Solar thermally-driven water purification and power generation integrated device and preparation method thereof

Abstract

The invention discloses a solar thermally-driven water purification and power generation integrated device and a preparation method thereof. The solar thermally-driven water purification and power generation integrated device comprises a PDA-Sponge photo-thermal material, a thermoelectric generator TEG and bamboo fiber filter paper. A polydopamine coating is formed on melamine sponge through in-situ polymerization, a PDA-Sponge photo-thermal material is obtained, the photo-thermal material is connected with the hot end of TEG, bamboo fiber filter paper is inserted into the bottom of the device to serve as a hydrophilic layer, water is conveyed to the PDA-Sponge photo-thermal material from the bamboo fiber paper through the capillary action, and the solar-driven water evaporation and thermal power generation dual-function device, namely PDA-Sponge / TEG, is formed. The core assembly of the invention is a PDA (at) Sponge photo-thermal material, bamboo fiber filter paper as a hydrophilic layer, and a TEG device. By optimizing the loading capacity of the PDA and adjusting the surface appearance of the PDA-Sponge, efficient water evaporation and thermal power generation performance are achieved at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of photothermal-thermoelectric conversion materials, and in particular to a PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device and a preparation method thereof. Background Art

[0002] With the rapid increase in global population and the continuous advancement of industrialization, water and energy have become the two most scarce resources today. Fresh water is the cornerstone of maintaining life and industrial operation, but its supply is limited and consumption demand is constantly rising. At the same time, the large-scale consumption of traditional energy not only depletes resources, but also aggravates environmental pollution and climate change. Faced with this grim situation, the development and utilization of renewable resources to alleviate the freshwater and energy crises has become a focus of global attention. As a clean, eco-friendly and renewable resource, solar energy is regarded as a promising energy source for desalination and power generation.

[0003] Solar steam generators (SSGs) have attracted extensive research interest in recent years due to their potential applications in water purification and desalination. One of the key steps is to use photothermal materials to convert solar energy into heat energy, thereby promoting water evaporation. However, this coating-based design not only requires advanced manufacturing technology, but also imposes restrictions on the geometry of the device, making it impossible to optimize the shape to accelerate the water evaporation rate. In addition, the functions of these devices are mainly limited to desalination, limiting their versatility.

[0004] As a low-cost and efficient evaporation material, melamine sponge has shown good potential in improving evaporation rate. However, due to the lack of the ability to directly convert solar energy into thermal energy, it needs to be combined with photothermal materials to achieve efficient energy conversion. Polydopamine (PDA), as a material with excellent absorption capacity in the solar spectrum, has become an ideal candidate. It is easy to synthesize and can form composite materials with a variety of flexible materials, bringing new possibilities to the design of photothermal evaporation materials.

[0005] Therefore, how to achieve the dual functions of efficient solar water heating evaporation and thermal power generation in an eco-friendly and cost-effective manner for seawater desalination and power generation has become one of the technical problems that need to be solved. Summary of the invention

[0006] In order to overcome the above problems, the purpose of the embodiment of the present invention is to provide a PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device and its preparation method. Through the integrated integration of solar thermal driven water purification and power generation, not only can photothermal water evaporation be carried out efficiently, but also thermoelectric power generation can be achieved. The device of the solar thermal driven water purification and power generation integrated device is prepared by simple immersion technology. By optimizing the PDA load and adjusting the surface morphology of the melamine sponge, efficient water evaporation and thermal power generation performance are achieved simultaneously. The formed dual-function device provides a certain solution for remote areas lacking electricity and drinking water infrastructure, and provides a new technical solution for synchronous low-energy electronic equipment power supply and wastewater purification.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a solar thermal driven water purification and power generation integrated device, comprising:

[0009] The PDA@Sponge photothermal material is composed of a melamine sponge substrate and a polydopamine coating. The melamine sponge is used as a carrier, and the polydopamine coating is formed by in-situ polymerization on the melamine sponge, thereby forming a uniform PDA coating on the surface of the melamine sponge substrate to obtain the PDA@Sponge photothermal material.

