Hydrogel-based water-energy-resource co-production solar evaporator and application thereof

Abstract

The invention discloses a hydrogel-based water-energy-resource co-production solar evaporator and application thereof, and belongs to the technical field of chemistry and environment, the hydrogel-based water-energy-resource co-production solar evaporator is prepared by taking sodium alginate hydrogel as a matrix, adding carbon nanotubes and a titanium-based lithium ion sieve or a metal-doped titanium-based lithium ion sieve into a solution of the sodium alginate hydrogel, taking polyurethane sponge as a carrier frame, and preparing the hydrogel-based water-energy-resource co-production solar evaporator. Ca2 + is adopted as a cross-linking agent to construct a solar evaporator with a flexible size (centimeter-level to meter-level components can be prepared according to application scenes), the solar evaporator is used for the solar driven evaporation process of lithium-containing water resources such as salt lake seawater, and Li + selective enrichment, fresh water collection and waste heat power generation are synchronously achieved. Moreover, the evaporator has the characteristics of simple preparation process, low cost and excellent environmental compatibility, also has a good removal effect on salt ions, and keeps stable fresh water collection performance in a long-time operation process.

Description

Technical Field

[0001] This invention belongs to the fields of chemistry and environmental technology, and particularly relates to a hydrogel-based water-energy-resource cogeneration solar evaporator and its application. Background Technology

[0002] The accelerated global clean energy transition and the freshwater crisis have led to a surge in strategic demand for lithium resources. However, early lithium extraction technologies from ores face challenges due to high energy consumption, environmental pollution, and freshwater depletion. Salt lake brines and seawater, with reserves exceeding those of terrestrial lithium resources by four orders of magnitude, represent a highly promising extraction route. However, their extremely low Li- content... + Concentration (salt lakes: 220-3800 mg / L, seawater: <0.2 mg / L) and high concentrations of competing ions (such as Mg) 2+ Na + Ca 2+ The coexistence of these characteristics leads to problems in traditional technologies, such as poor selectivity, high energy consumption, and significant freshwater loss. While the titanium / manganese-based lithium-ion sieves developed in recent years offer advantages in terms of Li... + It has the characteristics of high selective adsorption capacity and adsorption capacity and rate increasing with temperature, but direct addition of powder is prone to agglomeration, difficult recycling, secondary pollution and low efficiency; if an external heat source is used to enhance adsorption, additional energy input and increased cost are required. Solar evaporators use solar energy as the only energy input and rely on photothermal materials to achieve local heat energy enrichment at the gas / liquid interface, which can be used as a green and clean heat energy source. Existing solar evaporator designs mostly focus on water flux and antifouling optimization. Their evaporation process can only complete water-salt separation and lacks ion-specific capture function, resulting in the loss of high-value resources with concentrated wastewater, and the gradient temperature difference (ΔT≈15 - 25℃) generated is not utilized. Therefore, it is crucial to develop a multi-effect system integrating photothermal evaporation-lithium selective enrichment-waste heat thermoelectric conversion. Through solar single-drive synchronous realization: (1) freshwater co-production; (2) Li + Specific extraction; (3) waste heat power generation, and finally construct a comprehensive system for synergistic efficiency enhancement of water-energy-resources, which is of great significance.

[0003] As a crucial component of solar evaporators, the selection of photothermal conversion materials is paramount. Currently, photothermal conversion materials for solar evaporators include semiconductor materials, conjugated polymer materials, metal nanomaterials, and carbon-based materials. The first three types of materials suffer from high costs and production expenses; in contrast, carbon-based materials offer advantages such as low cost, good thermal conductivity, large specific surface area, high stability, and strong environmental friendliness. Therefore, the application of carbon-based materials in solar evaporators has become a recent research hotspot.

[0004] Lithium ion sieve (LIS) as the core extraction unit of lithium resources extraction from salt lake seawater should have good extraction capacity and stability. However, how to improve the extraction capacity and stability of LIS has been a difficult problem for those skilled in the art.

[0005] During the solar-driven evaporation process, the light-heat interface localizes solar radiation energy on the upper surface to form a high-temperature zone, and a stable thermoelectric potential difference can be generated between the upper surface and the lower water body. The heat energy that is not effectively captured constitutes the main energy loss of the system. How to further improve the recovery potential of local heat energy on the basis of optimizing the light-heat conversion efficiency and ion-specific extraction capacity is another difficult problem that has plagued those skilled in the art.

[0006] In summary, developing a multifunctional integrated system that can cooperatively realize selective extraction of lithium resources, efficient recovery of freshwater and completion of waste heat gradient utilization has become a problem that needs to be solved at present. SUMMARY

[0007] To solve the above technical problems, the present application provides a hydrogel-based water-energy-resource co-production solar evaporator and its application. The hydrogel-based water-energy-resource co-production solar evaporator can simultaneously realize Li + selective extraction, efficient recovery of freshwater and completion of waste heat gradient utilization.

[0008] To achieve the above purpose, the present application provides the following technical solutions.

[0009] The present application provides a hydrogel-based water-energy-resource co-production solar evaporator, which comprises a water-energy-resource co-production module, a condensation module and a water collection module.

[0010] The condensation module is located above the water-energy-resource co-production module and is used for condensing and collecting water vapor generated in the lithium extraction process.

[0011] The water collection module is located on the left side of the water-energy-resource co-production module and is used for collecting condensed water cooled by the condensation module.

[0012] The water-energy-resource co-production module is composed of a functional layer from top to bottom, a power generation plate, a cooling water circulator and an interface support heat management module.

[0013] The functional layer takes polyurethane (PU) sponge as the carrier and is internally filled with sodium alginate (SA) hydrogel, carbon nanotube (CNT) and titanium-based lithium ion sieve (HTO) or metal-doped titanium-based lithium ion sieve (M-HTO).

