and thermal catalytic components in the catalyst demonstrates significant advantages in improving reaction rates, comprehensively degrading various pollutants, and enhancing catalyst stability and adaptability. It can efficiently and continuously purify grease, fumes, and VOCs in the air, solving the problems of low efficiency, poor adaptability, and short lifespan in existing technologies. It can efficiently remove multiple pollutants and adapt to changes in light and temperature, maintaining high purification capacity in different environments. It achieves comprehensive and efficient degradation of complex pollutants generated during cooking, improving kitchen air quality. Moreover, the catalytic conditions are mild, environmentally friendly, and energy-saving, providing an innovative solution for kitchen air purification with broad application prospects and social value. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0062] Figure 1 This is a SEM image of the photothermal catalyst in Example 1 of the present invention.

[0063] Figure 2 This is a transmission electron microscope image of the photothermal catalyst in Example 1 of the present invention with spherical aberration correction.

[0064] Figure 3 This is a comparison diagram of adsorbed oxygen and bound oxygen in the photothermal catalyst of Example 1 of the present invention.

[0065] Figure 4 This is the photothermal catalyst of Example 1 of the present invention.

[0066] Figure 5 This is a schematic diagram showing the degradation rate of the photothermal catalyst in Example 1 of the present invention. Detailed Implementation

[0067] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0068] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0069] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0070] This invention provides a photothermal catalyst comprising the following structural formula: aα-bβOx-TiO2, wherein: α includes a noble metal, β includes a transition metal and / or an alkali metal, a includes an integer greater than or equal to 0, b includes an integer of 0 or greater than or equal to 1, x is greater than or equal to 0 and less than or equal to 3, and x can be 0.1, 0.5, 1, 2, 2.5, 3, etc.

[0071] It is understandable that the aα part in the structural formula refers to precious metals, where 'a' refers to the type of 'α'. For example, when a equals 1, it is represented as 1α, which is a single precious metal. When a equals 2, it is represented as 2α, which is a combination of two different types of precious metals. When a equals 3, it is represented as 3α, which is a combination of three different types of precious metals.

[0072] It is understood that the bβOx part in the structural formula refers to the oxide of a transition metal and / or an alkali metal. In bβOx, b refers to the type of β. For example, when b equals 1, it is represented as 1β, where 1β is a transition metal or an alkali metal. When b equals 2, it is represented as 2β, where 2β is a combination of any two metals among the transition metal and / or alkali metals. When b equals 3, it is represented as 3β, where 3β is a combination of any three metals among the transition metal and / or alkali metals. When b equals 0, the photothermal catalyst does not contain bβOx and can be represented as aα-TiO2. In this embodiment, x in bβOx refers to the amount of O, where x is greater than or equal to 0 and less than or equal to 3. x can be 0.1, 0.5, 1, 2, 2.5, 3, etc. When b equals 0, the photothermal catalyst does not contain transition metals and / or alkali metals, and x is also 0.

[0073] In the photothermal catalyst of the present invention, the thermocatalytic component aα-bβOx in the structural formula contains noble metals, or transition metals and / or alkali metals. Noble metals, transition metals and alkali metals all have good redox properties and can provide active oxygen species under heating conditions and at lower temperature conditions. They can chemically react with organic matter in oils, fumes and VOCs and degrade them into water and carbon dioxide, thereby improving the purification efficiency and performance stability of the photothermal catalyst.

[0074] In the photothermal catalyst of the present invention, the photocatalytic component includes TiO2. With semiconductor properties, when TiO2 is exposed to light, it can absorb light energy and generate electrons (e-) that jump to the conduction band, forming electron-hole (h+) pairs. These photogenerated charge carriers can undergo redox reactions with pollutants such as grease, fumes, and organic matter in VOCs adsorbed on the catalyst surface, decomposing the pollutants into harmless substances. With the above-mentioned photocatalytic performance, the photothermal catalyst of the present invention can use light energy to decompose pollutants such as grease, fumes, and VOCs in the cooking environment into harmless substances, achieving efficient removal of pollutants.

[0075] The photothermal catalyst of the present invention contains both photocatalytic and thermal catalytic components. When light energy and heat energy act on the photothermal catalyst simultaneously, the surface of the photothermal catalyst simultaneously possesses photogenerated electron-hole pairs and thermally excited active sites. These active species work together to enhance the redox ability of the photothermal catalyst, which can significantly improve the degradation rate and efficiency of pollutants.

