Photo-thermal micro-electrolysis floating material, preparation method and application thereof
By coupling photothermal interface water evaporation with micro-electrolysis, a photothermal micro-electrolysis float material was prepared, which solved the problem of low VOCs/water separation efficiency in photothermal interface water evaporation technology and realized efficient wastewater treatment and coal-based solid waste reuse.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHONGBEI UNIV
- Filing Date
- 2025-05-09
- Publication Date
- 2026-07-07
AI Technical Summary
Existing photothermal interface water evaporation technology suffers from low efficiency and VOCs enrichment in distilled water, especially in the deep treatment of coal chemical wastewater.
By coupling photothermal interface water evaporation with micro-electrolysis, a photothermal micro-electrolysis float material is prepared. Using materials such as iron-carbon composite powder, fly ash cenospheres, binders and pore-forming agents, combined with slurry molding and high-temperature sintering processes, a floating composite material with both photothermal and micro-electrolysis functions is prepared.
It achieves efficient separation of VOCs and water, improves wastewater treatment efficiency, reduces energy consumption, and promotes the reuse of coal-related solid waste.
Smart Images
Figure CN120247146B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of low-carbon and environmental protection technology, and specifically relates to photothermal interface water evaporation technology, specifically a photothermal micro-electrolysis float material and its preparation method and application. Background Technology
[0002] Coal chemical wastewater is complex in composition, highly toxic, and difficult to treat, posing a serious threat to the ecological environment and public health. Even after secondary biological treatment, coal chemical wastewater still contains a large amount of organic pollutants, making it difficult to meet discharge standards and requiring advanced treatment. Traditional advanced wastewater treatment methods include coagulation sedimentation, adsorption, catalytic oxidation, and membrane treatment. These methods are often accompanied by high costs, large-scale use of chemical reagents, and membrane fouling. Therefore, finding a low-cost, simple, environmentally friendly, and highly effective advanced treatment technology for coal chemical wastewater has become an important research objective.
[0003] In recent years, photothermal interface water evaporation technology has shown broad application prospects in wastewater treatment due to its unique advantages of efficiently utilizing solar energy to drive water evaporation while simultaneously accelerating interfacial physicochemical reactions through thermal convection. This technology is not only low-carbon and environmentally friendly, but also features low maintenance and operating costs, and high and stable performance. Through reasonable design of the morphology and composition of photothermal materials, the water evaporation rate at the photothermal interface can reach 3.0 kg•m³. -2 •h -1 The above demonstrates a significant increase in water distillation purification speed. However, single photothermal interface water evaporation technology still has certain limitations in the deep treatment of coal chemical wastewater, especially in the separation of VOCs and water. Due to the significant volatility of VOCs, single photothermal interface water evaporation is insufficient to achieve efficient VOCs / water separation, and may even lead to VOCs enrichment in the distilled water. Therefore, how to prepare advanced photothermal interface water evaporation materials to improve VOCs / water separation efficiency has become an important research direction. Summary of the Invention
[0004] The purpose of this invention is to address the problems existing in the prior art by providing a photothermal micro-electrolysis float material, its preparation method, and its application. This invention improves VOCs / water separation efficiency by coupling photothermal interface water evaporation with micro-electrolysis, providing a new technical solution for the deep treatment of coal chemical wastewater.
[0005] This invention is achieved through the following technical solution:
[0006] A photothermal micro-electrolysis float material is made from the following raw materials in parts by weight: 25-30 parts of iron-carbon composite powder, 55-60 parts of fly ash cenospheres, 10-20 parts of binder, 5-10 parts of pore-forming agent, and 30-40 parts of deionized water.
[0007] Preferably, the iron-carbon composite powder is composed of high-iron content nanopowder, coal-based carbon dot powder, and nano titanium dioxide powder in any proportion. The high-iron content nanopowder is high-purity nano iron powder or high-purity nano stainless steel powder. The fly ash cenospheres are hollow spherical particles with a size in the range of 200-500 mesh. The binder is bentonite. The pore-forming agent is sodium bicarbonate, sodium carbonate, or ammonium bicarbonate.
