A photothermal-thermoelectric synergistic catalyst, its preparation method, and its application.

Abstract

This invention provides a photothermal-thermoelectric synergistic catalyst, its preparation method, and its applications. The photothermal-thermoelectric synergistic catalyst includes a substrate and a catalyst layer coated on the substrate; wherein the substrate is an n-type thermoelectric material; and the catalyst layer is titanium dioxide. The photothermal-thermoelectric synergistic catalyst of this invention can be used in solar-thermoelectric synergistic degradation systems for organic matter. The degradation process is an energy conversion process that simultaneously utilizes photothermal and thermoelectric effects, which can greatly improve energy conversion efficiency. In environmental purification, it can be used for the efficient degradation of organic pollutants, enabling effective treatment of wastewater and waste gas.

Description

Technical Field

[0001] This invention relates to catalyst technology, and in particular to a photothermal-thermoelectric synergistic catalyst, its preparation method, and its application. Background Technology

[0002] The photothermal effect refers to the electrical property of materials undergoing changes in temperature. Photothermal catalysts convert solar energy into heat energy through the photothermal effect, activating active sites under high-temperature conditions and promoting catalytic reactions. Thermoelectric effect, on the other hand, refers to the phenomenon where electrons (holes) in a heated object move from a high-temperature region to a low-temperature region along a temperature gradient, generating current or accumulating charge. Thermoelectric effects can be used to convert locally generated heat energy into electrical energy, improving energy efficiency. Solar energy is a widely available clean energy source in clean energy production, but its efficient utilization still faces a series of challenges. Currently, the energy efficiency of solar energy conversion remains low, and the catalytic reaction efficiency of photothermal catalysis is also low. Summary of the Invention

[0003] The purpose of this invention is to provide a photothermal-thermoelectric synergistic catalyst, its preparation method, and its application, in order to solve the problems of low energy utilization efficiency and low catalytic reaction efficiency of photothermal catalysis in the prior art.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] A photothermal-thermoelectric synergistic catalyst includes a substrate and a catalyst layer coated on the substrate; wherein the substrate is an n-type thermoelectric material; and the catalyst layer is titanium dioxide.

[0006] Preferably, the substrate is one or more of Bi2Te3, GeTe, ZnO, PbTe, and Ag2Se.

[0007] Preferably, the titanium dioxide is one of nano-sized TiO2 powder, TiO2 rods, TiO2 flowers, or TiO2 ribbons.

[0008] This invention also provides a method for preparing a photothermal-thermoelectric synergistic catalyst, comprising the following steps:

[0009] (1) Take a substrate and a TiO2 precursor solution, convert the TiO2 precursor solution into TiO2 seed crystals, and adhere them to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals.

[0010] (2) The substrate coated with TiO2 seed obtained in step (1) is subjected to hydrothermal crystallization reaction and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

[0011] Preferably, in step (1), the precursor solution of TiO2 is a tetrabutyl titanate solution.

[0012] Preferably, in step (1), the TiO2 precursor solution is a mixture of tetrabutyl titanate and solvent at a volume ratio of 0.9:(10-50); the solvent is one or more of isopropanol, anhydrous ethanol, ethylene glycol, and water.

[0013] Preferably, the TiO2 precursor solution further includes hydrochloric acid.

[0014] Preferably, in step (1), the TiO2 precursor solution is transformed into TiO2 seed crystals by immersing or coating the substrate with the TiO2 precursor solution and then calcining it, and the seed crystals adhere to the surface of the substrate.

[0015] Preferably, in step (1), the calcination temperature is 400-500℃ and the time is 1-5h.

[0016] Preferably, in step (2), the reaction solution of the hydrothermal crystallization reaction contains toluene, tetrabutyl titanate, and hydrofluoric acid; or, the reaction solution of the hydrothermal crystallization reaction contains sodium hydroxide and hydrogen peroxide.

[0017] Preferably, in step (2), after the hydrothermal crystallization reaction, the product is washed with water and ethanol and then dried.

