Aerogel interfacial photothermal evaporation material, and preparation method therefor and use thereof

Abstract

An aerogel interfacial photothermal evaporation material, and a preparation method therefor and the use thereof. The aerogel interfacial photothermal evaporation material comprises graphene, a carbonized ternary precursor and oxide nanoparticles, wherein the graphene coats the surface of the carbonized ternary precursor, and the oxide nanoparticles are loaded on the surface of the carbonized ternary precursor coated with the graphene.

Description

An aerogel interface photothermal evaporation material and its preparation method and application Technical Field

[0001] The embodiments of the present application relate to the technical fields of waste recycling and utilization and wastewater evaporation and desalination in the ternary precursor industry, such as an aerogel interface photothermal evaporation material and its preparation method and application. Background Art

[0002] At present, due to technical limitations and instability of production lines in the relevant ternary precursor production process, a large number of large-particle and large-grain ternary precursors are inevitably produced during the production process. These large-particle ternary precursors cannot achieve specific performance. Therefore, screening is required to remove these large-particle ternary precursors to ensure that the physical and chemical properties are not affected.

[0003] As production capacity continues to increase, the amount of large-particle waste generated continues to increase and accumulate, resulting in not only a waste of resources, but also space occupation, environmental pollution, and certain safety hazards. However, large-particle ternary precursor waste, due to its original non-solid structure and the presence of a large number of short and abundant vacuum channels inside, has an excellent capillary effect. Furthermore, after high-temperature carbonization, it produces pores of varying sizes on the original basis. The combination of these two can achieve the goal of efficient water quality transmission during wastewater evaporation. The required raw materials are sourced from daily production, requiring no additional costs, and also solves the problem of large-particle waste accumulation.

[0004] On the other hand, the large-particle ternary precursor waste itself has low light absorption efficiency and photothermal conversion rate, which makes it unsuitable for use as a good aerogel interface photothermal evaporation material. In addition, its own water absorption makes it impossible to float stably on the liquid surface for a long time during use, and it is impossible to form an aerogel block with an inherent shape for a long time.

[0005] Related research has found that graphene has the characteristics of good hydrophobicity, high thermal conductivity, and fast heat transfer. It can absorb sunlight in a wide wavelength range and can carry and transport carriers excellently in wastewater photothermal evaporation. It is a commonly used photothermal evaporation material.

[0006] Therefore, how to rationally utilize the structural characteristics of large-particle waste of ternary precursors to design graphene aerogels with light absorption and photothermal evaporation properties is a technical problem that needs to be solved urgently.

[0007] Summary of the Invention

[0008] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0009] The embodiment of the present application provides an aerogel interfacial photothermal evaporation material and its preparation method and application. In this application, large-particle (D>40μm) waste of ternary precursors accumulated in the production of ternary precursors in the new energy industry is used as the substrate, which greatly reduces the cost of preparing aerogel raw materials and reduces the demand for substrates with pipeline structures and capillary effects, thereby realizing the reuse of waste produced by the ternary precursor process and improving resource utilization efficiency. After being coated with graphene, the aerogel photothermal evaporation material is obtained, which can be used for the evaporation of low-salt wastewater, playing a role in green environmental protection, energy saving and cost reduction.

[0010] In a first aspect, an embodiment of the present application provides an aerogel interface photothermal evaporation material, wherein the aerogel interface photothermal evaporation material includes graphene, a carbonized ternary precursor, and oxide nanoparticles;

[0011] The graphene is coated on the surface of the carbonized ternary precursor, and the oxide nanoparticles are loaded on the surface of the carbonized ternary precursor coated with the graphene.

[0012] Among them, graphene forms a coating layer, the carbonized ternary precursor is a substrate, and the aerogel interface photothermal evaporation material is a composite formed by the two.

