A preparation method of lithium chloride / molybdenum disulfide / wood-based composite aerogel for wet gas power generation

Abstract

The application discloses a preparation method of lithium chloride-molybdenum disulfide / wood-based composite aerogel for moisture power generation. The preparation method comprises the following steps: 1) wood-based aerogel preparation; and 2) lithium chloride-molybdenum disulfide / wood-based composite aerogel preparation. In the application, wood is selected as a base material, molybdenum disulfide is grown on the surface of the wood by a hydrothermal method, and then the wood is soaked in a lithium chloride solution, so that the lithium chloride-molybdenum disulfide / wood-based composite aerogel is successfully prepared. Lithium chloride serves as a moisture absorbent, absorbs water from air, and provides a power source for a generator. The aerogel has a large amount of cellulose nanometer network in a microchannel, movable ions (Li + ) and continuous ion bridges, and can be used as a moisture power generation material. The aerogel can continuously output voltage and current without any external auxiliary equipment, and provides a new idea for realizing environmental water collection and continuously and stably outputting electric energy.

Description

Technical Field

[0001] This invention relates to the field of nanomaterial preparation technology, specifically to a method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel for wet gas power generation. Background Technology

[0002] According to statistics from the International Energy Agency (IEA), electricity consumption has increased significantly over the past 30 years. This electricity generation relies primarily on the combustion of fossil fuels, which are non-renewable and finite resources. Their extensive use is detrimental to sustainable development and exacerbates global warming. Therefore, there is an urgent need to find sustainable resources to mitigate this problem. Human respiration, plant transpiration, and atmospheric water vapor are abundant resources, making wetland power generation a relatively new research area in recent years.

[0003] Moisture-powered electricity generation is a green technology that converts the chemical energy of water in the air into electrical energy, offering advantages such as simple structure and direct current generation. Existing moisture-powered electricity generation technologies primarily utilize carbon nanomaterials and polymers as raw materials. However, carbon nanomaterials are too expensive to produce, and polymers are difficult to degrade. Wood-based materials possess natural microscopic unidirectional channels, are rich in hydrophilic functional groups, exhibit a wet electrostatic effect, and are widely available, abundant, and biodegradable, making them ideal candidate materials for moisture generators. However, in long-term moisture-powered electricity generation, wood-based materials suffer from low photothermal conversion efficiency, weak evaporation rate, low moisture absorption efficiency, small moisture absorption capacity, and significant susceptibility to temperature changes. Molybdenum disulfide, on the other hand, has an adjustable bandgap and can be transformed from semiconductor to metallic properties through doping, greatly improving solar energy utilization. Lithium chloride, acting as a hygroscopic agent, absorbs moisture from the air to provide power for the generator. Combining the functions of these three materials, the prepared lithium chloride@molybdenum disulfide / wood-based composite aerogel can support continuous power generation and has broad practical application prospects. Summary of the Invention

[0004] To address the aforementioned issues, this invention, starting from the photothermal properties, evaporation properties, and moisture absorption properties of wood-based materials, and targeting the problems of low photothermal conversion efficiency and low power generation of existing wet power generation materials, discloses a method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel for wet power generation.

[0005] The technical solution of the present invention is as follows:

[0006] A method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel for wet gas power generation, characterized by comprising the following steps:

[0007] 1) Preparation of wood-based aerogel: Prepare a sodium chlorite solution, adjust the pH of the solution to 2-6 with acetic acid, soak natural wood in the solution, heat in a water bath at 50-150℃ for 8-16 hours, transfer the wood to a mixed solution of sodium hydroxide and sodium sulfite, heat in a water bath at 50-120℃ for 10-20 hours, rinse thoroughly with a large amount of deionized water until neutral, pre-freeze in a refrigerator for 12-24 hours, and freeze-dry in a vacuum freeze dryer for 12-72 hours to obtain wood-based aerogel.

[0008] 2) Preparation of lithium chloride@molybdenum disulfide / wood-based composite aerogel: Sodium molybdate dihydrate, urea, and thioacetamide were weighed and dissolved in anhydrous ethanol. After magnetic stirring until homogeneous, the wood-based aerogel prepared in step 1) was immersed in the solution and transferred to a hydrothermal reactor. The reaction was carried out at 150–250 °C for 10–30 h. After the hydrothermal reactor cooled, the reactants were washed with a large amount of deionized water until neutral. The reactants were pre-frozen in a refrigerator for 12–24 h and then freeze-dried in a vacuum freeze dryer for 24–72 h. The reactants were then removed and immersed in a lithium chloride solution for 10–30 h, pre-frozen again, and then freeze-dried in a vacuum freeze dryer for 12–72 h to obtain lithium chloride@molybdenum disulfide / wood-based composite aerogel.

