Fabric-based photo-thermal carbon material as well as preparation method and application thereof

Abstract

The invention provides a fabric-based photo-thermal carbon material and a preparation method and application thereof.The preparation method of the fabric-based photo-thermal carbon material comprises the steps that recycled cotton-based fabric serves as a raw material, pretreatment reaction, high-temperature roasting treatment and aftertreatment reaction are conducted on the recycled cotton-based fabric, and the fabric-based carbon material which is flexible, plastic in structure and high in photo-thermal conversion efficiency is prepared. The selected raw materials are wide, easy to obtain and low in price, and the treatment method is large in adjustable space. The prepared fabric-based photo-thermal carbon material is large in specific surface area, rich in pore channels and good in chemical stability, has the advantages of being good in flexibility, good in hydrophilicity, good in electrical conductivity and thermal conductivity, high in visible light absorption efficiency, good in expandability, unique in three-dimensional woven structure and the like when applied to photo-thermal driven seawater desalination, and has wide application prospects. Therefore, the photo-thermal conversion rate and the seawater evaporation rate are relatively high, and seawater can be efficiently converted into fresh water.

Description

Technical Field

[0001] This invention relates to the field of carbon materials, and in particular to a fabric-based photothermal carbon material, its preparation method, and its application. Background Technology

[0002] Freshwater resources are crucial for people's livelihoods, social development, and technological progress. Although my country has a large total freshwater reserve, its distribution is uneven, and the average per capita share of arable land is low. In particular, the northern coastal areas and near-shore islands face severe freshwater shortages. While implementing multiple measures, vigorously developing seawater desalination technology has become a vital strategic measure to address water scarcity in my country's coastal areas and islands.

[0003] In recent years, solar-driven seawater desalination technology has gradually attracted attention, becoming a new type of seawater desalination method with significant commercial value. This method uses solar energy as the sole energy source to drive the heating and evaporation of seawater. It not only consumes no energy and is unaffected by geographical location or terrain, but also features simple equipment that is easy to operate and manage. Depending on the heating component, solar seawater desalination is divided into bottom heating, overall heating, and interfacial heating. Among these, interfacial solar evaporation (ISVG) has become the most promising cutting-edge solar seawater desalination technology due to its highest photothermal conversion efficiency and evaporation efficiency.

[0004] Two-dimensional biomass carbon materials are well-suited for use in solar-driven seawater evaporation due to their unique structure and properties: (1) high light absorption efficiency and photothermal conversion efficiency across the entire solar spectrum; (2) wide availability, low price, abundant pores, non-toxic and harmless, and do not cause environmental pollution; (3) rich in oxygen-containing functional groups, giving biomass carbon materials good hydrophilicity; (4) two-dimensional biomass carbon materials do not require secondary molding, resulting in lower usage and management costs, and thus possessing both higher research and industrial value.

[0005] my country produces approximately 20 million tons of waste textiles annually, and disposing of these waste textiles requires a significant investment each year. However, this invention provides high-value-added processing for these waste textiles, which not only saves on processing costs but also enables their reuse. Summary of the Invention

[0006] In view of this, the present invention aims to propose a fabric-based photothermal carbon material, its preparation method and application, to obtain a carbon material with a unique three-dimensional woven structure, good flexibility, good hydrophilicity, good electrical and thermal conductivity, high visible light absorption efficiency and good scalability, which exhibits excellent seawater evaporation rate in photothermal-driven seawater desalination applications.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for preparing a fabric-based photothermal carbon material includes the following steps: S1. Pretreatment reaction: The recycled cotton fabric is immersed in a precursor solution containing metal cations and / or organic matter containing amino groups. It is first ultrasonically treated to remove air bubbles adhering to the surface of the recycled cotton fabric, and then allowed to stand and soak to complete ion exchange and / or adsorption. After drying, the modified cotton fabric is obtained. S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and calcined under an inert atmosphere to obtain carbon materials with in-situ metal loading and / or in-situ N atom doping. S3. Post-processing reaction: The carbon material obtained in S2 is subjected to a post-processing reaction of hydrothermal in-situ growth of crystal array and / or ionic liquid in-situ polymerization to finally obtain the fabric-based photothermal carbon material.

[0008] Furthermore, in S1, the metal cation is Cu. 2+ Ag + Fe 3+ Co 2+ Mn 2+ One or more of the following, wherein Cu 2+ and Ag + Loaded on the fabric surface, Fe generates photoelectrons under light, improving the fabric's photothermal conversion efficiency. 3+ Co 2+ and Mn 2+ Loaded on the surface of the fabric, it absorbs light across the entire wavelength range under illumination, exhibiting high light absorption efficiency in the entire visible light range, which greatly enhances the photon capture and light absorption efficiency of the fabric-based carbon material. The organic compound containing an amino group is one of urea, melamine, or ethylenediamine; The concentration of the precursor solution containing metal cations and / or organic compounds containing amino groups is 0.01-1 mol / L, and the precursor solution is added to the recycled cotton fabric at a ratio of (10-500) mL: 1 g. The ultrasonic treatment conditions are as follows: ultrasonic power of 70W and temperature of 30℃ for 10 minutes; soaking time of 24-72 hours and soaking temperature of 25-50℃; drying conditions are as follows: drying at 75℃ for 12 hours.