[0013] Graphene possesses excellent hydrophobicity, high thermal conductivity, and rapid heat transfer. It absorbs sunlight across a wide wavelength range and is an excellent carrier carrier for wastewater photothermal evaporation. The presence of oxide nanoparticles enhances the light absorption efficiency of the graphene surface. The carbonized ternary precursor, as a substrate material, exhibits an excellent capillary effect due to the numerous short, abundant vacuum channels within the precursor. After carbonization, pores of varying sizes are created within the original structure, enabling efficient water transport during wastewater evaporation.

[0014] This application obtains an aerogel material with excellent light absorption and photothermal evaporation properties by coating graphene and loading oxide nanoparticles on a carbonized ternary precursor. The three materials cooperate with each other in spatial structure, and can be applied to the evaporation of low-salt wastewater, which is conducive to scale and efficiency.

[0015] Preferably, the carbonized ternary precursor is ternary precursor particle waste that has been carbonized.

[0016] Preferably, the ternary precursor particle waste is nickel cobalt manganese hydroxide, wherein the mass ratio of nickel cobalt manganese elements is Ni:Co:Mn = (20-25%): (20-25%): (30-35%), for example, it can be 22%:20.5%:32.5%, 20%:20%:30%, 20%:25%:30%, 25%:20%:30% or 25%:25%:35%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the ternary precursor particle waste is waste generated during the preparation process of the ternary precursor, and its particle size is above 40 μm, for example, it can be 40 μm, 45 μm, 50 μm, 55 μm or 60 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In this application, the ternary precursor particle waste (particle size range is D>40μm) accumulated in the production of ternary precursors in the new energy industry is used as the base raw material, which greatly reduces the cost of preparing aerogel raw materials and reduces the demand for substrates with pipeline structures and capillary effects, thereby realizing the reuse of ternary precursor process production waste and improving resource utilization efficiency.

[0019] Among them, the ternary precursor particle waste itself is a non-solid structure, with short and abundant vacuum channels inside. As a consensus in the industry, the existence of vacuum channels in the ternary precursor is clearly observed through the cross-sectional electron microscope image of the ternary precursor. After carbonization, the ternary precursor particle waste will further produce abundant channels. The two have an excellent capillary effect under the joint action of the two. The capillary effect is used to construct a capillary network with efficient water quality transmission, which effectively improves the water transport efficiency of the photothermal evaporation process, thereby directly improving the photothermal evaporation efficiency.

[0020] After the ternary precursor particle waste is coated with graphene as the aerogel substrate, it not only enhances the heat retention capacity and reduces the heat loss during the evaporation process, but also enhances the light absorption ability of the graphene-coated ternary precursor large particle waste itself through the loading of nanoparticles, thereby improving the photothermal evaporation efficiency. Moreover, the hydrophobicity of graphene also prevents the ternary precursor large particle waste aerogel from freely dispersing in the water body, and can stably float on the liquid surface in a fixed block for a long time, which is conducive to large-scale and efficient photothermal evaporation applications.

[0021] Preferably, the aerogel interface photothermal evaporation material further comprises a polymer coating layer, and the polymer coating layer is modified on the surface of the graphene-coated carbonized ternary precursor.

[0022] Preferably, the polymer coating comprises a polydopamine coating.

[0023] The polydopamine coating layer serves to provide highly active functional groups.

[0024] Preferably, the oxide nanoparticles include titanium dioxide nanoparticles.

[0025] Titanium dioxide nanoparticles enhance the light absorption of the material, increase the light absorption efficiency, and increase the photothermal evaporation rate.

[0026] In a second aspect, an embodiment of the present application provides a method for preparing the aerogel interface photothermal evaporation material according to the first aspect, the preparation method comprising:

[0027] (1) preparing a carbonized ternary precursor;

[0028] (2) mixing graphene oxide and the obtained carbonized ternary precursor to obtain a graphene oxide-coated carbonized ternary precursor, and then mixing it with a reducing agent, and after the reaction is completed, obtaining a graphene-coated carbonized ternary precursor;

[0029] (3) mixing the nano-oxide and the obtained graphene-coated carbonized ternary precursor, and performing a hydrothermal reaction to obtain a supported material;

[0030] (4) The obtained loaded material is heated to form a hydrogel, and then freeze-dried to obtain the aerogel interface photothermal evaporation material.