[0008] Preferably, the iron-carbon composite powder is composed of 50-55 parts by weight of high iron content nano powder, 10-15 parts by weight of coal-based carbon dot powder, and 30-35 parts by weight of nano titanium dioxide powder.
[0009] Preferably, the preparation method of coal-based carbon dot powder is as follows: waste coal tar pitch is etched in formic acid and hydrogen peroxide, the volume ratio of formic acid to hydrogen peroxide is 8~12, the etching time is 20~25 h, and after etching, it is centrifuged and dried by rotary evaporation to obtain coal-based carbon dot powder.
[0010] Furthermore, the present invention also provides a method for preparing the above-mentioned photothermal micro-electrolysis float material, specifically including the following steps:
[0011] 1) Preparation of iron-carbon composite powder: High iron content nano powder, coal-based carbon dot powder and nano titanium dioxide powder are mixed and ball-milled, then calcined at high temperature to finally obtain iron-carbon composite powder.
[0012] 2) Preparation of molding slurry: Mix iron-carbon composite powder, fly ash cenospheres, binder and pore-forming agent, then add deionized water and stir thoroughly to prepare the molding slurry.
[0013] 3) Mold forming: The uniformly mixed molding slurry is poured into a stainless steel mold and molded under a fixed pressure. Finally, the material blank is demolded to obtain the floating material blank.
[0014] 4) Carbon dot spraying: Coal-based carbon dot powder is dispersed in anhydrous ethanol to obtain a coal-based carbon dot ethanol dispersion, and then the coal-based carbon dot ethanol dispersion is sprayed onto the upper surface of the floating material blank by spraying method.
[0015] 5) Drying and sintering: The float material blank is dried under natural conditions and then sintered in an argon atmosphere. After sintering, the photothermal micro-electrolysis float material is obtained.
[0016] Preferably, in step 1) of the above preparation method, the ball milling speed is 350~400 r / min, the ball milling time is 0.4~0.6 h; the high-temperature calcination temperature is 350~450 ℃, the calcination time is 1.5~2.5 h, and the calcination atmosphere is argon.
[0017] Preferably, in step 3) of the above preparation method, the fixed pressure during compression molding is (1.5~2.0)×10⁻⁶. 5 Pa.
[0018] Preferably, in step 4) of the above preparation method, coal-based carbon dot powder is added to anhydrous ethanol at a concentration of 10 g / L, magnetically stirred at 600 rpm for 30 min, and ultrasonically treated at 60 Hz for 10 min to obtain a uniform and stable coal-based carbon dot ethanol dispersion; the amount of coal-based carbon dot ethanol dispersion sprayed onto the surface of the float material is controlled at 25~30 mg / cm². 2 .
[0019] Preferably, in step 5) of the above preparation method, the sintering temperature is 750~850 ℃, the sintering time is 1.0~1.5 h, and the sintering atmosphere is argon.
[0020] Furthermore, the present invention also provides the application of the above-mentioned photothermal micro-electrolysis flotation material or the photothermal micro-electrolysis flotation material prepared by the above preparation method in wastewater purification.
[0021] In summary, this invention provides a photothermal micro-electrolysis float material, its preparation method, and its application. The float material uses high-iron content metal nanopowder, coal-based carbon dot powder, nano-titanium dioxide powder, and fly ash cenospheres as key raw materials, with bentonite as a binder and sodium bicarbonate and sodium carbonate as pore-forming agents. A slurry molding and high-temperature sintering process is employed to prepare a floating composite material that combines photothermal and micro-electrolysis functions. This composite material can float on water, efficiently utilizing solar energy for photothermal interface water evaporation, while simultaneously leveraging its micro-electrolysis characteristics to degrade volatile organic pollutants (VOCs), ultimately effectively separating water from VOCs and achieving efficient wastewater purification. Experimental results show that the composite material of this invention can achieve high efficiency at 1.0 kW•m³. -2 The simulated water evaporation rate under sunlight can reach 1.72 kg•m. -2 •h -1 The removal rate of volatile organic compound phenol in distilled water reached 92.0%, achieving synergistic effects of photothermal interface water evaporation and micro-electrolysis in wastewater treatment, which is beneficial for the deep treatment of industrial wastewater. Furthermore, the fly ash cenospheres involved in this invention are derived from power plant fly ash, and the coal-based carbon dots are derived from waste coal tar pitch. Both power plant fly ash and waste coal tar pitch are coal-related solid wastes, so the implementation of this invention also promotes the reuse of coal-related solid wastes.