[0009] 3) In the above scheme: by using natural wood as the substrate, molybdenum disulfide is grown in situ, and then lithium chloride is injected inside as a hygroscopic agent to prepare lithium chloride@molybdenum disulfide / wood-based composite aerogel. This aerogel can be applied to fields such as moisture evaporation and moisture absorption for electricity generation, accelerating water evaporation and improving electricity generation performance.

[0010] 4) Further, the preparation method of the above-mentioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is characterized in that: the mass fraction of sodium chlorite in step 1) is 2-10 wt%.

[0011] 5) Further, the preparation method of the above-mentioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is characterized in that: the molar concentration ratio of sodium hydroxide solution and sodium sulfite solution in step 1) is 1:2 to 1:10.

[0012] Furthermore, the preparation method of the above-mentioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is characterized in that: the mass ratio of sodium molybdate dihydrate, urea and thioacetamide in step 2) is 1:1:1 to 2:6:5.

[0013] Furthermore, the preparation method of the above-mentioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is characterized in that: the magnetic stirring time in step 2) is 5 to 30 minutes.

[0014] Furthermore, the preparation method of the above-mentioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is characterized in that: the mass percentage of the lithium chloride solution in step 2) is 5-20 wt%.

[0015] Furthermore, the preparation method of the above-mentioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is characterized in that: the freezing temperature in step 2) is -20 to -40°C; and the freeze-drying temperature is -50 to -80°C.

[0016] Furthermore, lithium chloride@molybdenum disulfide / wood-based composite aerogel was prepared by the above preparation method.

[0017] Furthermore, the aforementioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is applied to wet gas power generation. In some examples, the performance is as follows: under a light intensity of 1 kW m⁻², the surface temperature of its lithium chloride@molybdenum disulfide / wood-based composite aerogel is 38.0 °C after 25 minutes; under a light intensity of 1 kW m⁻², the evaporation rate is 2.49 kg m⁻² h⁻¹; and under 65% humidity and light conditions, the voltage of its lithium chloride@molybdenum disulfide / wood-based composite aerogel reaches as high as 138 mV.

[0018] Furthermore, the aforementioned lithium chloride@molybdenum disulfide / wood-based composite aerogel is applied in the field of wet gas power generation.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. This invention uses natural wood as the base material, which is green and environmentally friendly, low in cost, has natural microscopic unidirectional channels, is rich in hydrophilic functional groups, and has a wet electrostatic effect, making it an ideal candidate material for preparing wet power generation.

[0021] 2. The molybdenum disulfide selected in this invention has the characteristic of adjustable band gap width, and can be transformed from semiconductor properties to metallic properties through doping, which greatly improves the utilization rate of solar energy.

[0022] 3. This invention uses lithium chloride as a desiccant to absorb moisture from the air and provide a power source for the generator.

[0023] 4. The lithium chloride@molybdenum disulfide / wood-based composite aerogel prepared by this invention has the advantages of good photothermal conversion performance, good moisture absorption performance, and fast evaporation rate. It effectively solves the problems of weak water replenishment and slow evaporation rate within the aerogel. It can be used for wet gas power generation, and by combining with solar energy, it provides a sustainable green strategy for electricity production and alleviating the depletion of fossil fuels. Attached Figure Description

[0024] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0025] Figure 1 SEM images of wood-based composite aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel in the examples and comparative examples of this invention: (ac) SEM image of wood-based composite aerogel; (df) SEM image of lithium chloride@molybdenum disulfide / wood-based composite aerogel.

[0026] Figure 2 Here is the EDS elemental distribution diagram of the lithium chloride@molybdenum disulfide / wood-based composite aerogel in this invention example:

[0027] (a) SEM image; (b) Carbon element; (c) Oxygen element; (d) Sulfur element; (e) Molybdenum element; (f) EDS curve;

[0028] Figure 3 The image shows the XRD pattern of the lithium chloride@molybdenum disulfide / wood-based composite aerogel in this invention example.