[0031] Preferably, the preparation method of the carbonized ternary precursor in step (1) includes: calcining the ternary precursor particle waste under a protective gas atmosphere to obtain the carbonized ternary precursor.

[0032] After carbonization, the ternary precursor particle waste retains its original structure but is rich in pores. This is because during the calcination and carbonization process, the primary particles change from flakes to smaller blocks, the surface becomes smoother, and the pores between the particles increase to form pores.

[0033] Preferably, the heating rate of the calcination is 3 to 5°C / min, for example, 3°C / min, 3.5°C / min, 4°C / min, 4.5°C / min or 5°C / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] Preferably, the calcination temperature is 500-800°C, for example, 500°C, 550°C, 600°C, 700°C or 800°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] When the calcination temperature is between 300 and 500°C, the pores begin to increase slightly; at 500 to 800°C, the pores between the particles increase and form channels; at 800°C, the critical value is reached; above 800°C, the pores will continue to increase, causing the spherical shape of the ternary precursor to begin to crack into irregular fragments in large quantities, destroying the original structure.

[0036] Preferably, the calcination time is 2 to 4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] Preferably, the mixed graphene oxide and the obtained carbonized ternary precursor in step (2) are mixed graphene oxide aqueous solution and the obtained carbonized ternary precursor.

[0038] Preferably, the concentration of the graphene oxide aqueous solution is 3 to 10 mg / mL, for example, 3 mg / mL, 5 mg / mL, 7 mg / mL, 9 mg / mL or 10 mg / mL, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the solid-to-liquid ratio of the carbonized ternary precursor and the graphene oxide aqueous solution is 1:(4-6) g / mL, for example, it can be 1:4 g / mL, 1:4.5 g / mL, 1:5 g / mL, 1:5.5 g / mL or 1:6 g / mL, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] Preferably, after mixing the graphene oxide and the obtained carbonized ternary precursor in step (2), stirring and filtering are also included.

[0041] Preferably, the stirring time is 5 to 10 hours, for example, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the reducing agent in step (2) comprises any one of potassium borohydride solution, sodium borohydride solution or lithium borohydride solution, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of potassium borohydride solution and sodium borohydride solution, a combination of sodium borohydride solution and lithium borohydride solution, and a combination of potassium borohydride solution and lithium borohydride solution.

[0043] Preferably, the concentration of the reducing agent is 0.5 to 3 mol / L, for example, 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L or 3 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0044] Preferably, the solid-liquid ratio of the graphene oxide-coated carbonized ternary precursor and the reducing agent in step (2) is 1:(50-100) g / mL, for example, it can be 1:50 g / mL, 1:60 g / mL, 1:70 g / mL, 1:80 g / mL, 1:90 g / mL or 1:100 g / mL, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] Preferably, the reaction time of step (2) is 8 to 12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] Preferably, before step (3), the method further includes modifying the surface of the graphene-coated carbonized ternary precursor with a polymer.

[0047] Preferably, the modification method includes: mixing a dopamine solution, a buffer solution and the graphene-coated carbonized ternary precursor, adjusting the pH and stirring, and filtering and drying to obtain a polymer modified material.

