CN113772667B - Graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam and preparation method and application thereof - Google Patents

Graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam and preparation method and application thereof Download PDF

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CN113772667B
CN113772667B CN202110839357.9A CN202110839357A CN113772667B CN 113772667 B CN113772667 B CN 113772667B CN 202110839357 A CN202110839357 A CN 202110839357A CN 113772667 B CN113772667 B CN 113772667B
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graphene oxide
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thermal material
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CN113772667A (en
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哈斯其美格
陈丽华
张禹晗
肖朝虎
苏小平
郭玉萍
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Northwest Minzu University
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    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00Carbon; Compounds thereof
    • C01B32/15Nano-sized carbon materials
    • C01B32/182Graphene
    • C01B32/198Graphene oxide
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00Carbon; Compounds thereof
    • C01B32/15Nano-sized carbon materials
    • C01B32/182Graphene
    • C01B32/194After-treatment
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/02Treatment of water, waste water, or sewage by heating
    • C02F1/04Treatment of water, waste water, or sewage by heating by distillation or evaporation
    • C02F1/14Treatment of water, waste water, or sewage by heating by distillation or evaporation using solar energy
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22STEAM GENERATION
    • F22BMETHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00Methods of steam generation characterised by form of heating method
    • F22B1/006Methods of steam generation characterised by form of heating method using solar heat
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24SSOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S70/00Details of absorbing elements
    • F24S70/10Details of absorbing elements characterised by the absorbing material
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00Nature of the contaminant
    • C02F2101/30Organic compounds
    • C02F2101/308Dyes; Colorants; Fluorescent agents
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/08Seawater, e.g. for desalination
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124Water desalination
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124Water desalination
    • Y02A20/138Water desalination using renewable energy
    • Y02A20/142Solar thermal; Photovoltaics
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00Water conservation; Efficient water supply; Efficient water use
    • Y02A20/20Controlling water pollution; Waste water treatment
    • Y02A20/208Off-grid powered water treatment
    • Y02A20/212Solar-powered wastewater sewage treatment, e.g. spray evaporation
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/40Solar thermal energy, e.g. solar towers
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/10Process efficiency
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/10Process efficiency
    • Y02P20/133Renewable energy sources, e.g. sunlight

Abstract

The invention provides a preparation method of graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam, which comprises the following steps: s1, preparing graphene oxide by a hummers method; s2, preparing a graphene oxide-based porous photo-thermal material in a directional arrangement mode; s3, preparing the hydrophilic oleophobic graphene oxide based porous photo-thermal material. The invention firstly introduces a synthetic method of graphene oxide-based porous photo-thermal material which can efficiently generate solar steam and has an alignment channel and oleophobic property by taking directional freezing and simple carbonization as main means. The application of the catalyst in sea water desalination and waste water purification treatment (containing oil or dye) is described. The graphene oxide-based porous photo-thermal material has higher solar energy conversion efficiency, excellent salt resistance and anti-fouling performance, and has a certain practical application value in the aspects of future sea water desalination and (oil-containing and dye-containing) wastewater purification treatment.