[0014] Biomass-based hydrogels, with their tunable three-dimensional hydrophilic network and abundant polar functional groups, provide a dual guarantee for efficient water supply and optimized enthalpy of evaporation in solar evaporators. Natural polymers, represented by sodium alginate (SA), form multi-level interconnected channels through ionic cross-linking. The densely distributed hydroxyl (-OH) and carboxyl (-COOH) groups within their molecular chains lower the diffusion barrier of water molecules through hydrogen bonding, while simultaneously reconstructing the interfacial hydrogen bond network, significantly weakening the energy barrier required for phase transition. Compared to synthetic materials, this type of hydrogel combines capillary-driven continuous water supply, chemical stability against biofouling, and biodegradable ecocompatibility. Titanium-based lithium-ion sieves (HTO) have advantages over manganese-based lithium-ion sieves (HMO) in terms of structural stability and precise sieving capabilities. Specifically, titanium-based lithium-ion sieves have a stable framework, and Ti... 4+ The stable valence state and high Ti-O bond energy significantly suppress metal dissolution during acid leaching and desorption. The rigid Ti-O lattice forms uniformly sized vacancies, which is superior to manganese-based lithium-ion sieves with vacancy fluctuations caused by Jahn-Teller distortion. + It offers more precise size selectivity and introduces metal ions (such as Fe). 3+ Lattice doping (e.g., using metal ions) is an effective strategy to further improve lithium extraction capacity and structural stability, as well as optimize adsorption kinetics. The doped metal ions can replace some of the Ti. 4+ Substitution at the atomic scale enters the Ti-O lattice, forming a Ti-MO bonding network. This atomic-scale substitution induces controllable lattice distortion, moderately expanding the Li... + Transmission channel and add valid H + / Li + The density of exchange sites increases the adsorption capacity; on the other hand, the introduction of MO bonds enhances the stability of the framework and effectively inhibits the adsorption of Ti during acid leaching and desorption. 4+ The dissolution loss is significantly reduced, thus improving the cycle life of the material. Simultaneously, doping with dissimilar metal ions can further enhance the extraction efficiency of lithium resources through valence mismatch. This invention utilizes a thermoelectric conversion module to drive the directional migration of charge carriers via the natural temperature gradient at the solid-liquid interface, achieving the direct conversion of waste heat into electrical energy, and constructing a novel energy recovery scheme that synergistically enhances evaporation and power generation.

[0015] Furthermore, the method for preparing the functional layer includes the following steps:

[0016] Preparation of HTO or M-HTO (M is selected from molybdenum (Mo) or iron (Fe));

[0017] Mix carbon nanotubes, sodium alginate gel and water to obtain a mixed solution, add HTO or M-HTO, add water again, and stir until a homogeneous solution is formed.

[0018] The polyurethane sponge is immersed in the uniform solution, repeatedly squeezed and rubbed until the inside pores of the polyurethane sponge are completely and uniformly filled, and the surface is scraped to be flat, and then the polyurethane sponge is placed in a calcium chloride (CaCl2) solution for crosslinking, and then washed with water to obtain the functional layer.

[0019] Further, the preparation method of the titanium-based lithium ion sieve comprises the following steps:

[0020] a. Lithium hydroxide monohydrate and titanium dioxide are weighed according to the molar ratio of Li : Ti = 2:1, wet ball milling is performed to obtain a titanium-based lithium ion sieve precursor slurry;

[0021] b. The titanium-based lithium ion sieve precursor slurry is dried to obtain a dry material;

[0022] c. The dry material is calcined to obtain a titanium-based lithium ion sieve precursor;

[0023] d. The titanium-based lithium ion sieve precursor is ground into a powder, the powder is added to a hydrochloric acid solution for replacement, and then washed with water, dried, ground and sieved to obtain the titanium-based lithium ion sieve.

[0024] Further, the preparation method of the metal-doped titanium-based lithium ion sieve comprises the following steps:

[0025] a. Lithium hydroxide monohydrate, titanium dioxide and metal oxide are weighed according to the molar ratio of Li, Ti and M = 2:1:0.15, wet ball milling is performed to obtain a metal-doped titanium-based lithium ion sieve precursor slurry, and M is selected from iron or molybdenum;

[0026] b. The metal-doped titanium-based lithium ion sieve precursor slurry is dried to obtain a dry material;

[0027] c. The dry material is calcined to obtain a metal-doped titanium-based lithium ion sieve precursor;

[0028] d. The metal-doped titanium-based lithium ion sieve precursor is ground into a powder, the powder is added to a hydrochloric acid solution for replacement, and then washed with water, dried, ground and sieved to obtain the metal-doped titanium-based lithium ion sieve.

[0029] Further, in the preparation methods of the titanium-based lithium ion sieve and the metal-doped titanium-based lithium ion sieve, the temperature of the calcination is 650 ℃, the heating rate is 10 ℃ / min, and the holding time is 240 min;

[0030] And / or, the grinding medium during the wet ball milling is anhydrous ethanol.

[0031] Further, the wet ball milling is carried out by using Φ3 mm agate ball milling beads and Φ10 mm agate ball milling beads with a mass ratio of 1:1.

[0032] Further, in the preparation method of the titanium-based lithium ion sieve and the metal-doped titanium-based lithium ion sieve, the concentration of hydrochloric acid is 0.2 M, and the replacement time is 24 h.

[0033] Further, in the preparation method of the titanium-based lithium ion sieve and the metal-doped titanium-based lithium ion sieve, the sieving particle size is 100 mesh.

[0034] Further, the preparation method of the sodium alginate gel solution is as follows: sodium alginate powder is dissolved in water, and continuous stirring is carried out under heating conditions until a uniform and translucent sodium alginate gel solution is formed.

[0035] For example, in the preparation method of the sodium alginate gel solution, the heating temperature is 80 ℃, and the stirring time is 180 min.

[0036] Further, the addition amount of the carbon nanotube (CNT) is 2-8% of the mass of the sodium alginate gel solution, preferably 2%.

[0037] Further, the mass ratio of the HTO or M-HTO in the mixed solution is 4%.

[0038] Further, the density of the polyurethane sponge is 15 kg·m -3 , the thickness is 0.5 cm, and the extrusion times are 20-30 times.

[0039] Further, the concentration of the CaCl2 solution is 0.5 mol·L -1 , and the crosslinking time is 24 h.

[0040] The application also provides the application of the above-mentioned hydrogel-based water-energy-resource co-production solar evaporator in lithium resource recovery, fresh water collection and combined heat and power supply.

[0041] The above-mentioned biomass hydrogel-based water-energy-resource co-production solar evaporator can be used for lithium-containing water resource extraction, fresh water collection and waste heat power generation. In application, the functional layer of the biomass hydrogel-based water-energy-resource co-production solar evaporator is placed above the interface support heat management module, the lithium-containing water body transmission channel (cotton thread) connects the lithium-containing water body and the functional layer of the evaporator, which is conducive to the continuous transmission of water in the lithium-containing water body to the evaporator for efficient lithium extraction. The thermoelectric generator plate and the cooling water circulator are placed at the lower end of the functional layer. The solar water-energy-resource co-production module converts light into heat to form green heat energy and heat the water body to generate water vapor, which is condensed through the condensing module and then collected into the water collection module.