[0076] Furthermore, the photothermal catalyst of this invention can complementaryly degrade different pollutants, achieving the goal of comprehensively treating complex pollutants. For example, the photocatalytic component has a good degradation effect on low-molecular-weight organic compounds with photosensitive groups (such as alcohols and aldehydes), while the thermocatalytic component has a strong oxidizing ability on high-molecular-weight, recalcitrant organic compounds (such as fatty acids, esters, and polycyclic aromatic hydrocarbons) and some gaseous pollutants. The oils and fumes produced during cooking are complex in composition, and a single catalytic method is insufficient for comprehensive and efficient treatment. Applying the photothermal catalyst of this invention to the cooking field combines photocatalysis and thermocatalysis, utilizing their complementarity in degrading different pollutants to achieve comprehensive degradation of various complex pollutants and improve purification efficiency.

[0077] Furthermore, the photothermal catalyst of the present invention also has good thermal stability and catalytic durability. During the photocatalytic process, intermediate products may be formed on the surface of the catalyst, leading to catalyst deactivation. The introduction of thermocatalysis can further decompose these intermediate products and keep the catalyst surface clean. In addition, since the reaction conditions of the photocatalytic components and the thermocatalytic components are different, the catalyst can play a role under light or heating conditions, which can effectively ensure continuous and efficient pollutant degradation capabilities.

[0078] Under sufficient light conditions, the photocatalytic component of the photothermal catalyst of this invention plays the main catalytic role, making full use of light energy resources. Under weak light or no light conditions, such as at night or in darkness, the thermal catalytic component can ensure the activity of the catalyst, and can produce a good catalytic degradation effect on pollutants without relying on light. When the photothermal catalyst of this invention is applied to purification equipment, the purification equipment can operate stably in the kitchen environment, without being limited by changes in light and temperature, thus improving the reliability and practicality of the system.

[0079] In some embodiments, the noble metals include platinum (Pt), Au, Pd, Rh, and Ru. The oxides of these noble metals have good thermal catalytic properties and can catalytically degrade pollutants such as grease, fumes, and organic matter in VOCs into water and carbon dioxide.

[0080] In some embodiments, transition metals include Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, and W. Oxides of these transition metals have good thermocatalytic properties and can catalytically degrade pollutants such as grease, fumes, and organic matter in VOCs into water and carbon dioxide.

[0081] In some embodiments, alkali metals include Li, Na, K, Rb, Cs, and Fr. Oxides of these alkali metals have good thermal catalytic properties and can catalytically degrade pollutants such as grease, fumes, and organic matter in VOCs into water and carbon dioxide.

[0082] In the structural formula aα-bβOx-TiO2, when a is 0 or 1 and b is an integer greater than or equal to 2, or when a is an integer greater than or equal to 2 and b is an integer greater than or equal to 2, the aα part of the thermocatalytic component is a combination of two or more noble metal elements, or the bβOx part of the thermocatalytic component is a metal oxide obtained by a combination of two or more transition metals and / or alkali metals. This makes the photothermal catalyst form a mixed valence state, which not only can obtain different catalytic performances, but also provides stable oxygen vacancies, enhancing the thermal stability of the catalyst. Among them, the oxide part of the transition metal and / or alkali metal is a combination of two or more metals, which can also prevent the agglomeration of noble metals at high temperatures, further improving the photocatalytic performance and thermal stability of the catalyst.

[0083] In some embodiments, in the structural formula aα-bβOx-TiO2, a equals 0, b equals 2, and 2β includes any two metal elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr. Selecting two metal elements from transition metals and / or alkali metals for combination as a thermocatalytic component provides stable oxygen vacancies, enhances the thermal stability of the photothermal catalyst, and also expands the threshold of the photothermal catalyst's catalytic performance, for example, achieving a wider catalytic temperature range.

[0084] For example, in the structural formula aα-bβOx-TiO2, a equals 0, b equals 2, and 2β represents Mn and Ce. The structural formula of the photothermal catalyst is CeMnOx-TiO2. In this embodiment, the combination of Ce and Mn has the effect of providing oxygen vacancies and enhancing redox capacity.

[0085] For example, a equals 0, b equals 2, 2β represents Mn and Cu, and the structural formula of the photothermal catalyst is MnCuOx-TiO2. In this embodiment, the combination of Mn and Cu promotes electron transfer and enhances catalytic activity.

[0086] For example, a equals 0, b equals 2, 2β represents Fe and Co, and the structural formula of the photothermal catalyst is FeMnO. x -TiO2. In this embodiment, the combination of Fe and Mn enhances oxygen activation and improves the dispersibility of noble metals (such as Pt, Au, etc.).

[0087] For example, a equals 0, b equals 2, 2β represents Ce and Cu, and the structural formula of the photothermal catalyst is CeCuO. x -TiO2. In this embodiment, the combination of Fe and Mn enhances oxygen activation and improves the dispersibility of noble metals (such as Pt, Au, etc.).

