Experimental device and method for enhancing photo-thermal catalytic performance based on external permanent magnetic field

Abstract

The invention discloses an experimental device and method for enhancing photo-thermal catalytic performance based on an external permanent magnetic field, and belongs to the technical field of new energy. The experimental device comprises a reactor main body, a simulation light source is arranged above one side of the reactor main body, a catalyst bed layer is arranged in the reactor main body, two permanent magnets are oppositely arranged on the inner side wall of the reactor main body in parallel, and heteropoles of the two permanent magnets are opposite. According to the experimental device, the photo-thermal catalytic performance is enhanced by externally adding the permanent magnetic field, full-spectrum solar energy can be effectively utilized, and the behavior of electron-hole pairs can be regulated and controlled through the magnetic field, so that the photo-thermal catalytic efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of new energy technology, and specifically relates to an experimental device and method for enhancing photothermal catalytic performance based on an external permanent magnetic field. Background Art

[0002] Photothermal catalysis is an advanced technology that uses light energy and heat energy to drive catalytic reactions. Compared with traditional photocatalytic processes, photothermal catalysis is expected to solve the problem of slow reaction rates, and therefore has shown a wide range of application potential in water decomposition, carbon dioxide reduction, pollutant degradation, and C1 molecule conversion.

[0003] In the photothermal catalytic reaction system, the catalyst excites electrons in the semiconductor material from the valence band to the conduction band under the irradiation of incident light, generating electron-hole pairs (collectively referred to as carriers). These carriers then migrate to the active sites on the catalyst surface to participate in redox reactions. Traditional photocatalytic processes can usually only utilize photon energy in ultraviolet light and part of the visible light band, and fail to effectively utilize the energy of the rest of the spectrum. In contrast, photothermal catalysis can not only utilize this photon energy, but also convert the unabsorbed photon energy into thermal energy. This thermal energy not only helps to increase the temperature of the reaction system, but also further promotes the migration of charge carriers, enhances catalytic activity, and thus accelerates the chemical reaction.

[0004] However, despite the significant advantages of photothermal catalysis in increasing reaction rates, it still faces similar challenges as traditional photocatalysis, namely the problem of carrier recombination. Carrier recombination refers to the mutual combination of electrons and holes before reaching the catalytic active site, so that their energy cannot be effectively used to promote the catalytic reaction. Due to the high intensity of carrier recombination, the overall performance of photothermal catalysis is significantly restricted, thus affecting its effectiveness in practical applications.

[0005] An external magnetic field can effectively suppress the recombination of charge carriers. According to the Lorentz force law, when charged particles move in a magnetic field, they will be affected by a Lorentz force perpendicular to their direction of movement. In a photothermal catalytic system, an external magnetic field can exert forces in opposite directions on electrons and holes, thereby slowing down or suppressing their recombination process. This not only effectively prolongs the lifetime of charge carriers, but also enhances their migration ability, allowing more charge carriers to reach the reaction active sites and participate in the catalytic reaction.

[0006] However, the role of magnetic fields in photothermal catalytic reactions is still in the exploratory stage, and a mature experimental device and system design have not yet been formed.

[0007] For example, a Chinese patent with publication number CN106268569A provides a photothermal magnetic coupling hydrogen production experimental device based on magnetic particles. The invention uses a DC electromagnetic coil as a magnetic field generator. On the one hand, the photocatalyst can be evenly suspended in the solution. On the other hand, the photocatalyst can produce a considerable temperature effect under infrared light under the action of the magnetic field, realizing photothermal magnetic coupling hydrogen production. However, the magnetic field generator contained in the device requires electrical energy to maintain, and the additional power consumption will reduce the overall efficiency of hydrogen production by decomposing water. More importantly, the direction of the magnetic field in the experimental device is constantly changing, and it does not play a regulatory role in the kinetic characteristics of photoexcited carriers, and the technical solution is limited to magnetic semiconductor catalysts.