[0048] Preferably, the concentration of the dopamine solution is 1 to 3 mg / mL, for example, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL or 3 mg / mL, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0049] Preferably, the buffer comprises 0.05 to 0.15 mol / L Tris buffer, for example, 0.05 mol / L, 0.08 mol / L, 0.1 mol / L, 0.12 mol / L or 0.15 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0050] Preferably, the solid-to-liquid ratio of the graphene-coated carbonized ternary precursor and the dopamine solution is 1:100 to 200 g / mL, for example, it can be 1:100 g / mL, 1:120 g / mL, 1:150 g / mL, 1:180 g / mL or 1:200 g / mL, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] Preferably, the pH is adjusted to 8-13, for example, 8, 9, 10, 11, 12 or 13, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] Preferably, the stirring time is 8 to 12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0053] Preferably, the drying temperature is 40-60° C., for example, 40° C., 45° C., 50° C., 55° C. or 60° C., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0054] Preferably, the mixing in step (3) further includes an alkaline solution.

[0055] Preferably, the solid-liquid ratio of the graphene-coated carbonized ternary precursor and the alkaline solution is 1:(10-50) g / mL, for example, it can be 1:10 g / mL, 1:20 g / mL, 1:30 g / mL, 1:40 g / mL or 1:50 g / mL, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] Preferably, the alkaline solution comprises any one or a combination of at least two of sodium hydroxide, calcium hydroxide or barium hydroxide. Typical but non-limiting combinations include a combination of sodium hydroxide and calcium hydroxide, a combination of calcium hydroxide and barium hydroxide, and a combination of sodium hydroxide and barium hydroxide.

[0057] Preferably, the concentration of the alkaline solution is 8 to 10 mol / L, for example, 8 mol / L, 8.5 mol / L, 9 mol / L, 9.5 mol / L or 10 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0058] Titanium dioxide is easily soluble in strong alkaline solutions under high temperature and high pressure conditions. Under the action of highly active functional groups, titanium dioxide nanoparticles are in situ grown on the surface of large-particle waste of carbonized ternary precursor coated with graphene, thereby enhancing its light absorption.

[0059] Preferably, the mass ratio of the graphene-coated carbonized ternary precursor and the nano-oxide in step (3) is (4 to 6):1, for example, it can be 4:1, 4.5:1, 5:1, 5.5:1 or 6:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0060] Preferably, the temperature of the hydrothermal reaction in step (3) is 120-160°C, for example, 120°C, 130°C, 140°C, 150°C or 160°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0061] Preferably, the hydrothermal reaction time in step (3) is 12 to 24 hours, for example, 12 hours, 15 hours, 18 hours, 20 hours or 24 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0062] Preferably, the heating in step (4) is water bath heating.

[0063] Preferably, the heating time in step (4) is 3 to 5 hours, for example, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0064] Preferably, the heating temperature in step (4) is 70-90°C, for example, 70°C, 75°C, 80°C, 85°C or 90°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0065] In a third aspect, an embodiment of the present application provides an application of the aerogel interface photothermal evaporation material according to the first aspect, wherein the aerogel interface photothermal evaporation material is used for evaporating low-salt wastewater.

[0066] The aerogel interfacial photothermal evaporation material provided in this application is used in the evaporation of low-salt wastewater, which can play a role in green environmental protection and energy saving and cost reduction.

[0067] According to the above technical solution, the beneficial effects of the embodiment of the present application are as follows:

[0068] In the embodiment of the present application, graphene is coated on a carbonized ternary precursor and loaded with oxide nanoparticles. The three materials cooperate with each other in spatial structure to obtain an aerogel material with excellent light absorption and photothermal evaporation properties, which can be applied to the evaporation of low-salt wastewater, and is conducive to scale and efficiency.

[0069] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The accompanying drawings are used to provide a further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of this application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

[0071] FIG1 is a microscopic morphology of the aerogel photothermal evaporation material described in Example 1, magnified to: the image width is 20 μm.

[0072] FIG2 is a microscopic morphology of the aerogel photothermal evaporation material described in Example 1, magnified to: the image width is 2 μm.

[0073] FIG3 is a graph showing the time / evaporation rate variation of the aerogel photothermal evaporation material for pure water in Example 1.