[0022] Compared with existing technologies, the flotation material of this invention possesses excellent photothermal conversion performance, micro-electrolysis performance, good buoyancy, and mechanical strength. It can utilize solar energy to efficiently promote VOCs / water separation during wastewater distillation and purification, thereby improving wastewater treatment efficiency and reducing energy consumption. The flotation material preparation method provided by this invention is simple and easy to operate, using coal-based solid waste as raw material, resulting in low cost and promoting the reuse of coal-based solid waste, thus protecting the environment. Attached Figure Description
[0023] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.
[0024] Figure 1 The images show a physical picture of the photothermal micro-electrolysis float material prepared in Example 1 and a schematic diagram of it floating on the water surface.
[0025] Figure 2 This is a scanning electron microscope image of the photothermal microelectrolysis float material prepared in Example 1.
[0026] Figure 3 This is a transmission electron microscope (TEM) image of the iron-carbon composite powder prepared in Example 1.
[0027] Figure 4 This is the ultraviolet-visible-near-infrared absorption spectrum of the photothermal micro-electrolysis float material prepared in Example 1.
[0028] Figure 5 The photothermal micro-electrolysis float material prepared in Example 1 was used at 1.0 kW•m -2 Surface temperature-time curve under simulated sunlight.
[0029] Figure 6 This is a schematic diagram of the device structure used to test the performance of the photothermal micro-electrolysis float material prepared in Example 1 in treating phenol wastewater using solar energy.
[0030] Figure 7 The photothermal micro-electrolysis float material prepared in Example 1 was used at 1.0 kW•m -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0031] Figure 8 The photothermal micro-electrolysis float material prepared in Example 2 was used at 1.0 kW•m -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0032] Figure 9 The photothermal micro-electrolysis float material prepared in Example 3 was used at 1.0 kW•m -2The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0033] Figure 10 The photothermal micro-electrolysis float material prepared in Example 4 was used at 1.0 kW•m -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0034] Figure 11 The photothermal micro-electrolysis float material prepared in Example 5 was used at 1.0 kW•m -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0035] Figure 12 The photothermal micro-electrolysis float material prepared in Example 6 was used at 1.0 kW•m -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0036] Figure 13 The photothermal micro-electrolysis float material prepared in Example 7 was used at 1.0 kW•m -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0037] Figure 14 The images show a physical picture of the photothermal micro-electrolysis float material prepared in Example 8 and a schematic diagram of it sinking to the bottom of the water.
[0038] Figure 15 This is a physical image of the photothermal micro-electrolysis float material prepared in Example 9 and its performance at 1.0 kW•m. -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained.
[0039] Figure 16 This is a physical image of the photothermal micro-electrolysis float material prepared in Example 10 and its application at 1.0 kW•m. -2 The ultraviolet-visible absorption spectra of phenol wastewater and distilled water obtained under simulated sunlight were obtained. Detailed Implementation
[0040] This invention provides a photothermal micro-electrolysis float material, its preparation method, and its application.