[0088] In some embodiments, in the structural formula aα-bβOx-TiO2, 'a' equals 0, 'b' can be an integer greater than 2, and 'bβ' includes any 'b' metallic elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr. Selecting three or more metallic elements from transition metals and / or alkali metals for a composite composition as a thermocatalytic component provides stable oxygen vacancies, enhances the thermal stability of the photothermal catalyst, and also expands the threshold of the photothermal catalyst's catalytic performance, for example, achieving a wider catalytic temperature range.

[0089] In some embodiments, in the structural formula aα-bβOx-TiO2, a equals 1, b equals 2, 1α includes any one noble metal element selected from Pt, Au, Pd, Rh, and Ru, and 2β includes any two metal elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr. In this embodiment, the combination of noble metals, transition metals, and / or alkali metals can further improve the thermocatalytic performance of the photothermal catalyst. Furthermore, this embodiment selects two metal elements from transition metals and / or alkali metals for combination, providing stable oxygen vacancies, which can alleviate the aggregation of noble metals at high temperatures and enhance the thermal stability of the photothermal catalyst. The combination of different metals can also broaden the threshold of the photothermal catalyst's catalytic performance.

[0090] In some embodiments, in the structural formula aα-bβOx-TiO2, a equals 1, b equals 2, 1α is Pt, 2β is Ce and Mn, and the structural formula of the photothermal catalyst is Pt-CeMnOx-TiO2.

[0091] In some embodiments, in the structural formula aα-bβOx-TiO2, a equals 1, b equals 2, 1α is Au, 2β is Ce and Mn, and the structural formula of the photothermal catalyst is Au-CeMnOx-TiO2.

[0092] In some embodiments, in the structural formula aα-bβOx-TiO2, 'a' equals 1, 'b' is an integer greater than 2, 1α includes any one noble metal element selected from Pt, Au, Pd, Rh, and Ru, and 'bβ' includes any 'b' metal elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr. In this embodiment, the combination of noble metals, transition metals, and / or alkali metals can further improve the thermocatalytic performance of the photothermal catalyst. Furthermore, this embodiment selects two metal elements from transition metals and / or alkali metals for combination, providing stable oxygen vacancies, which can alleviate the aggregation of noble metals at high temperatures and enhance the thermal stability of the photothermal catalyst. The combination of different metals can also broaden the threshold of the photothermal catalyst's catalytic performance.

[0093] In some embodiments, in the structural formula aα-bβOx-TiO2, a equals 2, b equals 0, and 2α includes any two noble metal elements selected from pt, Au, Pd, Rh, and Ru.

[0094] For example, a equals 2, b equals 0, 2α represents Pt and Au, and the structural formula of the photothermal catalyst is PtAu-TiO2. The combination of Pt and Au can enhance the low-temperature activity of the catalyst.

[0095] For example, a equals 2, b equals 0, 2α represents Pt and Pd, and the structural formula of the photothermal catalyst is PtPd-TiO2. The combination of Pt and Pd enhances the ability to resist sulfur poisoning.

[0096] For example, a equals 2, b equals 0, 2α represents Pt and Rh, and the structural formula of the photothermal catalyst is PtRh-TiO2. The combination of Pt and Rh enhances the activation effect of CH bonds.

[0097] In some embodiments, in the structural formula aα-bβOx-TiO2, a equals 2, b equals 2, 2α includes any two noble metal elements selected from Pt, Au, Pd, Ba, Rh, and Ru, and 2β includes any two metal elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr.

[0098] For example, α represents Pt and Au, 2β represents Ce and Mn, and the structural formula of the photothermal catalyst is PtAu-CeMnOx-TiO2.

[0099] In some embodiments, in the structural formula aα-bβOx-TiO2, a equals 2, b is an integer greater than or equal to 3, 2α includes any two noble metal elements selected from Pt, Au, Pd, Ba, Rh, and Ru, and bβ includes any b metal elements selected from calcium Ca, Mg, aluminum Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, rubidium Rb, Cs, and Fr.

[0100] In some embodiments, a in the structural formula aα-bβOx-TiO2 can also be an integer greater than or equal to 3, for example, a can be 3, 4, 5, 6, etc. aα includes any a noble metal element among Pt, Au, Pd, Ba, Rh and Ru, while b can be an integer greater than or equal to 2, and bβ includes any b metal elements among Pt, Au, Pd, Ba, Rh and Ru.

[0101] The photothermal catalyst of the present invention comprises adsorbed oxygen and bound oxygen, and the mass percentage of adsorbed oxygen is 5% to 45%, calculated with the total mass of adsorbed oxygen and bound oxygen as 100%.

[0102] In some embodiments, the electron density of the photothermal catalyst is (2 × 10⁻⁶). 19 ~6×10 19 )cm -3 .

[0103] In some embodiments, the starting temperature of the photothermal catalyst under no-light conditions is 100°C.