[0074] FIG4 is a graph showing the time / evaporation rate variation of the aerogel photothermal evaporation material for salt water in Example 1. DETAILED DESCRIPTION

[0075] The technical solution of the present application will be further described below with reference to the accompanying drawings and through specific implementation methods. However, the following examples are merely simplified examples of the present application and do not represent or limit the scope of protection of the present application. The scope of protection of the present application shall be subject to the claims.

[0076] Example 1

[0077] This embodiment provides an aerogel interfacial photothermal evaporation material (the microscopic morphology when enlarged to a size of 20 μm in width is shown in Figure 1, and the microscopic morphology when enlarged to a size of 2 μm in width is shown in Figure 2). The aerogel interfacial photothermal evaporation material includes graphene, a carbonized ternary precursor and titanium dioxide nanoparticles; the graphene is coated on the surface of the carbonized ternary precursor, and the oxide nanoparticles are loaded on the surface of the graphene-coated carbonized ternary precursor.

[0078] The carbonized ternary precursor is a substrate, which is a carbonized ternary precursor particle waste (nickel cobalt manganese hydroxide, Ni:Co:Mn=22%:20.5%:32.5%, D>40μm). The aerogel interface photothermal evaporation material also includes a polydopamine coating layer, which is modified on the surface of the graphene-coated carbonized ternary precursor.

[0079] The aerogel interface photothermal evaporation material is prepared by the following method:

[0080] (1) In an argon atmosphere, the temperature was raised to 800°C at a rate of 4°C / min, and the ternary precursor waste particles were calcined for 3 h to obtain a carbonized ternary precursor;

[0081] (2) Mix 50 mL of 8 mg / mL graphene oxide aqueous solution and 10 g of the obtained carbonized ternary precursor, stir for 8 h, modify the carbonized ternary precursor by using the π-π stacking effect of graphene oxide, filter and wash with deionized water to obtain graphene oxide-coated carbonized ternary precursor, then weigh 10 g of graphene oxide-coated carbonized ternary precursor and mix with 500 mL of 1 mol / L potassium borohydride solution as a reducing agent. After the reaction is completed for 10 h, filter and obtain the graphene-coated carbonized ternary precursor;

[0082] (3) 10 g of the obtained graphene-coated carbonized ternary precursor was placed in a 2 mg / L dopamine solution, and 0.1 mol / L Tris buffer was added to adjust the pH to 9, followed by stirring for 10 h. After filtration, the mixture was dried in an oven at 60 ° C to obtain a polydopamine coating layer modification material. 2 g of nano-titanium dioxide and 10 g of the obtained polydopamine coating layer modification material were mixed in a mass ratio of 5:1 and placed in 100 mL of a 10 mol / L sodium hydroxide solution. The mixture was hydrothermally reacted at 160 ° C for 24 h to obtain a loaded material.

[0083] (4) The obtained loaded material was heated in a water bath at 70° C. for 3 h to form a hydrogel, and then filtered and freeze-dried to obtain the aerogel interface photothermal evaporation material.

[0084] Example 2

[0085] This embodiment provides an aerogel interfacial photothermal evaporation material, which includes graphene, a carbonized ternary precursor and titanium dioxide nanoparticles; the graphene is coated on the surface of the carbonized ternary precursor, and the oxide nanoparticles are loaded on the surface of the graphene-coated carbonized ternary precursor.

[0086] The carbonized ternary precursor is a substrate, which is a carbonized ternary precursor particle waste (nickel cobalt manganese hydroxide, Ni:Co:Mn=22%:20.5%:32.5%, D>40μm). The aerogel interface photothermal evaporation material also includes a polydopamine coating layer, which is modified on the surface of the graphene-coated carbonized ternary precursor.