[0041] The aforementioned photothermal micro-electrolysis float material is made from the following raw materials in parts by weight: 25-30 parts iron-carbon composite powder, 55-60 parts fly ash cenospheres, 10-20 parts binder, 5-10 parts pore-forming agent, and 30-40 parts deionized water. The iron-carbon composite powder is composed of high-iron content nanoparticles, coal-based carbon dot powder, and nano-titanium dioxide powder in any proportion. Preferably, the iron-carbon composite powder can be composed of 50-55 parts by weight of high-iron content nanoparticles, 10-15 parts by weight of coal-based carbon dot powder, and 30-35 parts by weight of nano-titanium dioxide powder. The coal-based carbon dot powder is prepared by etching waste coal tar pitch in formic acid and hydrogen peroxide, with a volume ratio of formic acid to hydrogen peroxide of 8-12, and an etching time of 20-25 minutes. After etching, centrifugation and rotary evaporation drying are performed to obtain coal-based carbon dot powder. The coal-based carbon dot powder is prepared using waste coal tar pitch as a precursor and has excellent photothermal conversion performance. The high-iron content nanopowder is high-purity nano-iron powder or high-purity nano-stainless steel powder, which can provide electrons in the micro-electrolysis reaction. The nano-titanium dioxide powder is commercial P25 powder, which has excellent hydrophilic properties and can ensure water transport. The fly ash cenospheres are hollow spherical particles with a size in the range of 200~500 mesh, which have the characteristics of lightweight buoyancy. The binder is bentonite. The pore-forming agent is sodium bicarbonate or sodium carbonate or ammonium bicarbonate.
[0042] The preparation method of the aforementioned photothermal micro-electrolysis float material specifically includes the following steps:
[0043] 1) Preparation of iron-carbon composite powder: High-iron content nanopowder, coal-based carbon dot powder, and nano titanium dioxide powder are mixed and first ball-milled, then calcined at high temperature to finally obtain iron-carbon composite powder; in this step, the ball milling speed is 350~400 r / min, the ball milling time is 0.4~0.6h; the high-temperature calcination temperature is 350~450 ℃, the calcination time is 1.5~2.5 h, and the calcination atmosphere is argon.
[0044] 2) Preparation of molding slurry: Mix iron-carbon composite powder, fly ash cenospheres, binder and pore-forming agent, then add deionized water and stir thoroughly to prepare the molding slurry.
[0045] 3) Mold forming: The uniformly mixed molding slurry is poured into a stainless steel mold and molded under a fixed pressure. Finally, the material is demolded to obtain the floating material blank. In this step, the fixed pressure during molding is (1.5~2.0)×10 5 Pa.
[0046] 4) Carbon dot spraying: Coal-based carbon dot powder is dispersed in anhydrous ethanol to obtain a coal-based carbon dot ethanol dispersion. This dispersion is then sprayed onto the upper surface of the float material blank using a spraying method. In this step, coal-based carbon dot powder is added to anhydrous ethanol at a concentration of 10 g / L, magnetically stirred at 600 rpm for 30 min, and ultrasonically treated at 60 Hz for 10 min to obtain a uniform and stable coal-based carbon dot ethanol dispersion. The spraying amount of the coal-based carbon dot ethanol dispersion on the upper surface of the float material blank is controlled at 25~30 mg / cm². 2 .
[0047] 5) Drying and sintering: The float material blank is dried under natural conditions and then sintered in an argon atmosphere. After sintering, the photothermal micro-electrolysis float material is obtained. In this step, the sintering temperature is 750~850 ℃, the sintering time is 1.0~1.5 h, and the sintering atmosphere is argon.
[0048] The application of the photothermal micro-electrolysis flotation material or the photothermal micro-electrolysis flotation material prepared by the preparation method in wastewater purification.
[0049] To enable those skilled in the art to better understand the present invention, the present invention will be further described clearly and completely below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention. Example 1
[0050] A method for preparing a photothermal micro-electrolysis float material specifically includes the following steps:
[0051] 1) Weigh high-purity nano-iron powder, coal-based carbon dot powder, and nano-titanium dioxide powder in a weight ratio of 52:13:32.5. After mixing, transfer the mixture to a planetary ball mill with a ball-to-material ratio of 40:3. Ball mill at 368 r / min for 0.5 h. After ball milling, refrigerate the resulting powder at 400 °C. o C, calcined under argon atmosphere for 2.0 h, to obtain iron-carbon composite powder.
[0052] 2) Weigh the iron-carbon composite powder, fly ash cenospheres, bentonite, sodium bicarbonate and deionized water in a weight ratio of 25:55:15:5:40, mix and stir for 0.5 h to obtain the molding slurry.
