A kind of sediment nano-silver composite material and its preparation method and application

Abstract

The present invention belongs to the field of photothermal conversion materials technology and discloses a sediment-nanosilver composite material, its preparation method, and application. The preparation method comprises: modifying sediment to introduce functionalized functional groups on the sediment surface to obtain modified sediment; the functionalized functional groups are one or more of amino, hydroxyl, and amide groups; dispersing a silver salt and a reducing agent in an aqueous solvent A to obtain a nanosilver precursor solution; uniformly dispersing the modified sediment in the nanosilver precursor solution, sealing, stirring at a temperature of 60 to 80°C, and after solid-liquid separation, sequentially incubating, drying, and grinding the solid phase components to obtain the sediment-nanosilver composite material. The preparation method of the present invention is simple to operate, the raw materials are readily available and low in cost, and it is conducive to promotion and large-scale use. The prepared composite material has good light absorption rate, heat conversion efficiency, adsorption and antibacterial properties, and can be used as a photothermal conversion material and water purification material.

Description

Technical Field

[0001] The present invention relates to the technical field of photothermal conversion materials, and in particular to a sediment nano-silver composite material and a preparation method and application thereof. Background Art

[0002] Nanosilver has high efficiency in light absorption and heat conduction, and is an excellent photothermal conversion material. However, there are the following problems when using nanosilver as a photothermal conversion material for practical application: 1) Nanosilver has a narrow absorption spectrum range, and its photothermal conversion efficiency still has some limitations. For example, it can only absorb light within a specific wavelength range, and its surface area is small, making it difficult to achieve efficient photothermal conversion. 2) Nanosilver has poor stability. The spacing between nanosilver particles will affect the photothermal conversion efficiency. Moreover, nanosilver is prone to aggregation, oxidation and violent evaporation under strong light irradiation, which reduces its stability and lifespan. 3) The cost of using pure nanosilver is relatively high.

[0003] In order to solve the above technical problems, those skilled in the art have proposed solutions such as improving the surface activity of nanosilver, the stability of the lattice structure, and combining nanosilver with suitable materials to form high-efficiency composite materials. However, these solutions still have the disadvantages of large energy waste, high preparation cost, low recovery rate, and short life of photothermal materials due to factors such as poor stability of certain materials, great production difficulty, easy aggregation of nanosilver particles, and high technical requirements.

[0004] Therefore, the present invention provides a sediment nano-silver composite material and a preparation method and application thereof. Summary of the Invention

[0005] To address the deficiencies in the prior art, the present invention provides a sediment-nanosilver composite material, its preparation method, and its application. The present invention uses sediment as a matrix, introduces functional groups onto the sediment surface through modification, then mixes the sediment with a silver salt reducing agent. In situ thermal reduction is performed to form nanosilver particles on the sediment surface, resulting in a sediment-nanosilver composite material. This improves the absorption and conversion efficiency of the solar energy, while also enhancing the durability and stability of the sediment material to a certain extent, extending its service life, thereby facilitating the sustainable development of energy and resources.

[0006] The present invention provides a nanosilver composite material of sediment and sand and its preparation method and application, which are achieved through the following technical solutions:

[0007] The present invention provides a method for preparing a sediment nano-silver composite material, comprising the following steps:

[0008] Step 1: using sediment as a carrier, performing a modification treatment on the sediment to introduce functional groups on the surface of the sediment to obtain modified sediment;

[0009] The functionalized functional group is one or more of an amino group, a hydroxyl group and an amide group;

[0010] Step 2, uniformly dispersing the silver salt and the reducing agent in the aqueous solvent A to obtain a nanosilver precursor solution;

[0011] Step 3: uniformly disperse the modified mud and sand in the nanosilver precursor solution, seal it, and stir it at a temperature of 60-80° C. After solid-liquid separation, the obtained solid phase component is incubated, dried, and ground in sequence to obtain the mud and sand nanosilver composite material.

[0012] Furthermore, the modification treatment is prepared by the following steps:

[0013] Alkali metal hydroxide is used as a modifier and is uniformly dispersed in aqueous solvent B to obtain a modified solution; subsequently, the cleaned sediment is placed in the modified solution and stirred at room temperature for 3 to 5 hours, solid-liquid separation is performed, and the modified sediment is obtained after washing and drying;

[0014] Wherein, the alkali metal hydroxide is one or both of potassium hydroxide and sodium hydroxide;

[0015] The usage ratio of the alkali metal hydroxide to the aqueous solvent B is 1-2 mol:1L.