[0042] Compared with the prior art, the application has the following advantages and technical effects:

[0043] 1、The water-hydrogen-energy resource co-production solar evaporator based on biomass hydrogel has the characteristics of high hydrophilicity and high efficient light-heat conversion, disperses and encapsulates carbon-based light-heat conversion materials and lithium ion sieves by means of the three-dimensional network of the gel, and effectively avoids the problems of limited hydrophilicity of the light-heat conversion materials, easy agglomeration of the lithium ion sieves and poor recyclability.

[0044] 2、The water-hydrogen-energy resource co-production solar evaporator based on biomass hydrogel not only has efficient lithium resource recycling effect, but also realizes fresh water collection and waste heat gradient utilization by virtue of excellent light-heat conversion effect, and simultaneously realizes Li + selective enrichment, fresh water collection and waste heat gradient utilization, and realizes the application of the water-hydrogen-energy resource co-production solar evaporator driven by solar energy.

[0045] 3、The water-hydrogen-energy resource co-production solar evaporator based on biomass hydrogel can be used for resource extraction of different lithium content water bodies such as salt lakes and seawater, the evaporation rate effect is good during long-term operation, the main evaporator of the device is simple to prepare, and the shape and size are flexible, the size of the evaporator can be adjusted according to the actual application scene, and it is beneficial to popularize and use.

[0046] 4、The water-hydrogen-energy resource co-production solar evaporator based on biomass hydrogel couples the low-cost advantage of the core material (i.e. the functional layer) with the solar interface evaporation technology, and implements the sustainable principles of reduced input and cyclic regeneration from the design source. BRIEF DESCRIPTION OF DRAWINGS

[0047] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application. The embodiments of the present application and its description are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0048] Figure 1 It is a structural schematic diagram of the water-hydrogen-energy resource co-production solar evaporator of the present application;

[0049] Figure 2 It is a quality change comparison diagram of the water-hydrogen-energy resource co-production solar evaporator (encapsulated HTO) of the present application embodiment 9-embodiment 12;

[0050] Figure 3 It is a quality change comparison diagram of the water-hydrogen-energy resource co-production solar evaporator (encapsulated Fe-HTO) of the present application embodiment 1-embodiment 4;

[0051] Figure 4The mass change comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating Mo-HTO) of the embodiment 5 to the embodiment 8 of the present application;

[0052] Figure 5 The lithium extraction effect comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating HTO) of the embodiment 9 to the embodiment 12 of the present application under different CNT loadings;

[0053] Figure 6 The lithium extraction effect comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating Fe-HTO) of the embodiment 1 to the embodiment 4 of the present application under different CNT loadings;

[0054] Figure 7 The lithium extraction effect comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating Mo-HTO) of the embodiment 5 to the embodiment 8 of the present application under different CNT loadings;

[0055] Figure 8 The lithium extraction comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating HTO) of the embodiment 9 of the present application under different sunlight conditions;

[0056] Figure 9 The lithium extraction comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating Fe-HTO) of the embodiment 1 of the present application under different sunlight conditions;

[0057] Figure 10 The lithium extraction comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating Mo-HTO) of the embodiment 5 of the present application under different sunlight conditions;

[0058] Figure 11 The waste heat power generation current generation amount comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating HTO) of the embodiment 9 of the present application under different sunlight conditions;

[0059] Figure 12 The waste heat power generation current generation amount comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating Fe-HTO) of the embodiment 1 of the present application under different sunlight conditions;

[0060] Figure 13 The waste heat power generation current generation amount comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (encapsulating Mo-HTO) of the embodiment 5 of the present application under different sunlight conditions;

[0061] Figure 14The figure is a comparison of the waste heat power generation voltage of the hydrogel-based water-energy-resource co-production solar evaporator (packaged HTO) of the embodiment 9 of the present application under different sunlight conditions;

[0062] Figure 15 The figure is a comparison of the waste heat power generation voltage of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Fe-HTO) of the embodiment 1 of the present application under different sunlight conditions;

[0063] Figure 16 The figure is a comparison of the waste heat power generation voltage of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Mo-HTO) of the embodiment 5 of the present application under different sunlight conditions;

[0064] Figure 17 The figure is a comparison of the lithium extraction amount of the hydrogel-based water-energy-resource co-production solar evaporator (packaged HTO) of the embodiment 9 of the present application in solutions with different lithium contents under 1 solar intensity;

[0065] Figure 18 The figure is a comparison of the lithium extraction amount of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Fe-HTO) of the embodiment 1 of the present application in solutions with different lithium contents under 1 solar intensity;

[0066] Figure 19 The figure is a comparison of the lithium extraction amount of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Mo-HTO) of the embodiment 5 of the present application in solutions with different lithium contents under 1 solar intensity;

[0067] Figure 20 The figure is a comparison of the lithium extraction experiment of the hydrogel-based water-energy-resource co-production solar evaporator (packaged HTO) of the embodiment 9 of the present application under different pH conditions under 1 solar intensity;

[0068] Figure 21 The figure is a comparison of the lithium extraction experiment of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Fe-HTO) of the embodiment 1 of the present application under different pH conditions under 1 solar intensity;

[0069] Figure 22 The figure is a comparison of the lithium extraction experiment of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Mo-HTO) of the embodiment 5 of the present application under different pH conditions under 1 solar intensity;

[0070] Figure 23 The figure is a comparison of the cyclic extraction experiment of the hydrogel-based water-energy-resource co-production solar evaporator (packaged HTO) of the embodiment 9 of the present application in a 200 mg / L lithium content solution under 1 solar intensity;

[0071] Figure 24 Figure 1 is a comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Fe-HTO) of Example 1 of the present application under 1 solar irradiance intensity in the cyclic extraction experiment of a 200 mg / L lithium content solution;

[0072] Figure 25 Figure 5 is a comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Mo-HTO) of Example 5 of the present application under 1 solar irradiance intensity in the cyclic extraction experiment of a 200 mg / L lithium content solution;

[0073] Figure 26 Figure 9 is a comparison chart of the 12h evaporation effect of the hydrogel-based water-energy-resource co-production solar evaporator (packaged HTO) of Example 9 of the present application under 1 solar irradiance intensity in actual seawater;

[0074] Figure 27 Figure 1 is a comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Fe-HTO) of Example 1 of the present application under 1 solar irradiance intensity in the cyclic extraction experiment of a 200 mg / L lithium content solution;

[0075] Figure 28 Figure 5 is a comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Mo-HTO) of Example 5 of the present application under 1 solar irradiance intensity in the cyclic extraction experiment of a 200 mg / L lithium content solution;

[0076] Figure 29 Figure 9 is a comparison chart of the 12h evaporation effect of the hydrogel-based water-energy-resource co-production solar evaporator (packaged HTO) of Example 9 of the present application under 1 solar irradiance intensity in actual seawater;