[0010] The PDA@Sponge photothermal material is connected to the hot end of TEG, and bamboo fiber filter paper is inserted at the bottom as a hydrophilic layer to form a solar-driven water evaporation and thermal power generation dual-function device, namely PDA@Sponge / TEG; wherein, the heat energy obtained by converting light energy into heat energy by the PDA@Sponge photothermal material increases the temperature of the hot end of the thermoelectric generator. Due to the Seebeck effect, a temperature difference is generated between the hot and cold ends, and the thermoelectric generator further converts the heat energy into electrical energy, thereby realizing photothermal-thermoelectric conversion, that is, achieving thermal power generation performance; using bamboo fiber filter paper, water can be transferred from the bamboo fiber filter paper to the PDA@Sponge photothermal material through capillary action, thereby realizing photothermal water evaporation.

[0011] As a further solution of the present invention, the polydopamine (PDA) coating is a uniform polydopamine coating formed directly on the surface of the melamine sponge by an in-situ polymerization method. The polydopamine coating is formed by polymerization of dopamine monomers in an alkaline aqueous solution.

[0012] As a further solution of the present invention, the polydopamine (PDA) coating is prepared by in-situ polymerization of dopamine on a melamine sponge using a Tris-HCl buffer solution through a solution oxidation method.

[0013] As a further solution of the present invention, the preparation method of the PDA@Sponge photothermal material comprises the following steps:

[0014] 1) Preparation of dopamine hydrochloride solution: dissolving dopamine monomer in an alkaline aqueous solution;

[0015] 2) In-situ polymerization: The melamine sponge is placed in the above-mentioned dopamine hydrochloride solution, and the dopamine monomer will spontaneously oxidize and polymerize on the sponge surface to form a polydopamine coating;

[0016] 3) Synthesis of PDA@Sponge: The loading amount of polydopamine on the melamine sponge was adjusted by controlling the dosage of monomer dopamine, immersion time and temperature. After the reaction was carried out for a certain period of time, the surface was washed with deionized water to obtain the PDA@Sponge photothermal material.

[0017] As a further solution of the present invention, the alkaline aqueous solution adopts a Tris-HCl buffer solution with a pH value of 8.5, and different masses of dopamine solid monomers are dispersed in the Tris-HCl buffer solution, and dopamine hydrochloride solutions of different concentrations are obtained after stirring and dissolving.

[0018] As a further embodiment of the present invention, the concentration of the dopamine hydrochloride solution is 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 4 mg / mL, 6 mg / mL, etc.

[0019] As a further solution of the present invention, a certain volume of melamine sponge is placed in a dopamine hydrochloride solution, and the surface shape of the melamine sponge is cut into a plane shape, a zigzag shape, an arc shape, etc.

[0020] As a further solution of the present invention, when preparing the PDA@Sponge photothermal material, the structure is optimized by optimizing the loading concentration of polydopamine (PDA) and changing the surface morphology of the carrier melamine sponge. When the concentration of the dopamine hydrochloride solution is 4 mg / mL and the jagged PDA@Sponge photothermal material has the best performance.

[0021] As a further solution of the present invention, the water evaporation and thermal power generation dual-function device can be connected to an energy storage device for storing the generated electrical energy.

[0022] As a further solution of the present invention, the solar thermal driven water purification and power generation integrated device is a dual-function water cup with water evaporation and thermoelectric power generation. The core components of the dual-function water cup include PDA@Sponge photothermal material, thermoelectric generator, bamboo fiber filter paper, thermal insulation layer and energy storage device. The PDA@Sponge photothermal material is coated on the hot end of the thermoelectric generator (TEG), wherein the PDA@Sponge photothermal material can be exposed to sunlight. The heat generated can, on the one hand, transfer the bamboo fiber filter paper to the water evaporation of the PDA@Sponge photothermal material to generate water vapor, thereby playing a role in water purification; on the other hand, the heat converted by the photothermal material can increase the temperature of the hot end of the thermoelectric generator (TEG), and a temperature difference is generated between the hot and cold ends. According to the Seebeck effect, the carriers move in a directional manner to generate electrical energy, which can be stored through an energy storage device. In the second aspect, the present invention also provides a method for preparing a solar thermal driven water purification and power generation integrated device combining PDA@Sponge with a thermoelectric generator (TEG), comprising the following steps:

[0023] 1. Preparation of PDA@Sponge photothermal material:

[0024] Preparation of dopamine hydrochloride solution: dispersing different weights of dopamine in a Tris-HCl buffer solution, stirring and dissolving to obtain dopamine hydrochloride solutions of different concentrations;

[0025] In-situ polymerization: A melamine sponge with a suitable surface morphology is placed in a dopamine hydrochloride solution, and the dopamine monomer begins to spontaneously oxidize and polymerize in-situ on the melamine sponge;

[0026] Preparation of PDA@Sponge: By controlling the amount of monomer dopamine, immersion time, and temperature, the loading amount of polydopamine on the melamine sponge is adjusted. After the reaction is carried out for a certain period of time, the surface is washed with deionized water to obtain the PDA@Sponge photothermal material.

[0027] 2. Assemble PDA@Sponge / TEG:

[0028] The PDA@Sponge photothermal material is connected to the hot end of a thermoelectric generator (TEG) to form a solar-driven water evaporation and thermal power generation dual-function device, namely PDA@Sponge / TEG.

[0029] 3. Prepare the bamboo fiber filter paper bottom layer:

[0030] Bamboo fiber filter paper was used as a hydrophilic layer and inserted into the bottom of the bifunctional device to transfer water from the bamboo fiber paper to the PDA@Sponge photothermal material by capillary action.

[0031] 4.Electric energy storage:

[0032] The thermoelectric generator is further connected to an energy storage device to achieve electrical energy storage.

[0033] As a further embodiment of the present invention, when preparing the dopamine hydrochloride solution, dopamine solids weighed according to different masses are poured into five beakers, and added into 75 mL of a Tris-HCl buffer solution having a pH value of 8.5 and a concentration of 10 mM, and stirred to dissolve to obtain dopamine hydrochloride solutions with concentrations of 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 4 mg / mL, 6 mg / mL, etc.

[0034] As a further solution of the present invention, a certain volume of melamine sponge cut into plane, zigzag and arc-shaped surface shapes is placed in a dopamine hydrochloride solution.

[0035] As a further solution of the present invention, the method for preparing the solar thermal driven water purification and power generation integrated device also includes a dual-function water cup, and the steps are as follows:

[0036] 1) Coat the PDA@Sponge photothermal material on the hot end of the thermoelectric generator (TEG);

[0037] 2)PDA@Sponge photothermal materials can be exposed to sunlight, and the photothermal materials can convert light energy into heat energy;

[0038] 3) On the one hand, the heat generated can transfer the water from the bamboo fiber filter paper to the PDA@Sponge photothermal material to evaporate and generate water vapor, thereby playing a role in water purification;

[0039] 4) On the other hand, the temperature of the hot end of the thermoelectric generator (TEG) can be increased, and a temperature difference can be generated between the hot and cold ends. According to the Seebeck effect, the carriers move in a directional manner to generate electrical energy, which can be stored through an energy storage device.

[0040] Through the above steps, the preparation of the PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device can be completed. The device combines solar water evaporation and thermoelectric power generation technology, which can not only effectively purify water quality, but also generate electricity at the same time, and has potential environmental protection and economic applicability value.

[0041] Compared with the prior art, the solar thermal driven water purification and power generation integrated device and its preparation method of the present invention have the following beneficial effects:

[0042] 1. Efficient solar energy utilization: PDA@Sponge photothermal materials efficiently absorb sunlight and convert light energy into heat energy. When combined with TEG, the heat energy can be further converted into electrical energy, achieving efficient utilization of solar energy and performing two-level energy conversion.

[0043] 2. The device realizes the integration of water purification and power generation: the device uses solar energy to drive water evaporation, and uses a thermoelectric generator to convert heat energy into electrical energy, realizing the dual functions of water purification and power generation. Through the heat-driven water evaporation process, impurities and salt in the water can be effectively removed to obtain purified fresh water, which is suitable for use in areas with poor water quality. The electricity generated by TEG can be stored in capacitors to power small electronic devices or to achieve electrical energy output in the absence of sunlight.

[0044] Therefore, the solar thermal driven water purification and power generation integrated device of the present invention effectively combines solar water purification and power generation technologies, which is of great significance for the supply of clean energy and drinking water in areas with limited resources or far away from the power grid, and can achieve solar thermal water evaporation and thermal power generation in an eco-friendly and economical and efficient manner.

