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

Abstract

The application discloses a solar heat-driven water purification and power generation integrated device and a preparation method thereof, which comprises a PDA@Sponge light-heat material, a thermoelectric generator TEG and a bamboo fiber filter paper. A polydopamine coating is formed by in-situ polymerization on a melamine sponge to obtain the PDA@Sponge light-heat material. The light-heat material is connected with the TEG hot end, the device bottom is inserted into the bamboo fiber filter paper as a hydrophilic layer, water is transmitted from the bamboo fiber paper to the PDA@Sponge light-heat material through capillary action, and a solar-driven water evaporation and heat power generation dual-function device, namely PDA@Sponge / TEG, is formed. The core components of the application are the PDA@Sponge light-heat material, the bamboo fiber filter paper as the hydrophilic layer and the TEG device. By optimizing the PDA loading amount and adjusting the surface morphology of the PDA@Sponge, efficient water evaporation and heat power generation performance are simultaneously realized.

Description

TECHNICAL FIELD

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

[0002] With the global population explosion 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 rising. At the same time, the large consumption of traditional energy not only exhausts resources, but also exacerbates environmental pollution and climate change. In the face of this serious situation, developing and utilizing renewable resources to alleviate the water and energy crisis has become the focus of global attention. Solar energy, as a clean, eco-friendly renewable resource, is considered to be a promising energy power for seawater desalination and power generation.

[0003] In recent years, solar steam generators (SSG) have attracted extensive research interest for their potential applications in water purification and seawater desalination. One of the key steps is to convert solar energy into heat energy using photothermal materials to promote water evaporation. However, this coating-based design not only requires advanced manufacturing technology, but also limits the geometry of the device, which cannot be optimized to speed up water evaporation. In addition, the functions of these devices are mainly limited to seawater desalination, limiting their multifunctionality.

[0004] Melamine sponge, as a low-cost and efficient evaporation material, has shown good potential in improving evaporation rate. However, due to the lack of the ability to directly convert solar energy into heat 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 range has become an ideal candidate, it is easy to synthesize, and can form composite materials with a variety of flexible materials, bringing new possibilities for the design of photothermal evaporation materials.

[0005] Therefore, how to achieve efficient photothermal water evaporation and thermal power generation in an eco-friendly and economically efficient way for seawater desalination and power generation has become one of the technical problems to be solved. SUMMARY

[0006] In order to overcome the above problems, the purpose of the embodiment of the present application is to provide a PDA@Sponge combined with TEG solar heat driven water purification and power generation integrated device and a preparation method thereof, which can not only efficiently perform photo-thermal water evaporation, but also realize heat power generation through solar heat driven water purification and power generation integration. The device of the solar heat driven water purification and power generation integrated device is prepared by simple soaking technology, and through optimization of PDA load and adjustment of the surface morphology of melamine sponge, efficient water evaporation and heat power generation performance are realized simultaneously. The dual functional device provides a certain solution for remote areas lacking of power and drinking water infrastructure, and provides a new technical scheme for simultaneously powering low energy consumption electronic equipment and purifying wastewater.

[0007] In order to achieve the above purpose, the present application provides the following technical scheme:

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

[0009] The PDA@Sponge photo-thermal material is composed of a melamine sponge substrate and a polydopamine coating layer, adopts the melamine sponge as a carrier, and forms the polydopamine coating layer in situ on the melamine sponge to form a uniform PDA coating layer coated on the surface of the melamine sponge substrate, thereby obtaining the PDA@Sponge photo-thermal material;

[0010] The PDA@Sponge photo-thermal material is connected with the hot end of the TEG, and the bottom is inserted with a bamboo fiber filter paper as a hydrophilic layer to constitute a solar driven water evaporation and heat power generation dual functional device, namely PDA@Sponge / TEG. The heat energy obtained by converting light energy by the PDA@Sponge photo-thermal material makes the hot end temperature of the thermoelectric generator rise, and due to the Seebeck effect, a temperature difference is generated between the cold end and the hot end, and the thermoelectric generator further converts the heat energy into electric energy, thereby realizing photo-thermal-thermoelectric conversion, that is, realizing heat power generation performance. The bamboo fiber filter paper can transport water from the bamboo fiber filter paper to the PDA@Sponge photo-thermal material through capillary action, thereby realizing photo-thermal water evaporation.