[0008] In summary, a key technical challenge facing photothermal catalytic reactions is how to effectively suppress the recombination of charge carriers (i.e., electrons and holes) to improve the overall performance and reaction efficiency of photothermal catalysis. This challenge requires the development of new strategies or methods to reduce the mutual binding of charge carriers before they migrate to the catalytic active sites, thereby ensuring that more energy can be used to promote the catalytic reaction and ultimately improve the practical efficiency of the photothermal catalytic system. Summary of the invention

[0009] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an experimental device and method for enhancing photothermal catalytic performance based on an external permanent magnetic field. The experimental device is a general experimental device that is not limited to magnetic semiconductor catalysts. By enhancing the photothermal catalytic performance through an external permanent magnetic field, not only can the full spectrum of solar energy be effectively utilized, but also the behavior of electron-hole pairs can be regulated by the magnetic field, thereby significantly improving the photothermal catalytic efficiency.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] The present invention provides an experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field, comprising a reactor body, a simulated light source is arranged above one side of the reactor body, a catalyst bed is arranged inside the reactor body, and two permanent magnets are arranged in parallel and opposite to each other on the inner side wall of the reactor body, and the two permanent magnets have opposite poles.

[0012] In one embodiment, the catalyst powder in the catalyst bed is non-magnetic catalyst powder or paramagnetic catalyst powder.

[0013] In one embodiment, the catalyst powder in the catalyst bed is any one of TiO2, ZnFe2O4 and a TiO2 / ZnFe2O4 composite material.

[0014] In one embodiment, the catalyst bed is located within the magnetic field formed by a permanent magnet.

[0015] In one embodiment, a focusing lens is disposed on the simulated light source.

[0016] In one embodiment, a viewing window is disposed on the top of the reactor body.

[0017] In one embodiment, a sealing component is provided on the top of the reactor body, and the sealing component includes a fixed connection component and a graphite gasket;

[0018] The graphite gasket is arranged below the visual window, and the reactor body is connected to the visual window via a fixed connection component.

[0019] In one embodiment, a heating system is disposed at the bottom of the reactor body, and the heating system is disposed below the catalyst bed.

[0020] In one embodiment, a quartz sand core is disposed below the catalyst bed, and the quartz sand core is in contact with a heating system.

[0021] The present invention also provides an experimental method for an experimental device based on an external permanent magnetic field to enhance photothermal catalytic performance, comprising the following steps:

[0022] S1: After CO2 and H2O reach adsorption equilibrium on the surface of the catalyst bed, turn on the simulated light source to illuminate the catalyst bed;

[0023] S2: Under illumination conditions, two permanent magnets with opposite poles and parallel to each other apply a magnetic field to the catalyst bed to conduct the experiment.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention proposes an experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field, and introduces a permanent magnetic field into a photothermal catalytic system. By applying a parallel magnetic field to the photothermal catalytic system with two parallel permanent magnets with opposite poles, no additional power consumption is required, and the high efficiency of the catalytic reaction is successfully achieved. By organically combining photothermal catalysis with an external permanent magnetic field, the utilization efficiency of light energy and thermal energy is significantly enhanced, thereby improving the overall performance and economic benefits of the catalytic reaction. The device uses an external permanent magnetic field to effectively suppress the recombination phenomenon of carriers (electrons and holes), prolong the life of carriers, and enhance their migration ability. This design overcomes the problem of low efficiency caused by carrier recombination in traditional photocatalytic reactions, thereby significantly accelerating the progress of chemical reactions, especially in key reactions such as water decomposition and carbon dioxide reduction. Showing excellent performance advantages. In summary, through the introduction of a permanent magnetic field, the present invention significantly improves the catalytic performance of the catalyst, and adopts a permanent magnet, a technology that does not require additional energy supply, to further reduce the energy consumption and maintenance cost of the system, ensuring the economic benefits of the catalytic reaction. The present invention enhances the photothermal catalytic performance by combining an external permanent magnetic field with photothermal catalysis, and has broad application prospects and sustainable development potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of an experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to the present invention;

[0027] Figure 2 150 mW / cm 2 Catalytic performance of TiO2 in the presence and absence of magnetic field under illumination conditions;

[0028] Figure 3 150 mW / cm 2 Catalytic performance of ZnFe2O4 in the presence and absence of magnetic field under light conditions;

[0029] Figure 4 150 mW / cm 2 Catalytic performance of TiO2 / ZnFe2O4 in the presence and absence of a magnetic field under light conditions.