[0029] Figure 4 XPS images of wood-based composite aerogels in comparison to those in this invention;

[0030] Figure 5 Infrared thermal images of wood-based composite aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel under 1kWm-2 light intensity in the examples and comparative examples of this invention: (a) wood-based composite aerogel; (b) infrared thermal image of molybdenum disulfide / wood-based composite aerogel.

[0031] Figure 6 Evaporation rate diagrams of wood-based composite aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel in the examples and comparative examples of this invention;

[0032] Figure 7 This is a graph showing the moisture absorption rate of lithium chloride@molybdenum disulfide / wood-based composite aerogel under different humidity levels in an example of the present invention.

[0033] Figure 8 Thermocouple temperature variation diagrams of wood-based composite aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel in the examples and comparative examples of this invention;

[0034] Figure 9 Time-voltage curves of wood-based composite aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel under different conditions are shown in the examples and comparative examples of this invention: (a) Time-voltage curve under 65% humidity and light conditions; (b) Time-voltage curve under 65% humidity and no light conditions. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment describes in detail a method for preparing a lithium chloride@molybdenum disulfide / wood-based composite aerogel for wet gas power generation, including the following steps:

[0038] 1) Preparation of wood-based aerogel: 12.000g of sodium chlorite was dissolved in 188mL of deionized water. The pH of the solution was adjusted to 4.6 with acetic acid. Natural wood was soaked in the solution and heated in a water bath at 90℃ for 12h. The wood was then transferred to a mixed solution of 2.5mol / L sodium hydroxide solution and 0.4mol / L sodium sulfite solution and heated in a constant temperature water bath at 80℃ for 12h. After that, it was thoroughly rinsed with a large amount of deionized water until neutral and pre-frozen in a refrigerator (-20℃) for 12h. Finally, it was freeze-dried in a vacuum freeze dryer (-60℃) for 48h to obtain wood-based aerogel.

[0039] 2) Preparation of lithium chloride@molybdenum disulfide / wood-based composite aerogel: Weigh 0.2500g sodium molybdate dihydrate, 0.5000g urea, and 0.3000g thioacetamide, dissolve them in 50mL anhydrous ethanol, stir magnetically for 20min, then immerse the wood-based aerogel prepared in step 1) in the solution and transfer it to a 50mL hydrothermal reactor. React at 200℃ for 22h. After the hydrothermal reactor cools down, wash the reactants with deionized water until neutral, freeze them in a refrigerator (-15℃) for 24h, and freeze-dry them in a vacuum freeze dryer (-60℃) for 48h. Take out the reactants and immerse them in an 8wt% lithium chloride solution for 24h, then freeze them in a refrigerator (-15℃) for 24h, and freeze-dry them in a vacuum freeze dryer (-60℃) for 48h to obtain lithium chloride@molybdenum disulfide / wood-based composite aerogel.

[0040] Comparative Example 1

[0041] This comparative example details a method for preparing a wood-based composite aerogel for wet gas power generation, including the following steps:

[0042] Preparation of wood-based aerogel: 12.000g of sodium chlorite was dissolved in 188mL of deionized water. The pH of the solution was adjusted to 4.6 with acetic acid. Natural wood was soaked in the solution and heated in a water bath at 90℃ for 12h. The wood was then transferred to a mixed solution of 2.5mol / L sodium hydroxide solution and 0.4mol / L sodium sulfite solution and heated in a constant temperature water bath at 80℃ for 12h. After that, it was thoroughly rinsed with a large amount of deionized water until neutral and then pre-frozen in a refrigerator (-20℃) for 12h. Finally, it was freeze-dried in a vacuum freeze dryer (-60℃) for 48h to obtain wood-based aerogel.

[0043] Testing of lithium chloride@molybdenum disulfide / wood-based composite aerogel materials

[0044] Figure 1 The following are SEM images of the wood-based aerogel and the lithium chloride@molybdenum disulfide / wood-based composite aerogel in the examples and comparative examples of this invention: (ac) is the SEM image of the wood-based aerogel; (df) is the SEM image of the lithium chloride@molybdenum disulfide / wood-based composite aerogel. From (ac), it can be seen that the microstructure of the wood-based aerogel exhibits a vertical layered channel, facilitating the transport of ions and small molecules. From (df), it can be seen that the lithium chloride@molybdenum disulfide / wood-based composite aerogel exhibits a converging vertical layered channel, with good dispersibility and no obvious agglomeration. Furthermore, the aerogel surface displays a three-dimensional flower-like structure, indicating that it can effectively promote the adsorption of water by the aerogel, achieving good water storage and rapid water transport in the subsequent desorption process.