[0104] In some embodiments, the starting temperature of the photothermal catalyst under illumination is 90°C.

[0105] In some embodiments, the morphology of TiO2 in the photothermal catalyst includes at least one of sheet-like, tubular, and spherical shapes;

[0106] In some embodiments, the particle size of TiO2 in the photothermal catalyst is 10 nm to 10 μm.

[0107] In some embodiments, the mass percentage of TiO2 in the photothermal catalyst is below 90%.

[0108] In some embodiments, the TiO2 content in the photothermal catalyst is 20% by mass.

[0109] The present invention also provides methods for preparing the above-mentioned photothermal catalyst, including method one, method two and method three.

[0110] Method 1 includes the following steps:

[0111] A metal nitrate solution is obtained by dissolving nitrates corresponding to at least two metal elements, and then adding nitric acid to the metal nitrate solution to prepare solution A1. The metal elements include transition metals and / or alkali metals.

[0112] Solution B1 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol;

[0113] Solution B1 and solution A1 were mixed and stirred to obtain gel C1;

[0114] The photothermal catalyst is obtained by calcining the gel C1.

[0115] The photothermal catalyst prepared by method one can be represented by the structural formula aα-bβOx-TiO2, where a equals 0, b is an integer greater than or equal to 2, β includes transition metals and / or alkali metals, and x is greater than 0.

[0116] In some embodiments, the transition metals include Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, and W; the alkali metals include Li, Na, K, Rb, Cs, and Fr.

[0117] For example, the nitrates corresponding to the metal elements include calcium nitrate, magnesium nitrate, aluminum nitrate, zinc nitrate, copper nitrate, iron nitrate, cerium nitrate, cobalt nitrate, titanium nitrate, zirconium nitrate, nickel nitrate, vanadium nitrate, manganese nitrate, lanthanum nitrate, tungsten nitrate, lithium nitrate, sodium nitrate, potassium nitrate, rubidium nitrate, cesium nitrate, and francium nitrate.

[0118] In some embodiments, the concentration of nitric acid added to the metal nitrate solution is 68% to 99%.

[0119] In some embodiments, the ratio of tetrabutyl titanate to anhydrous ethanol and ethylene glycol is 1:1 to 3:1.

[0120] In some embodiments, the calcination temperature is 600℃-800℃, for example, any value in the range of 600℃-800℃, such as 600℃, 700℃, 800℃, etc.

[0121] In Method 1, the amount of titanium dioxide doping can be controlled by adjusting the amount of added tetrabutyl titanate.

[0122] Method 2 includes the following steps:

[0123] Dissolve the nitrates corresponding to at least two metal elements to obtain a metal nitrate solution, and add nitric acid to the metal nitrate solution to obtain solution A2. The metal elements include transition metals and / or alkali metals.

[0124] Solution B2 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol;

[0125] At least one noble metal salt is added to solution B2, and solution A2 is added. The mixture is stirred to obtain gel C2.

[0126] The photothermal catalyst was obtained by calcining gel C2.

[0127] The photothermal catalyst prepared by method 2 can be represented by the structural formula aα-bβOx-TiO2, where α includes noble metals, β includes transition metals and / or alkali metals, a includes integers greater than or equal to 1, b includes integers greater than or equal to 2, and x is greater than 0.

[0128] The photothermal catalyst prepared by method 2 contains at least two metal elements in its thermocatalytic component, or at least two noble metals, or at least two metal elements in combination with at least two noble metals.

[0129] In some embodiments, the noble metal salt includes chloroplatinic acid, ammonium tetrachloroaurate, palladium chloride, rhodium acetate, ruthenium acetate, and silver nitrate.

[0130] In some embodiments, the concentration of nitric acid in Method 2 is 68% to 99%.

[0131] In some embodiments, the calcination temperature in Method 2 is 300℃-500℃, which can be any value in the range of 300℃-500℃, such as 300℃, 400℃, or 500℃.

[0132] In Method 2, the content of precious metals in the photothermal catalyst can be controlled by adjusting the amount of precious metal salts used.

[0133] Method 3 includes the following steps:

[0134] Solution A3 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol;

[0135] Nitric acid was poured into solution A3 and stirred, and then two or more noble metal salts were added and stirred to obtain gel B3.

[0136] The photothermal catalyst was obtained by calcining the gel B3.

[0137] In some embodiments, the concentration of nitric acid in method three is 68% to 99%.

[0138] In some embodiments, the calcination temperature in Method 3 is 300℃-500℃, which can be any value in the range of 300℃-500℃, such as 300℃, 400℃, or 500℃.

[0139] In some embodiments, the noble metal salt includes chloroplatinic acid, ammonium tetrachloroaurate, palladium chloride, rhodium acetate, ruthenium acetate, and silver nitrate.