[0045] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the structure of the PDA@Sponge photothermal material coated on the thermoelectric generator (TEG) in a solar thermal driven water purification and power generation integrated device provided by the present invention.

[0047] Figure 2 This is a schematic structural diagram of a solar thermal driven water purification and power generation integrated device provided by the present invention, in which the PDA@Sponge photothermal material is coated on a thermoelectric generator (TEG) and inserted into a bamboo fiber filter paper bottom layer.

[0048] Figure 3 A schematic diagram of the principle of converting thermal energy into electrical energy by a generator (TEG) in a solar thermal driven water purification and power generation integrated device provided by the present invention.

[0049] Figure 4 A schematic structural diagram of a melamine sponge in a solar thermal driven water purification and power generation integrated device provided by the present invention.

[0050] Figure 5 Schematic diagram of PDA@Sponge and its preparation process in a solar thermal driven water purification and power generation integrated device provided by the present invention.

[0051] Figure 6Schematic diagram of solar-driven water purification and thermoelectric power generation of PDA@Sponge / TEG in a solar thermal-driven water purification and power generation integrated device provided by the present invention; wherein, (a) experimental structure of solar water purification and thermoelectric power generation. (b) Water mass loss of PDA@Sponge / TEG. (c) UV-visible absorption spectrum of water contaminated with MO and MB dyes, and condensed water collected from steam generation. Application of PDA@Sponge / TEG to power small electronic devices (d) smart watches and (e) small light bulbs.

[0052] Figure 7 This is a schematic diagram of the structure of a dual-function water cup used in a solar thermal driven water purification and power generation integrated device provided by the present invention.

[0053] Figure 8 This is a front view of a solar thermal driven water purification and power generation integrated device provided by the present invention.

[0054] Fig. 9 This is a schematic AA cross-sectional view of a solar thermal driven water purification and power generation integrated device provided by the present invention. DETAILED DESCRIPTION

[0055] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0056] The present invention provides a PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device and its preparation method, which can realize photothermal water evaporation and thermal power generation in an eco-friendly and economical and efficient manner. Under sunlight, the device effectively purifies water through surface evaporation and uses heat for thermal power generation. The device is easily made through a simple immersion technique and consists of two key components: (1) PDA@Sponge photothermal material, which has broadband light absorption and high photothermal conversion efficiency, serves as both a structural support and a water transmission substrate, and is easy to cut; (2) bamboo fiber filter paper, which acts as a hydrophilic layer to enhance water absorption and transmission.

[0057] Therefore, the PDA@Sponge of the present invention combines TEG's solar thermal driven water purification and power generation integrated device, and optimizes the structure by optimizing the loading concentration of polydopamine and changing the surface morphology of the carrier melamine sponge. When the concentration of dopamine hydrochloride solution is 4 mg / mL and due to its unique tip thermal positioning, the jagged PDA@Sponge photothermal material has the best performance. In addition, after integrating the PDA@Sponge material with a thermoelectric generator (TEG), the thermoelectric performance is significantly improved, generating higher current and voltage, and the output power at the load resistance is sufficient to power low-energy electronic devices.

[0058] The PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device of the present invention can use renewable solar energy to solve the global energy and water crisis, especially in remote areas lacking power and drinking water infrastructure. The dual-function device provides a promising method for powering low-energy electronic devices, desalinating seawater, and purifying wastewater.

[0059] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0060] See also Figures 1 to 4 As shown, an embodiment of the present invention provides a solar thermal driven water purification and power generation integrated device, including a PDA@Sponge photothermal material, a thermoelectric generator (TEG) and a bamboo fiber filter paper B. The PDA@Sponge photothermal material is composed of a melamine sponge substrate and a polydopamine coating. The melamine sponge is used as a carrier to form a uniform PDA coating on the surface of the melamine sponge substrate to obtain the PDA@Sponge photothermal material.

[0061] The PDA@Sponge photothermal material is connected to the hot end of the TEG to form a PDA@Sponge / TEG device. The heat energy converted by the PDA@Sponge photothermal material is used to increase the temperature of the hot end of the thermoelectric generator. Due to the Seebeck effect, a temperature difference is generated between the hot and cold ends, and the thermoelectric generator further converts the heat energy into electrical energy, thereby achieving photothermal-thermoelectric conversion, that is, achieving thermal power generation performance. Bamboo fiber filter paper B, as a hydrophilic layer, is inserted into the bottom of the PDA@Sponge / TEG device. Water can be transferred from the bamboo fiber filter paper to the PDA@Sponge photothermal material through capillary action, thereby achieving photothermal water evaporation.