[0030] Among them: 1-simulated light source; 2-condensing lens; 3-bolt; 4-quartz glass window; 5-graphite gasket; 6-first NdFeB permanent magnet; 7-second NdFeB permanent magnet; 8-catalyst bed; 9-quartz sand core; 10-heating plate. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0034] The present invention provides an experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field, the device mainly includes a reactor body, a simulated light source 1 above one side of the reactor body, a built-in catalyst bed 8 inside the reactor body, and two permanent magnets with opposite polarities are arranged in parallel on both side walls inside the reactor body. The device organically combines photothermal catalytic technology with permanent magnetic field technology, and uses parallel permanent magnets with opposite polarities to apply a parallel magnetic field in the photothermal catalytic reaction area, which effectively suppresses the recombination phenomenon of carriers (electrons and holes), prolongs the life of carriers, and enhances their migration ability, thereby realizing an efficient catalytic reaction without additional power consumption. This system significantly improves the utilization efficiency of light energy and thermal energy, and improves the overall performance and economic benefits of the catalytic reaction.

[0035] The present invention also provides an experimental method for an experimental device based on an external permanent magnetic field to enhance photothermal catalytic performance, comprising the following steps:

[0036] S1: After CO2 and H2O reach adsorption equilibrium on the surface of the catalyst bed 8, the simulated light source 1 is turned on to illuminate the catalyst bed 8;

[0037] S2: Under illumination conditions, two permanent magnets with opposite poles and parallel to each other apply a magnetic field to the catalyst bed 8 to conduct an experiment.

[0038] The above experimental method, through the application of an external permanent magnetic field, can directly act on the carriers (electrons and holes) in the photocatalyst through its unique physical effects, such as the Lorentz force. This force can effectively suppress the recombination of carriers in the early stage of generation, allowing more electrons and holes to participate in the subsequent catalytic reaction. Specifically, the magnetic field can cause electrons and holes to separate in space, reducing the chance of them meeting and recombination, thereby improving the separation efficiency of carriers.

[0039] In a specific implementation process, the catalyst powder in the catalyst bed 8 is a non-magnetic catalyst powder or a paramagnetic catalyst powder. More specifically, the catalyst powder in the catalyst bed 8 is any one of TiO2, ZnFe2O4 and a TiO2 / ZnFe2O4 composite material. The catalyst bed 8 uses non-magnetic or paramagnetic catalyst powders such as TiO2, ZnFe2O4 and a TiO2 / ZnFe2O4 composite material, BaTiO3, ZnO, CdS, BiOCl, etc. These materials will not be directly disturbed by the magnetic field, but can effectively utilize the photothermal effect that may be brought about by the external magnetic field to enhance the catalytic efficiency.

[0040] In a specific implementation process, the catalyst bed 8 is located within the magnetic field formed by the permanent magnet. The permanent magnet is preferably a NdFeB permanent magnet, including a first NdFeB permanent magnet 6 and a second NdFeB permanent magnet. Permanent magnets such as NdFeB permanent magnets are arranged with opposite poles to form a stable magnetic field environment, ensuring that the catalyst bed 8 is completely within the magnetic field. This configuration helps to optimize the magnetic field distribution and further improve the photothermal catalytic performance.

[0041] In a specific implementation process, a condenser lens 2 is provided on the simulated light source 1. The simulated light source 1 is equipped with a condenser lens 2, which can effectively concentrate the light source energy, improve the light utilization efficiency, make the light intensity received by the catalyst bed 8 more uniform and powerful, and promote the catalytic reaction rate.

[0042] In a specific implementation process, a visual window is provided on the top of the reactor body. A sealing component is provided on the top of the reactor body, and the sealing component includes a fixed connection component and a graphite gasket 5; the graphite gasket 5 is provided below the visual window, and the reactor body is connected to the visual window through a fixed connection component. Specifically, the fixed connection component is a bolt 3, and the visual window is a quartz glass window 4. A visual window such as a quartz glass window 4 is provided on the top of the reactor body, which is convenient for observing the state change of the catalyst bed 8 during the experiment. At the same time, a sealing component composed of bolts 3 and graphite gaskets 5 is used to ensure the airtightness of the reaction system, prevent external pollution and internal gas leakage, and ensure the accuracy of the experimental results.

[0043] In a specific implementation process, a heating system is provided at the bottom of the reactor body, and the heating system is provided below the catalyst bed 8. The heating system is preferably a heating plate 10. A quartz sand core 9 is provided below the catalyst bed 8, and the quartz sand core 9 is in contact with the heating system. The bottom heating system such as the heating plate 10 combined with the quartz sand core 9 can evenly heat the catalyst bed 8, improve the reaction temperature control accuracy, and promote the catalytic reaction. At the same time, the quartz sand core 9, as a heat conduction medium, has good high temperature resistance and chemical stability, ensuring the safety and effectiveness of the heating process.