[0009] Among them, in-situ loading of metal cations: at a high temperature of 75°C, the metal cations exchanged on the surface of cotton fabric are transformed into nanoparticles and in-situ loaded onto the fabric-based carbon material. N-atom modification of amino-containing organic compounds: Under a high temperature of 75℃, the adsorbed amino-containing organic compounds undergo gasification and decomposition, and combine with cotton-based carbon materials, in situ doping them into the structure of fabric-based carbon materials to obtain N-atom modified fabric-based carbon materials.

[0010] Furthermore, in S2, the inert atmosphere is nitrogen or argon, the heating rate of the calcination treatment is 1-10℃ / min, the calcination temperature is 600-1000℃, and the holding time is 1-4h.

[0011] Furthermore, the specific method for hydrothermal in-situ growth of crystal arrays is as follows: the carbon material obtained in S2 is immersed in a metal solution to obtain a mixed solution, and the pH is adjusted to 5-8. Then, the mixed solution is transferred to a reaction vessel for hydrothermal reaction to obtain the fabric-based carbon material for in-situ growth of crystal arrays.

[0012] Furthermore, the metal solution is Ni 2+ and [MoO4] 2- Solution, Ni 2+ and Co 2+ Solution, Ni 2+ and [WO4] 2- One of the solutions has a concentration of 0.1-0.6 mol / L and a volume of 30-35 mL; the hydrothermal reaction temperature is 140-200℃ and the time is 4-48 h.

[0013] Furthermore, the specific method for in-situ polymerization of ionic liquids is as follows: the carbon material obtained in S2 is completely immersed in an aqueous solution of ionic liquid to carry out a polymerization reaction, thereby obtaining a fabric-based carbon material supported by polyionic liquid.

[0014] Furthermore, the ionic liquid aqueous solution is one of vinylimidazole aqueous solution, methylpyrrolidone aqueous solution, or vinylpyridine aqueous solution, the concentration of the ionic liquid aqueous solution is 0.01-1 mol / L, the soaking time is 8-10 h, and the soaking temperature is 35-50℃.

[0015] Furthermore, the recycled cotton-based fabric is a cellulose-based fabric, including one of the following: recycled pure cotton fiber fabric, recycled acrylic / cotton fiber fabric, recycled polyester / cotton fiber fabric, recycled nylon / cotton fiber fabric, modal fabric, and lyocell fiber fabric.

[0016] The present invention also provides a fabric-based photothermal carbon material prepared by the preparation method described above.

[0017] The present invention also provides an application of the fabric-based photothermal carbon material as described above in photothermal-driven seawater desalination.

[0018] Compared with existing technologies, the fabric-based photothermal carbon material of the present invention has the following advantages: 1. This invention uses recycled cotton-based fabrics as raw materials. The raw materials are inexpensive and widely available. After functional modification, the invention achieves the goal of turning waste into treasure.

[0019] 2. The processing method involved in this invention is simple to operate. The structure and properties of the obtained fabric-based carbon material can be controlled by changing the pretreatment method, calcination process parameters, and post-treatment method.

[0020] 3. The fabric-based photothermal carbon material described in this invention has good hydrophilicity, and its special three-dimensional woven structure provides a rapid channel for transporting seawater to the material surface for evaporation; the high light absorption rate and high photothermal conversion rate of carbon materials are well maintained in the fabric-based photothermal carbon material. Therefore, this fabric-based photothermal carbon material has good seawater desalination efficiency under sunlight irradiation.

[0021] 4. The prepared fabric-based photothermal carbon material retains good mechanical toughness and has stable chemical and physical structures, making it very suitable for maintaining high-efficiency desalination of seawater under different environments without causing marine pollution. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 Images showing the mechanical properties of the fabric-based photothermal carbon material obtained in Example 1 of this invention; Figure 2 This is a schematic diagram of the water contact angle of the fabric-based photothermal carbon material obtained in Example 1 of the present invention; Figure 3 This is a scanning electron microscope image of the fabric-based photothermal carbon material obtained in Example 2 of the present invention; Figure 4 The images show the ultraviolet-visible-near-infrared spectra of the fabric-based photothermal carbon materials obtained in Examples 1-6 of this invention under solar radiation. Figure 5 The ultraviolet-visible-near-infrared spectra of the fabric-based photothermal carbon materials obtained in Comparative Examples 1-10 of the present invention under one solar radiation. Figure 6 The images shown are thermal infrared images of the fabric-based photothermal carbon materials obtained in Examples 1-6 of this invention under solar radiation. Figure 7 The above are thermal infrared images of the fabric-based photothermal carbon materials obtained in Comparative Examples 1-10 of the present invention under solar radiation. Figure 8This is a comparison chart of the concentration of cations in water before and after outdoor seawater desalination of the fabric-based photothermal carbon material obtained in Example 6 of the present invention. Figure 9 This is a structural diagram of a solar-powered seawater desalination device. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 A method for preparing a fabric-based photothermal carbon material includes the following steps: S1. Pretreatment reaction of in-situ supported Cu metal: At a temperature of 30℃, 1g of recycled cotton fabric was immersed in 40mL of 0.15mol / L Cu(NO3)2 solution. First, it was sonicated for 10min at an ultrasonic power of 70W and a temperature of 30℃ to remove air bubbles adhering to the surface of the recycled cotton fabric. Then, it was allowed to stand and soak for 24h at a temperature of 30℃ to complete ion exchange. After that, it was taken out and dried in a forced-air drying oven at 75℃ for 12h to obtain modified cotton fabric.