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

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

[0013] As a further scheme of the present application, the preparation method of the PDA@Sponge photo-thermal material comprises the following steps:

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

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

[0016] 3) Synthesis of PDA@Sponge: By controlling the amount of dopamine monomer, soaking time and temperature, the loading amount of polydopamine on melamine sponge is adjusted, and after a certain time of reaction, the surface is washed with deionized water to obtain PDA@Sponge photothermal material.

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

[0018] As a further scheme of the present application, 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 scheme of the present application, a certain volume of melamine sponge is placed in the dopamine hydrochloride solution, and the surface shape of the melamine sponge is tailored into a plane shape, a zigzag shape and an arc shape, etc.

[0020] As a further scheme of the present application, when preparing the PDA@Sponge photothermal material, the loading concentration of polydopamine (PDA) is optimized and the surface morphology of the carrier melamine sponge is changed for structure optimization, and the performance of the zigzag PDA@Sponge photothermal material is optimal when the concentration of the dopamine hydrochloride solution is 4 mg / mL.

[0021] As a further scheme of the present application, the water evaporation and heat power generation dual-function device can be connected with an energy storage device for storing the generated electric energy.

[0022] As a further scheme of the present application, the solar heat-driven water purification and power generation integrated device is a dual-functional water cup with water evaporation and thermoelectric power generation, and the core components of the dual-functional water cup include a PDA@Sponge photothermal material, a thermoelectric generator, a bamboo fiber filter paper, a heat insulation layer and an 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, and the heat generated can be used for water evaporation of the bamboo fiber filter paper to the PDA@Sponge photothermal material, to generate water vapor, thereby playing a role in water purification; the heat converted by the photothermal material can also make the temperature of the hot end of the thermoelectric generator (TEG) rise, and the cold and hot ends generate a temperature difference, according to the Seebeck effect, the directional movement of carriers generates electric energy, which can be stored through the energy storage device. In a second aspect, the present application also provides a preparation method of a solar heat-driven water purification and power generation integrated device combining a PDA@Sponge and a thermoelectric generator (TEG), which includes the following steps:

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

[0024] Preparation of dopamine hydrochloride solution: disperse different amounts of dopamine in Tris-HCl buffer solution, stir and dissolve to obtain dopamine hydrochloride solutions with different concentrations;

[0025] In-situ polymerization: place the melamine sponge with a suitable surface morphology in the dopamine hydrochloride solution, and the dopamine monomer starts to spontaneously oxidize and grow in-situ on the melamine sponge;

[0026] Preparation of PDA@Sponge: by controlling the amount of monomer dopamine, soaking time and temperature, adjust the loading amount of polydopamine on the melamine sponge, after a certain time of reaction, wash the surface with deionized water to obtain the PDA@Sponge photothermal material.

[0027] 2. Assembly of PDA@Sponge / TEG:

[0028] Connect the PDA@Sponge photothermal material with the hot end of the thermoelectric generator (TEG) to form a solar-driven water evaporation and heat power generation dual-functional device, namely PDA@Sponge / TEG.

[0029] 3. Preparation of bamboo fiber filter paper bottom layer:

[0030] Insert the bamboo fiber filter paper as a hydrophilic layer into the bottom of the dual-functional device to transmit 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 the energy storage device to realize electric energy storage.