[0045] Figure 2 The following are EDS elemental distribution diagrams of the lithium chloride@molybdenum disulfide / wood-based composite aerogel in this invention example: (a) SEM image; (b) carbon element; (c) oxygen element; (d) sulfur element; (e) molybdenum element; (f) EDS curve. The figures show that sulfur and molybdenum are uniformly distributed, consistent with the distribution of molybdenum disulfide on the surface of the wood-based composite aerogel.

[0046] Figure 3 The image shows the XRD pattern of lithium chloride@molybdenum disulfide / wood-based composite aerogel in this invention example. As shown, the characteristic peak of molybdenum disulfide corresponds to the crystal plane (002) at approximately 9°. Compared with the standard card (002) in JCPDS No. 75-1952, there is a significant shift, and a new second-order diffraction peak appears at 35.53°. At this point, the 2H phase of molybdenum disulfide has transformed into the 1T phase structure, indicating that the properties of molybdenum disulfide have changed from semiconductor to metallic, which enhances light absorption in the near-infrared region and improves photothermal conversion efficiency.

[0047] Figure 4This is the XPS spectrum of the wood-based aerogel in the comparative example of this invention. As can be seen from the figure, the C 1s spectrum of the wood-based aerogel consists of four types of carbon bonds: C=C, COH, CC, and C=O. The peak centers at 283 eV, 284.8 eV, 286.2 eV, and 287.8 eV represent the sp2 hybridized C in COH and CC, and the C in CO and C=O, respectively.

[0048] Figure 5 Infrared thermal images of wood-based aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel under a light intensity of 1 kW m⁻² are shown in the examples and comparative examples of this invention: (a) wood-based aerogel; (b) infrared thermal image of lithium chloride@molybdenum disulfide / wood-based composite aerogel. Under a light intensity of 1 kW m⁻², the temperatures of the wood-based aerogel and the lithium chloride@molybdenum disulfide / wood-based composite aerogel increased by 16.1 °C and 22.8 °C, respectively. This indicates that the lithium chloride@molybdenum disulfide / wood-based composite aerogel has good photothermal conversion performance.

[0049] Figure 6 This diagram shows the evaporation rates of wood-based aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel in the examples and comparative examples of this invention. Under a light intensity of 1 kW m⁻², the evaporation rates of the wood-based aerogel and the lithium chloride@molybdenum disulfide / wood-based composite aerogel are 1.35 kg m⁻² h⁻¹ and 2.49 kg m⁻² h⁻¹, respectively. After 20 minutes, the wood-based aerogel released 6.3% of its absorbed water, while the molybdenum disulfide / wood-based composite aerogel released 8.5%, indicating that the lithium chloride@molybdenum disulfide / wood-based composite aerogel possesses excellent evaporation performance and can effectively provide continuous power generation for the generator.

[0050] Figure 7 This diagram shows the moisture absorption performance of the lithium chloride@molybdenum disulfide / wood-based composite aerogel under different humidity levels in this invention example. The moisture absorption rates of the molybdenum disulfide / wood-based composite aerogel reached 22.45%, 58.99%, and 109.7% at humidity levels of 50%, 65%, and 80%, respectively. This indicates that the molybdenum disulfide / wood-based composite aerogel can absorb moisture over a wide humidity range, exhibiting good moisture absorption properties.

[0051] Figure 8 The graph shows the thermocouple temperature changes of wood-based aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel in the examples and comparative examples of this invention. Under a light intensity of 1 kW m⁻², the lithium chloride@molybdenum disulfide / wood-based composite aerogel heats up faster than the wood-based aerogel. After a period of time, the temperature rise rate of the lithium chloride@molybdenum disulfide / wood-based composite aerogel gradually slows down and reaches a relatively stable state. This indicates that the lithium chloride@molybdenum disulfide / wood-based composite aerogel is beneficial for the stable power generation of nanogenerators.