[0026] S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 900℃ at a rate of 4℃ / min under a nitrogen atmosphere. The temperature is then maintained at this temperature for 2.5h and then naturally cooled to room temperature to obtain Cu / CFT carbon material supported by Cu nanoparticles.

[0027] S3. Post-treatment reaction of in-situ polymerization of polyvinylimidazolium: The obtained Cu / CFT was completely immersed in water containing vinylimidazole and phosphoric acid, with a vinylimidazole concentration of 0.05 mol / L, and polymerized at 50°C for 10 h. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber, ultimately yielding a Cu / CFT fabric material of in-situ polymerized polyvinylimidazole, named Cu / CFT@[Hvim]3PO4.

[0028] Figure 1The invention demonstrates that the carbon material can recover its original shape after being bent and twisted, indicating that the carbon material prepared according to the present invention has good mechanical properties.

[0029] like Figure 2 As shown, the contact angle of the carbon material was tested, and it can be seen that the water droplet was completely absorbed by the fabric within 60 ms, indicating that the carbon material prepared according to the present invention has good hydrophilicity.

[0030] Example 2 S1. Pretreatment reactions of organic compounds containing amino groups: 1g of recycled cotton fabric was immersed in 30mL of 0.3mol / L urea solution. It was first sonicated for 10min at an ultrasonic power of 70W and a temperature of 30℃ to remove air bubbles adhering to the surface of the recycled cotton fabric. Then, it was left to stand at 30℃ for 30h, and then placed in a forced-air drying oven at 75℃ for 12h to obtain N-atom modified cotton fabric.

[0031] S2, Calcination treatment: The N-atom modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 900℃ at a rate of 5℃ / min under a nitrogen atmosphere. The temperature is then maintained at this temperature for 2 hours and then naturally cooled to room temperature to obtain N-atom in-situ doped fabric-based carbon material N-CFT.

[0032] S3. Post-processing reaction of hydrothermal in-situ grown crystal array: The obtained N-CFT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 6. 2+ and [MoO4] 2- The concentrations were 0.134 mol / L and 0.13 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 150°C for 4 hours. During this process, Ni... 2+ and [MoO4] 2- A crystallization reaction occurs on the surface of the fabric-based carbon fiber, forming needle-like NiMoO4 crystals that are vertically distributed on the carbon fiber surface. Finally, an N-CFT fabric material loaded with NiMoO4 array is obtained, named N-CFT@NiMoO4.

[0033] like Figure 3 As shown in the SEM image of the fabric-based photothermal carbon material, the NiMoO4 array can be seen successfully loaded onto the fabric surface.

[0034] Similarly, the carbon material can still recover its original shape after being bent and twisted, which shows that the carbon material prepared according to the present invention has good mechanical properties.

[0035] The contact angle of the carbon material was tested, and it can be seen that the water droplet was completely absorbed by the fabric within 30 ms, indicating that the carbon material prepared according to the present invention has good hydrophilicity.

[0036] Example 3 S1, pretreatment reaction of in-situ supported metal Ag and Mn: At a temperature of 25℃, 1g of recycled cotton fabric was immersed in a mixed solution of 40mL of 0.1mol / L Ag(NO3) and 0.2mol / L Mn(NO3)2. The fabric was first sonicated for 10min at an ultrasonic power of 70W and a temperature of 30℃ to remove air bubbles adhering to the surface of the recycled cotton fabric. Then, it was left to stand at a temperature of 35℃ for 25h, and then placed in a forced-air drying oven and dried at a temperature of 75℃ for 12h to obtain the modified cotton fabric.

[0037] S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 800℃ at a rate of 5℃ / min under a nitrogen atmosphere. It is then held at this temperature for 2 hours and then naturally cooled to room temperature to obtain Ag-Mn / CFT fabric-based carbon material supported by Ag and Mn nanoparticles.

[0038] S3. Post-treatment reaction of in-situ polymerization of polyvinylimidazolium: The obtained Ag-Mn / CFT was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.04 mol / L, and polymerized at 40°C for 9 hours. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber, ultimately yielding the Ag-Mn / CFT fabric material with in-situ polymerization of polyvinylimidazole, named Ag-Mn / CFT@[Hvim]3PO4.

[0039] Similarly, the carbon material can still recover its original shape after being bent and twisted, which shows that the carbon material prepared according to the present invention has good mechanical properties.

[0040] The contact angle of the carbon material was tested, and it can be seen that the water droplet was completely absorbed by the fabric within 50 ms, indicating that the carbon material prepared according to the present invention has good hydrophilicity.

[0041] Example 4 S1. Pretreatment reactions of organic compounds containing amino groups: 1g of recycled cotton fabric was immersed in 30mL of 0.2mol / L urea solution. It was first sonicated for 10min at an ultrasonic power of 70W and a temperature of 30℃ to remove air bubbles adhering to the surface of the recycled cotton fabric. Then it was left to stand at 35℃ for 30h, and then placed in a forced-air drying oven at 75℃ for 12h to obtain N-atom modified cotton fabric.

[0042] S2, Calcination treatment: The N-atom modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 900℃ at a rate of 5℃ / min under a nitrogen atmosphere. The temperature is then maintained at this temperature for 3 hours and then naturally cooled to room temperature to obtain N-atom in-situ doped fabric-based carbon material N-CFT.