[0033] As a further scheme of the present application, when preparing the dopamine hydrochloride solution, the dopamine solids weighed according to different masses are poured into five beakers, and 75 mL of Tris-HCl buffer solution with a pH value of 8.5 and a concentration of 10 mM is added, and stirring and dissolution are performed 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 scheme of the present application, the melamine sponge with a certain volume and a surface shape of plane, zigzag and arc is respectively placed in the dopamine hydrochloride solution.

[0035] As a further scheme of the present application, the preparation method of the solar heat-driven water purification and power generation integrated device further comprises a dual-function water cup, and the steps are as follows:

[0036] 1) The PDA@Sponge photo-thermal material is coated on the hot end of the thermoelectric generator (TEG);

[0037] 2) The PDA@Sponge photo-thermal material can be exposed to sunlight, and the photo-thermal material can convert light energy into heat energy;

[0038] 3) The generated heat can transmit the bamboo fiber filter paper to the water evaporation of the PDA@Sponge photo-thermal material, generate water vapor, and thus play a role in water purification;

[0039] 4) On the other hand, the temperature of the hot end of the thermoelectric generator (TEG) is increased, and a temperature difference between the hot end and the cold end is generated, according to the Seebeck effect, the directional movement of the carrier generates electric energy, and the electric energy can be stored through the energy storage device.

[0040] Through the above steps, the preparation of the solar heat-driven water purification and power generation integrated device combining PDA@Sponge and TEG is completed, the device combines solar water evaporation and thermoelectric power generation technology, can effectively purify water quality, and can also generate electric energy at the same time, and has potential environmental protection and economic application value.

[0041] Compared with the prior art, the solar heat-driven water purification and power generation integrated device and the preparation method thereof have the following beneficial effects:

[0042] 1. High solar energy utilization rate: the PDA@Sponge photo-thermal material efficiently absorbs sunlight and converts light energy into heat energy, and after being combined with the TEG, the heat energy can be further converted into electric energy, realizing efficient utilization of solar light energy and two-stage energy conversion.

[0043] 2. Achieving water purification and power generation integration: The device utilizes solar energy to drive water evaporation, and at the same time utilizes a thermoelectric generator to convert heat energy into electrical energy, achieving the dual functions of water purification and power generation. Through the heat-driven water evaporation process, impurities and salts in the water can be effectively removed, obtaining purified fresh water suitable for use in areas with poor water quality. The electrical energy generated by the TEG can be stored in a capacitor to power small electronic devices or to achieve electrical energy output in the absence of solar radiation.

[0044] Therefore, the solar heat-driven water purification and power generation integrated device of the present application effectively combines solar water purification and power generation technologies, which is of great significance for clean energy and drinking water supply in resource-limited or off-grid areas, and can achieve photo-thermal water evaporation and thermal power generation in an eco-friendly and economically efficient manner.

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

[0046] Figure 1 A structure diagram of a solar heat-driven water purification and power generation integrated device provided by the present application, in which PDA@Sponge photothermal material is coated on a thermoelectric generator (TEG).

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

[0048] Figure 3 A principle diagram of a solar heat-driven water purification and power generation integrated device provided by the present application, in which a generator (TEG) converts heat energy into electrical energy.

[0049] Figure 4 A structure diagram of a solar heat-driven water purification and power generation integrated device provided by the present application, in which melamine sponge.

[0050] Figure 5 A structure diagram of a solar heat-driven water purification and power generation integrated device provided by the present application, in which PDA@Sponge and preparation process.

[0051] Figure 6A schematic diagram of PDA@Sponge / TEG for solar-driven water purification and thermoelectric power generation in a solar heat-driven water purification and power generation integrated device provided by the present application; wherein (a) experimental structure of solar water purification and thermoelectric power generation. (b) water mass loss of PDA@Sponge / TEG. (c) UV-Vis absorption spectrum of water contaminated by MO and MB dyes, and condensed water collected from steam generation. PDA@Sponge / TEG is applied to power small electronic devices (d) smart watch and (e) small bulb.