[0062] When preparing the PDA@Sponge photothermal material, the polydopamine (PDA) coating is formed by directly forming a uniform polydopamine coating on the surface of the melamine sponge by an in-situ polymerization method. The polydopamine coating is formed by polymerization of dopamine monomers in an alkaline aqueous solution. In this example, the polydopamine (PDA) coating is formed by spontaneous polymerization of dopamine monomers in a Tris-HCl alkaline buffer solution using a solution oxidation method.

[0063] Among them, the preparation method of PDA@Sponge photothermal material is:

[0064] 1) Preparation of dopamine hydrochloride solution: dissolving dopamine monomer in an alkaline aqueous solution;

[0065] 2) In-situ polymerization: The melamine sponge is placed in the above-mentioned dopamine hydrochloride solution, and the dopamine monomer will spontaneously oxidize and polymerize on the sponge surface to form a polydopamine coating;

[0066] 3) Synthesis of PDA@Sponge: The loading amount of polydopamine on the melamine sponge was adjusted by controlling the dosage of monomer dopamine, immersion time and temperature. After the reaction was carried out for a certain period of time, the surface was washed with deionized water to obtain the PDA@Sponge photothermal material.

[0067] In the above steps, the alkaline aqueous solution is a Tris-HCl buffer solution with a pH value of 8.5, and different masses of dopamine solid monomers are dispersed in the Tris-HCl buffer solution, and dopamine hydrochloride solutions of different concentrations are obtained after stirring and dissolving. The concentration of the dopamine hydrochloride solution is 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 4 mg / mL, 6 mg / mL, etc.

[0068] In the above steps, see Figure 4 As shown, when preparing the PDA@Sponge photothermal material, a certain volume of melamine sponge is placed in a dopamine hydrochloride solution, and the surface shape of the melamine sponge is cut into a flat shape, a zigzag shape, an arc shape, etc.

[0069] In this embodiment, when the PDA@Sponge photothermal material is prepared, the solution oxidation in situ synthesis method is used, and the dopamine solution is oxidized to polydopamine using a Tris-HCl buffer solution and grown in situ on a melamine sponge substrate. The pH of the Tris buffer solution is 8.5, and the concentration of the dopamine hydrochloride solution is 4 mg / mL. The polydopamine under this ratio can be uniformly and stably loaded on the melamine sponge. The uniformity is verified by scanning electron microscopy, and the stability is observed by ultrasonic cleaning before and after. In this method, the shape of the melamine sponge is pointed, and the tip thermal effect is used, which is beneficial to the application of photothermal-thermoelectric conversion, wherein the tip thermal effect refers to the pointed morphology of the melamine sponge during the preparation process.

[0070] The PDA@Sponge material prepared above has dual application functions, one is water evaporation, and the other is thermoelectric power generation.

[0071] In some embodiments, the water evaporation and thermal power generation dual-function device is further connected to a capacitor C, which is charged by a thermoelectric generator (TEG) and is used to store the generated electrical energy.

[0072] The embodiment of the present invention also provides a method for preparing a solar thermal driven water purification and power generation integrated device, comprising the following steps:

[0073] 1) Preparation of PDA@Sponge photothermal material:

[0074] Preparation of dopamine hydrochloride solution: dispersing different weights of dopamine in a Tris-HCl buffer solution, stirring and dissolving to obtain dopamine hydrochloride solutions of different concentrations;

[0075] In-situ polymerization: A melamine sponge with a suitable morphology is placed in a dopamine hydrochloride solution, and the dopamine monomer begins to spontaneously oxidize and polymerize in-situ on the melamine sponge;

[0076] Preparation of PDA@Sponge: By controlling the amount of monomer dopamine, immersion time, and temperature, the loading amount of polydopamine on the melamine sponge is adjusted. After the reaction is carried out for a certain period of time, the surface is washed with deionized water to obtain the PDA@Sponge photothermal material.