[0043] S3. Post-treatment reaction of hydrothermal in-situ growth of crystal arrays and in-situ polymerization of polyvinyl imidazole: First, post-processing is performed on the hydrothermal in-situ grown NiMoO4 array: The obtained N-CFT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 5. 2+ and [MoO4] 2- The concentrations were 0.15 mol / L and 0.2 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 140°C for 5 hours. During this process, Ni... 2+ and [MoO4] 2- A crystallization reaction occurs on the surface of the fabric-based carbon fiber, forming needle-like NiMoO4 crystals that are vertically distributed on the carbon fiber surface. Finally, an N-CFT fabric material loaded with NiMoO4 array is obtained, named N-CFT@NiMoO4.

[0044] Finally, a post-treatment reaction involving the in-situ polymerization of polyvinyl imidazole is carried out: The obtained N-CFT@NiMoO4 was completely immersed in water containing vinylimidazole and phosphoric acid (0.1 mol / L concentration of vinylimidazole) and polymerized at 35°C for 8 hours. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber. This resulted in an N-CFT@NiMoO4 fabric material with NiMoO4 array support and in-situ polymerization of polyvinylimidazole, named N-CFT@NiMoO4@[Hvim]3PO4.

[0045] Similarly, the carbon material can still recover its original shape after being bent and twisted, which shows that the carbon material prepared according to the present invention has good mechanical properties.

[0046] The contact angle of the carbon material was tested, and it can be seen that the water droplet was completely absorbed by the fabric within 150 ms, indicating that the carbon material prepared according to the present invention has good hydrophilicity.

[0047] Example 5 S1. Pretreatment reaction of in-situ supported metal Fe and amino-containing organic compounds: 1g of recycled cotton fabric was immersed in a mixed solution of 0.3mol / L urea and 0.1mol / L Fe(NO3)3 in 35mL. The fabric was first sonicated for 10min at 70W and 30℃ to remove air bubbles adhering to the surface. Then it was left to stand at 26℃ for 24h. Finally, it was placed in a forced-air drying oven and dried at 75℃ for 12h to obtain the modified cotton fabric.

[0048] S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 850°C at a rate of 5°C / min under a nitrogen atmosphere. The temperature is then maintained at this temperature for 3 hours and then naturally cooled to room temperature to obtain the fabric-based carbon material Fe / N-CFT, which is modified with N atoms and supported by Fe nanoparticles.

[0049] S3. Post-processing reaction of hydrothermal in-situ grown crystal array: The obtained Fe / N-CFT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 6. 2+ and [MoO4] 2- The concentrations were 0.1 mol / L and 0.15 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 160°C for 5 hours. During this process, Ni... 2+ and [MoO4] 2- A crystallization reaction occurs on the surface of the fabric-based carbon fiber, forming needle-like NiMoO4 crystals that are vertically distributed on the carbon fiber surface. Finally, a NiMoO4 array-loaded Fe / N-CFT fabric material is obtained, named Fe / N-CFT@NiMoO4.

[0050] Similarly, the carbon material can still recover its original shape after being bent and twisted, which shows that the carbon material prepared according to the present invention has good mechanical properties.

[0051] The contact angle of the carbon material was tested, and it can be seen that the water droplet was completely absorbed by the fabric within 100 ms, indicating that the carbon material prepared according to the present invention has good hydrophilicity.

[0052] Example 6 S1. Pretreatment reaction of in-situ supported metal Fe and amino-containing organic compounds: 1g of recycled cotton fabric was immersed in a mixed solution of 0.4mol / L urea and 0.2mol / L Fe(NO3)3 in 40mL. The fabric was first sonicated for 10min at 70W and 30℃ to remove air bubbles adhering to the surface. Then it was left to soak at 40℃ for 24h. After that, it was placed in a forced-air drying oven and dried at 75℃ for 12h to obtain the modified cotton fabric.

[0053] S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere, and held at this temperature for 2 hours. Then it is naturally cooled to room temperature to obtain the doped fabric-based carbon material Fe / N-CFT.

[0054] S3. Post-treatment reaction of hydrothermal in-situ growth of crystal arrays and in-situ polymerization of polyvinyl imidazole: First, post-processing is performed on the hydrothermal in-situ grown NiMoO4 array: The obtained Fe / N-CFT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 7. 2+ and [MoO4] 2- The concentrations were 0.2 mol / L and 0.25 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 170 °C for 8 h. The resulting NiMoO4 array-supported Fe / N-CFT fabric material was named Fe / N-CFT@NiMoO4.

[0055] Finally, a post-treatment reaction involving the in-situ polymerization of polyvinyl imidazole is carried out: The obtained Fe / N-CFT@NiMoO4 was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.06 mol / L, and polymerized at 45℃ for 8 h. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber. The final product was a Fe / N-CFT@NiMoO4 fabric material with NiMoO4 array support and in-situ polymerization of polyvinylimidazole, named Fe / N-CFT@NiMoO4@[Hvim]3PO4.

[0056] Similarly, the carbon material can still recover its original shape after being bent and twisted, which shows that the carbon material prepared according to the present invention has good mechanical properties.

[0057] The contact angle of the carbon material was tested, and it can be seen that the water droplet was completely absorbed by the fabric within 20 ms, indicating that the carbon material prepared according to the present invention has good hydrophilicity.

[0058] Comparative Example 1: No pre- or post-processing performed. The difference from Example 6 is that no pre- or post-processing is performed: One gram of recycled pure cotton fabric was placed in a tube furnace for calcination without any pretreatment. The temperature was raised to 1000°C at a rate of 4°C / min under a nitrogen atmosphere and held at that temperature for 2 hours, followed by natural cooling to room temperature. No post-treatment was then performed to obtain pure cotton-based carbon material.