[0077] Figure 30 Figure 1 is a comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Fe-HTO) of Example 1 of the present application under 1 solar irradiance intensity in the cyclic extraction experiment of a 200 mg / L lithium content solution;

[0078] Figure 31 Figure 5 is a comparison chart of the hydrogel-based water-energy-resource co-production solar evaporator (packaged Mo-HTO) of Example 5 of the present application under 1 solar irradiance intensity in the cyclic extraction experiment of a 200 mg / L lithium content solution;

[0079] Figure 32 Figure 9 is a comparison chart of the 12h evaporation effect of the hydrogel-based water-energy-resource co-production solar evaporator (packaged HTO) of Example 9 of the present application under 1 solar irradiance intensity in actual seawater;

[0080] Figure 33Figure 1 shows the ion removal profile of the hydrogel-based solar energy- water-energy co-production evaporator (encapsulated Fe-HTO) of Example 1 of the present application in seawater;

[0081] Figure 34 Figure 5 shows the ion removal profile of the hydrogel-based solar energy- water-energy co-production evaporator (encapsulated Mo-HTO) of Example 5 of the present application in seawater. DETAILED DESCRIPTION

[0082] Various illustrative embodiments of the present application are described in detail herein below with reference to the attached drawings. These embodiments are listed by way of example only, and should not be construed as limiting the present application. It should be understood that the detailed description and specific examples, while indicating certain embodiments of the application, are intended for purposes of illustration only and are not intended to limit the scope of the application.

[0083] It should be understood that the terms used herein are merely for the purpose of describing particular embodiments and are not intended to limit the present application. In addition, for numerical ranges in the present application, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or stated range, as well as each individual value within the stated range, is also encompassed. The upper and lower limits of these smaller ranges can independently be included or excluded in the range.

[0084] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict, the content of the present specification will control.

[0085] Various modifications and changes can be made to the specific embodiments of the present application described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples herein. The description and examples are illustrative of the application and are not intended to limit the scope of the application.

[0086] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean including, but not limited to.

[0087] Unless otherwise specified, the room temperature in the present application is 25±2°C.

[0088] The raw materials used in the embodiments of the present application are all commercially available. As an example, the PVC-coated polystyrene foam is purchased from the Pioneer Service Flagship Store, with a specification of 180 mm x 180 mm; the sodium alginate powder is purchased from the National Pharmaceutical Group Chemical Reagent Co., Ltd., with a model number of 30164428; and the carbon nanotube (CNT) material is purchased from the Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, with an outer diameter of 10-20 nm and a length of 10-30 μm.

[0089] 1 solar intensity (1-sun) refers to an illumination condition of 1.0 kW / m 2 .

[0090] In the following embodiments of the present application, the density of the polyurethane sponge is 15 kg·m -3 , and the thickness is 0.5 cm.

[0091] The present application provides a hydrogel-based water-energy-resource co-production solar evaporator, a structural diagram of which is shown in Figure 1 , which comprises a water-energy-resource co-production module, a condensation module, and a water collection module. The water-energy-resource co-production module is composed of a functional layer from top to bottom, a power generation plate, a cooling water circulator, and an interface support thermal management module. The functional layer takes polyurethane (PU) sponge as a carrier, and is internally filled with sodium alginate (SA) hydrogel, carbon nanotube (CNT), and titanium-based lithium ion sieve (HTO) or metal-doped titanium-based lithium ion sieve (M-HTO). The interface support thermal management module uses PVC-coated polystyrene foam to improve heat utilization rate, reduce heat loss, and improve evaporation efficiency. The power generation plate uses a semiconductor thermoelectric power generation plate to realize the utilization of waste heat gradient after water vapor is generated for water collection. A cotton rope is used to construct a lithium-containing water transport channel to connect the lithium-containing water and the functional layer, which is conducive to the continuous transportation of water containing lithium to the hydrogel-based water-energy-resource co-production solar evaporator for efficient lithium extraction.

[0092] The condensation module is located above the water-energy-resource co-production module to condense and collect water vapor generated during lithium extraction in a timely manner.

[0093] The water collection module is located on the left side of the water-energy-resource co-production module to collect condensed water (i.e., fresh water) cooled by the condensation module.

[0094] It should be noted that Figure 1 the left side of the above-mentioned structure is a place for collecting fresh water (i.e., the water collection module), and the condensed water flows down the inclined surface (the condensation module) after evaporation, and the whole process is that the lithium-containing water is transported to the functional layer by the cotton rope, and then lithium is collected in the functional layer. Because the functional layer has good photo-thermal effect, it can heat the transported water to generate a large amount of water vapor, which condenses when reaching the uppermost inclined surface, and then flows down the inclined surface to the water collection module.

[0095] The present application takes sodium alginate (SA) hydrogel as a matrix, adds carbon nanotubes (CNT) (as a photothermal material) and titanium-based lithium ion sieve (HTO) or metal-doped titanium-based lithium ion sieve (M-HTO) into the solution, relies on polyurethane (PU) sponge as a carrier framework, and constructs a solar evaporator with flexible size (centimeter to meter components can be prepared according to application scenarios) by Ca 2+ The present application is a solar evaporator with flexible size (centimeter to meter components can be prepared according to application scenarios) for the solar-driven evaporation process of salt lake seawater and other lithium-containing water resources, which realizes Li + The present application is a solar evaporator with flexible size (centimeter to meter components can be prepared according to application scenarios) for the solar-driven evaporation process of salt lake seawater and other lithium-containing water resources, which realizes Li

[0096] The present application relates to a hydrogel-based water-energy-resource co-production solar evaporator, which is a multifunctional hydrogel composite structure-based solar-driven collaborative solar evaporator that integrates lithium resource recovery, freshwater collection and combined heat and power into one, and constructs a new energy-substance collaborative management architecture of "photothermal-evaporation-adsorption-thermoelectric" four-in-one. The core purpose of the present application is to solve the problems of high energy consumption, low efficiency, easy agglomeration and deactivation of powder materials, difficult recovery of adsorbents and long production cycle in the process of extracting lithium resources from low-concentration, high-magnesium-lithium ratio salt lake brine or seawater.