[0018] Preferably, in step (2), the calcination temperature is 300-600℃ and the time is 1-5h.

[0019] The present invention also provides an application of the photothermal-thermoelectric synergistic catalyst described above or the photothermal-thermoelectric synergistic catalyst obtained by the preparation method described above in the field of catalytic organic matter degradation reaction.

[0020] Preferably, the organic compound is one or more of Rhodamine B, methyl orange, salicylic acid, and phenol.

[0021] The above-described solution of the present invention has at least the following beneficial effects:

[0022] (1) The photothermal-thermoelectric synergistic catalyst of the present invention includes a substrate and a catalyst layer coated on the substrate; wherein the substrate is an n-type thermoelectric material; and the catalyst layer is titanium dioxide. The photothermal-thermoelectric synergistic catalyst utilizes a combination of photothermal and thermoelectric effects to achieve synergistic catalytic degradation of organic matter. Under sunlight irradiation, the catalyst layer, being titanium dioxide, absorbs light energy, generating a localized heating phenomenon, thus achieving a photothermal effect. Simultaneously, the substrate converts the locally generated heat energy into electrical energy through a thermoelectric effect. In the above process, the active sites of the photothermal-thermoelectric synergistic catalyst are activated at high temperatures due to the photothermal effect, while simultaneously utilizing the thermoelectric effect to convert the locally generated heat energy into chemical energy to degrade organic matter, achieving high catalytic efficiency. The synergistic effect of photothermal and thermoelectric effects enables the catalyst to have higher catalytic efficiency and energy conversion efficiency in the photothermal-thermoelectric synergistic catalytic process, achieving efficient utilization of solar energy.

[0023] In clean energy production, the aforementioned photothermal-thermoelectric synergistic catalyst can be used in solar-thermoelectric synergistic degradation systems for organic matter. The degradation process is an energy conversion process that utilizes both photothermal and thermoelectric effects, which can greatly improve energy conversion efficiency. In environmental purification, it can be used to efficiently degrade organic pollutants, enabling effective treatment of wastewater and waste gas.

[0024] (2) The photothermal-thermoelectric synergistic catalyst of the present invention, wherein the substrate is one or more of Bi2Te3, GeTe, ZnO, PbTe, and Ag2Se. The titanium dioxide in the catalyst layer has photocatalytic activity. When irradiated with light with energy greater than the band gap width, electrons in the valence band are excited and jump to the conduction band, generating corresponding holes in the valence band, thereby producing excited electron-hole pairs. Under the action of an electric field, electrons and holes migrate to different positions on the surface of titanium dioxide, allowing electrons and holes to react with donors or acceptors on the surface, thereby completing the catalytic reaction. At the same time, the substrate located within the catalyst layer has a high-temperature condition on its surface due to the photothermal effect, forming a temperature difference and a corresponding Seebeck voltage with the bottom surface of the substrate, providing electrons for the catalytic reaction and inhibiting electron-hole recombination, thereby promoting the catalytic reaction. More importantly, when the substrate is one or more of Bi2Te3, GeTe, ZnO, PbTe, and Ag2Se, it matches the energy level of the titanium dioxide in the catalyst layer, has a lower electron transfer energy barrier, improves electron transfer efficiency, and enhances the visible light absorption capacity of the titanium dioxide in the catalyst layer, effectively utilizing sunlight and greatly improving the efficiency of the catalytic reaction, thereby achieving efficient utilization of solar energy.

[0025] (3) The preparation method of the photothermal-thermoelectric synergistic catalyst of the present invention is simple, efficient and mild, and can be widely used in clean energy production and environmental purification. Attached Figure Description

[0026] Figure 1 These are performance graphs of the photocatalytic, thermocatalytic, and photothermal-thermoelectric synergistic catalytic oxidation of Rhodamine B prepared in Experimental Example 1 of this invention.