[0016] Furthermore, the silver salt is one or both of silver nitrate and silver chloride;

[0017] The reducing agent is one or more of glucose, sucrose, polyol, citrate and borohydride.

[0018] Furthermore, the molar ratio of the reducing agent to the silver salt is 9 to 11:1.

[0019] Furthermore, the usage ratio of the aqueous solvent A to the silver salt is 1L:50-200mmol.

[0020] Furthermore, the usage ratio of the sediment to the nanosilver precursor solution is 20-30 g:0.1 L.

[0021] Furthermore, the stirring rate of the stirring treatment is 200-400 r / min, and the stirring time is 0.5-1.5 h.

[0022] Furthermore, the incubation temperature is 45-85° C., and the treatment time is 3-5 hours.

[0023] The second object of the present invention is to provide a sediment nano-silver composite material prepared by the above preparation method.

[0024] The third object of the present invention is to provide an application of the above-mentioned sediment nano-silver composite material in photothermal conversion materials and water purification materials.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention uses silt as raw material, which can significantly reduce the manufacturing cost of the entire material. After the present invention modifies the silt, the modified silt obtained effectively expands the spectral absorption range, can fully absorb visible light and infrared light, promote the transfer and dispersion of photothermal energy, and evenly distributes heat throughout the material, avoiding excessive heating in some locations that lead to material failure, and effectively improving the photothermal conversion efficiency. At the same time, the silt has a larger specific surface area and porous structure, which can provide better support and dispersion effects, prevent the agglomeration of nanosilver particles, improve the stability of the photothermal conversion material, and can perform photothermal conversion more stably to extend the life of the photothermal material. This low-cost technology can achieve water purification efficiently and continuously, and while efficiently utilizing light energy, it greatly reduces the technical cost of the water purification process. It is an economical and sustainable technology for the efficient production of clean water, and can provide human society with a more efficient, economical and sustainable water purification solution.

[0027] After the silt is modified by the present invention, the surface of the modified silt has more active functional groups, such as amino, hydroxyl and amide groups. These active functional groups can interact with visible light or infrared radiation within the absorption spectrum of metal ions or organic dyes to form surface complexes to improve light absorption performance. The present invention prepares a nanosilver solution by an in-situ thermal reduction method, and then adds the modified silt to the nanosilver solution, fully mixes, and compounds at an appropriate temperature, so that the modified silt and nanosilver interact with each other based on multiple mechanisms such as charge adsorption, physical adsorption and chemical reaction to form a silt-nanosilver composite material. The nanosilver layer on the surface of the silt has a high absorptivity and a low reflectivity, which can further improve the absorption and conversion efficiency of the overall composite material for solar energy. To a certain extent, it also enhances the durability and stability of the silt material, prolongs its service life, and is conducive to the sustainable development of energy and resources. It can not only achieve efficient and sustainable water purification, but also greatly reduce the technical cost of the water purification process while efficiently utilizing light energy. This application is an economical and sustainable technology for the efficient production of clean water, which can provide human society with a more efficient, economical and sustainable water purification solution.

[0028] In the sediment-nanosilver composite material prepared by the present invention, the sediment as a raw material not only reduces the preparation cost, but the black minerals such as quartz, feldspar, magnetite, ilmenite, and black ochre on the surface of the sediment particles also contribute to light absorption, thereby improving its photothermal conversion performance. At the same time, the sediment has good heat capacity and can store and release heat energy for a long time. Furthermore, the sediment can also serve as a carrier, providing a matrix for the growth of nanosilver and fixing the position of the formed nanosilver. When the prepared photothermal conversion material absorbs light energy through the surface plasmon resonance effect, it can keep the nanosilver particles in a fixed position, thereby enabling it to stably absorb light energy, further improving its photothermal conversion performance.