[0140] The present invention also provides a purification device, which includes a catalytic coating comprising the above-mentioned photothermal catalyst.

[0141] The photothermal catalyst of this invention is applied to purification equipment. The synergistic effect of the photocatalytic and thermal catalytic components in the catalyst shows significant advantages in improving reaction rate, comprehensively degrading different pollutants, and enhancing catalyst stability and adaptability. It can efficiently and continuously purify grease, fumes, and VOCs in the air, solving the problems of low efficiency, poor adaptability, and short lifespan in existing technologies. It can efficiently remove multiple pollutants and adapt to changes in light and temperature, maintaining high purification capacity in different environments. It achieves comprehensive and efficient degradation of complex pollutants generated during cooking, improving kitchen air quality. Moreover, the catalytic conditions are mild, environmentally friendly, and energy-saving, providing an innovative solution for kitchen air purification with broad application prospects and social value.

[0142] The purification equipment of this invention can be applied to the cooking field. The photothermal catalyst can not only efficiently remove pollutants such as grease, fumes and volatile VOCs generated during cooking, but also adapt to the working temperature changes of different kitchen environments and can continuously and effectively purify the air, ensuring that the kitchen air is always fresh. Compared with traditional purification technologies, the photothermal catalyst of this invention has many advantages, including high efficiency in decontamination, long service life and stability, as well as environmental protection and energy saving, which can bring a cleaner and healthier home environment to society.

[0143] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0144] Example 1

[0145] Example 1: Preparation of a photothermal catalyst using Method 1:

[0146] S1. Dissolve cerium nitrate and manganese nitrate to obtain a metal nitrate solution, and add 98% nitric acid to the metal nitrate solution to prepare solution A1;

[0147] S2. Add tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol to obtain solution B1;

[0148] S3. Mix and stir solutions B1 and A1 to obtain gel C1;

[0149] S3 and gel C1 were calcined at 400℃ to obtain the photothermal catalyst CeMnO. x -TiO2.

[0150] Example 1 prepared four groups of photothermal catalysts CeMnO x The difference lies in the mass percentage of TiO2 in the photothermal catalyst, which is controlled to be 10%, 20%, 60%, and 80%, respectively.

[0151] Example 2

[0152] Example 2: Preparation of photothermal catalyst using method two:

[0153] S1. Dissolve cerium nitrate and manganese nitrate to obtain a metal nitrate solution, and add 98% nitric acid to the metal nitrate solution to prepare solution A2;

[0154] S2. Add tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol to obtain solution B2;

[0155] S3. Add the precious metal salt platinum nitrate to solution B2, and then add solution A2. Stir to obtain gel C2.

[0156] S4 and gel C2 were calcined at 400℃ to obtain the photothermal catalyst Pt-CeMnO. x -TiO2.

[0157] Example 3

[0158] Example 3: A photothermal catalyst was prepared according to the preparation method of Example 2, with a TiO2 doping amount of 20%. The difference was that in step S1, equimolar amounts of copper nitrate were used instead of cerium nitrate. The resulting photothermal catalyst was Pt-CuMnO. x -TiO2.

[0159] Example 4

[0160] Example 4 describes the preparation of a photothermal catalyst using the same method as in Example 1, with a TiO2 doping amount of 20%. The difference is that in Example 4, lanthanum nitrate was used instead of manganese nitrate in equimolar amounts, resulting in a CeLaO2 photothermal catalyst. x -TiO2.

[0161] Example 5

[0162] Example 5 describes the preparation of a photothermal catalyst using the same method as Example 1, with a TiO2 doping amount of 20%. The difference is that in Example 5, equimolar amounts of copper nitrate were used instead of cerium nitrate, resulting in a CuMnO photothermal catalyst. x -TiO2.

[0163] Example 6

[0164] Example 6 describes the preparation of a photothermal catalyst using the same method as Example 1, with a TiO2 doping amount of 20%. The difference is that in Example 6, equimolar amounts of zirconium nitrate and cobalt nitrate are used instead of manganese nitrate, wherein the molar masses of cobalt nitrate and zirconium nitrate are the same. The resulting photothermal catalyst is CeZrCoO. x -TiO2.

[0165] Example 7

[0166] Example 7 prepared a photothermal catalyst according to the method of Example 2, with a TiO2 doping amount of 20%. The difference is that in step S1 of Example 7, cerium nitrate was not added, and in step S3, in addition to adding platinum nitrate, palladium nitrate with an equimolar mass of platinum nitrate was also added. The photothermal catalyst prepared was PtPd-MnO2-TiO2.