[0052] Figure 9The following are time-voltage curves of wood-based aerogel and lithium chloride@molybdenum disulfide / wood-based composite aerogel under different conditions in the examples and comparative examples of this invention: (a) under light conditions with 65% humidity; (b) under light-free conditions with 65% humidity. Under light conditions, the voltage of the wood-based composite aerogel is around 30mV, and under light-free conditions, its voltage is around 20mV. In contrast, the voltage of the molybdenum disulfide / wood-based composite aerogel fluctuates around 120mV under both light and light-free conditions. This indicates that the molybdenum disulfide / wood-based composite aerogel can provide continuous and stable electrical energy output, demonstrating stable power generation performance.

[0053] As can be seen from Example 1 and the comparative example above, this invention addresses the existing problems and shortcomings of the technology by considering the photothermal properties, evaporation properties, and hygroscopic properties of the materials. Specifically, it provides a method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogels for wet power generation, addressing the issues of low photothermal conversion efficiency and low power generation in existing wet power generation materials. This invention uses natural wood as the substrate to prepare lithium chloride@molybdenum disulfide / wood-based composite aerogels.

[0054] Wood-based composite aerogels. These aerogels possess a large number of cellulose nanonetworks within microchannels, with mobile ions (Li+) and continuous ion bridges. They can serve as moisture nanogenerators, continuously outputting voltage and current without any external auxiliary equipment, providing a new approach to environmental moisture collection and continuous, stable power output.

[0055] The above embodiments are a limited number of preferred implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel for wet gas power generation, characterized in that, Includes the following steps: 1) Preparation of wood-based aerogel: Prepare sodium chlorite solution, adjust the pH of the solution to 2-6 with acetic acid, soak natural wood in the solution, heat in a water bath at 50-150℃ for 8-16 hours, transfer the wood to a mixed solution of sodium hydroxide solution and sodium sulfite solution, heat in a water bath at 50-120℃ for 10-20 hours, rinse thoroughly with a large amount of deionized water until neutral, pre-freeze in a refrigerator for 12-24 hours, and freeze-dry in a vacuum freeze dryer for 12-72 hours to obtain wood-based aerogel; 2) Preparation of lithium chloride@molybdenum disulfide / wood-based composite aerogel: Weigh sodium molybdate dihydrate, urea, and thioacetamide, dissolve them in anhydrous ethanol, stir magnetically until homogeneous, immerse the wood-based aerogel prepared in step 1) in the solution, and transfer it to a hydrothermal reactor. React at 150-250℃ for 10-30 h. After the hydrothermal reactor cools down, wash the reactants with a large amount of deionized water until neutral, pre-freeze them in a refrigerator for 12-24 h, freeze-dry them in a vacuum freeze dryer for 24-72 h, remove the reactants and immerse them in lithium chloride solution for 10-30 h, pre-freeze them again in a refrigerator, and freeze-dry them in a vacuum freeze dryer for 12-72 h to obtain lithium chloride@molybdenum disulfide / wood-based composite aerogel.

2. The method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel according to claim 1, characterized in that: In step 1), the mass fraction of sodium chlorite is 2–10 wt%.

3. The method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel according to claim 1, characterized in that: In step 1), the molar concentration ratio of sodium hydroxide solution to sodium sulfite solution is 1:2 to 1:

10.

4. The method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel according to claim 1, characterized in that: In step 2), the mass ratio of sodium molybdate dihydrate, urea, and thioacetamide is 1:1:1 to 2:6:

5.

5. The method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel according to claim 1, characterized in that: In step 2), the magnetic stirring time is 5 to 30 minutes.

6. The method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel according to claim 1, characterized in that: In step 2), the lithium chloride solution has a mass percentage of 5–20 wt%.

7. The method for preparing lithium chloride@molybdenum disulfide / wood-based composite aerogel according to claim 1, characterized in that: The freezing temperature of the refrigerator in step 2) is -20 to -40°C; the freeze-drying temperature is -50 to -80°C.

8. Lithium chloride@molybdenum disulfide / wood-based composite aerogel prepared by any of the preparation methods described in claims 1 to 7.

9. The application of the lithium chloride@molybdenum disulfide / wood-based composite aerogel according to claim 8, characterized in that, Application of the lithium chloride@molybdenum disulfide / wood-based composite aerogel in wet gas power generation.

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