[0029] When the modified sediment is compounded with nanosilver through in-situ thermal reduction, the nanosilver particles and sediment particles are mixed together to form a composite photothermal conversion material. First, a nanosilver solution is prepared through in-situ thermal reduction. Then, the sediment is added to the nanosilver solution, mixed thoroughly, and reacted at an appropriate temperature to fully compound the nanosilver and sediment. This mixing can be achieved at room temperature through simple mechanical stirring or ultrasonic treatment. After the reaction, the sediment-nanosilver composite photothermal conversion material is washed and dried to obtain the final product. In the process of preparing the sediment-nanosilver composite material, we also ensured that the composite material has good adsorption and antibacterial properties by controlling the proportion of nanosilver added and the reaction conditions.

[0030] Therefore, the composite of nanosilver and sediment is an important step in the preparation of photothermal conversion materials. This composite can improve the material's light absorption rate and heat conversion efficiency, providing better performance for the application of photothermal conversion materials. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below.

[0032] The present invention provides a sediment nano-silver composite material, which is prepared by the following steps:

[0033] Step 1: using sediment as a carrier, performing a modification treatment on the sediment to introduce functional groups on the surface of the sediment to obtain modified sediment;

[0034] It should be noted that the present invention preferably uses mud and sand as a carrier material, which can significantly reduce the manufacturing cost of the entire material. The present invention takes into account that mud and sand itself does not have good photothermal conversion performance. By changing the physical, chemical or microstructural characteristics of mud and sand, it can be made to have good photothermal conversion performance. Before the mud and sand are composited with nanosilver, the present invention first modifies them to introduce one or more functional groups of amino, hydroxyl and amide groups on their surface to increase their affinity with the mud and sand matrix, thereby improving the stability and performance of the composite material. The modified mud and sand obtained by the present invention effectively expands the spectral absorption range, can fully absorb visible light and infrared light, promote the transfer and dispersion of photothermal energy, evenly distribute heat throughout the material, avoid excessive heating of some parts leading to material failure, and effectively improve the photothermal conversion efficiency. At the same time, mud and sand have a larger specific surface area and porous structure, can provide better support and dispersion effects, prevent nanosilver particles from agglomerating, improve the stability of the photothermal conversion material, and can more stably perform photothermal conversion to extend the life of the photothermal material.

[0035] The present invention can adopt the following steps to carry out modification treatment:

[0036] Alkali metal hydroxide is used as a modifier. Alkali metal hydroxide reacts with carboxyl, hydroxyl and other functional groups on the surface of sediment to form corresponding amide or amino groups. At the same time, electrophilic substitution reaction occurs to convert the hydroxide ion (OH - ) reacts with halogen atoms, alkyl groups, etc. on the surface of the sediment to form corresponding amino or amide groups. It is then uniformly dispersed in aqueous solvent B to obtain a modified solution; subsequently, the cleaned sediment is placed in the modified solution and stirred at room temperature for 3 to 5 hours, solid-liquid separation is performed, and the modified sediment is obtained after washing and drying; wherein the alkali metal hydroxide is one or both of potassium hydroxide and sodium hydroxide; and the ratio of the alkali metal hydroxide to the aqueous solvent B is 1 to 2 mol:1L. The present invention does not limit the stirring rate when stirring the sediment and the modified solution, as long as the sediment is kept in a suspended state in the modified solution so that the sediment is in uniform contact with the modifier in the modified solution.

[0037] Step 2, uniformly dispersing the silver salt and the reducing agent in the aqueous solvent A to obtain a nanosilver precursor solution;

[0038] It should be noted that the silver salt of the present invention can be selected from one or both of silver nitrate and silver chloride, and the reducing agent can be selected from one or more of glucose, sucrose, polyols, citrate, and borohydride. Furthermore, to facilitate better recombination of the subsequently modified sediment with the nanosilver, the present invention preferably mixes the silver salt and reducing agent before adding the modified sediment. This effectively controls the particle size and dispersion of the nanosilver, avoiding insufficient reaction of the silver salt or reducing agent, and ensuring a more thorough reaction. This allows the nanosilver precursor to be evenly dispersed around the modified sediment during subsequent processing, further facilitating uniform precipitation of the nanosilver on the sediment surface. Furthermore, the molar ratio of the reducing agent to the silver salt is preferably 9-11:1, and the ratio of the aqueous solvent A to the silver salt is preferably 1 L:50-200 mmol.