[0044] In one embodiment, an experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field is provided, and a photothermal catalytic experimental device for introducing an external permanent magnetic field is provided. The device organically combines photothermal catalytic technology with permanent magnetic field technology, and uses parallel NdFeB permanent magnets placed in parallel to apply a parallel magnetic field in the photothermal catalytic reaction area, thereby achieving an efficient catalytic reaction without additional power consumption. This system significantly improves the utilization efficiency of light energy and thermal energy, and enhances the overall performance and economic benefits of the catalytic reaction.

[0045] The experimental device is mainly composed of the following key components: a simulated light source 1, a focusing lens 2, a bolt 3, a quartz glass window 4, a graphite gasket 5, a first NdFeB permanent magnet 6 and a second NdFeB permanent magnet 7, a catalyst bed 8, a quartz sand core 9 and a heating plate 10. Figure 1 shown.

[0046] Simulated light source 1: equipped with full-spectrum reflectors to simulate sunlight to reproduce the photothermal catalytic reaction conditions in the natural environment. The light source can provide full-spectrum illumination including ultraviolet light, visible light and infrared light to ensure that the catalyst can fully absorb the required light energy in the experiment.

[0047] Condensing lens 2: can be added to the simulated light source 1 to adjust the light intensity so as to increase the photon energy density reaching the catalyst surface, thereby enhancing the photothermal catalytic reaction effect.

[0048] Reactor body and sealing structure: The reactor body is made of stainless steel, and a quartz glass window 4 is installed on the top of the reactor body for light transmission and internal visualization operation. A graphite gasket 5 is provided under the quartz glass window 4 to ensure the airtightness of the reactor and prevent the infiltration of external gas or the leakage of reaction gas. In addition, in order to further enhance the sealing performance, the reactor is also fixed with bolts 3 to ensure the safety and stability of the reaction process.

[0049] The first NdFeB permanent magnet 6 and the second NdFeB permanent magnet 7: The two NdFeB permanent magnets are placed in parallel on both sides of the reactor to generate a parallel magnetic field, and the first NdFeB permanent magnet 6 and the second NdFeB permanent magnet 7 have opposite poles to each other, which is used to suppress the recombination of carriers and prolong their life, thereby improving the efficiency of the catalytic reaction. The magnetic field strength can be controlled by adjusting the size of the permanent magnet.

[0050] Catalyst bed 8 and heating system: Catalyst bed 8 is supported by quartz sand core 9 and paved with catalyst powder. Quartz sand core 9 is in close contact with heating plate 10, which is used to adjust the working temperature of the catalyst to ensure that the reaction can proceed under the optimal temperature conditions and only work when the temperature is insufficient.

[0051] The experimental operation steps of the experimental device are as follows:

[0052] First, 20 mg of catalyst powder is weighed and evenly spread on the quartz sand core 9. The quartz sand core 9 with the catalyst is placed on the heating plate 10 in the reactor body to ensure that the catalyst is in full contact with the heating plate 10.

[0053] To prevent the catalyst from directly contacting water, 100 μL of ultrapure water (resistivity of 18.2 MΩ·cm) was uniformly injected into the bottom of the reactor to provide a proton source. Next, the pressure in the reactor was pumped down to 10-3 Pa, and high-purity CO2 (99.999%) was introduced, and the pressure in the reactor was monitored by a mechanical pressure gauge. To remove residual impurity gases, the ventilation step was repeated three times, and finally the pressure of CO2 in the reactor was stabilized at -10 kPa.

[0054] Before the reaction started, the reactor was placed in a dark environment for 30 minutes to ensure that CO2 and H2O reached adsorption equilibrium on the catalyst surface.

[0055] Then, the simulated light source 1 is turned on to illuminate the catalyst to drive the reaction. Under the illumination condition, the magnetic field applied by the first NdFeB permanent magnet 6 and the second NdFeB permanent magnet 7 acts on the catalyst, promoting the effective separation of electrons and holes, reducing the recombination effect, and thus improving the reaction efficiency.