[0087] The aerogel interface photothermal evaporation material is prepared by the following method:

[0088] (1) In an argon atmosphere, the temperature was raised to 780°C at a rate of 4°C / min, and the ternary precursor waste particles were calcined for 4 h to obtain a carbonized ternary precursor;

[0089] (2) Mix 60 mL of a 10 mg / mL graphene oxide aqueous solution and 10 g of the obtained carbonized ternary precursor, stir for 10 h, modify the carbonized ternary precursor using the π-π stacking effect of graphene oxide, filter and wash with deionized water to obtain a graphene oxide-coated carbonized ternary precursor, and then mix with a 2 mol / L sodium borohydride solution as a reducing agent at a solid-liquid ratio of 1:100 g / mL. After the reaction is completed for 12 h, filter and obtain the graphene-coated carbonized ternary precursor;

[0090] (3) The obtained graphene-coated carbonized ternary precursor was placed in a 3 mg / mL dopamine solution with a solid-liquid ratio of 1:200 g / mL, and 0.1 mol / L Tris buffer was added to adjust the pH to 11, followed by stirring for 12 h, filtering and drying in a 60 ° C oven to obtain a polydopamine coating layer modification material, and nano-titanium dioxide and the obtained polydopamine coating layer modification material were mixed in a mass ratio of 4:1 and placed in a sodium hydroxide solution with a concentration of 8 mol / L, with a solid-liquid ratio of 1:30 g / mL, and subjected to a hydrothermal reaction at 160 ° C for 20 h to obtain a loaded material;

[0091] (4) The obtained loaded material was heated in a water bath at 80° C. for 5 h to form a hydrogel, and then filtered and freeze-dried to obtain the aerogel interface photothermal evaporation material.

[0092] Example 3

[0093] This embodiment provides an aerogel interfacial photothermal evaporation material, which differs from Example 1 in that it does not contain a polydopamine coating layer modified on the surface of the graphene-coated carbonized ternary precursor.

[0094] Example 4

[0095] This embodiment provides an aerogel interfacial photothermal evaporation material, which differs from Example 1 in that the ternary precursor particle waste is not carbonized.

[0096] Example 5

[0097] This embodiment provides an aerogel interfacial photothermal evaporation material, which differs from embodiment 1 in that the ternary precursor particle waste is nickel cobalt manganese hydroxide, Ni:Co:Mn=22%:20.5%:32.5%, and D=35 μm.

[0098] Example 6

[0099] This embodiment provides an aerogel interface photothermal evaporation material, which differs from embodiment 1 in that the temperature is raised to 850° C. in step (1).

[0100] Example 7

[0101] This embodiment provides an aerogel interface photothermal evaporation material, which differs from embodiment 1 in that the dopamine solution in step (3) is replaced by an H3PO4 solution for impregnation.

[0102] Comparative Example 1

[0103] This comparative example provides an aerogel interfacial photothermal evaporation material, which differs from Example 1 in that it does not contain loaded titanium dioxide nanoparticles.

[0104] Comparative Example 2

[0105] This comparative example provides an aerogel interfacial photothermal evaporation material, which differs from Example 1 in that it does not contain loaded titanium dioxide nanoparticles and the ternary precursor particle waste is not carbonized.

[0106] The water evaporation performance of the aerogel interface photothermal evaporation material was tested using a conventional photothermal evaporation process. The specific steps are as follows: 200 mL of pure water was poured into two plastic beakers, and the aerogel interface photothermal evaporation material was placed in one beaker and allowed to float freely above the liquid surface. The other beaker was left empty and allowed to evaporate naturally under light for comparison. Finally, the two beakers were placed on a precision electronic balance, and the initial masses were recorded. A xenon lamp was turned on 20 to 30 cm above each beaker to simulate sunlight. The xenon lamp aperture was adjusted to the same size as the beaker opening, and the light source above the two beakers was adjusted to illuminate the plastic beakers with standard sunlight of the same intensity. The mass of pure water displayed on the precision electronic balance was recorded every 5 minutes, and the change in mass was recorded using the precision electronic balance. The photothermal evaporation performance test was terminated after 60 minutes. By calculating the change in water mass over time before and after the addition of the sample, a time / evaporation rate curve was plotted to compare the effects of the sample on the water evaporation rate. Finally, the pure water in the plastic beaker was replaced with low-salt wastewater produced daily in the ternary precursor synthesis workshop, and the above water evaporation performance experiment was repeated to obtain the photothermal evaporation performance of the aerogel interface photothermal evaporation material for low-salt wastewater. The time / evaporation rate curves of the aerogel interface photothermal evaporation material for pure water and salt water in Example 1 are shown in Figures 3 and 4, and the test results are shown in Table 1.