[0097] This invention relates to a hydrogel-based water-energy-resource co-production solar evaporator that uses inexpensive, high-porosity, and high-performance commercial polyurethane sponge as a three-dimensional scaffold support. Unlike the approach of extracting lithium resources using PA membranes under solar energy, the extraction mechanism of this hydrogel-based water-energy-resource co-production solar evaporator (system) is based on the endothermic exchange of hydrogen and lithium ions in a lithium ion sieve. Solar energy in this system accelerates and promotes the forward movement of the reaction, thereby increasing the lithium extraction capacity. In contrast, the former utilizes photothermal vaporization to generate evaporation driving force, promoting the passage of small-sized lithium ions while blocking the passage of larger ions such as magnesium ions. Furthermore, the extraction method of this invention is obtained through liquid enrichment, which avoids crystallization on the functional layer surface, reducing damage to the system. The polyurethane sponge possesses interconnected macroscopic macroporous channels and micron-level surface roughness, providing ample loading space and a robust adhesion interface for the hydrogel, ensuring the integrity of the composite structure; it also enables high-speed and stable water transport. Sodium alginate hydrogel networks were constructed within a sponge framework using an in-situ crosslinking process. This hydrogel system serves two main purposes: firstly, it acts as an encapsulation matrix for functional materials, effectively dispersing and immobilizing powdered titanium-based lithium ion sieves, significantly mitigating the reduction in active sites caused by aggregation, and increasing the effective contact area between the ion sieves and lithium-containing water, thereby improving lithium extraction kinetics efficiency; secondly, the abundant carboxyl groups (-COO-) in the hydrogel network... - Functional groups such as ) can affect Li + This generates initial weak selective coordination, providing a pre-enrichment basis for high-precision capture by subsequent ion sieves.

[0098] Building upon this, titanium-based lithium-ion sieves and carbon nanotubes (CNTs) were uniformly dispersed and anchored within a sodium alginate hydrogel network. CNTs, acting as highly efficient photothermal conversion units, convert absorbed solar energy into heat energy, driving the evaporation of interfacial moisture; while the lithium-ion sieves distributed around them act as molecular traps, utilizing their unique crystal tunnel structure to trap Li-ion molecules. + This enables specific recognition and efficient embedding. Crucially, the heat energy generated by photothermal conversion significantly reduces the lithium-ion hydration barrier, promoting H+ ion hydration. + -Li + The exchange reaction kinetics enabled the functional synergy and energy coupling of photothermal evaporation and ion adsorption.

[0099] To further improve ion selectivity and photothermal performance, this invention modifies the lithium-ion sieve with metal doping, achieving synergistic control of crystal and electronic structures. The introduction of doped ions induces lattice distortion and charge imbalance, thereby triggering oxygen vacancy formation. On the one hand, a moderately increased tunnel window size is more conducive to Li... +The migration and embedding of lithium ions improve the site utilization efficiency and significantly improve the lithium recovery capacity; on the other hand, the lattice distortion and oxygen vacancies together enhance the electronegativity of the material surface, and produce strong electrostatic repulsion to interference ions (such as Mg 2+ ) with high hydration energy and large hydration radius, thereby effectively improving the separation factor. In terms of photothermal performance, the defect energy level introduced by doping effectively narrows the optical band gap of the material, expands the photon capture ability of visible-near infrared light; at the same time, the defect site as a carrier trapping center promotes the non-radiative recombination path, and more photoenergy is converted into heat energy through phonon scattering, which effectively improves the photo-thermal conversion efficiency.

[0100] In addition to the lithium selective extraction function, the hydrogel-based water-energy-resource co-production solar evaporator of the application also realizes the synergistic output of fresh water preparation and cogeneration. The hydrogel-sponge composite matrix relies on its excellent water transport capacity and photothermal evaporation performance to continuously produce water vapor, which can be recovered as fresh water after condensation. In addition, experimental results show that the hydrogel-based water-energy-resource co-production solar evaporator of the application has good water transport capacity while significantly improving its salt crystallization resistance. In terms of cogeneration, the temperature gradient generated between the photothermal interface and the water body by virtue of the inherent thermal localization effect of the evaporator, the application innovatively integrates a thermoelectric power generation module, connects the thermoelectric sheet with the evaporation interface, and thus directly converts the waste heat gradient generated during system operation into electrical energy, realizing the resource-energy synergistic recovery of "lithium-water-electricity" tri-production.

[0101] The hydrogel-based water-energy-resource co-production solar evaporator of the application utilizes solar light to convert solar energy into system heat, uses this green heat to provide energy for lithium extraction and heat the water body to produce steam, and then utilizes the waste heat gradient to generate electricity by means of temperature difference.

[0102] It should be noted that the parts not described in detail in the application are conventional operating means in the art and are not the focus of the application.

[0103] The technical solutions of the application are further described below through examples.

[0104] Example 1

[0105] The hydrogel-based water-energy resource co-production solar evaporator comprises a water-energy resource co-production module, a condensation module and a water collection module. The water-energy resource co-production module is composed of a functional layer from top to bottom, a power generation plate, a cooling water circulator and an interface support heat management module. The functional layer takes polyurethane (PU) sponge as a carrier, and is internally filled with sodium alginate (SA) hydrogel, carbon nanotubes (CNT) and iron (Fe) doped titanium-based lithium ion sieve (M-HTO). The interface support heat management module uses PVC-coated polystyrene foam to improve heat utilization rate, reduce heat loss and improve evaporation efficiency. The power generation plate uses a semiconductor thermoelectric power generation plate to realize the utilization of waste heat gradient after water vapor is generated for water purification and collection. A cotton rope is used to build a lithium-containing water body transmission channel to connect the lithium-containing water body and the functional layer, which is conducive to the continuous transmission of water in the lithium-containing water body to the hydrogel-based water-energy resource co-production solar evaporator for efficient lithium extraction.

[0106] The condensation module is located on the left side of the water-energy resource co-production module to condense and collect water vapor generated during lithium extraction in time.

[0107] The water collection module is located above the water-energy resource co-production module to collect condensed water cooled by the condensation module.

[0108] The functional layer of the water-energy resource co-production module is prepared by the following method:

[0109] (1) Put 0.05 mol of titanium dioxide powder, 0.1 mol of lithium hydroxide monohydrate and 0.0075 mol of ferric sesquioxide into a maroon ball mill jar with 10 mL of anhydrous ethanol, add Φ3 mm and Φ10 mm maroon milling beads (mass ratio of 1:1), then put them into a ball mill, and mill at a speed of 300 r / min in revolution and 600 r / min in rotation for 60 min to obtain Fe-doped titanium-based lithium ion sieve (Fe-HTO) precursor slurry;

[0110] (2) Put the Fe-HTO precursor slurry prepared in step (1) into an electric heating air drying oven and dry at a temperature of 60 ℃ until it becomes dry;

[0111] (3) Accurately scrape the dry material obtained in step (2) with a clean stainless steel spoon, and transfer it to a maroon mortar for preliminary grinding treatment. After grinding uniformly, put it into a crucible and place it in a muffle furnace. In the oxygen-rich atmosphere of air, heat calcination is carried out at a calcination temperature of 650 ℃, a heating rate of 10 ℃ / min and a holding time of 240 min to form Fe-doped lithium ion sieve (Fe-LTO) precursor;

[0112] (4) Grind and sieve the sample obtained in step (3) into uniform precursor powder (particle size of 100 mesh) for subsequent use.