[0056] Each experiment lasted for 2 hours. After the experiment, the reaction products were analyzed by online gas chromatography to determine the reaction efficiency and product selectivity.

[0057] This experiment is conducted on commercial TiO2 (non-magnetic), ZnFe2O4 (paramagnetic) and TiO2 / ZnFe2O4 composite materials (paramagnetic). 2 Under the light intensity, the test was carried out with and without magnetic field (magnetic field intensity is 125mT). The results are as follows Figure 2 , 3 and 4.

[0058] The experimental results show that under the condition of magnetic field, the catalytic performance of TiO2, ZnFe2O4 and TiO2 / ZnFe2O4 are significantly improved, among which the TiO2 / ZnFe2O4 composite material shows a more significant enhancement effect. This result verifies the effectiveness of introducing a permanent magnetic field to improve the efficiency of photothermal catalytic reactions.

[0059] Through the experimental verification of the above embodiments, the photothermal catalytic experimental device of the present invention has shown a significant improvement in catalytic performance in the carbon dioxide reduction reaction. In particular, after the introduction of the permanent magnetic field, the photothermal catalytic efficiency of different materials has been significantly enhanced, which provides an important basis for the development of photothermal catalytic technology and further verifies the innovation and practicality of the present invention.

[0060] The present invention introduces a permanent magnetic field into the photothermal catalytic system for the first time, using two parallel NdFeB permanent magnets with opposite poles to apply a parallel magnetic field to the catalytic reaction system. This design can significantly improve the efficiency and stability of the catalytic reaction without requiring additional power consumption.

[0061] The present invention effectively suppresses the recombination of carriers (electrons and holes) by applying an external permanent magnetic field, prolongs the life of carriers, and enhances their migration ability. This mechanism significantly improves the efficiency of photothermal catalytic reactions, especially in reactions such as water decomposition and carbon dioxide reduction, showing excellent catalytic performance.

[0062] The present invention uses NdFeB permanent magnets to apply magnetic fields, and does not require external power supply, thereby reducing energy consumption and system maintenance costs, ensuring the sustainability and economic benefits of the catalytic reaction. By combining photothermal catalysis with an external permanent magnetic field, the present invention significantly enhances the utilization efficiency of light energy and thermal energy, and improves the performance and economic benefits of the overall catalytic reaction.

[0063] The experimental device proposed in the present invention can be extended to multiple fields, including water decomposition, carbon dioxide reduction, pollutant degradation, and C1 molecule conversion.

[0064] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. An experimental device based on an external permanent magnetic field to enhance photothermal catalytic performance, characterized in that: The invention comprises a reactor body, wherein a simulated light source (1) is arranged above one side of the reactor body, a catalyst bed (8) is arranged inside the reactor body, and two permanent magnets are arranged parallel and opposite to each other on the inner side wall of the reactor body, and the two permanent magnets have opposite poles.

2. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 1 is characterized in that: The catalyst powder in the catalyst bed (8) is non-magnetic catalyst powder or paramagnetic catalyst powder.

3. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 1 is characterized in that: The catalyst bed (8) is located within the magnetic field formed by the permanent magnet.

4. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 1 is characterized in that: The simulated light source (1) is provided with a condenser lens (2).

5. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 1 is characterized in that: A viewing window is arranged on the top of the reactor body.

6. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 5 is characterized in that: A sealing component is arranged on the top of the reactor body, and the sealing component comprises a fixed connection component and a graphite gasket (5); The graphite gasket (5) is arranged below the visual window, and the reactor body is connected to the visual window via a fixed connection component.

7. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 1, characterized in that: A heating system is arranged at the bottom of the reactor body.

8. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 7 is characterized in that: The heating system is arranged below the catalyst bed (8).

9. The experimental device for enhancing photothermal catalytic performance based on an external permanent magnetic field according to claim 7, characterized in that: A quartz sand core (9) is arranged below the catalyst bed (8), and the quartz sand core (9) is in contact with a heating system.

10. An experimental method for an experimental device based on an external permanent magnetic field to enhance photothermal catalytic performance according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: After CO2 and H2O reach adsorption equilibrium on the surface of the catalyst bed (8), the simulated light source (1) is turned on to illuminate the catalyst bed (8); S2: Under light conditions, two permanent magnets with opposite polarities and parallel to each other apply a magnetic field to the catalyst bed (8) to conduct an experiment.

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