[0059] Comparative Example 2: No pre- or post-treatment or roasting was performed. The difference from Example 6 is that no pre- or post-treatment and calcination are performed: 1g of recycled pure cotton fabric was dried in an oven to obtain a two-dimensional cotton fiber fabric.

[0060] Comparative Example 3: No preprocessing performed. The difference from Example 6 is that no pretreatment is performed: S1. Calcination treatment: 1g of recycled cotton-based fabric is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere. The temperature is maintained at this temperature for 2h and then naturally cooled to room temperature to obtain fabric-based carbon material CFT.

[0061] S2. Post-treatment reaction of hydrothermal in-situ growth of crystal arrays and in-situ polymerization of polyvinyl imidazole: First, post-processing is performed on the hydrothermal in-situ grown NiMoO4 array: The obtained CFT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 7. 2+ and [MoO4] 2- The concentrations were 0.2 mol / L and 0.25 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 170 °C for 8 h. The resulting NiMoO4 array-supported CFT fabric material was named CFT@NiMoO4.

[0062] Finally, a post-treatment reaction involving the in-situ polymerization of polyvinyl imidazole is carried out: The obtained CFT@NiMoO4 was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.06 mol / L, and polymerized at 45°C for 8 hours. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber. The final product was a CFT@NiMoO4 fabric material with NiMoO4 array support and in-situ polymerization of polyvinylimidazole, named CFT@NiMoO4@[Hvim]3PO4.

[0063] Comparative Example 4: No post-processing performed. The difference from Example 6 is that no post-processing is performed: S1. Pretreatment reaction of in-situ supported metal Fe and amino-containing organic compounds: 1g of recycled cotton fabric was immersed in a mixed solution of 0.4mol / L urea and 0.2mol / L Fe(NO3)3 in 40mL. The fabric was first sonicated for 10min at 70W and 30℃ to remove air bubbles adhering to the surface. Then it was left to soak at 40℃ for 24h. After that, it was placed in a forced-air drying oven and dried at 75℃ for 12h to obtain the modified cotton fabric.

[0064] S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere, and held at this temperature for 2 hours. Then it is naturally cooled to room temperature to obtain the doped fabric-based carbon material Fe / N-CFT.

[0065] Comparative Example 5: Metal cations replaced with Al 3+ The difference from Example 6 is that the metal cation is replaced with Al. 3+ : S1. Pretreatment reaction of in-situ supported metal Al and amino-group-containing organic compounds: 1g of recycled cotton fabric was immersed in a mixed solution of 0.4mol / L urea and 0.2mol / L Al(NO3)3 in 40mL. The fabric was first sonicated for 10min at 70W and 30℃ to remove air bubbles adhering to the surface. Then, it was left to soak at 40℃ for 24h. After that, it was placed in a forced-air drying oven and dried at 75℃ for 12h to obtain the modified cotton fabric.

[0066] S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere, and held at this temperature for 2 hours. Then it is naturally cooled to room temperature to obtain the doped fabric-based carbon material Al / N-CFT.

[0067] S3. Post-treatment reaction of hydrothermal in-situ growth of crystal arrays and in-situ polymerization of polyvinyl imidazole: First, post-processing is performed on the hydrothermal in-situ grown NiMoO4 array: The obtained Al / N-CFT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 7. 2+ and [MoO4] 2-The concentrations were 0.2 mol / L and 0.25 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 170 °C for 8 h. The resulting NiMoO4 array-supported Al / N-CFT fabric material was named Al / N-CFT@NiMoO4.

[0068] Finally, a post-treatment reaction involving the in-situ polymerization of polyvinyl imidazole is carried out: The obtained Al / N-CFT@NiMoO4 was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.06 mol / L, and polymerized at 45°C for 8 hours. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber. This resulted in an Al / N-CFT@NiMoO4 fabric material with NiMoO4 array support and in-situ polymerization of polyvinylimidazole, named Al / N-CFT@NiMoO4@[Hvim]3PO4.

[0069] Comparative Example 6: Different Post-treatment Reaction Order The difference from Example 6 lies in the order of the post-processing reactions: S1. Pretreatment reaction of in-situ supported metal Fe and amino-containing organic compounds: 1g of recycled cotton fabric was immersed in a mixed solution of 0.4mol / L urea and 0.2mol / L Fe(NO3)3 in 40mL. The fabric was first sonicated for 10min at 70W and 30℃ to remove air bubbles adhering to the surface. Then it was left to soak at 40℃ for 24h. After that, it was placed in a forced-air drying oven and dried at 75℃ for 12h to obtain the modified cotton fabric.

[0070] S2, Calcination treatment: The modified cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere, and held at this temperature for 2 hours. Then it is naturally cooled to room temperature to obtain the doped fabric-based carbon material Fe / N-CFT.

[0071] S3, Post-processing reactions of in-situ polymerization of polyvinyl imidazole and hydrothermal in-situ growth of NiMoO4 arrays: First, a post-treatment reaction is carried out during the in-situ polymerization of polyvinyl imidazole: The obtained Fe / N-CFT was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.06 mol / L, and polymerized at 45°C for 8 hours. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber, ultimately yielding a Fe / N-CFT fabric material with in-situ polymerization of polyvinylimidazole, named Fe / N-CFT@[Hvim]3PO4.