[0113] (5) The uniformly ground precursor powder is added to hydrochloric acid with a concentration of 0.2 M and placed on a magnetic stirrer for stirring and replacement for 24 h to obtain Fe-HTO after acid washing;

[0114] (6) The Fe-HTO after acid washing is added to deionized water and washed by centrifugation until neutral;

[0115] (7) The Fe-HTO washed to neutral is placed in an electric heating air drying oven and dried at a temperature of 60 ℃ until the Fe-HTO presents a dry material state, accurately scraped and transferred to a pre-cooled agate mortar with a clean stainless steel spoon for grinding treatment until all pass through a 100-mesh screen;

[0116] (8) 2.8 g of sodium alginate powder and 54 mL of deionized water are mixed, heated in an oil bath at 80 ℃ and continuously stirred for 180 min until the sodium alginate gel solution becomes uniform and translucent;

[0117] (9) The sodium alginate gel solution prepared in step (8) is continuously heated at 80 ℃, and CNT powder (the mass fraction of CNT powder in the sodium alginate gel solution is 2%, that is, the mass fraction of CNT in the functional layer of the water-energy-resource co-production module in this example is 2%) is added, and 6.5 mL of deionized water is added, and the stirring is continued for 60 min until the solution is uniformly mixed;

[0118] (10) The uniformly mixed solution in step (9) is continuously heated at 80 ℃, and the Fe-HTO prepared in step (7) (the addition amount of Fe-HTO is 4% of the mass of the uniformly mixed solution in step (9)) and 6.5 mL of deionized water are added, and the stirring is continued at 80 ℃ for 10 min until the solution is uniformly mixed;

[0119] (11) A polyurethane sponge with a thickness of 0.5 cm is immersed in the mixed solution prepared in step (10), and repeatedly squeezed and kneaded until the internal pores of the sponge are completely and uniformly filled, and a glass rod is scraped to the surface to be flat;

[0120] (12) The sponge in step (11) is placed in a CaCl2 solution with a concentration of 0.5 mol·L -1 -1 for crosslinking for 24 h, and then washed with deionized water for 15 times to form the functional layer of the water-energy-resource co-production module required finally. The final product of this example is a water gel-based water-energy-resource co-production solar evaporator encapsulating Fe-HTO.

[0121] Example 2 (as a comparison)

[0122] This embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that of embodiment 1, except that the mass fraction of CNT in the functional layer of the water-energy-resource co-production module in step (9) is 0%.

[0123] Embodiment 3

[0124] This embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that of embodiment 1, except that the mass fraction of CNT in the functional layer of the water-energy-resource co-production module in step (9) is 4%.

[0125] Embodiment 4

[0126] This embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that of embodiment 1, except that the mass fraction of CNT in the functional layer of the water-energy-resource co-production module in step (9) is 8%.

[0127] Embodiment 5

[0128] This embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that of embodiment 1, except that the Fe-doped titanium-based lithium ion sieve in the functional layer is replaced by a molybdenum (Mo)-doped titanium-based lithium ion sieve, and the same amount of molybdenum dioxide is used to replace the ferric trioxide in step (1) to obtain a Mo-HTO precursor slurry. The final product of this embodiment is a hydrogel-based water-energy-resource co-production solar evaporator encapsulating Mo-HTO.

[0129] Embodiment 6 (as a comparison)

[0130] This embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that of embodiment 5, except that the mass fraction of CNT in the functional layer of the water-energy-resource co-production module in step (9) is 0%.

[0131] Embodiment 7

[0132] This embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that of embodiment 5, except that the mass fraction of CNT in the functional layer of the water-energy-resource co-production module in step (9) is 4%.

[0133] Embodiment 8

[0134] This embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that of embodiment 5, except that the mass fraction of CNT in the functional layer of the water-energy-resource co-production module in step (9) is 8%.

[0135] Embodiment 9

[0136] The embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that in Embodiment 1, except that no ferric oxide is added, and a titanium-based lithium ion sieve (HTO) precursor slurry is obtained. The final product of the embodiment is a hydrogel-based water-energy-resource co-production solar evaporator encapsulating the HTO.

[0137] Embodiment 10 (as a comparison)

[0138] The embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that in Embodiment 9, except that the mass fraction of the CNT in the functional layer of the water-energy-resource co-production module in step (9) is 0%.

[0139] Embodiment 11

[0140] The embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that in Embodiment 9, except that the mass fraction of the CNT in the functional layer of the water-energy-resource co-production module in step (9) is 4%.

[0141] Embodiment 12

[0142] The embodiment provides a hydrogel-based water-energy-resource co-production solar evaporator, which is the same as that in Embodiment 9, except that the mass fraction of the CNT in the functional layer of the water-energy-resource co-production module in step (9) is 8%.

[0143] Lithium extraction experiments are carried out on the hydrogel-based water-energy-resource co-production solar evaporators prepared in the above embodiments under the intensity of 1 sun, and the specific process is as follows: the concentration of the lithium chloride solution is controlled to be 200 mg / L, the pH value is controlled to be 12, the xenon lamp irradiation intensity is controlled to be 1.0 kW / m 2 , and the reaction time is controlled to be 14 h. The mass change comparison chart of the hydrogel-based water-energy-resource co-production solar evaporators (encapsulating HTO) of Embodiments 9-12 is shown in Figure 2 , the mass change comparison chart of the hydrogel-based water-energy-resource co-production solar evaporators (encapsulating Fe-HTO) of Embodiments 1-4 is shown in Figure 3 , the mass change comparison chart of the hydrogel-based water-energy-resource co-production solar evaporators (encapsulating Mo-HTO) of Embodiments 5-8 is shown in Figure 4 , the lithium extraction effect comparison chart of the hydrogel-based water-energy-resource co-production solar evaporators (encapsulating HTO) of Embodiments 9-12 with different encapsulation amounts of the photothermal materials is shown in Figure 5 , the lithium extraction effect comparison chart of the hydrogel-based water-energy-resource co-production solar evaporators (encapsulating Fe-HTO) of Embodiments 1-4 with different encapsulation amounts of the photothermal materials is shown in Figure 6As shown in the figure; the comparison of lithium extraction effects of different photothermal material encapsulation amounts in the hydrogel-based water-energy-resource cogeneration solar evaporators (encapsulated Mo-HTO) of Examples 5-8 of the present invention is as follows. Figure 7 As shown, the biomass hydrogel-based water-energy-resource co-production solar evaporator constructed in this invention exhibits excellent photothermal-adsorption synergistic performance and structural adaptability under different functional component ratios and metal doping strategies. Figures 2-4 As shown, with the increase of CNT addition, the evaporation mass loss of each system significantly increased, indicating a continuous enhancement of photothermal conversion efficiency and evaporation driving force. Among them, the system encapsulated with 2 wt% CNT showed little difference in performance compared to other encapsulation amounts and still exhibited good evaporation performance; at the same CNT addition amount, the Mo-HTO system ( Figure 4 It showed superior performance compared to the HTO system. Figure 2 Evaporation performance. Regarding lithium extraction performance ( Figures 5-7 After removing the background from matrix extraction, the lithium extraction capacity showed a trend of first increasing and then decreasing with the addition of CNTs. Combined with a comprehensive evaluation of evaporation performance, 2 wt% CNTs was the optimal ratio for this invention. Furthermore, under the same CNT addition amount, the Fe-HTO system ( Figure 6 Its lithium extraction performance is significantly better than that of the undoped system. Figure 5 ).