[0107] Table 1

[0108] This application obtains an aerogel material with excellent light absorption and photothermal evaporation properties by coating graphene and loading oxide nanoparticles on a carbonized ternary precursor. The three materials cooperate with each other in spatial structure, and can be applied to the evaporation of low-salt wastewater, which is conducive to scale and efficiency.

[0109] This application uses large-particle waste of ternary precursors accumulated in the production of ternary precursors in the new energy industry as the substrate, which greatly reduces the cost of preparing aerogel raw materials and reduces the demand for substrates with pipeline structures and capillary effects, thereby realizing the reuse of waste produced by the ternary precursor process and improving resource utilization efficiency; after being coated with graphene, the aerogel photothermal evaporation material is obtained, which can be used for the evaporation of low-salt wastewater, playing a role in green environmental protection, energy saving and cost reduction.

[0110] After being coated with graphene, the large-particle waste of the ternary precursor is used as the aerogel substrate, which not only enhances the heat retention capacity and reduces the heat loss during the evaporation process, but also enhances the light absorption ability of the large-particle waste of the ternary precursor after the graphene coating through the loading of nanoparticles, thereby improving the photothermal evaporation efficiency. In addition, the hydrophobicity of graphene also prevents the large-particle waste of the ternary precursor aerogel from freely dispersing in the water body, and can stably float on the liquid surface in a fixed block for a long time, which is conducive to large-scale and efficient photothermal evaporation applications.

[0111] The present application uses the above-mentioned embodiments to illustrate the detailed structural features of the present application. However, the present application is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present application must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present application, equivalent replacements of selected components of the present application, addition of auxiliary components, selection of specific methods, etc., all fall within the scope of protection and disclosure of the present application.

Claims

1. An aerogel interface photothermal evaporation material, wherein: The aerogel interface photothermal evaporation material includes graphene, carbonized ternary precursor and oxide nanoparticles; The graphene is coated on the surface of the carbonized ternary precursor, and the oxide nanoparticles are loaded on the surface of the carbonized ternary precursor coated with the graphene.

2. The aerogel interface photothermal evaporation material according to claim 1, wherein: The carbonized ternary precursor is ternary precursor particle waste that has been carbonized.

3. The aerogel interface photothermal evaporation material according to claim 1 or 2, wherein: The ternary precursor particle waste is nickel-cobalt-manganese hydroxide, wherein the mass ratio of nickel-cobalt-manganese elements is Ni:Co:Mn=(20-25%):(20-25%):(30-35%).

4. The aerogel interface photothermal evaporation material according to any one of claims 1 to 3, wherein: The ternary precursor particle waste is waste generated during the preparation of the ternary precursor, and the particle size thereof is above 40 μm.

5. The aerogel interface photothermal evaporation material according to any one of claims 1 to 4, wherein: The aerogel interface photothermal evaporation material further comprises a polymer coating layer, and the polymer coating layer is modified on the surface of the graphene-coated carbonized ternary precursor; Preferably, the polymer coating comprises a polydopamine coating; Preferably, the oxide nanoparticles include titanium dioxide nanoparticles.

6. The method for preparing the aerogel interface photothermal evaporation material according to any one of claims 1 to 5, comprising: (1) preparing a carbonized ternary precursor; (2) mixing graphene oxide and the obtained carbonized ternary precursor to obtain a graphene oxide-coated carbonized ternary precursor, and then mixing with a reducing agent, and after the reaction is completed, obtaining a graphene-coated carbonized ternary precursor; (3) mixing the nano-oxide and the obtained graphene-coated carbonized ternary precursor, and performing a hydrothermal reaction to obtain a supported material; (4) The obtained loaded material is heated to form a hydrogel, and then freeze-dried to obtain the aerogel interface photothermal evaporation material.