[0039] Step 3, uniformly dispersing the modified sediment in the nanosilver precursor solution, sealing, and stirring at a temperature of 60 to 80° C., and after solid-liquid separation, incubating, drying, and grinding the obtained solid phase component in sequence to obtain the sediment nanosilver composite material;

[0040] It should be noted that the present invention preferably uses a ratio of 20-30g of modified silt to 0.1L of nanosilver precursor solution, uniformly dispersing the modified silt in the nanosilver precursor solution, and then stirring at a temperature of 60-80°C and a stirring rate of 200-400 r / min for 0.5-1.5 hours to uniformly distribute the nanosilver on the modified silt. In order to prevent evaporation of the solution during the stirring process, the present invention seals the stirring container before stirring to prevent loss of the solution during the stirring process.

[0041] Furthermore, the present invention takes into account the fact that organic matter and pollutants in the sediment will reduce the efficiency of material treatment. After the product after the stirring treatment is subjected to solid-liquid separation, the obtained solid phase component is incubated at a temperature of 45 to 85°C for 3 to 5 hours, so that the incubation treatment can stimulate the growth of microorganisms in the sediment, so that the organic matter and pollutants in the sediment can be efficiently degraded and removed, thereby improving the stability and reliability of the treatment system. It should also be noted that in the treatment process, physical and chemical methods can be used instead of incubation treatment. However, through incubation treatment, the consumption and cost of chemicals, energy, labor costs, etc. required by traditional physical and chemical treatment methods can be reduced. At the same time, the method of removing organic matter and pollutants by incubation treatment is more environmentally friendly, safe and sustainable than traditional treatment methods.

[0042] The present invention dries the incubated product to remove moisture and volatile organic compounds (VOCs) from the material, thereby ensuring the purity and stability of the material. The dried product is then further ground to prevent agglomeration or caking during the drying process, and then re-ground back to its original, distinct state.

[0043] Example 1

[0044] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0045] Step 1: Preparation of modified sediment

[0046] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0047] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 5 hours to obtain modified sediment.

[0048] Step 2: Preparation of nanosilver precursor solution

[0049] Using glucose as a reducing agent and silver nitrate as a silver salt, glucose and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in an 80°C oven for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0050] The molar ratio of glucose to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 50 mmol:1 L.

[0051] Example 2

[0052] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0053] Step 1: Preparation of modified sediment

[0054] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0055] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 5 hours to obtain the modified sediment.

[0056] Step 2: Preparation of nanosilver precursor solution

[0057] Using glucose as a reducing agent and silver nitrate as a silver salt, glucose and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in an 80°C oven for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0058] The molar ratio of glucose to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 100 mmol:1 L.

[0059] Example 3

[0060] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0061] Step 1: Preparation of modified sediment

[0062] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0063] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 5 hours to obtain modified sediment.

[0064] Step 2: Preparation of nanosilver precursor solution

[0065] Using glucose as a reducing agent and silver nitrate as a silver salt, glucose and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in an 80°C oven for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0066] The molar ratio of glucose to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 150 mmol:1 L.

[0067] Example 4

[0068] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0069] Step 1: Preparation of modified sediment

[0070] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0071] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 4 hours to obtain modified sediment.

[0072] Step 2: Preparation of nanosilver precursor solution

[0073] Using glucose as a reducing agent and silver nitrate as a silver salt, glucose and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in an 80°C oven for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0074] The molar ratio of glucose to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 200 mmol:1 L.

[0075] Example 5

[0076] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0077] Step 1: Preparation of modified sediment

[0078] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0079] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 4 hours to obtain modified sediment.

[0080] Step 2: Preparation of nanosilver precursor solution

[0081] Using glucose as a reducing agent and silver nitrate as a silver salt, glucose and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in a 45°C oven for 5 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0082] The molar ratio of glucose to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 50 mmol:1 L.

[0083] Example 6

[0084] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0085] Step 1: Preparation of modified sediment

[0086] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0087] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 4 hours to obtain modified sediment.

[0088] Step 2: Preparation of nanosilver precursor solution

[0089] Using glucose as a reducing agent and silver nitrate as a silver salt, glucose and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in a 65°C oven for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0090] The molar ratio of glucose to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 50 mmol:1 L.

[0091] Example 7

[0092] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0093] Step 1: Preparation of modified sediment

[0094] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0095] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 4 hours to obtain modified sediment.