[0052] Figure 7 A schematic diagram of a dual-function water cup structure applied in a solar heat-driven water purification and power generation integrated device provided by the present application.

[0053] Figure 8 A front view of a solar heat-driven water purification and power generation integrated device provided by the present application.

[0054] Figure 9 A schematic diagram of A-A cross section of a solar heat-driven water purification and power generation integrated device provided by the present application. DETAILED DESCRIPTION

[0055] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized 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 application provides a solar heat-driven water purification and power generation integrated device combining PDA@Sponge and TEG and a preparation method thereof, which can realize photo-thermal water evaporation and heat power generation in an ecological friendly and economically efficient manner. Under solar irradiation, the device effectively purifies water through surface evaporation, and simultaneously generates heat power using heat. The device is easily made by simple soaking technology and consists of two key components: (1) PDA@Sponge photo-thermal material with wide-band light absorption and high photo-thermal conversion efficiency, which is both a structural support and a water transport substrate, and is easy to cut; (2) bamboo fiber filter paper as a hydrophilic layer, which enhances water absorption and transmission.

[0057] Therefore, the PDA@Sponge solar heat-driven water purification and power generation integrated device of the application combines TEG, and through optimizing the loading concentration of polydopamine and changing the surface morphology of the melamine sponge carrier for structure optimization, the sawtooth-shaped PDA@Sponge photothermal material has optimal performance when the concentration of the dopamine hydrochloride solution is 4 mg / mL and due to its unique sharp thermal positioning. In addition, after the PDA@Sponge material is integrated with a thermoelectric generator (TEG), the thermoelectric performance is significantly improved, and a higher current and voltage are generated, and the output power when a load resistance is connected is sufficient to power low-energy-consumption electronic devices.

[0058] The PDA@Sponge solar heat-driven water purification and power generation integrated device of the application can solve the global energy and water crises by using renewable solar energy, especially in remote areas lacking power and drinking water infrastructure. The dual-function device provides a promising method for powering low-energy-consumption electronic devices, seawater desalination, and wastewater purification.

[0059] The technical solutions of the application will be further described below in combination with the drawings and specific embodiments.

[0060] Referring to Figures 1 to 4 As shown in the drawings, the embodiment of the application provides a solar heat-driven water purification and power generation integrated device, which comprises 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 layer, and adopts melamine sponge as a carrier to form a uniform PDA coating layer coated on the surface of the melamine sponge substrate, thereby obtaining 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, and the heat energy converted by the PDA@Sponge photothermal material makes the hot end temperature of the thermoelectric generator rise. Due to the Seebeck effect, a temperature difference is generated between the cold and hot ends, and the thermoelectric generator further converts heat energy into electrical energy, thereby realizing photothermal-thermoelectric conversion, i.e., thermal power generation performance. The bamboo fiber filter paper B, as a hydrophilic layer, is inserted into the bottom of the PDA@Sponge / TEG device, and water can be transmitted from the bamboo fiber filter paper to the PDA@Sponge photothermal material through capillary action, thereby realizing photothermal water evaporation.

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

[0063] The preparation method of PDA@Sponge photothermal material is as follows:

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

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

[0066] 3) PDA@Sponge synthesis: By controlling the amount of monomer dopamine, soaking time and temperature, the loading of polydopamine on melamine sponge is adjusted. After the reaction has been carried out for a certain time, the surface is washed with deionized water to obtain PDA@Sponge photothermal material.

[0067] In the above steps, the alkaline aqueous solution is a Tris-HCl buffer solution with a pH of 8.5. Different masses of dopamine solid monomers are dispersed in the Tris-HCl buffer solution, and after stirring and dissolving, dopamine hydrochloride solutions of different concentrations are obtained. The concentrations of the dopamine hydrochloride solutions are 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 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 planar, serrated, and arc shapes, etc.