[0144] Taking the hydrogel-based water-energy-resource cogeneration solar evaporators prepared in Examples 1, 5, and 9 as examples, waste heat power generation experiments were conducted under different solar irradiance intensities. The specific process was as follows: the xenon lamp irradiation intensity was controlled at 1.0 kW / m². 2 The components were arranged in the following order from top to bottom: functional layer, thermoelectric generator, and cooling water circulator. The power generation time for each component was 30 minutes (one cycle lasting 10 minutes). Experimental results are as follows: Figures 8-10 As shown, light intensity and metal doping strategy both significantly affect the lithium extraction performance of the hydrogel-based water-energy-resource cogeneration solar evaporator of this invention, and the doped system exhibits superior synergistic performance and stability under different light intensities. Regarding lithium extraction performance, the HTO system ( Figure 8 The lithium extraction capacity of Fe-HTO only increases slowly with increasing light intensity, while that of Fe-HTO ( Figure 9 The light intensity showed a significant positive correlation.

[0145] Taking the hydrogel-based water-energy-resource co-generation solar evaporators prepared in Examples 1, 5, and 9 as examples, lithium extraction experiments were conducted. The specific process was as follows: the xenon lamp irradiation intensity was controlled at 1.0 kW / m². 2 The lithium chloride solution concentration was 200 mg / L, the pH value was 12, and the xenon lamp irradiation intensity was 0.5 kW / m². 2 and 2.0kW / m2 The reaction time was 14 hours for all reactions. The experimental results are as follows: Figures 11-16 As shown, light intensity and metal doping strategy have a significant synergistic effect on thermoelectric output performance. The doped system exhibits superior energy output capability and temperature difference response characteristics under higher light intensity. With the light intensity increasing from 1 sun to 3 sun, the undoped system ( Figure 11 , Figure 14 ), Fe doped system ( Figure 12 , Figure 15 ) and Mo-doped systems ( Figure 13 , Figure 16 The power generation current and voltage of the Mo-HTO system both increased significantly. This indicates that the enhanced light intensity increased the temperature gradient between the evaporation interface and the water body by improving the photothermal conversion efficiency, thus providing a stronger driving force for the thermoelectric module. Under the same light conditions, the current and voltage output of the Mo-HTO system were consistently higher than those of the HTO system.

[0146] Taking the hydrogel-based water-energy-resource co-generation solar evaporators prepared in Examples 1, 5, and 9 as examples, lithium extraction experiments were conducted under one solar irradiance and in solutions with different lithium contents. Specifically, the xenon lamp irradiation intensity was controlled at 1.0 W / m². 2 The lithium chloride solution had a pH of 12, and the concentrations of the lithium chloride solutions were 0.2 mg / L, 2 mg / L, 20 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, and 400 mg / L, with a reaction time of 14 h for all cases. The experimental results are as follows: Figures 17-19 As shown, the hydrogel-based water-energy-resource co-production solar evaporator of the present invention exhibits excellent extraction capabilities in solutions with different initial lithium concentrations. As the initial lithium concentration increases from 0.2 mg / L to 400 mg / L, the HTO system ( Figure 17 ), Fe-HTO system ( Figure 18 ) and Mo-HTO system ( Figure 19 The lithium extraction capacity of all samples showed an upward trend, indicating that the hydrogel-based water-energy-resource cogeneration solar evaporator has a wide range of concentration adaptability.

[0147] Taking the hydrogel-based water-energy-resource cogeneration solar evaporators prepared in Examples 1, 5, and 9 as examples, lithium extraction experiments were conducted under different pH conditions at one solar irradiance. Specifically, the xenon lamp irradiation intensity was controlled at 1.0 kW / m². 2 The lithium chloride solution concentration was 200 mg / L, and the pH values ​​of the lithium chloride solution were 6, 7, 8, 10, and 12, respectively, with a reaction time of 14 h for all cases. The experimental results are as follows: Figures 20-22 As shown, the system of the present invention exhibits good lithium extraction stability over a wide pH range, and the Fe-HTO system (Figure 21 Compared to the HTO system ( Figure 20 It has superior lithium extraction capabilities.

[0148] Taking the hydrogel-based water-energy-resource co-production solar evaporators prepared in Examples 1, 5, and 9 as examples, a cyclic extraction experiment was conducted in a lithium content solution with a concentration of 200 mg / L under one solar irradiance. The specific process was as follows: the xenon lamp irradiation intensity was controlled at 1.0 kW / m². 2 The lithium chloride solution concentration was 200 mg / L, the pH value of the lithium chloride solution was 12, and the reaction time was 14 h. The experimental results are as follows: Figures 23-25 As shown, the system of the present invention exhibits good cycle stability and structural durability, and the Fe-HTO system ( Figure 24 ) and Mo-HTO system ( Figure 25 Compared to the HTO system ( Figure 23 It exhibits superior cycle stability and higher extraction capacity retention across multiple cycles.