[0167] Example 8

[0168] Example 8: A photothermal catalyst was prepared according to the method of Example 2, with a TiO2 doping amount of 20%. The difference is that in Example 7, cerium nitrate was not added in step S1, and in step S3, in addition to platinum nitrate, gold nitrate with an equimolar mass of platinum nitrate was added. The resulting photothermal catalyst was PtAu-MnO2-TiO2.

[0169] Example 9

[0170] Example 9 uses method 3 to prepare a photothermal catalyst, the steps of which are as follows:

[0171] S1. Add tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol to obtain solution A3;

[0172] S2. Nitric acid is poured into solution A3 and stirred. Platinum nitrate and gold nitrate are then added and stirred to obtain gel B3.

[0173] S3 and gel B3 were calcined at 400℃ to obtain the photothermal catalyst PtAu-TiO2.

[0174] Comparative Example 1

[0175] Comparative Example 1 prepared a catalyst according to the preparation method of Example 1, with a TiO2 doping amount of 20%. The difference is that in Comparative Example 1, copper nitrate was dissolved in step S1 to obtain a metal nitrate solution, and then the subsequent preparation steps were continued to obtain a CuO-TiO2 catalyst.

[0176] Comparative Example 2

[0177] Comparative Example 2 prepared a catalyst according to the preparation method of Example 1, with a TiO2 doping amount of 20%. The difference is that in Comparative Example 2, cerium nitrate was dissolved in step S1 to obtain a metal nitrate solution, and then the subsequent preparation steps were continued to obtain a CeO-TiO2 catalyst.

[0178] Comparative Example 3

[0179] Comparative Example 3 prepared a catalyst according to the preparation method of Example 1, with a TiO2 doping amount of 20%. The difference is that in Comparative Example 3, cerium nitrate was dissolved in step S1 to obtain a metal nitrate solution, and then the subsequent preparation steps were continued to obtain a catalyst of MnO-TiO2.

[0180] Comparative Example 4

[0181] Comparative Example 4 prepared a photothermal catalyst according to the method of Example 2, except that only manganese nitrate was added in step S1 of Comparative Example 4, and cerium nitrate was not added. The resulting photothermal catalyst was Pt-MnO. x -TiO2.

[0182] Performance testing

[0183] 1. Morphological observation

[0184] (1) The photothermal catalyst CeMnOx-TiO2 in Examples 1-2 was observed using an electron microscope. The results are shown in the figure. Figure 1 ,like Figure 1 As shown, CeMnOx is uniformly distributed on the spherical TiO2 surface.

[0185] (2) The photothermal catalysts CeMnOx-TiO2 in Examples 1-2 were observed using aberration-corrected transmission electron microscopy. The results are shown in […]. Figure 2 ,like Figure 2 As shown, lattice distortion leads to the formation of numerous defects in the CeMnOx-TiO2 catalyst, resulting in a significant increase in oxygen vacancies and active sites. These defects not only enhance the catalyst's redox capacity but also improve its adsorption and decomposition efficiency for oil fumes and VOCs. Furthermore, the presence of these defects further optimizes the CeMnOx-TiO2 catalyst's oxidation-reduction potential. 3+ / Ce 4+ and Mn 3+ / Mn 3+ / Mn 4+ The valence cycle is beneficial to improving the thermal stability and catalytic performance of the catalyst.

[0186] 2. Catalyst activity determination

[0187] The adsorbed oxygen and electron density on the surface of the four photothermal catalysts in Example 1 and the photothermal catalyst in Example 2 were measured, and the results are shown in Table 1. The results of the CeMnOx-TiO2 photothermal catalyst with 20% TiO2 doping in Examples 1-2 are shown in Table 1. Figure 3 and Figure 4 .

[0188] Table 1 Relationship between catalyst type and activity

[0189]

[0190] As shown in Table 1, the four photothermal catalysts in Example 1 and the catalyst in Example 2 all have adsorbed oxygen content ranging from 5% to 45%, and their electron densities are in the range of (2 × 10⁻⁶). 19 ~6×10 19 )cm -3 Between these, it has both good thermal catalytic performance and good photocatalytic performance. In addition, as can be seen from the four sets of experiments in Example 1, when the proportion of TiO2 is 20%, the adsorption oxygen and electron density of the photothermal catalyst reach equilibrium, which enables the photothermal catalyst to obtain both high thermal catalytic performance and better photocatalytic performance.

[0191] 3. Photocatalysis-thermal catalysis test

[0192] 1.0g of photothermal catalyst was loaded inside a quartz tube with a length of 40cm, a thickness of 2mm, and an inner diameter of 1.5cm. The photothermal catalyst section was inserted into a specific rectangular metal box with a length of 20cm, a width of 10cm, and a height of 10cm. A halogen tube with a power of 100W and a length of 20cm was installed on top of the metal box for irradiation and heating. Two experiments were conducted, with VOCs and a fume generator being used for 35,000h of irradiation respectively. -1 100 ppm toluene gas and 0.13 μg / m 3 The reaction time for the oil fumes was fixed at 6 hours, and the test temperature was 50℃~500℃.