[0053] 3) Weigh 1.0 g of the molding slurry and add it to the round mold, controlling the pressure to be 1.6 × 10⁻⁶. 5 After pressing for 10 minutes, the material is demolded to obtain a floating material blank with a diameter of 2 cm and a thickness of 5 mm.
[0054] 4) Coal-based carbon dot powder was added to anhydrous ethanol at a concentration of 10 g / L, magnetically stirred at 600 rpm for 30 min, and ultrasonically treated at 60 Hz for 10 min to obtain a homogeneous and stable coal-based carbon dot ethanol dispersion. The coal-based carbon dot ethanol dispersion was sprayed onto the surface of the float material blank using a spraying method, with a carbon dot spraying amount of 28 mg / cm³. 2 .
[0055] 5) Dry the floating material blank under natural conditions for 24 hours, then transfer it to a tubular atmosphere sintering furnace under argon atmosphere, setting the heating rate to 15°C. o C / min, heating up to 800 o After being kept at C for 1.0 h and cooled, the photothermal micro-electrolysis float material was obtained.
[0056] The resulting photothermal micro-electrolysis float exhibits a loose, porous structure, allowing it to float stably on the water surface, such as... Figure 1 As shown, a) is a photothermal micro-electrolysis float material exhibiting a loose and porous structure; b) is a photothermal micro-electrolysis float material that can float stably on the water surface; the photothermal micro-electrolysis float material contains a large number of micropores and mesopores, such as... Figure 2 and Figure 3 As shown, Figure 2 Image a is a low-magnification SEM image of the photothermal micro-electrolysis float material, image b is a medium-magnification SEM image of the photothermal micro-electrolysis float material, and image c is a high-magnification SEM image of the photothermal micro-electrolysis float material. Figure 3 Image a shows a low-magnification TEM image of the iron-carbon composite powder, and image b shows a high-magnification TEM image of the iron-carbon composite powder; the photothermal micro-electrolysis float material can achieve an absorption rate of over 80% in the ultraviolet-visible-near-infrared region, such as... Figure 4 As shown. At 1.0 kW•m -2 Under simulated sunlight irradiation, the surface temperature of the photothermal micro-electrolysis float material increased from 20°C to 30°C within 20 minutes. o C rises to 60 o C demonstrates its excellent photothermal conversion performance, such as Figure 5 As shown. Using... Figure 6 The apparatus shown was used in an experiment to treat phenol wastewater (phenol concentration: 100 mg / L) using solar energy. The water evaporation rate was measured to be 1.72 kg•m. -2 •h -1 The phenol removal rate in the resulting distilled water reached 92.0%, demonstrating its excellent performance in solar energy treatment of phenol wastewater. Figure 7 As shown. Example 2
[0057] A method for preparing a photothermal micro-electrolysis float material specifically includes the following steps:
[0058] 1) Weigh high-purity nano-iron powder and coal-based carbon point powder in a weight ratio of 4:1, mix them, and then transfer them to a planetary ball mill with a ball-to-material ratio of 40:3. Ball mill at 368 r / min for 0.5 h. After ball milling, the resulting powder is then subjected to a 400°C test. o C, calcined under argon atmosphere for 2.0 h, to obtain iron-carbon composite powder.
[0059] 2) Weigh the iron-carbon composite powder, fly ash cenospheres, bentonite, sodium bicarbonate and deionized water in a weight ratio of 25:55:15:5:40, mix and stir for 0.5 h to obtain the molding slurry.
[0060] 3) Weigh 1.0 g of the molding slurry and add it to the round mold, controlling the pressure to be 1.6 × 10⁻⁶. 5 After pressing for 10 minutes, the material is demolded to obtain a floating material blank with a diameter of 2 cm and a thickness of 5 mm.
[0061] 4) Coal-based carbon dot powder was added to anhydrous ethanol at a concentration of 10 g / L, magnetically stirred at 600 rpm for 30 min, and ultrasonically treated at 60 Hz for 10 min to obtain a homogeneous and stable coal-based carbon dot ethanol dispersion. The coal-based carbon dot ethanol dispersion was sprayed onto the surface of the float material blank using a spraying method, with a carbon dot spraying amount of 28 mg / cm³. 2 .