[0096] Step 2: Preparation of nanosilver precursor solution

[0097] Using glucose as a reducing agent and silver nitrate as a silver salt, glucose and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in an 85°C oven for 3 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0098] The molar ratio of glucose to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 50 mmol:1 L.

[0099] Example 8

[0100] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0101] Step 1: Preparation of modified sediment

[0102] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0103] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 5 hours to obtain modified sediment.

[0104] Step 2: Preparation of nanosilver precursor solution

[0105] Using sodium citrate as a reducing agent and silver nitrate as a silver salt, the sodium citrate and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in an 80°C oven for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0106] The molar ratio of sodium citrate to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 50 mmol:1 L.

[0107] Example 9

[0108] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0109] Step 1: Preparation of modified sediment

[0110] Sodium hydroxide was used as a modifier and dissolved in deionized water to prepare a sodium hydroxide concentration of 1.5 mol / L to obtain a modified solution;

[0111] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 25 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 4 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 80°C for 5 hours to obtain modified sediment.

[0112] Step 2: Preparation of nanosilver precursor solution

[0113] Using sodium borohydride as a reducing agent and silver nitrate as a silver salt, sodium borohydride and silver nitrate were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 70°C. After stirring for 1 hour, the solid and liquid were separated, and the treated sediment was incubated in an 80°C oven for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0114] The molar ratio of sodium borohydride to silver nitrate is 10:1, and the dosage ratio of silver nitrate to deionized water is 50 mmol:1 L.

[0115] Example 11

[0116] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0117] Step 1: Preparation of modified sediment

[0118] Potassium hydroxide is used as a modifier, which is dissolved in deionized water to prepare a potassium hydroxide concentration of 1 mol / L to obtain a modified solution;

[0119] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 20 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 3 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 70°C for 8 hours to obtain modified sediment.

[0120] Step 2: Preparation of nanosilver precursor solution

[0121] Sucrose was used as a reducing agent and silver chloride was used as a silver salt. Sucrose and silver chloride were placed in deionized water, then stirred using a multi-point intelligent magnetic stirrer and heated to 60°C. After stirring for 1.5 hours, the solid and liquid were separated. The treated sediment was then incubated in an oven at 80°C for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0122] The molar ratio of sucrose to silver chloride is 9:1, and the dosage ratio of silver chloride to deionized water is 50 mmol:1 L.

[0123] Example 12

[0124] This embodiment provides a sediment nano-silver composite material, and the preparation method thereof is as follows:

[0125] Step 1: Preparation of modified sediment

[0126] Potassium hydroxide is used as a modifier, which is dissolved in deionized water to prepare a potassium hydroxide concentration of 2 mol / L to obtain a modified solution;

[0127] In this example, Yellow River sediment was used as the sediment raw material. After washing the sediment with distilled water, 30 g of the washed sediment was placed in 0.1 L of the prepared modification solution. The solution was then stirred at room temperature to keep the sediment suspended in the modification solution. After stirring for 5 hours, the solution was filtered and the modified sediment was washed with distilled water until the pH of the washing solution was neutral. The modified sediment was then dried in an oven at 90°C for 3 hours to obtain modified sediment.

[0128] Step 2: Preparation of nanosilver precursor solution

[0129] Using sodium borohydride as a reducing agent and silver nitrate as a silver salt, sodium borohydride and silver nitrate were placed in deionized water. The mixture was then stirred using a multi-point intelligent magnetic stirrer and heated to 80°C. The stirring was carried out at a rate of 400 r / min for 0.5 hours, followed by solid-liquid separation. The treated sediment was then incubated in an oven at 80°C for 4 hours. During this process, the color of the Yellow River sediment changed from yellow to black, resulting in a sediment nanosilver composite material.

[0130] The molar ratio of sodium borohydride to silver nitrate is 11:1, and the dosage ratio of silver nitrate to deionized water is 50 mmol:1 L.

[0131] Comparative Example 1

[0132] The difference between this comparative example and Example 1 is only that:

[0133] In this comparative example, no silver nitrate was added.

[0134] Experimental part

[0135] The present invention takes the materials prepared in Examples 1-4 and Comparative Example 1 as examples, prepares each material into a sediment loading cage, and tests the evaporation performance of the sediment loading cage corresponding to each embodiment. The photothermal conversion performance of the composite material of nanosilver and sediment is described by measuring its water evaporation rate, and the test results are shown in Tables 1 to 5, respectively.