[0027] Figure 2 The graphs show the photocatalytic, thermocatalytic, and photothermal-thermoelectric synergistic catalytic oxidation performance of the photothermal-thermoelectric synergistic catalyst prepared in Experimental Example 6 of this invention. Detailed Implementation

[0028] Unless otherwise specified in the embodiments of this invention, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available products; different manufacturers and models of raw materials do not affect the implementation of the technical solution or the achievement of the technical effect of this invention.

[0029] Example 1

[0030] The photothermal-thermoelectric synergistic catalyst in this embodiment includes a substrate and a catalytic layer coated on the substrate; wherein the substrate is Bi2Te3; the catalytic layer is titanium dioxide, and the titanium dioxide is nano-sized TiO2 rods. That is, the photothermal-thermoelectric synergistic catalyst is a TiO2 nanorod composite material.

[0031] The preparation method of the photothermal-thermoelectric synergistic catalyst described in this embodiment includes the following steps:

[0032] (1) Take a substrate and a TiO2 precursor solution, add the TiO2 precursor solution to the substrate, dry at 60°C for 30 min, and then calcine to convert the TiO2 precursor solution into TiO2 seed crystals, which adhere to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals.

[0033] The calcination temperature is 450℃ and the time is 2 hours. The TiO2 precursor solution is a mixture of tetrabutyl titanate and solvent at a volume ratio of 0.9:10; the solvent is isopropanol; the TiO2 precursor solution also includes hydrochloric acid.

[0034] As a preferred implementation of this embodiment, the preparation method of the TiO2 precursor solution is as follows: 0.90 ml of tetrabutyl titanate is added to 10.0 ml of isopropanol, stirred for 30 min, then 0.40 ml of hydrochloric acid is added, stirred for 30 min, and aged at 25°C for 12 h to obtain the solution.

[0035] (2) The substrate coated with TiO2 seed obtained in step (1) is placed in the reaction solution to carry out a hydrothermal crystallization reaction. After the hydrothermal crystallization reaction, the product is washed with water and ethanol, dried, and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

[0036] The reaction solution contains toluene, tetrabutyl titanate, and hydrofluoric acid, and is composed of 20.0 ml of toluene, 1.5 ml of tetrabutyl titanate, and 0.6 ml of hydrofluoric acid. The hydrothermal crystallization reaction is carried out at 70°C for 24 hours. The calcination reaction is carried out at 500°C for 2 hours.

[0037] The photothermal-thermoelectric synergistic catalyst described in this embodiment can be applied to the field of catalytic organic matter degradation reactions. The organic matter is one or more of Rhodamine B, methyl orange, salicylic acid, and phenol. In this embodiment, the photothermal-thermoelectric synergistic catalyst is used to degrade Rhodamine B (CAS No. 81-88-9, molecular formula C). 28 H 31 ClN2O3), specifically includes the following steps:

[0038] The photothermal-thermoelectric synergistic catalyst was placed into the pores of a foam insulation pad, and a heating element was placed on top or it was exposed to light. The bottom was immersed in a Rhodamine B solution for degradation.

[0039] Figure 1 The figures shown are the performance graphs for photocatalysis, thermocatalysis, and photothermal-thermoelectric synergistic catalysis of Rhodamine B oxidation, with the following test conditions:

[0040] Photocatalysis involves irradiating the solution with sunlight (one sun); thermal catalysis involves heating the Rhodamine B solution to 50°C; photothermal-thermoelectric synergistic catalysis involves heating the Rhodamine B solution to approximately 50°C while irradiating it with sunlight (one sun).

[0041] Example 2

[0042] The photothermal-thermoelectric synergistic catalyst in this embodiment includes a substrate and a catalytic layer coated on the substrate; wherein the substrate is GeTe; the catalytic layer is titanium dioxide, and the titanium dioxide is nano-sized TiO2 powder, which is titanium dioxide P25 in this embodiment.

[0043] The preparation method of the photothermal-thermoelectric synergistic catalyst described in this embodiment includes the following steps:

[0044] (1) Take a substrate and a TiO2 precursor solution, coat the substrate with the TiO2 precursor solution, and then calcine it to convert the TiO2 precursor solution into TiO2 seed crystals, which adhere to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals.