[0077] 2) Assemble PDA@Sponge / TEG:

[0078] Connect the PDA@Sponge to the hot end of the TEG;

[0079] 3) Preparation of bamboo fiber filter paper bottom layer:

[0080] The bamboo fiber filter paper was used as a hydrophilic layer and inserted into the bottom of the dual-function device to transfer water from the bamboo fiber paper to the PDA@Sponge photothermal material by capillary action.

[0081] 4) Electrical energy storage:

[0082] The thermoelectric generator is further connected to an energy storage device to achieve electrical energy storage.

[0083] The method for preparing the solar thermal driven water purification and power generation integrated device also includes a dual-function water cup, and the steps are as follows:

[0084] 1) Coat the PDA@Sponge photothermal material on the hot end of the thermoelectric generator (TEG);

[0085] 2)PDA@Sponge photothermal materials can be exposed to sunlight, and the photothermal materials can convert light energy into heat energy;

[0086] 3) On the one hand, the heat generated can transfer the water from the bamboo fiber filter paper to the PDA@Sponge photothermal material to evaporate and generate water vapor, thereby playing a role in water purification;

[0087] 4) On the other hand, the temperature of the hot end of the thermoelectric generator (TEG) can be increased, and a temperature difference can be generated between the hot and cold ends. According to the Seebeck effect, the carriers move in a directional manner to generate electrical energy, which can be stored through an energy storage device.

[0088] Through the above steps, the preparation of the PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device can be completed. The device combines solar water evaporation and thermoelectric power generation technology, which can not only effectively purify water quality, but also generate electricity at the same time, and has potential environmental protection and economic applicability value.

[0089] The PDA@Sponge prepared by the above method combined with TEG solar thermal driven water purification and power generation integrated device was used to measure the evaporation rate through a solar simulator, where a simulated solar irradiation lamp with a standard AM 1.5G spectrum was used to study the evaporation performance of water. During the evaporation experiment, an electronic balance (Leqi) with an accuracy of 0.001 grams was used to record the mass change of deionized water. The evaporation efficiency of water was calculated using the following formula:

[0090]

[0091] in, is the evaporation rate under different lighting conditions, minus the intrinsic evaporation rate in the dark and the support. LV represents the enthalpy of vaporization; C opt is the optical density; q i is the standard solar radiation.

[0092] In the present invention, melamine sponge is selected as the base material because it has a porous structure and a large surface area, which is conducive to achieving a high evaporation rate. In the design of the present invention, polydopamine (PDA) is used for the following reasons: (1) PDA exhibits excellent absorption capacity throughout the solar spectrum, representing its high efficiency as a photothermal material; (2) PDA can be combined with other flexible materials for easy customization and design, thus paving the way for photothermal evaporation materials with diverse structures. The above factors are crucial to the manufacture of photothermal evaporators, so melamine sponge and polydopamine (PDA) become indispensable components of the present invention.

[0093] When testing the PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device prepared by the present invention, the structure and performance characterization of the PDA@Sponge combined with TEG solar thermal driven water purification and power generation integrated device are first tested. Among them:

[0094] First, the melamine sponge is precisely cut into pieces with a size of 40×40×40mm. 3 Cube, such as Figure 5 (a). The foam was then immersed in a dopamine hydrochloride solution (Tris-HCl buffer solution with a pH value of 8.5) and gently squeezed to ensure sufficient water absorption. Figure 5 As shown in (b), after being sealed and reacted in the culture dish for a certain period of time, PDA@Sponge was thoroughly washed with deionized water to remove unreacted chemicals and impurities. Figure 5 As can be seen in (c), the PDA is evenly coated on the sponge, transitioning from the initial white to varying shades of gray and finally to black, indicating that the PDA is successfully loaded. In order to further explore the potential effect of surface morphology on water evaporation rate, the present invention made the PDA@Sponge material into various shapes, such as flat, zigzag and arc. Figure 5 In addition, the present invention combines PDA@Sponge with TEG to produce a dual-function device powered by solar energy, such as Figure 5 As shown in (e), under simulated solar irradiation, the device can not only promote thermoelectric power generation and energy storage, but also effectively drive the water evaporation process, providing a new way for seawater desalination or wastewater treatment.