[0072] Finally, post-processing of the hydrothermal in-situ grown NiMoO4 array was performed: The obtained Fe / N-CFT@[Hvim]3PO4 was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 7. 2+ and [MoO4] 2- The concentrations were 0.2 mol / L and 0.25 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 170 °C for 8 h. Finally, a fabric material of Fe / N-CFT@[Hvim]3PO4 supported by in-situ polymerization of polyvinyl imidazole and NiMoO4 array was obtained, named Fe / N-CFT@NiMoO4@[Hvim]3PO4.

[0073] Comparative Example 7: Roasting followed by processing The difference from Example 6 is that the product is roasted first and then processed: S1. Calcination treatment: 1g of recycled cotton-based fabric is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere. The temperature is then maintained at this temperature for 2 hours and then naturally cooled to room temperature to obtain fabric-based carbon material CFT.

[0074] S2, Pretreatment reaction of in-situ supported metal Fe and amino-group-containing organic compounds: The CFT obtained in S1 was immersed in a mixed solution of 40 mL of 0.4 mol / L urea and 0.2 mol / L Fe(NO3)3. It was first sonicated for 10 min at an ultrasonic power of 70 W and a temperature of 30 °C to remove air bubbles adhering to the surface of the recycled cotton fabric. Then it was left to soak at 40 °C for 24 h. After that, it was placed in a forced-air drying oven and dried at a temperature of 75 °C for 12 h to obtain the modified cotton fabric Fe / N-CFT.

[0075] S3. Post-treatment reaction of hydrothermal in-situ growth of crystal arrays and in-situ polymerization of polyvinyl imidazole: First, post-processing is performed on the hydrothermal in-situ grown NiMoO4 array: The obtained Fe / N-CFT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 7. 2+ and [MoO4] 2- The concentrations were 0.2 mol / L and 0.25 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 170 °C for 8 h. The resulting NiMoO4 array-supported Fe / N-CFT fabric material was named Fe / N-CFT@NiMoO4.

[0076] Finally, a post-treatment reaction involving the in-situ polymerization of polyvinyl imidazole is carried out: The obtained Fe / N-CFT@NiMoO4 was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.06 mol / L, and polymerized at 45℃ for 8 h. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber. The final product was a Fe / N-CFT@NiMoO4 fabric material with NiMoO4 array support and in-situ polymerization of polyvinylimidazole, named Fe / N-CFT@NiMoO4@[Hvim]3PO4.

[0077] Comparative Example 8: Final roasting The difference from Example 6 is that the final calcination is performed: S1. Pretreatment reaction of in-situ supported metal Fe and amino-containing organic compounds: 1g of recycled cotton fabric was immersed in a mixed solution of 0.4mol / L urea and 0.2mol / L Fe(NO3)3 in 40mL. The fabric was first sonicated for 10min at 70W and 30℃ to remove air bubbles adhering to the surface. Then, it was left to soak at 40℃ for 24h. After that, it was placed in a forced-air drying oven and dried at 75℃ for 12h to obtain the modified cotton fabric Fe / N-CT.

[0078] S2. Post-treatment reaction of hydrothermal in-situ growth of crystal arrays and in-situ polymerization of polyvinyl imidazole: First, post-processing is performed on the hydrothermal in-situ grown NiMoO4 array: The obtained Fe / N-CT was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 7. 2+ and [MoO4] 2-The concentrations were 0.2 mol / L and 0.25 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 170 °C for 8 h. The resulting Fe / N-CT fabric material supported on a NiMoO4 array was named Fe / N-CT@NiMoO4.

[0079] Then, a post-treatment reaction is carried out for the in-situ polymerization of polyvinylimidazolium: The obtained Fe / N-CT@NiMoO4 was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.06 mol / L, and polymerized at 45℃ for 8 h. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric-based carbon fiber, and the resulting polyvinylimidazole interacted strongly with the carbon fiber. The final product was a Fe / N-CT@NiMoO4 fabric material with NiMoO4 array support and in-situ polymerization of polyvinylimidazole, named Fe / N-CT@NiMoO4@[Hvim]3PO4.

[0080] S3. Calcination treatment: The Fe / N-CT@NiMoO4@[Hvim]3PO4 obtained in S2 is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere. The temperature is held at this temperature for 2 hours and then naturally cooled to room temperature to obtain the final carbon material Fe / N-CFT@NiMoO4@[Hvim]3PO4.

[0081] Comparative Example 9: Different processing order before and after. The difference from Example 6 lies in the order of pre- and post-processing: S1. Post-treatment reaction of hydrothermal in-situ growth of crystal array and in-situ polymerization of polyvinyl imidazole: First, post-processing is performed on the hydrothermal in-situ grown NiMoO4 array: 1g of recycled cotton fabric was completely immersed in a metal solution containing Ni(NO3)2 and Na2MoO4 to obtain a mixed solution, and the pH was adjusted to 7. 2+ and [MoO4] 2- The concentrations were 0.2 mol / L and 0.25 mol / L, respectively. The mixture was placed in a high-pressure reactor and hydrothermally reacted at 170 °C for 8 h. The final product was a NiMoO4 array-supported CFT cotton-based fabric material, named CFT@NiMoO4.