[0045] The calcination temperature is 500℃ and the time is 5 hours. The TiO2 precursor solution is a mixture of tetrabutyl titanate and solvent at a volume ratio of 0.9:50; the solvent is anhydrous ethanol and water at a volume ratio of 3:2.

[0046] As a preferred implementation of this embodiment, the TiO2 precursor solution is prepared as follows: 0.90 ml of tetrabutyl titanate is added to 30.0 ml of anhydrous ethanol and stirred for 30 min, then 20 ml of water is added and stirred for 30 min to obtain the solution.

[0047] (2) The substrate coated with TiO2 seed obtained in step (1) is placed in the reaction solution to carry out a hydrothermal crystallization reaction. After the hydrothermal crystallization reaction, the product is washed with water and ethanol, dried, and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

[0048] The reaction solution contains sodium hydroxide and hydrogen peroxide, and is composed of 50 ml of sodium hydroxide and 1 ml of hydrogen peroxide. The hydrothermal crystallization reaction is carried out at 130°C for 1 hour. The calcination is carried out at 300°C for 5 hours.

[0049] The photothermal-thermoelectric synergistic catalyst described in this embodiment can be applied to the field of catalytic organic matter degradation reactions. The organic matter is one or more of Rhodamine B, methyl orange, salicylic acid, and phenol. In this embodiment, the degradation of methyl orange using the photothermal-thermoelectric synergistic catalyst specifically includes the following steps:

[0050] The photothermal-thermoelectric synergistic catalyst was placed into the pores of a foam insulation pad, and a heating element was placed on top or it was exposed to light. The bottom was immersed in a methyl orange solution for degradation.

[0051] Example 3

[0052] The photothermal-thermoelectric synergistic catalyst in this embodiment includes a substrate and a catalytic layer coated on the substrate; wherein the substrate is ZnO; and the catalytic layer is titanium dioxide. The titanium dioxide is nano-sized TiO2 flowers.

[0053] The preparation method of the photothermal-thermoelectric synergistic catalyst described in this embodiment includes the following steps:

[0054] (1) Take a substrate and a TiO2 precursor solution, immerse the substrate in the TiO2 precursor solution, and then calcine it to convert the TiO2 precursor solution into TiO2 seed crystals, which adhere to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals.

[0055] The TiO2 precursor solution is prepared by mixing tetrabutyl titanate and solvent at a volume ratio of 0.9:30; the solvent is ethylene glycol. The calcination temperature is 400℃ and the time is 1 hour.

[0056] (2) The substrate coated with TiO2 seed obtained in step (1) is subjected to hydrothermal crystallization reaction. The product is washed with water and ethanol, dried, and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

[0057] The reaction solution contains sodium hydroxide and hydrogen peroxide, and is composed of 50 ml of sodium hydroxide and 1 ml of hydrogen peroxide. The hydrothermal crystallization reaction is carried out at 120°C for 2 hours. The calcination reaction is carried out at 600°C for 1 hour.

[0058] The photothermal-thermoelectric synergistic catalyst described in this embodiment can be applied to the field of catalytic organic matter degradation reactions. The organic matter is one or more of Rhodamine B, methyl orange, salicylic acid, and phenol. In this embodiment, the degradation of salicylic acid using the photothermal-thermoelectric synergistic catalyst specifically includes the following steps:

[0059] The photothermal-thermoelectric synergistic catalyst is placed into the pores of a foam insulation pad, and a heating element is placed on top or it is exposed to light. The bottom is immersed in a salicylic acid solution for degradation.

[0060] Example 4

[0061] The photothermal-thermoelectric synergistic catalyst in this embodiment includes a substrate and a catalytic layer coated on the substrate; wherein the substrate is PbTe; and the catalytic layer is titanium dioxide. The titanium dioxide is nanoscale TiO2 bands.