[0193] The formulas for calculating the degradation rate of toluene and oils are as follows:

[0194]

[0195] The degradation rates calculated from test 3 above are shown in Table 2. The results for the CeMnOx-TiO2 photothermal catalyst with 20% TiO2 doping in Examples 1-2 are shown in Table 2. Figure 5 Table 2 shows the temperature range of 50℃ to 500℃ and the total reaction time of 6 hours using a programmed temperature rise method.

[0196] Table 2. Catalytic degradation rate of the photothermal catalyst under light and heating when TiO2 addition is 20%.

[0197]

[0198] As shown in Table 2, the photothermal catalysts used in Examples 1-2 to 8 require relatively low temperatures to degrade 50% of toluene and 50% of oils, ranging from 90°C to 181°C, and even as low as 95°C. In contrast, the temperatures required to degrade 100% of toluene and 100% of oils range from 112°C to 201°C, and even as low as 122°C.

[0199] 4. Thermal catalysis test:

[0200] The photothermal catalysts CeMnOx-TiO2 in Examples 1-2 and Pt-CuMnO in Example 3 were tested according to the method described in Test 3. x -TiO2 was tested, but the temperature was kept constant at 100℃ for 6 hours, and the test was divided into light-illuminated and light-free scenarios. In the light-free scenario, the hot catalyst section was placed in a regular tube furnace and heated under light-free conditions. The degradation rate of toluene was calculated according to the calculation method of Test 3 and compared with the degradation rate of Test 3. The results are shown in Table 3.

[0201] Table 3

[0202]

[0203] As shown in Table 3, the photothermal catalysts CeMnOx-TiO2 in Examples 1-2 and Pt-CuMnOx-TiO2 in Example 3 exhibit significantly higher degradation rates of toluene and oils under light and heat conditions compared to under dark and heat conditions.

[0204] 5. High-temperature stability test

[0205] The photothermal catalysts of Examples 1-2, 2, and 4 were coated onto the surface of a substrate to prepare corresponding catalytic coatings. The substrates coated with the catalytic coatings were placed in a reaction apparatus and maintained at 200°C for 400 hours. Toluene gas of the same concentration was introduced, and the degradation rate of toluene was calculated. The data are shown in Table 4.

[0206] Table 4. Results of high temperature stability test

[0207]

[0208] Under prolonged high temperatures, the nanoparticles of the noble metal Pt will agglomerate, resulting in decreased activity and a reduced degradation rate of toluene. However, Example 2 combines Cu and Mn metals, which anchor Pt nanoparticles through strong interactions, thereby improving catalyst stability and effectively mitigating the agglomeration of the noble metal Pt. This allows the catalyst to maintain a good degradation effect even under prolonged high-temperature conditions.

[0209] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A photo-thermal catalyst, characterized by, The photo-thermal catalyst comprises the following structural formula aα-bβO x -TiO2, in the structural formula: The α includes precious metals; The β includes transition metals and / or alkali metals; The a includes integers greater than or equal to 0, the b includes integers of 0 or greater than or equal to 1, and the x is greater than or equal to 0 and less than or equal to 3; When 'a' is 0 or 1, and 'b' is an integer greater than or equal to 2, When 'a' is an integer greater than or equal to 2, and 'b' is 0 or an integer greater than or equal to 2, When b is 0, x is 0.

2. The photo-thermal catalyst of claim 1, wherein, The noble metals include Pt, Au, Pd, Rh and Ru; the transition metals include Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La and W; and the alkali metals include Li, Na, K, Rb, Cs and Fr.

3. The photothermal catalyst according to claim 1 or 2, characterized in that, The a equals 0, the b equals 2, and 2β includes any two metallic elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr.

4. The photo-thermal catalyst of claim 3, wherein, The 2β is Mn and Ce, and the photothermal catalyst has the structural formula CeMnO. x -TiO2; or, the 2β is Mn and Cu, and the photothermal catalyst has the structural formula MnCuO. x -TiO2; or, the 2β is Ce and Cu, and the structural formula of the photothermal catalyst is CeCuOx-TiO2.

5. The photo-thermal catalyst according to claim 1 or 2, wherein a equals 1, b equals 2, 1α includes any one of the noble metal elements Pt, Au, Pd, Rh and Ru, and 2β includes any two of the metal elements Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs and Fr.

6. The photo-thermal catalyst of claim 5, wherein, The 1α is Pt, the 2β is Ce and Mn, and the structural formula of the photothermal catalyst is Pt-CeMnOx-TiO2, or the 1α is Au, the 2β is Ce and Mn, and the structural formula of the photothermal catalyst is Au-CeMnOx-TiO2.