[0069] In this embodiment, the PDA@Sponge photothermal material was prepared using an in-situ synthesis method involving solution oxidation. A Tris-HCl buffer solution was used to oxidize dopamine solution into polydopamine, which was then grown in situ on a melamine sponge substrate. The Tris buffer solution had a pH of 8.5, and the dopamine hydrochloride solution concentration was 4 mg / mL. This ratio ensured that the polydopamine was uniformly and stably loaded onto the melamine sponge. Uniformity was verified using scanning electron microscopy, and stability was observed before and after ultrasonic cleaning. In this method, the melamine sponge was pointed in shape, utilizing the tip thermal effect, which is beneficial for photothermal-thermoelectric conversion applications. 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 for water evaporation and the other for thermoelectric power generation.

[0071] In some embodiments, the water evaporation and heat power generation dual-function device is further connected with a capacitor C, the capacitor C is charged by the thermoelectric generator (TEG), and the capacitor C is used for storing the generated electric energy.

[0072] The embodiment of the present application also provides a preparation method of a solar heat driven water purification and power generation integrated device, including the following steps:

[0073] 1) preparing a PDA@Sponge photo-thermal material:

[0074] Preparation of a dopamine hydrochloride solution: different mass of dopamine is dispersed in a Tris-HCl buffer solution, and stirring and dissolution are carried out to obtain a dopamine hydrochloride solution with different concentrations;

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

[0076] Preparation of PDA@Sponge: by controlling the amount of dopamine monomer, soaking time and temperature, the loading amount of polydopamine on the melamine sponge is adjusted, after a certain time of reaction, the surface is washed with deionized water, and the PDA@Sponge photo-thermal material is obtained.

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

[0078] The PDA@Sponge is connected with the hot end of the TEG;

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

[0080] The bamboo fiber filter paper is used as a hydrophilic layer and is inserted into the bottom of the dual-function device, so as to transmit water from the bamboo fiber paper to the PDA@Sponge photo-thermal material by capillary action;

[0081] 4) electric energy storage:

[0082] The thermoelectric generator is further connected with an energy storage device, so as to realize electric energy storage.

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

[0084] 1) the PDA@Sponge photo-thermal material is coated on the hot end of the thermoelectric generator (TEG);

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

[0086] 3) The generated heat can on the one hand transmit the bamboo fiber filter paper to the water evaporation of the PDA@Sponge light-heat material, generate water vapor, and thus play 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 between the cold end and the hot end can be generated. According to the Seebeck effect, the directional movement of the carrier generates electric energy, and the electric energy can be stored through an energy storage device.

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

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

[0090]

[0091] Among them, is the evaporation rate under different light conditions, minus the inherent evaporation rate of the dark and support. LV indicates the evaporation enthalpy; C opt is the optical concentration; q i is the standard solar radiation.

[0092] In the present application, melamine sponge is selected as the basic material, because it has a porous structure and a large surface area, which is beneficial to achieve high evaporation rate. In the design of the present application, the reasons for using polydopamine (PDA) are as follows: (1) PDA shows excellent absorption capacity in the entire solar spectrum, which represents its high efficiency as a light-heat material; (2) PDA can be combined with other flexible materials, which is convenient for customization and design, thereby paving the way for light-heat evaporation materials with diversified structures. The above factors are crucial for the manufacture of light-heat evaporators, so melamine sponge and polydopamine (PDA) become indispensable components of the present application.

[0093] The PDA@Sponge combined with TEG solar heat-driven water purification and power generation integrated device prepared by the present application is tested. First, the structure and performance of the PDA@Sponge combined with TEG solar heat-driven water purification and power generation integrated device are tested.