[0062] The preparation method of the photothermal-thermoelectric synergistic catalyst described in this embodiment includes the following steps:

[0063] (1) Take a substrate and a TiO2 precursor solution, coat the substrate with the TiO2 precursor solution, and then calcine it to convert the TiO2 precursor solution into TiO2 seed crystals, which adhere to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals.

[0064] The calcination temperature is 450℃ and the time is 2 hours. The TiO2 precursor solution is a mixture of tetrabutyl titanate and solvent at a volume ratio of 0.9:10; the solvent is isopropanol; the TiO2 precursor solution also contains hydrochloric acid.

[0065] As a preferred implementation of this embodiment, the preparation method of the TiO2 precursor solution is as follows: 0.90 mL of tetrabutyl titanate is added to 10.0 mL of isopropanol, stirred for 30 min, then 0.40 mL of hydrochloric acid is added, stirred for 30 min, and aged at 25 °C for 12 h to obtain the solution.

[0066] (2) The substrate coated with TiO2 seed obtained in step (1) is placed in the reaction solution to carry out a hydrothermal crystallization reaction. After the hydrothermal crystallization reaction, the product is washed with water and ethanol, dried, and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

[0067] The reaction solution contains toluene, tetrabutyl titanate, and hydrofluoric acid, and is composed of 20.0 ml of toluene, 1.5 ml of tetrabutyl titanate, and 0.6 ml of hydrofluoric acid. The hydrothermal crystallization reaction is carried out at 70°C for 12 hours. The calcination reaction is carried out at 500°C for 2 hours.

[0068] The photothermal-thermoelectric synergistic catalyst described in this embodiment can be applied to the field of catalytic organic matter degradation reactions. The organic matter is one or more of Rhodamine B, methyl orange, salicylic acid, and phenol. In this embodiment, the degradation of phenol using the photothermal-thermoelectric synergistic catalyst specifically includes the following steps:

[0069] The photothermal-thermoelectric synergistic catalyst is placed into the pores of a foam insulation pad, and a heating element is placed on top or it is exposed to light. The bottom is immersed in a phenol solution for degradation.

[0070] Example 5

[0071] The photothermal-thermoelectric synergistic catalyst in this embodiment includes a substrate and a catalytic layer coated on the substrate; wherein the substrate is Ag₂Se; and the catalytic layer is titanium dioxide. The titanium dioxide is nanoscale TiO₂ rods. That is, the photothermal-thermoelectric synergistic catalyst is a TiO₂ nanorod composite material.

[0072] The preparation method of the photothermal-thermoelectric synergistic catalyst described in this embodiment includes the following steps:

[0073] (1) Take a substrate and a TiO2 precursor solution. Soak or coat the substrate with the TiO2 precursor solution and then calcine it to convert the TiO2 precursor solution into TiO2 seed crystals, which adhere to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals.

[0074] The TiO2 precursor solution is prepared by mixing tetrabutyl titanate and a solvent at a volume ratio of 0.9:40; the solvent is ethylene glycol. The TiO2 precursor solution also includes hydrochloric acid. The calcination temperature is 500℃, and the time is 1 hour.

[0075] As a preferred implementation of this embodiment, the TiO2 precursor solution is prepared as follows: 0.90 mL of tetrabutyl titanate is added to 40.0 mL of ethylene glycol and stirred for 30 min. Then, 0.40 mL of hydrochloric acid is added and stirred for 30 min. The solution is then aged at 25 °C for 12 h to obtain the product.

[0076] (2) The substrate coated with TiO2 seed obtained in step (1) is subjected to hydrothermal crystallization reaction. The product is washed with water and ethanol, dried, and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

[0077] The hydrothermal crystallization reaction solution contains toluene, tetrabutyl titanate, and hydrofluoric acid, and is composed of 20 ml of toluene, 1.5 ml of tetrabutyl titanate, and 0.6 ml of hydrofluoric acid. The hydrothermal crystallization reaction is carried out at 75°C for 24 hours. The calcination is carried out at 400°C for 3 hours.