7. The photothermal catalyst according to claim 1 or 2, characterized in that, The a equals 2, the b equals 0, and 2α includes any two noble metal elements selected from pt, Au, Pd, Rh, and Ru.

8. The photothermal catalyst according to claim 7, characterized in that, The 2α is Pt and Pd, and the photothermal catalyst has the structural formula PtPd-TiO2; or, the 2α is Pt and Au, and the photothermal catalyst has the structural formula PtAu-TiO2.

9. The photothermal catalyst according to claim 1 or 2, characterized in that, The a equals 2, the b equals 2, 2α includes any two noble metal elements selected from Pt, Au, Pd, Ba, Rh, and Ru, 2β includes any two noble metal elements selected from Pt, Au, Pd, Rh, and Ru, and 1β includes any two metal elements selected from Ca, Mg, Al, Zn, Cu, Fe, Ce, Co, Ti, Zr, Ni, V, Mn, La, W, Li, Na, K, Rb, Cs, and Fr.

10. The photothermal catalyst according to claim 9, characterized in that, The 2α is Pt and Au, the 2β is Ce and Mn, and the structural formula of the photothermal catalyst is PtAu-CeMnOx-TiO2.

11. The photothermal catalyst according to any one of claims 1 to 10, characterized in that, The photothermal catalyst comprises adsorbed oxygen and bound oxygen, and the mass percentage of adsorbed oxygen is 5% to 45%, calculated with the total mass of adsorbed oxygen and bound oxygen being 100%. The photo-thermal catalyst has an electron density of (2 x 10 19 ~ 6 x 10 19 ) cm -3 . And / or, the TiO2 mass percentage in the photothermal catalyst is below 90%; And / or, the starting point of the photothermal catalyst under no-light conditions is 100°C; And / or, the catalytic temperature starting point of the photothermal catalyst under light irradiation is 90°C; And / or, the morphology of TiO2 in the photothermal catalyst includes at least one of the following: plate-like, tubular, and spherical. And / or, the particle size of TiO2 in the photothermal catalyst is 10 nm to 10 μm.

12. The photothermal catalyst according to claim 11, characterized in that, The mass percentage of TiO2 in the photothermal catalyst is below 90%, and the mass percentage of TiO2 in the photothermal catalyst is 20%.

13. A method for preparing the photothermal catalyst according to any one of claims 1 to 12, characterized in that, This includes Method 1, Method 2, or Method 3; The first method includes the following steps: A metal nitrate solution is obtained by dissolving nitrates corresponding to at least two metal elements, and nitric acid is added to the metal nitrate solution to prepare solution A1, wherein the metal elements include transition metals and / or alkali metals; Solution B1 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol; Solution B1 and solution A1 were mixed and stirred to obtain gel C1; The photothermal catalyst was obtained by calcining the gel C1. The second method includes the following steps: Dissolve nitrates corresponding to at least two metal elements to obtain a metal nitrate solution, and add nitric acid to the metal nitrate solution to obtain solution A2, wherein the metal elements include transition metals and / or alkali metals; Solution B2 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol; At least one noble metal salt is added to solution B2, and solution A2 is added. The mixture is stirred to obtain gel C2. The photothermal catalyst was obtained by calcining the gel C2. Method 3 includes the following steps: Solution A3 is obtained by adding tetrabutyl titanate to a mixed solution of anhydrous ethanol and ethylene glycol; Nitric acid was poured into solution A3 and stirred, and then two or more noble metal salts were added and stirred to obtain gel B3. The photothermal catalyst was obtained by calcining the gel B3.

14. The method for preparing the photothermal catalyst according to claim 13, characterized in that, In the first method, The calcination temperature is 600℃-800℃; And / or, the concentration of the nitric acid is 68% to 99%.

15. The method for preparing the photothermal catalyst according to claim 14, characterized in that, In the second method, The calcination temperature is 300℃-500℃; And / or, the concentration of the nitric acid is 68% to 99%; And / or, the noble metal salt includes chloroplatinic acid, ammonium tetrachloroaurate, palladium chloride, rhodium acetate, ruthenium acetate, or silver nitrate.

16. The method for preparing the photothermal catalyst according to claim 15, characterized in that, In the third method, The calcination temperature is 300℃-500℃; And / or, the concentration of the nitric acid is 68% to 99%; And / or, the noble metal salt includes chloroplatinic acid, ammonium tetrachloroaurate, palladium chloride, rhodium acetate, ruthenium acetate, or silver nitrate.

17. A purification device, characterized in that, The purification device includes a catalytic coating, which includes the photothermal catalyst according to any one of claims 1 to 12.

Images