[0062] 5) Dry the floating material blank under natural conditions for 24 hours, then transfer it to a tubular atmosphere sintering furnace under argon atmosphere, setting the heating rate to 15°C. o C / min, heating up to 800 o After being kept at C for 1.0 h and cooled, the photothermal micro-electrolysis float material was obtained.
[0063] The obtained photothermal micro-electrolysis flotation material was used in an experiment to treat phenol wastewater (phenol concentration: 100 mg / L) using solar energy. The water evaporation rate was measured to be 1.45 kg•m. -2 •h -1 The phenol removal rate in the distilled water obtained reached 62.41%, which is significantly lower than the performance of the solar energy treatment of phenol wastewater by the photothermal micro-electrolysis flotation material obtained in Example 1. Figure 8 As shown, this demonstrates the importance of nano-titanium dioxide powder (P25 titanium dioxide nanopowder) as a raw material. Example 3
[0064] A method for preparing a photothermal micro-electrolysis float material differs from the method in Example 1 in that kaolin is used instead of bentonite to prepare the photothermal micro-electrolysis float material.
[0065] The above-mentioned photothermal micro-electrolysis flotation material was used for solar energy treatment of phenol wastewater (phenol concentration: 100 mg•L). -1 The experiment measured the water evaporation rate to be 1.61 kg•m. -2 •h -1 The phenol removal rate in the distilled water obtained reached 76.1%, which is significantly lower than the performance of the solar energy treatment of phenol wastewater by the photothermal micro-electrolysis flotation material obtained in Example 1. Figure 9 As shown, bentonite is a better raw material than kaolin. Example 4
[0066] A method for preparing a photothermal micro-electrolysis float differs from the method in Example 1 in that sodium carbonate is used instead of sodium bicarbonate in the preparation of the photothermal micro-electrolysis float.
[0067] The above-mentioned photothermal micro-electrolysis flotation material was used for solar energy treatment of phenol wastewater (phenol concentration: 100 mg•L). -1 The experiment measured the water evaporation rate to be 1.70 kg•m. -2 •h -1 The phenol removal rate in the distilled water obtained can reach 89.3%, and the performance of the solar energy treatment of phenol wastewater by the photothermal micro-electrolysis flotation material obtained in Example 1 is not significantly reduced. Figure 10 As shown, this demonstrates the feasibility of using sodium carbonate as a raw material. Example 5
[0068] A method for preparing a photothermal micro-electrolysis float differs from the method in Example 1 in that ammonium bicarbonate is used instead of sodium bicarbonate in the preparation of the photothermal micro-electrolysis float.
[0069] The above-mentioned photothermal micro-electrolysis flotation material was used for solar energy treatment of phenol wastewater (phenol concentration: 100 mg•L). -1 The experiment measured the water evaporation rate to be 1.64 kg•m. -2 •h -1 The phenol removal rate in the distilled water obtained can reach 89.2%, and the performance of the solar energy treatment of phenol wastewater by the photothermal micro-electrolysis flotation material obtained in Example 1 is not significantly reduced. Figure 11 As shown, this demonstrates the feasibility of using ammonium bicarbonate as a raw material. Example 6
[0070] A method for preparing a photothermal micro-electrolysis float differs from the method in Example 1 in that: after the float blank is obtained by slurry molding, a coal-based carbon dot ethanol dispersion is not sprayed on the surface of the float blank; other process parameters and operating steps are exactly the same as in Example 1.
[0071] The above-mentioned photothermal micro-electrolysis flotation material was used for solar energy treatment of phenol wastewater (phenol concentration: 100 mg•L). -1 The experiment measured the water evaporation rate to be 1.62 kg•m. -2 •h -1 The phenol removal rate in the distilled water obtained reached 71.4%, which is significantly lower than the performance of the solar energy treatment of phenol wastewater by the photothermal micro-electrolysis flotation material obtained in Example 1. Figure 12 As shown, this demonstrates the necessity of spraying a coal-based carbon dot ethanol dispersion onto the surface of the floating material blank. Example 7
[0072] A method for preparing a photothermal micro-electrolysis float material differs from the method in Example 1 in that high-purity nano-stainless steel powder is used instead of high-purity nano-iron powder, while other process parameters and operating steps are exactly the same as in Example 1.