[0078] The photothermal-thermoelectric synergistic catalyst described in this embodiment can be applied to the field of catalytic organic matter degradation reactions. The organic matter is one or more of Rhodamine B, methyl orange, salicylic acid, and phenol. In this embodiment, the degradation of Rhodamine B using the photothermal-thermoelectric synergistic catalyst specifically includes the following steps:

[0079] The photothermal-thermoelectric synergistic catalyst was placed into the pores of a foam insulation pad, and a heating element was placed on top or it was exposed to light. The bottom was immersed in a Rhodamine B solution for degradation.

[0080] Example 6

[0081] The photothermal-thermoelectric synergistic catalyst in this embodiment includes a substrate and a catalytic layer coated on the substrate; wherein the substrate is Ag2Se. The catalytic layer is titanium dioxide, and the titanium dioxide is nano-sized TiO2 flowers.

[0082] The preparation method of the photothermal-thermoelectric synergistic catalyst described in this embodiment includes the following steps:

[0083] (1) Take a substrate and a TiO2 precursor solution, immerse the substrate in the TiO2 precursor solution, and then calcine it to convert the TiO2 precursor solution into TiO2 seed crystals, which adhere to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals.

[0084] The calcination temperature is 450℃ and the time is 2 hours. The TiO2 precursor solution is a mixture of tetrabutyl titanate and solvent at a volume ratio of 0.9:30; the solvent is anhydrous ethanol and water at a volume ratio of 1:2.

[0085] As a preferred implementation of this embodiment, the TiO2 precursor solution is prepared as follows: 0.90 mL of tetrabutyl titanate is added to 10.0 mL of anhydrous ethanol and stirred for 30 min, then 20 mL of water is added and stirred for 30 min to obtain the solution.

[0086] (2) The substrate coated with TiO2 seed obtained in step (1) is placed in the reaction solution to carry out a hydrothermal crystallization reaction. After the hydrothermal crystallization reaction, the product is washed with water and ethanol, dried, and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

[0087] The reaction solution contains sodium hydroxide and hydrogen peroxide, and is composed of 50 ml of sodium hydroxide and 1 ml of hydrogen peroxide. The hydrothermal crystallization reaction is carried out at 120°C for 2 hours. The calcination reaction is carried out at 500°C for 2 hours.

[0088] The photothermal-thermoelectric synergistic catalyst described in this embodiment can be applied to the field of catalytic organic matter degradation reactions. The organic matter is one or more of Rhodamine B, methyl orange, salicylic acid, and phenol. In this embodiment, the degradation of Rhodamine B using the photothermal-thermoelectric synergistic catalyst specifically includes the following steps:

[0089] The photothermal-thermoelectric synergistic catalyst was placed into the pores of a foam insulation pad, and a heating element was placed on top or it was exposed to light. The bottom was immersed in a Rhodamine B solution for degradation.

[0090] Figure 2 The figures shown are the performance graphs for photocatalysis, thermocatalysis, and photothermal-thermoelectric synergistic catalysis of Rhodamine B oxidation, with the following test conditions:

[0091] Photocatalysis involves irradiating the solution with sunlight; thermal catalysis involves heating the Rhodamine B solution to 50°C; photothermal-thermoelectric synergistic catalysis involves irradiating the solution with sunlight and heating it to approximately 50°C.

[0092] Example 7

[0093] The photothermal-thermoelectric synergistic catalyst in this embodiment is the same as that in Example 6 and is prepared using the same method, the only difference being that the substrate is ZnO.

[0094] Example 8

[0095] The photothermal-thermoelectric synergistic catalyst in this embodiment is the same as that in Example 6 and is prepared using the same method, except that the substrate is PbTe.

[0096] Example 9

[0097] The photothermal-thermoelectric synergistic catalyst in this embodiment is the same as that in Example 6 and is prepared using the same method, except that the substrate is Bi2Te3.

[0098] Example 10

[0099] The photothermal-thermoelectric synergistic catalyst in this embodiment is the same as that in Example 6 and is prepared using the same method, the only difference being that the substrate is GeTe.