[0082] Then, a post-treatment reaction is carried out for the in-situ polymerization of polyvinylimidazolium: The obtained CFT@NiMoO4 was completely immersed in water containing vinylimidazole and phosphoric acid at a concentration of 0.06 mol / L, and polymerized at 45°C for 8 hours. During this process, vinylimidazole underwent in-situ polymerization on the surface of the fabric matrix fibers, and the resulting polyvinylimidazole interacted strongly with the fabric matrix fibers. Finally, a CFT@NiMoO4 fabric material with NiMoO4 array support and in-situ polymerization of polyvinylimidazole was obtained, named CFT@NiMoO4@[Hvim]3PO4.

[0083] S2. Calcination treatment: The CFT@NiMoO4@[Hvim]3PO4 cotton-based fabric obtained in S1 is placed in a tube furnace and heated to 1000℃ at a rate of 4℃ / min under a nitrogen atmosphere. The temperature is then maintained at this temperature for 2 hours and then naturally cooled to room temperature to obtain the fabric-based carbon material CFT@NiMoO4@[Hvim]3PO4.

[0084] S3. Pretreatment reaction of in-situ supported metal Fe and amino-containing organic compounds: The fabric-based carbon material CFT@NiMoO4@[Hvim]3PO4 obtained in S2 was immersed in 40 mL of a mixed solution of 0.4 mol / L urea and 0.2 mol / L Fe(NO3)3. First, it was sonicated for 10 min at an ultrasonic power of 70 W and a temperature of 30 °C to remove air bubbles adhering to the surface of the recycled cotton fabric. Then, it was left to soak at 40 °C for 24 h. After that, it was taken out and dried in a forced-air drying oven at a temperature of 75 °C for 12 h to obtain the fabric-based carbon material Fe / N-CFT@NiMoO4@[Hvim]3PO4 with in-situ metal Fe support and N atom modification.

[0085] test: The evaporation efficiency, photothermal conversion efficiency, and cation concentration in water before and after seawater desalination were tested on the fabric-based photothermal carbon materials obtained in Examples 1-6 and Comparative Examples 1-9.

[0086] 1) Evaporation performance: The fabric-based carbon material was exposed to simulated sunlight of a certain intensity (a simulated sunlight intensity refers to the intensity of sunlight under standard test conditions, i.e., 1000 W / m²). 2 The continuous evaporation performance of the sample on pure water was tested over a 1-hour period. The evaporation rate and photothermal conversion efficiency of the sample under simulated sunlight of a certain intensity were finally obtained, as shown in Table 1 below.

[0087] 2) Photothermal conversion efficiency

[0088] The evaporation performance of fabric-based photothermal carbon materials is typically evaluated based on the evaporation rate and its corresponding efficiency (also known as photothermal conversion efficiency), where the photothermal conversion efficiency is: ; in (kg / s) is the instantaneous mass change caused by evaporation. The intensity of the incident solar radiation is 1.0 kW / m². 2 A is the area of ​​the fabric-based photothermal carbon material. It is the total enthalpy of the liquid-gas phase transition.

[0089] ; here It is the latent heat of water vaporization at atmospheric pressure, given as 2257 kJ / kg. -1 ,in This is the specific heat capacity of water, quantified as 4.2 kJ / kg. -1 K -1 , It is the difference between the surface temperature of the fabric-based photothermal carbon material and the ambient temperature. Therefore, It can be written as: .

[0090] The photothermal conversion efficiencies of each embodiment and comparative example are shown in Table 1.

[0091] 3) Cation concentration in water before and after seawater desalination A solar-powered seawater desalination device consists of fabric-based photothermal carbon material, heat-insulating sponge, a water generator, and a water collector, such as... Figure 9 As shown.

[0092] First, fill the water generator halfway with seawater. Then, place a 5cm diameter circular insulating sponge inside the generator, and simultaneously place a 5cm diameter circular fabric-based photothermal carbon material on top of the sponge. Connect a water collector to the conduit on the right side of the water generator to collect freshwater. Under actual sunlight, the seawater evaporates using the excellent photothermal conversion capabilities of the fabric-based photothermal carbon material. The evaporated water vapor condenses on the inner wall of the water generator, forming small water droplets, which then flow through the conduit into the water collector, thus completing the collection of freshwater.

[0093] On a sunny summer day, the designed solar desalination device was placed outdoors for seawater desalination. The changes in sunlight intensity, surface temperature of the fabric-based photothermal carbon material, and the amount of purified water collected were recorded every hour during the outdoor seawater desalination process from 8:00 to 18:00. The evaporator was always facing the sun as the sun's position changed throughout the day.

[0094] Experiments revealed that the highest surface temperature of the fabric-based photothermal carbon material occurred at 12:00 noon, while the peak solar radiation intensity occurred between 14:00 and 15:00. For example... Figure 6 and Figure 7 As shown, the temperature of the fabric-based carbon material under solar radiation was tested. It can be seen that the fabric-based carbon material reached the highest equilibrium temperature at 10 minutes, and the average temperature is shown in the figure. This indicates that the fabric-based photothermal carbon material prepared according to the present invention has excellent photothermal conversion performance.

[0095] The purified water collection volume of each embodiment and comparative example during the period from 8:00 to 18:00 is shown in Table 1.