[0136] It should be noted that the above-mentioned sediment loading cage of the present invention is prepared by the following steps:

[0137] 1) Design three loading cages of different heights for loading sediment: the diameter of each of the three loading cages is 2.5 cm, and the heights are 1 cm, 2 cm, and 3 cm, respectively. Furthermore, the three loading cages of the present invention have low thermal conductivity, providing insulation and reducing heat loss.

[0138] 2) According to the sizes of the three loads designed above, a corresponding 3D model is established, and polyethylene material is used to perform 3D printing based on the established 3D model to obtain the corresponding three loading cages.

[0139] 3) The bottoms of the three printed loading cages were all laid with filter cloth, and then hung on the top of three 25 mL beakers filled with 20 mL of deionized water. The cages were then covered with the mud-sand nano-silver composite material prepared by the present invention to achieve the purpose of fixing the sand and isolating the heat of the sand from being transferred to the water, so that the heat is stored inside the sand.

[0140] Steaming performance test:

[0141] The light intensity is 1kW / m 2A xenon lamp was used to simulate sunlight. Each prepared sediment-laden cage was placed under the lamp, and the illumination diameter was adjusted to match the diameter of the evaporation device. As the simulated sunlight illuminated the sample, an electronic balance was used to monitor changes in water mass and surface temperature in real time. Each sample was tested for one hour, with data recorded every five minutes. Three replicates were run. The evaporation performance of Yellow River sediment at different loading silver concentrations was analyzed to investigate the evaporation patterns.

[0142] Table 1 Test results of Example 1

[0143]

[0144]

[0145] Table 2 Test results of Example 2

[0146] Time / min Group 1 Group 2 Group 3 average value Standard deviation <![CDATA[Water evaporation rate (kg / m 2 / h)]]> 0 0 0 0 0 0 0 5 0.0286 0.0302 0.0284 0.0291 0.000986577 0.91803969 10 0.0663 0.0672 0.0665 0.0667 0.000472582 1.05279781 15 0.1114 0.1100 0.1100 0.1105 0.00080829 1.162990648 20 0.1600 0.1572 0.1608 0.1593 0.001890326 1.258093383 25 0.2097 0.2103 0.2105 0.2102 0.000416333 1.327578039 30 0.2644 0.2619 0.2624 0.2629 0.001322876 1.383902721 35 0.3181 0.3148 0.3184 0.3171 0.001997498 1.430752224 40 0.3736 0.3697 0.3735 0.3723 0.002223361 0.979803829 45 0.4334 0.4254 0.4311 0.4300 0.004118657 1.414587391 50 0.4887 0.4805 0.4897 0.4863 0.005047772 1.535926725 55 0.5462 0.5375 0.5482 0.5440 0.005688878 1.561873406 60 0.6048 0.5987 0.6079 0.6038 0.004680812 1.589198294

[0147] Table 3 Test results of Example 3

[0148] Time / min Group 1 Group 2 Group 3 average value Standard deviation <![CDATA[Water evaporation rate (kg / m 2 / h)]]> 0 0 0 0 0 0 0 5 0.0240 0.0257 0.0250 0.0249 0.0008544 0.786439964 10 0.0555 0.0590 0.0582 0.0576 0.001833939 0.909090909 15 0.0946 0.0991 0.0972 0.0970 0.002259056 1.020862943 20 0.1380 0.1413 0.1421 0.1405 0.002173323 1.109122493 25 0.1836 0.1882 0.1867 0.1862 0.002345918 1.175975154 30 0.2320 0.2353 0.2363 0.2345 0.002250185 1.234580899 35 0.2831 0.2852 0.2851 0.2845 0.001184624 1.28351093 40 0.3345 0.3370 0.3377 0.3364 0.00168226 1.328104438 45 0.3855 0.3901 0.3902 0.3886 0.002685144 1.278491341 50 0.4380 0.4427 0.4406 0.4404 0.002354428 1.391061747 55 0.4915 0.4969 0.4964 0.4949 0.002983845 1.421085626 60 0.5480 0.5527 0.5510 0.5506 0.002379776 1.449088453

[0149] Table 4 Test results of Example 4

[0150]

[0151]