[0149] Taking the hydrogel-based water-energy-resource cogeneration solar evaporators prepared in Examples 1, 5, and 9 as examples, an evaporation experiment was conducted continuously for 12 hours under one solar irradiance. The specific process was as follows: actual seawater from Qingdao Jimo Coastal Park was used, and the xenon lamp irradiation intensity was controlled at 1.0 kW / m². 2 The reaction time was 12 hours for all reactions. The experimental results are as follows: Figures 26-34 As shown, the system of the present invention exhibits excellent stability, resistance to salt crystallization, and practical water treatment potential during long-term operation. After 12 hours of continuous evaporation, in actual seawater treatment ( Figures 29-31 The Mo-HTO system exhibits superior ion separation selectivity. Figure 31 Analysis of ion content in collected freshwater ( Figures 32-34 This indicates that the produced water from all systems meets the freshwater standard, and the Fe-HTO system ( Figure 32 ) and Mo-HTO system ( Figure 34 The product has a lower concentration of impurity ions. Furthermore, all systems of this invention (HTO system, Fe-HTO system, Mo-HTO system) showed no significant salt crystal accumulation on their surface after 12 hours of continuous evaporation, indicating that the hydrogel-based water-energy-resource co-generation solar evaporator prepared by this invention possesses excellent anti-fouling and self-cleaning capabilities.

[0150] With the increase of CNT concentration, the evaporation rate and waste heat power generation of the hydrogel-based water-energy-resource co-production solar evaporator showed a continuous upward trend, but the lithium extraction amount of the evaporator (after matrix extraction correction) showed a nonlinear change law of first increasing and then decreasing; the light intensity had a significant positive regulation effect on the performance of the hydrogel-based water-energy-resource co-production solar evaporator, and with the increase of incident light intensity, the evaporation rate of the hydrogel-based water-energy-resource co-production solar evaporator showed a monotonic increasing trend, and the synchronous monitoring showed that the waste heat recovery efficiency of the hydrogel-based water-energy-resource co-production solar evaporator kept a coordinated growth with the evaporation rate, which confirmed the effective strengthening of the photo-thermal-thermal-electric coupling effect. In terms of lithium extraction performance, the improvement of light intensity significantly improved the migration dynamics of Li + , so that the extraction rate was improved; the hydrogel-based water-energy-resource co-production solar evaporator of the present application showed good adaptability to the concentration gradient and pH value range of the lithium-containing solution, and exhibited stable lithium extraction performance; in different salinity solution systems, the evaporation rate remained relatively stable, indicating that the hydrogel-based water-energy-resource co-production solar evaporator of the present application had strong adaptability; in addition, the evaporator also achieved good removal effect on metal salt ions.

[0151] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A hydrogel-based water-energy-resource co-production solar evaporator, characterized in that, The water-energy-resource co-production module, the condensation module and the water collection module; The condensation module is located above the water-energy-resource co-production module and is used for condensing water vapor generated in the lithium extraction process; The water collection module is located on the left side of the water-energy-resource co-production module and is used for collecting condensed water cooled by the condensation module; The water-energy-resource co-production module is composed of a functional layer from top to bottom, a power generation plate, a cooling water circulator and an interface support thermal management module; The functional layer takes polyurethane sponge as a carrier and is internally filled with sodium alginate hydrogel, carbon nanotubes and titanium-based lithium ion sieve or metal-doped titanium-based lithium ion sieve.

2. The hydrogel-based solar energy-hydrogen co-production evaporator according to claim 1, wherein, The preparation method of the functional layer comprises the following steps: The titanium-based lithium ion sieve or the metal-doped titanium-based lithium ion sieve is prepared; The carbon nanotubes, the sodium alginate gel solution and water are uniformly mixed to obtain a mixed solution, the titanium-based lithium ion sieve or the metal-doped titanium-based lithium ion sieve is added, water is added again, and stirring is performed until a uniform solution is formed; The polyurethane sponge is immersed in the uniform solution, repeatedly squeezed and kneaded until the internal pores of the polyurethane sponge are completely and uniformly filled, scraped to be flat on the surface, placed in a calcium chloride solution for crosslinking, and then washed with water to obtain the functional layer.

3. The hydrogel-based solar energy-hydrogen co-production evaporator according to claim 2, wherein, The preparation method of the titanium-based lithium ion sieve comprises the following steps: a. Lithium hydroxide monohydrate and titanium dioxide are weighed according to a molar ratio of Li to Ti of 2:1, wet ball milling is performed to obtain titanium-based lithium ion sieve precursor slurry; b. The titanium-based lithium ion sieve precursor slurry is dried to obtain dry material; c. The dry material is calcined to obtain titanium-based lithium ion sieve precursor; d. The titanium-based lithium ion sieve precursor is ground into powder, the powder is added to a hydrochloric acid solution for replacement, and then washed with water, dried, ground and sieved to obtain the titanium-based lithium ion sieve.

4. The hydrogel-based solar energy-hydrogen co-production evaporator according to claim 2, wherein, The preparation method of the metal-doped titanium-based lithium ion sieve comprises the following steps: a. Lithium hydroxide monohydrate, titanium dioxide and metal oxide are weighed according to a molar ratio of Li, Ti and M of 2:1:0.15, wet ball milling is performed to obtain metal-doped titanium-based lithium ion sieve precursor slurry, and M is selected from iron or molybdenum; b. The metal-doped titanium-based lithium ion sieve precursor slurry is dried to obtain dry material; c. The dry material is calcined to obtain metal-doped titanium-based lithium ion sieve precursor; d. The metal-doped titanium-based lithium ion sieve precursor is ground into powder, the powder is added to a hydrochloric acid solution for replacement, and then washed with water, dried, ground and sieved to obtain the metal-doped titanium-based lithium ion sieve.

5. The hydrogel-based solar energy-hydrogen co-production evaporator according to claim 3 or 4, characterized in that, The temperature of the calcination is 650 ℃, the heating rate is 10 ℃ / min, and the holding time is 240 min; And / or, the grinding medium during the wet ball milling is anhydrous ethanol.

6. The hydrogel-based solar energy-hydrogen co-production evaporator according to claim 2, wherein, The preparation method of the sodium alginate gel solution is that sodium alginate powder is dissolved in water, and continuous stirring is performed under heating conditions until the sodium alginate gel solution is formed.

7. The hydrogel-based solar energy-harvesting and water-evaporating co-production device according to claim 2, wherein, The addition amount of the carbon nanotubes is 2-8% of the mass of the sodium alginate gel solution.

8. The hydrogel-based solar energy-harvesting and water-evaporating co-production device according to claim 2, wherein, The mass proportion of the titanium-based lithium ion sieve or the metal-doped titanium-based lithium ion sieve in the mixed solution is 4%.

9. The hydrogel-based solar energy-harvesting and water-evaporating co-production device according to claim 2, wherein, The density of the polyurethane sponge is 15 kg·m -3 , the thickness is 0.5 cm, and the number of extrusions is 20-30 times.

10. Use of the hydrogel-based water-energy resource co-production solar still according to any one of claims 1-9 in lithium resource recovery, fresh water harvesting, and combined heat and power.

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