[0073] The above-mentioned photothermal micro-electrolysis flotation material was used for solar energy treatment of phenol wastewater (phenol concentration: 100 mg•L). -1 The experiment measured the water evaporation rate to be 1.67 kg•m. -2 •h -1 The phenol removal rate in the distilled water obtained can reach 85.3%, and the performance of the solar energy treatment of phenol wastewater by the photothermal micro-electrolysis flotation material obtained in Example 1 is not significantly reduced. Figure 13 As shown, this demonstrates the feasibility of using high-purity nano-stainless steel powder as a raw material. Example 8
[0074] A method for preparing a photothermal micro-electrolysis float material differs from the method in Example 1 in that the pressure is adjusted to 2.1 × 10⁻⁶ during the slurry molding process. 5 Pa, other process parameters and operating steps are the same as in Example 1.
[0075] The resulting photothermal micro-electrolysis float exhibits a dense structure and cannot float on the water surface, such as... Figure 14 As shown, a) indicates that the photothermal micro-electrolysis float material exhibits a dense structure, while b) indicates that the photothermal micro-electrolysis float material cannot float on the water surface; this indicates that the molding pressure needs to be less than 2.0 × 10⁻⁶. 5 Pa. Example 9
[0076] A method for preparing a photothermal micro-electrolysis float material differs from the method in Example 1 in that: in step 1), the weight ratio of high-purity nano-iron powder, coal-based carbon dot powder, and nano-titanium dioxide powder is 50:15:35; the ball milling speed is 400 r / min; the ball milling time is 0.4 h; and after ball milling, the resulting powder is subjected to a 450°C test. oC, calcined under argon atmosphere for 1.5 h; in step 2), the weight ratio of iron-carbon composite powder, fly ash cenospheres, bentonite, sodium bicarbonate, and deionized water is 28:60:10:10:35; in step 3), the controlled pressure is 1.5 × 10⁻⁶ h. 5 Pa; In step 4), the carbon dot spraying amount is 30 mg / cm 2 In step 5), the temperature is raised to 750°C. o Maintain at C for 1.2 h. Other process parameters and operating procedures are exactly the same as in Example 1.
[0077] The resulting photothermal micro-electrolysis float exhibits a loose, porous structure, allowing it to float stably on the water surface, such as... Figure 15 As shown in a; the above-mentioned photothermal micro-electrolysis flotation material was used for solar energy treatment of phenol wastewater (phenol concentration: 100 mg•L). -1 The experiment measured the water evaporation rate to be 1.70 kg•m. -2 •h -1 The phenol removal rate in the resulting distilled water reached 91.5%, demonstrating its excellent performance in solar energy treatment of phenol wastewater. Figure 15 As shown in b in the figure. Example 10
[0078] A method for preparing a photothermal micro-electrolysis float material differs from the method in Example 1 in that: in step 1), the weight ratio of high-purity nano-iron powder, coal-based carbon dot powder, and nano-titanium dioxide powder is 55:10:30; the ball milling speed is 350 r / min; the ball milling time is 0.6 h; and after ball milling, the resulting powder is subjected to a 350 r / min test. o C, calcined under argon atmosphere for 2.5 h; in step 2), the weight ratio of iron-carbon composite powder, fly ash cenospheres, bentonite, sodium bicarbonate, and deionized water is 30:57:20:8:30; in step 3), the controlled pressure is 2.0 × 10⁻⁶. 5 Pa; In step 4), the carbon dot spraying amount is 25 mg / cm. 2 In step 5), the temperature is raised to 850°C. o Maintain at C for 1.5 h. Other process parameters and operating procedures are exactly the same as in Example 1.
[0079] The resulting photothermal micro-electrolysis float exhibits a loose, porous structure, allowing it to float stably on the water surface, such as... Figure 16 As shown in a; the above-mentioned photothermal micro-electrolysis flotation material was used for solar energy treatment of phenol wastewater (phenol concentration: 100 mg•L). -1 The experiment measured the water evaporation rate to be 1.69 kg•m. -2 •h -1The phenol removal rate in the resulting distilled water reached 91.0%, demonstrating its excellent performance in solar energy treatment of phenol wastewater. Figure 16 As shown in b in the figure.