[0094] First, the melamine sponge is accurately cut into a cube with a size of 40x40x40mm 3 , as shown in Figure 5 (a). Then the foam is immersed in a dopamine hydrochloride solution (Tris-HCl buffer solution with a pH value of 8.5), and slightly squeezed to ensure sufficient water absorption. As shown in Figure 5 (b), after sealing and reacting in a culture dish for a certain period of time, the PDA@Sponge is thoroughly washed with deionized water to remove unreacted chemicals and impurities. As shown in Figure 5 (c), the sponge is uniformly coated with PDA, which transitions from white to various shades of gray and finally to black, indicating successful PDA loading. To further explore the potential influence of surface morphology on water evaporation rate, the present application prepares PDA@Sponge materials into various shapes, such as flat, zigzag, and arc, as shown in Figure 5 (d). In addition, the present application combines PDA@Sponge with TEG to manufacture a dual-function device powered by solar energy, as shown in Figure 5 (e). Under simulated solar irradiation, this device not only promotes thermoelectric power generation and energy storage, but also effectively drives water evaporation, providing a new approach for seawater desalination or wastewater treatment.

[0095] The present application also tests the performance of the PDA@Sponge combined with TEG solar heat-driven dual-function device. The present application studies the photo-thermal evaporation performance and thermoelectric power generation capacity of PDA@Sponge. In order to effectively integrate these two functions, as shown in Figure 6 (a), the present application designs a dual-function device according to the aforementioned dual-function device powered by solar energy, aiming to produce both pure water and electrical energy. As shown in Figure 6 (b), under a certain solar intensity, the water evaporation rate of this device is high. To verify the water purification capacity of this device, the present application measures the ultraviolet-visible absorption spectrum of water contaminated by methylene blue (MB) and methyl orange (MO) dyes and the condensed water collected during the evaporation process, as shown in Figure 6 (c). The experimental results show that the obtained condensed liquid achieves almost 100% pollutant removal rate. Notably, this device simultaneously charges the capacitor C through TEG, which can charge the capacitor C to 1.5V within 1 minute. This design facilitates the storage of generated electrical energy, which can subsequently power low-energy electronic devices, as shown in Figure 6(d) the smartwatch shown and Figure 6 (e) the LED lamp shown.

[0096] In view of the PDA@Sponge combined with the TEG solar heat driven water purification and power generation integrated device having dual functional applications of water evaporation and thermoelectric power generation, a dual functional water cup is designed. Figures 7 to 9 As shown, the dual functional water cup includes a PDA@Sponge photothermal material, a thermoelectric generator, a bamboo fiber filter paper, a thermal insulation layer, and an energy storage device. Among them, the dual functional water cup is provided with a sewage chamber 2 and a pure water chamber 3, and the top of the dual functional water cup is provided with a lid 1, and the bottom is provided with a bulb 5 and a super capacitor 4 connected with the bulb 5; the top of the sewage chamber 2 of the dual functional water cup is provided with a steam condensation area 6, the PDA sponge 7 is filled as the PDA@Sponge photothermal material outside the sewage chamber 2 and the pure water chamber 3, the bamboo fiber filter paper is used as the drainage cotton 8, the water in the sewage chamber 2 is transmitted from the drainage cotton 8 to the PDA sponge 7 by capillary action, and flows into the pure water chamber 3 after condensation in the steam condensation area 6; the PDA sponge 7 converts the heat energy obtained from light energy, so that the hot end temperature of the thermoelectric generator 9 is increased, and due to the Seebeck effect, the cold and hot ends generate temperature difference, the thermoelectric generator 9 further converts the heat energy into electric energy, so as to realize the conversion of photothermal-thermoelectric; finally, the generated electric energy is stored through the super capacitor 4. The dual functional water cup of the application can be carried in the field, and can purify sewage into pure water through photothermal water evaporation. At the same time, the heat energy can be further converted into electric energy through the thermoelectric generator, and the generated electricity can be stored through the energy storage device, which can be used for night lighting and the like.

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

[0098] The above describes the technical principles of the application in combination with specific embodiments, which are only preferred embodiments of the application. The protection scope of the application is not limited to the above-mentioned embodiments only, and any technical solutions falling within the idea of the application shall fall within the protection scope of the application. Other specific embodiments of the application can be conceived by those skilled in the art without creative labor, and these embodiments shall fall within the protection scope of the application.