[0095] The present invention also tests the performance of the dual-function device of PDA@Sponge combined with TEG solar thermal drive. The present invention studies the photothermal evaporation performance and thermal power generation capacity of PDA@Sponge respectively. In order to effectively integrate these two functions, such as Figure 6 As shown in (a), the present invention designs a dual-function device based on the aforementioned solar-powered dual-function device, aiming to produce pure water and electricity at the same time. Figure 6 As shown in (b), the water evaporation rate of the device is high under one sun intensity. In order to verify the water purification ability of the device, the present invention measures the UV-visible absorption spectra of water contaminated by methylene blue (MB) and methyl orange (MO) dyes and condensed water collected during the evaporation process, as shown in Figure 6 (c) The experimental results show that the obtained condensate achieves almost 100% pollutant removal rate. It is worth noting that the device simultaneously charges the capacitor C through TEG, and the capacitor C can be charged to 1.5V within 1 minute. This design facilitates the storage of generated electrical energy, which can then power low-energy electronic devices, such as Figure 6(d) The smart watch and Figure 6 (e) The LED lamp shown.

[0096] Considering that the PDA@Sponge combined with TEG's solar thermal driven water purification and power generation integrated device has dual functions of water evaporation and thermoelectric power generation, a dual-function water cup is designed. Figures 7 to 9 As shown, the dual-function water cup includes PDA@Sponge photothermal material, thermoelectric generator, bamboo fiber filter paper, heat insulation layer and energy storage device. Among them, the dual-function water cup is provided with a sewage chamber 2 and a pure water chamber 3, and the top of the dual-function water cup is provided with a cover 1, and the bottom is provided with a light bulb 5 and a supercapacitor 4 connected to the light bulb 5; a steam condensation area 6 is provided on the top of the sewage chamber 2 of the dual-function water cup, and a PDA sponge 7 is filled outside the sewage chamber 2 and the pure water chamber 3 as a PDA@Sponge photothermal material, and the drainage cotton 8 is used as bamboo fiber filter paper, and the water in the sewage chamber 2 is transferred from the drainage cotton 8 to the PDA sponge 7 through capillary action, and flows into the pure water chamber 3 after condensation in the steam condensation area 6; the PDA sponge 7 converts the light energy into heat energy, so that the temperature of the hot end of the thermoelectric generator 9 increases, and due to the Seebeck effect, the temperature difference between the cold and hot ends is generated, and the thermoelectric generator 9 further converts the heat energy into electrical energy, thereby realizing photothermal-thermoelectric conversion; finally, the generated electrical energy is stored by the supercapacitor 4. The dual-function water cup of the present invention can be carried outdoors and can purify sewage into pure water through photothermal water evaporation. At the same time, the thermal energy can be further converted into electrical energy through a thermoelectric generator, and stored and generated through energy storage equipment for nighttime lighting, etc.

[0097] In the symbols and abbreviations of the present invention, PDA is the abbreviation of polydopamine, Sponge is the abbreviation of melamine sponge, TEG is the abbreviation of thermoelectric generator, Tris is the abbreviation of tris(hydroxymethyl)aminomethane, MB is the abbreviation of methylene blue, MO is the abbreviation of methyl orange, PDA@Sponge is the abbreviation of polydopamine-loaded melamine sponge, and AM 1.5G is the abbreviation of standard spectrum on the earth's surface.

[0098] The technical principle of the present invention is described above in combination with the specific embodiments, which are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments, and all technical solutions under the idea of ​​the present invention belong to the protection scope of the present invention. Those skilled in the art can think of other specific implementations of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A solar thermal driven water purification and power generation integrated device, the characteristics of which include: The PDA@Sponge photothermal material is composed of a melamine sponge substrate and a polydopamine coating. The melamine sponge is used as a carrier, and the polydopamine coating is formed by in-situ polymerization on the melamine sponge, thereby forming a uniform PDA coating on the surface of the melamine sponge substrate to obtain the PDA@Sponge photothermal material. Thermoelectric generator, the TEG hot end of the thermoelectric generator is connected to the PDA@Sponge photothermal material, and bamboo fiber filter paper is inserted at the bottom as a hydrophilic layer. Water is transferred from the bamboo fiber filter paper to the PDA@Sponge photothermal material through capillary action, forming a solar-driven water evaporation and thermal power generation dual-function device, namely PDA@Sponge / TEG.