7. The preparation method according to claim 6, wherein: The preparation method of the carbonized ternary precursor in step (1) includes: calcining the ternary precursor particle waste under a protective gas atmosphere to obtain the carbonized ternary precursor.

8. The preparation method according to claim 7, wherein: The heating rate of the calcination is 3-5°C / min; Preferably, the calcination temperature is 500-800°C; Preferably, the calcination time is 2 to 4 hours.

9. The preparation method according to any one of claims 6 to 8, wherein: The mixed graphene oxide and the obtained carbonized ternary precursor in step (2) are a mixed graphene oxide aqueous solution and the obtained carbonized ternary precursor; Preferably, the concentration of the graphene oxide aqueous solution is 3 to 10 mg / mL; Preferably, the solid-to-liquid ratio of the carbonized ternary precursor and the graphene oxide aqueous solution is 1:(4-6) g / mL.

10. The preparation method according to any one of claims 6 to 9, wherein: After the step (2) of mixing the graphene oxide and the obtained carbonized ternary precursor, stirring and filtering are also included; Preferably, the stirring time is 5 to 10 hours; Preferably, the reducing agent in step (2) comprises any one of potassium borohydride solution, sodium borohydride solution or lithium borohydride solution, or a combination of at least two thereof; Preferably, the concentration of the reducing agent in step (2) is 0.5 to 3 mol / L; Preferably, in step (2), the solid-liquid ratio of the graphene oxide-coated carbonized ternary precursor and the reducing agent is 1:(50-100) g / mL; Preferably, the reaction time in step (2) is 8 to 12 hours.

11. The preparation method according to any one of claims 6 to 10, wherein: Prior to step (3), the method further includes modifying the surface of the graphene-coated carbonized ternary precursor with a polymer; Preferably, the modification method comprises: mixing a dopamine solution, a buffer solution and the graphene-coated carbonized ternary precursor, adjusting the pH and stirring, and filtering and drying to obtain a polymer modified material; Preferably, the concentration of the dopamine solution is 1 to 3 mg / mL; Preferably, the buffer comprises 0.05 to 0.15 mol / L Tris buffer; Preferably, the solid-liquid ratio of the graphene-coated carbonized ternary precursor and the dopamine solution is 1:(100-200) g / mL; Preferably, the pH is adjusted to 8-13; Preferably, the stirring time is 8 to 12 hours; Preferably, the drying temperature is 40-60°C.

12. The preparation method according to any one of claims 6 to 11, wherein: The mixing in step (3) further comprises an alkaline solution; Preferably, the solid-liquid ratio of the graphene-coated carbonized ternary precursor and the alkaline solution is 1:(10-50) g / mL; Preferably, the alkaline solution comprises any one of sodium hydroxide, calcium hydroxide or barium hydroxide, or a combination of at least two thereof; Preferably, the concentration of the alkaline solution is 8-10 mol / L.

13. The preparation method according to any one of claims 6 to 12, wherein: In step (3), the mass ratio of the graphene-coated carbonized ternary precursor to the nano-oxide is (4-6):1; Preferably, the temperature of the hydrothermal reaction in step (3) is 120-160° C. Preferably, the hydrothermal reaction time in step (3) is 12 to 24 hours.

14. The preparation method according to any one of claims 6 to 13, wherein: The heating in step (4) is water bath heating; Preferably, the heating time in step (4) is 3 to 5 hours; Preferably, the heating temperature in step (4) is 70-90°C.

15. An application of the aerogel interface photothermal evaporation material according to any one of claims 1 to 5, wherein: The aerogel interface photothermal evaporation material is used for evaporating low-salt wastewater.

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