[0152] Table 5 Test results of comparative example 1

[0153] Time / min Group 1 Group 2 average value Standard deviation <![CDATA[Water evaporation rate (kg / m 2 / h)]]> 0 0 0 0 0 0 5 0.0143 0.0184 0.0164 0.002899138 0.516397326 10 0.0333 0.0420 0.0377 0.006151829 0.594567563 15 0.0574 0.0718 0.0646 0.010182338 0.680107385 20 0.0836 0.1028 0.0932 0.01357645 0.735905669 25 0.1129 0.1340 0.1235 0.014919953 0.779807338 30 0.1441 0.1668 0.1555 0.016051324 0.818287098 35 0.1773 0.2003 0.1888 0.016263456 0.851863828 40 0.2117 0.2348 0.2233 0.016334167 0.881389167 45 0.2465 0.2700 0.2583 0.016617009 0.849640733 50 0.2826 0.3054 0.2940 0.016122035 0.928567669 55 0.3184 0.3407 0.3296 0.015768481 0.946225959 60 0.3550 0.3775 0.3663 0.015909903 0.963967995

[0154] Table 1 is the test results of Example 1, Table 2 is the test results of Example 2, Table 3 is the test results of Example 3, Table 4 is the test results of Example 4, and Table 5 is the test results of Comparative Example 1. It can be seen from the test results of Tables 1-5 that the water evaporation efficiency of the photothermal conversion material formed after the nanosilver formed by silver nitrate and glucose solution is compounded is higher than the water evaporation efficiency when there is only pure sand without nanosilver loading. After loading nanosilver, the photothermal water evaporation performance of the sediment is significantly improved. As the water evaporation time increases, the water evaporation efficiency gradually increases. The color of the sediment changes from yellow to black during this process, and the color of the sediment gradually deepens as the concentration increases. The sediment and the nanosilver material are fully compounded.

[0155] Moreover, by comparing the test results of Examples 1-4 and Comparative Example 1, it can be seen that the water evaporation rates of Examples 1-4 are all higher than the water evaporation rate of Comparative Example 1 without nanosilver, which shows that the photothermal conversion efficiency of the composite of sediment as the matrix and nanosilver is effectively improved compared with the performance without nanosilver.

[0156] Obviously, the above embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A method for preparing a sediment nano-silver composite material, characterized in that: The following steps are involved: Step 1: using sediment as a carrier, performing a modification treatment on the sediment to introduce functional groups on the surface of the sediment to obtain modified sediment; The functionalized functional group is one or more of an amino group, a hydroxyl group and an amide group; Step 2: uniformly dispersing a silver salt and a reducing agent in an aqueous solvent A to obtain a nanosilver precursor solution; wherein the molar ratio of the reducing agent to the silver salt is 9 to 11:1; Step 3: uniformly dispersing the modified sediment in the nanosilver precursor solution, sealing the solution, and stirring the solution at a temperature of 60 to 80° C. After solid-liquid separation, the obtained solid phase component is sequentially incubated, dried, and ground to obtain the sediment-nanosilver composite material; the amount ratio of the sediment to the nanosilver precursor solution is 20 to 30 g:0.1 L; The modification treatment is prepared by the following steps: Using alkali metal hydroxide as a modifier, uniformly dispersing it in aqueous solvent B to obtain a modified solution; Subsequently, the cleaned sediment is placed in the modified solution and stirred at room temperature for 3 to 5 hours, solid-liquid separation is performed, and the modified sediment is obtained after washing and drying; Wherein, the alkali metal hydroxide is one or both of potassium hydroxide and sodium hydroxide; The usage ratio of the alkali metal hydroxide to the aqueous solvent B is 1-2 mol:1L.

2. The preparation method according to claim 1, wherein The silver salt is one or both of silver nitrate and silver chloride; The reducing agent is one or more of glucose, sucrose, polyol, citrate and borohydride.

3. The preparation method according to claim 1, wherein The usage ratio of the aqueous solvent A to the silver salt is 1L:50-200mmol.

4. The preparation method according to claim 1, wherein The stirring rate of the stirring treatment is 200-400 r / min, and the stirring time is 0.5-1.5 h.

5. The preparation method according to claim 1, wherein The incubation temperature is 45-85° C., and the treatment time is 3-5 hours.

6. A sediment nano-silver composite material prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the sediment nano-silver composite material according to claim 6 in photothermal conversion materials and water purification materials.

Images