2. The solar thermal driven water purification and power generation integrated device according to claim 1, characterized in that: The polydopamine coating is a uniform polydopamine coating directly formed on the surface of the melamine sponge by an in-situ polymerization method, and the polydopamine coating is formed by polymerization of dopamine monomers in an alkaline aqueous solution.

3. The solar thermal driven water purification and power generation integrated device according to claim 2, characterized in that: The polydopamine coating is prepared by in-situ polymerization of dopamine on a melamine sponge using a Tris-HCl buffer solution through a solution oxidation method.

4. The solar thermal driven water purification and power generation integrated device according to claim 3, characterized in that: The preparation method of the PDA@Sponge photothermal material comprises the following steps: 1) Preparation of dopamine hydrochloride solution: dissolving dopamine monomer in an alkaline aqueous solution; 2) In-situ polymerization: placing the melamine sponge in the above-mentioned dopamine hydrochloride solution, the dopamine monomer spontaneously oxidizes and polymerizes on the sponge surface to form a polydopamine coating; 3) Synthesis of PDA@Sponge: The loading amount of polydopamine on the melamine sponge was adjusted by controlling the dosage of monomer dopamine, immersion time and temperature. After the reaction was carried out for a certain period of time, the surface was washed with deionized water to obtain the PDA@Sponge photothermal material.

5. The solar thermal driven water purification and power generation integrated device according to claim 4, characterized in that: The alkaline aqueous solution adopts a Tris-HCl buffer solution with a pH value of 8.5, and dopamine monomers of different masses are dispersed in the Tris-HCl buffer solution. After stirring and dissolving, dopamine hydrochloride solutions of different concentrations are obtained.

6. The solar thermal driven water purification and power generation integrated device according to claim 5, characterized in that: The concentrations of dopamine hydrochloride solutions are 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 4 mg / mL, and 6 mg / mL.

7. The solar thermal driven water purification and power generation integrated device according to claim 5, characterized in that: A certain volume of melamine sponge is placed in a dopamine hydrochloride solution, and the surface shape of the melamine sponge is further cut into a plane shape, a zigzag shape and an arc shape.

8. The solar thermal driven water purification and power generation integrated device according to claim 7, characterized in that: When preparing PDA@Sponge photothermal materials, the structure was optimized by optimizing the loading concentration of polydopamine and changing the surface morphology of the carrier melamine sponge. The performance of the PDA@Sponge photothermal material was optimal when the concentration of dopamine hydrochloride solution was 4 mg / mL and it was serrated.

9. The solar thermal driven water purification and power generation integrated device according to claim 4, characterized in that: The water evaporation and thermal power generation dual-function device is also connected to an energy storage device for storing the generated electrical energy.

10. A method for preparing the solar thermal driven water purification and power generation integrated device as claimed in claim 9, characterized in that: The following steps are involved: 1) Preparation of PDA@Sponge photothermal material: Preparation of dopamine hydrochloride solution: dispersing different weights of dopamine in a Tris-HCl buffer solution, stirring and dissolving to obtain dopamine hydrochloride solutions of different concentrations; In-situ polymerization: A melamine sponge with a suitable morphology is placed in a dopamine hydrochloride solution, and the dopamine monomer begins to spontaneously oxidize and polymerize in-situ on the melamine sponge; Preparation of PDA@Sponge: By controlling the amount of monomer dopamine, immersion time, and temperature, the loading amount of polydopamine on the melamine sponge is adjusted. After the reaction is carried out for a certain period of time, the surface is washed with deionized water to obtain the PDA@Sponge photothermal material. 2) Assemble PDA@Sponge / TEG: Connect the PDA@Sponge to the hot end of the TEG to form a solar-driven water evaporation and thermal power generation dual-function device, namely PDA@Sponge / TEG; 3) Preparation of bamboo fiber filter paper bottom layer: The bamboo fiber filter paper was used as a hydrophilic layer and inserted into the bottom of the dual-function device to transfer water from the bamboo fiber paper to the PDA@Sponge photothermal material by capillary action. 4) Electrical energy storage: The thermoelectric generator is further connected to an energy storage device to achieve electrical energy storage.

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