Claims

1. A solar heat-driven water purification and power generation integrated device, characterized by comprising: PDA@Sponge photothermal material, composed of melamine sponge substrate and polydopamine coating, using melamine sponge as carrier, in-situ polymerization of polydopamine coating on melamine sponge, forming uniform PDA coating on the surface of the melamine sponge substrate, obtaining PDA@Sponge photothermal material; wherein the polydopamine coating is formed by polymerization of dopamine monomers in alkaline aqueous solution; the polydopamine coating is prepared by in-situ polymerization of dopamine on melamine sponge by solution oxidation method through Tris-HCl buffer solution; thermoelectric generator, the TEG hot end of the thermoelectric generator is connected with the PDA@Sponge photothermal material, and the bottom is inserted with bamboo fiber filter paper as a hydrophilic layer, which transmits water from the bamboo fiber filter paper to the PDA@Sponge photothermal material by capillary action, forming a solar-driven water evaporation and heat power generation dual-function device, namely PDA@Sponge / TEG; wherein the preparation method of the PDA@Sponge photothermal material comprises the following steps: 1) Preparation of dopamine hydrochloride solution: dissolve dopamine monomers in alkaline aqueous solution; 2) In-situ polymerization: place melamine sponge in the above dopamine hydrochloride solution, and the dopamine monomers spontaneously oxidize and polymerize on the surface of the sponge to form a polydopamine coating; 3) PDA@Sponge synthesis: by controlling the amount of dopamine monomer, soaking time and temperature, adjusting the loading amount of polydopamine on melamine sponge, after a certain time of reaction, washing the surface with deionized water to obtain PDA@Sponge photothermal material.

2. The solar energy heat-driven water purification and power generation integrated device according to claim 1, characterized in that, The alkaline aqueous solution uses Tris-HCl buffer solution with a pH value of 8.5, and different mass of dopamine monomers are dispersed in the Tris-HCl buffer solution to obtain dopamine hydrochloride solutions with different concentrations after stirring and dissolving.

3. The solar energy heat-driven water purification and power generation integrated device according to claim 2, characterized in that, The concentration of the dopamine hydrochloride solution is 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 4 mg / mL, or 6 mg / mL.

4. The solar energy heat-driven water purification and power generation integrated device according to claim 3, characterized in that, A certain volume of melamine sponge is placed in the dopamine hydrochloride solution, and the surface shape of the melamine sponge is further trimmed into a plane shape, a zigzag shape, and an arc shape.

5. The solar thermal driven water purification and power generation integrated device according to claim 4, characterized in that, When preparing the PDA@Sponge photothermal material, the loading concentration of polydopamine is optimized and the surface morphology of the carrier melamine sponge is changed for structure optimization, and the PDA@Sponge photothermal material with a dopamine hydrochloride solution concentration of 4 mg / mL and a zigzag shape has the best performance.

6. The solar thermal driven water purification and power generation integrated device according to claim 5, characterized in that, The water evaporation and heat power generation dual-function device is further connected with an energy storage device for storing the generated electric energy.

7. The method for preparing the solar thermal driven water purification and power generation integrated device according to claim 6, characterized in that, comprising the following steps: 1) Preparation of PDA@Sponge photothermal material: 2) Assembly of PDA@Sponge / TEG: Connect PDA@Sponge with the TEG hot end to form a solar-driven water evaporation and heat power generation dual-function device, namely PDA@Sponge / TEG; 3) Preparation of bamboo fiber filter paper bottom layer: Bamboo fiber filter paper as a hydrophilic layer, inserted into the bottom of the dual functional device, to take advantage of the capillary effect from the bamboo fiber paper to the PDA@Sponge light-thermal material; 4) Electrical energy storage: Further connect the thermoelectric generator energy storage device, to achieve electrical energy storage.

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