[0096] Table 1. Data Comparison Table of Each Embodiment and Comparative Example

[0097] Combination Figures 4-5 As shown in Table 1, the evaporation rate, photothermal conversion efficiency, and purified water collection volume of the embodiments are all superior to those of the comparative examples, indicating that the photothermal carbon material prepared according to the present invention has good evaporation performance and seawater desalination capability. Furthermore, in the embodiments, the effect of using two treatment methods for pretreatment and posttreatment is better than the effect of using two treatment methods for either pretreatment or posttreatment, and the effect of using two treatment methods for either pretreatment or posttreatment is better than the effect of using only one treatment method for both pretreatment and posttreatment. In the comparative examples, the absence of pretreatment and / or posttreatment, different orders of pretreatment and posttreatment, and the use of unsuitable metals in the pretreatment will all affect the evaporation rate, photothermal conversion efficiency, and purified water collection volume of the material.

[0098] Figure 8 The seawater desalination effect of the solar evaporator composed of fabric-based photothermal carbon material prepared in Example 6 is shown, and the Mg in the purified water is also demonstrated. 2+ Ca 2+ Na + and K + The ion concentration in the water was reduced by 2-3 orders of magnitude compared to seawater, far below the ion concentrations in drinking water stipulated by the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA). Furthermore, the fabric-based photothermal carbon materials prepared in Examples 1-5 of this invention can achieve the same effect. This indicates that solar evaporators composed of fabric-based photothermal carbon materials prepared by the method of this invention have excellent seawater desalination capabilities in real-world environments.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of making a fabric-based photo-thermal carbon material, characterized by, The method comprises the following steps: S1, pretreatment reaction: immersing the recycled cotton-based fabric into a precursor solution containing metal cations and / or amino group-containing organic matter, first ultrasonic treatment to remove bubbles adhering to the surface of the recycled cotton-based fabric, then standing for soaking to complete ion exchange and / or adsorption, and finally drying to obtain a modified cotton-based fabric; S2, calcination treatment: placing the modified cotton-based fabric obtained in S1 into a tube furnace, and performing calcination treatment under an inert atmosphere to obtain a carbon material with metal in-situ loading and / or N atom in-situ doping; S3, post-treatment reaction: performing a post-treatment reaction of hydrothermal in-situ growth of crystal array and / or in-situ polymerization of ionic liquid on the carbon material obtained in S2, and finally obtaining the fabric-based photo-thermal carbon material.

2. The method of claim 1, wherein the fabric-based photothermal carbon material is prepared by a process comprising: In S1, the metal cation is one or more of Cu 2+ , Ag + , Fe 3+ , Co 2+ , Mn 2+ , and the amino group-containing organic compound is one of urea, melamine, or ethylenediamine. The concentration of the precursor solution containing metal cations and / or amino group-containing organic matter is 0.01-1 mol / L, and the precursor solution is added in a ratio of (10-500) mL:1 g to the recycled cotton-based fabric. The ultrasonic treatment conditions are: ultrasonic treatment for 10 min at an ultrasonic power of 70 W and a temperature of 30 ℃; the soaking time is 24-72 h, and the soaking temperature is 25-50 ℃; and the drying conditions are: drying at a temperature of 75 ℃ for 12 h.

3. The method of claim 1, wherein the fabric-based photothermal carbon material is prepared by a process comprising: In S2, the inert atmosphere is nitrogen or argon, the heating rate of the calcination treatment is 1-10 ℃ / min, the calcination temperature is 600-1000 ℃, and the holding time is 1-4 h.

4. The method of claim 1, wherein the fabric-based photothermal carbon material is prepared by a process comprising: The specific method of hydrothermal in-situ growth of crystal array is: immersing the carbon material obtained in S2 into a metal solution to obtain a mixed solution, adjusting the pH to 5-8, and then transferring the mixed solution into a reaction kettle for hydrothermal reaction to obtain a fabric-based carbon material with in-situ grown crystal array.

5. The method of claim 4, wherein the fabric-based photothermal carbon material is prepared by a process comprising: metallic solution is Ni 2+ and [MoO4] 2- solution, Ni 2+ and Co 2+ solution, Ni 2+ and [WO4] 2- solution, the concentration of each metallic solution is 0.1-0.6 mol / L, the volume is 30-35 mL; the temperature of hydrothermal reaction is 140-200℃, the time is 4-48 h.

6. The method of claim 1, wherein the fabric-based photothermal carbon material is prepared by a process comprising: The specific method of in-situ polymerization of ionic liquid is: completely immersing the carbon material obtained in S2 into an ionic liquid aqueous solution for polymerization reaction to obtain a fabric-based carbon material loaded with poly-ionic liquid.

7. The method of claim 6, wherein the fabric-based photothermal carbon material is prepared by a process comprising: The ionic liquid aqueous solution is one of a vinyl imidazole aqueous solution, a methyl pyrrolidone aqueous solution, or a vinyl pyridine aqueous solution, the concentration of the ionic liquid aqueous solution is 0.01-1 mol / L, the soaking time is 8-10 h, and the soaking temperature is 35-50 ℃.

8. The method of claim 1, wherein the fabric-based photothermal carbon material is prepared by a process comprising: The recycled cotton-based fabric is a cellulose-based fabric, including one of a recycled pure cotton fiber fabric, a recycled acrylic / cotton fiber fabric, a recycled polyester / cotton fiber fabric, a recycled polyamide / cotton fiber fabric, a modal fabric, and a lyocell fiber fabric.

9. A fabric-based photo-thermal carbon material prepared by the preparation method of any one of claims 1-8.

10. Use of the fabric-based photo-thermal carbon material of claim 9 in photo-thermal driven seawater desalination.

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