[0080] The embodiments described above merely illustrate the preferred implementation of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.
Claims
1. A photothermal micro-electrolysis float material, characterized in that, The raw materials include the following parts by weight: 25-30 parts of iron-carbon composite powder, 55-60 parts of fly ash cenospheres, 10-20 parts of binder, 5-10 parts of pore-forming agent, and 30-40 parts of deionized water. The iron-carbon composite powder is composed of 50-55 parts by weight of high-iron content nano powder, 10-15 parts by weight of coal-based carbon dot powder, and 30-35 parts by weight of nano titanium dioxide powder. The high-iron content nano powder is high-purity nano iron powder or high-purity nano stainless steel powder. The fly ash cenospheres are hollow spherical particles with a size in the range of 200-500 mesh. The binder is bentonite. The pore-forming agent is sodium bicarbonate, sodium carbonate, or ammonium bicarbonate.
2. The photothermal micro-electrolysis float material according to claim 1, characterized in that: The preparation method of coal-based carbon dot powder is as follows: waste coal tar pitch is etched in formic acid and hydrogen peroxide, the volume ratio of formic acid to hydrogen peroxide is (8~12):1, the etching time is 20~25h, after etching is completed, centrifugation and rotary evaporation are performed to dry the coal-based carbon dot powder.
3. The method for preparing the photothermal micro-electrolysis float material according to claim 2, characterized in that, Includes the following steps: 1) Preparation of iron-carbon composite powder: High iron content nano powder, coal-based carbon dot powder and nano titanium dioxide powder are mixed and ball-milled, then calcined at high temperature to finally prepare iron-carbon composite powder. 2) Preparation of molding slurry: Mix iron-carbon composite powder, fly ash cenospheres, binder and pore-forming agent, then add deionized water and stir thoroughly to prepare the molding slurry. 3) Mold forming: The uniformly mixed molding slurry is poured into a stainless steel mold and molded under a fixed pressure. Finally, the material blank is demolded to obtain the floating material blank. 4) Carbon dot spraying: Coal-based carbon dot powder is dispersed in anhydrous ethanol to obtain a coal-based carbon dot ethanol dispersion, and then the coal-based carbon dot ethanol dispersion is sprayed onto the upper surface of the floating material blank by spraying method. 5) Drying and sintering: The float material blank is dried under natural conditions and then sintered in an argon atmosphere. After sintering, the photothermal micro-electrolysis float material is obtained.
4. The method for preparing the photothermal micro-electrolysis float material according to claim 3, characterized in that: In step 1), the ball milling speed is 350~400 r / min and the ball milling time is 0.4~0.6 h; the high-temperature calcination temperature is 350~450℃ and the calcination time is 1.5~2.5 h, and the calcination atmosphere is argon.
5. The method for preparing the photothermal micro-electrolysis float material according to claim 3, characterized in that: In step 3), the fixed pressure during compression molding is (1.5~2.0)×10 5 Pa.
6. The method for preparing the photothermal micro-electrolysis float material according to claim 3, characterized in that: In step 4), coal-based carbon dot powder is added to anhydrous ethanol at a concentration of 10 g / L, magnetically stirred at 600 rpm for 30 min, and ultrasonically treated at 60 Hz for 10 min to obtain a uniform and stable coal-based carbon dot ethanol dispersion. The amount of coal-based carbon dot ethanol dispersion sprayed onto the surface of the float material is controlled at 25~30 mg / cm². 2 .
7. The method for preparing the photothermal micro-electrolysis float material according to claim 3, characterized in that: In step 5), the sintering temperature is 750~850℃, the sintering time is 1.0~1.5h, and the sintering atmosphere is argon.
8. The application of the photothermal micro-electrolysis flotation material according to claim 1 or 2 or the photothermal micro-electrolysis flotation material prepared by the preparation method according to claim 3 in wastewater purification.