[0100] Example 11

[0101] The photothermal-thermoelectric synergistic catalyst in this embodiment is the same as that in Example 6 and is prepared using the same method. The only difference is that in step (2), the reaction solution for the hydrothermal crystallization reaction contains toluene, tetrabutyl titanate, and hydrofluoric acid, and is a mixture of 20 ml toluene, 1.5 ml tetrabutyl titanate, and 0.6 ml hydrofluoric acid. The hydrothermal crystallization reaction is carried out at a temperature of 70°C for 24 hours.

[0102] Effect Experiment Example

[0103] To verify the technical effect of the photothermal-thermoelectric synergistic catalyst described in this invention, the following experiments were conducted:

[0104] The photothermal-thermoelectric synergistic catalysts obtained in Examples 1-11 were used to degrade the organic matter in each example. The degradation rate was measured for 2 hours under thermocatalytic, photocatalytic, and photothermal-thermoelectric synergistic conditions using a UV-Vis spectrophotometer. The test conditions for each example were the same as those for Example 6.

[0105] The results of the experiment are as follows:

[0106] Group Thermocatalysis (%) Photocatalysis (%) Photothermal-thermoelectric synergistic catalysis (%) Example 1 2％ 15％ 28％ Example 2 12％ 23％ 48％ Example 3 5％ 21％ 32％ Example 4 20％ 43％ 82％ Example 5 18％ 34％ 71％ Example 6 25％ 40％ 95％ Example 7 21％ 38％ 90％ Example 8 18％ 32％ 82％ Example 9 23％ 30％ 86％ Example 10 15％ 28％ 60％ Example 11 20％ 32％ 89％

[0107] Based on the above results, it can be seen that the photothermal-thermoelectric synergistic catalyst of the present invention exhibits significantly improved catalytic efficiency under photothermal-thermoelectric synergistic conditions. A comparison of Examples 6-10 shows that the catalytic efficiency is highest when the substrate is Ag₂Se under photothermal-thermoelectric synergistic conditions. A comparison of Examples 5 and 6 shows that the catalytic efficiency is higher when the titanium dioxide is in the form of nanoflowers than nanorods. A comparison of Examples 6 and 11 shows that the composition of the reaction solution used in the hydrothermal crystallization reaction also has a certain impact on the performance of the obtained photothermal-thermoelectric synergistic catalyst.

[0108] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. The application of a photothermal-thermoelectric synergistic catalyst in the degradation of Rhodamine B, characterized in that, Photothermal-thermoelectric synergistic catalysis involves heating a Rhodamine B solution to 50°C under sunlight. The photothermal-thermoelectric synergistic catalyst includes a substrate and a catalytic layer coated on the substrate; wherein the substrate is an n-type thermoelectric material Ag2Se; and the catalytic layer is nanoscale TiO2 flowers; The preparation method of the aforementioned photothermal-thermoelectric synergistic catalyst includes the following steps: (1) Take a substrate and a TiO2 precursor solution, convert the TiO2 precursor solution into TiO2 seed crystals, and adhere them to the surface of the substrate to obtain a substrate covered with TiO2 seed crystals; (2) The substrate coated with TiO2 seed obtained in step (1) is subjected to hydrothermal crystallization reaction and then calcined to obtain a photothermal-thermoelectric synergistic catalyst.

2. The application according to claim 1, characterized in that, In step (1), the precursor solution of TiO2 is a tetrabutyl titanate solution.

3. The application according to claim 1, characterized in that, In step (1), the TiO2 precursor solution is soaked or coated on the substrate and then calcined to convert the TiO2 precursor solution into TiO2 seed crystals, which then adhere to the surface of the substrate.

4. The application according to claim 1, characterized in that, In step (2), the reaction solution of the hydrothermal crystallization reaction contains toluene, tetrabutyl titanate and hydrofluoric acid; or, the reaction solution of the hydrothermal crystallization reaction contains sodium hydroxide and hydrogen peroxide.

5. The application according to claim 1, characterized in that, In step (2), the calcination temperature is 300-600℃ and the time is 1-5h.

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