Description

Graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam and preparation method and application thereof
Technical Field
The invention relates to a graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam, a preparation method and application thereof, and also relates to application of the material in sea water desalination and (oil-containing and dye-containing) wastewater purification treatment.
Background
Today, global warming and industrial pollution are becoming more and more serious, and conventional sea water desalination technologies such as Reverse Osmosis (RO), microfiltration, ultrafiltration, multi-effect distillation, multi-stage flash evaporation, adsorption, etc., have limitations of low efficiency, high cost, redundant operation and huge energy consumption, which aggravate greenhouse effect and environmental pollution, thereby impeding their large-scale application. Therefore, the efficient production of fresh water by using clean energy as input in a more practical manner is not trivial. Solar energy is an inexhaustible renewable energy source. Recently, solar steam desalination (SSG) has received increasing attention due to its high evaporation rate and solar conversion efficiency, simplicity and ease of operation, and the use of only clean solar radiation as an energy input. Compared to ordinary water evaporation using solar radiation as a heat source, ordinary water evaporation has a disadvantage of low conversion efficiency due to ineffective conversion of most of solar energy into a large amount of water or loss into the external environment, the high solar conversion efficiency of SSG is attributed to its unique interfacial evaporation mode, i.e., solar radiation is collected only and located at the water-air interface, heating a thin air-water surface layer, and thus heat loss can be effectively reduced. Based on these advantages, SSG is considered one of the most effective methods for desalination and production of fresh water. The ideal interface heating device for SSG generation has the following advantages: a broad solar absorption range, high photo-thermal conversion efficiency, low thermal conductivity, oriented porosity, and rich porosity for water molecule transport. Materials used for efficient solar interfacial evaporation to date include carbon-based materials, conjugated microporous polymers, composites, biomass materials, and metal nanomaterials. It is well known that petroleum is ubiquitous in water, and most photothermal materials are hydrophilic and lipophilic. Once the oil contaminates the pores, water molecules cannot be normally transported to the surface of the sample, and the photo-thermal conversion efficiency of the photo-thermal material is greatly reduced. Fortunately, the development of oleophobic and hydrophilic materials solves these problems, further building up the oleophobic properties. The practical application of the photo-thermal material in the aspect of solar interface evaporation, especially in the field of oily wastewater, expands the application range of interface evaporation. Therefore, the development of novel high-performance photo-thermal materials will become the main direction of future research.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a graphene oxide-based porous photo-thermal material which can efficiently generate solar steam and has an alignment channel and oleophobic property, a preparation method thereof and application thereof in sea water desalination and (oil-containing and dye-containing) wastewater purification treatment.
The invention provides a preparation method of graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam, which comprises the following steps:
s1, preparing graphene oxide by a hummers method;
s2, preparing a graphene oxide-based porous photo-thermal material in a directional arrangement mode: dispersing or dissolving graphene oxide and polyvinyl alcohol with deionized water respectively, uniformly mixing, removing bubbles by adopting an ultrasonic method, then putting the mixture into liquid nitrogen at uniform speed to freeze to obtain a cured product, freeze-drying the cured product in a freeze dryer to obtain a graphene oxide precursor, carbonizing the graphene oxide precursor to obtain a directional arrangement graphene oxide porous photo-thermal material named as GO-1;
s3, preparing a hydrophilic oleophobic graphene oxide based porous photo-thermal material: immersing GO-1 into polydiallyl dimethyl ammonium chloride solution to obtain PDDA modified GO-1; soaking PDDA modified GO-1 in sodium alginate salt solution and calcium chloride solution to obtain Ca 2+ Alginate hydrogel coating; then Ca is added 2+ The surface of the alginate hydrogel coating is immersed in polydiallyl dimethyl ammonium chloride, and finally immersed in the wholeAnd (3) carrying out oleophobic modification in sodium fluooctoate, taking out and drying to obtain the hydrophilic oleophobic graphene oxide based porous photo-thermal material.
Preferably, in step S2, the mass ratio of the graphene oxide to the polyvinyl alcohol is 1:1.
Preferably, in step S2, the mixture is frozen in liquid nitrogen at a constant speed of 3-5mm/min.
Preferably, in step S2, the freeze-drying specifically includes: freeze-drying at-50℃for 3 days.
Preferably, in step S2, the carbonization specifically includes: and uniformly heating the graphene oxide precursor to 200 ℃ for carbonization for 2 hours, and then uniformly cooling.
Preferably, in step S2, the carbonization specifically includes: the graphene oxide precursor is uniformly heated to 200 ℃ at a speed of 2 ℃/min, carbonized for 2 hours, and then uniformly cooled at a speed of 2 ℃/min.
In the step S3, the GO-1 is immersed in the polydiallyl dimethyl ammonium chloride solution for 18-22min; soaking PDDA modified GO-1 in sodium alginate solution for 2min and in calcium chloride solution for 18-22min; ca is added with 2+ The surface of the alginate hydrogel coating is immersed in the PDDA solution for 2min and immersed in the sodium perfluorooctanoate solution for 18-22min.
The invention also provides the graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam, which is prepared by the method.
The invention also provides application of the graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam in sea water desalination or purification treatment of oil-containing dye-containing wastewater.
Preferably, the graphene oxide-based porous photothermal material capable of efficiently generating solar steam is placed in seawater or oily dye-containing wastewater for sunlight irradiation.
The invention firstly introduces a synthetic method of graphene oxide-based porous photo-thermal material which can efficiently generate solar steam and has an alignment channel and oleophobic property by taking directional freezing and simple carbonization as main means. The application of the catalyst in sea water desalination and waste water purification treatment (containing oil or dye) is described. In addition, the ordered structure is obtained by liquid nitrogen directional freezing, so that the material has good salt tolerance, and then the oleophobic layer is prepared by surface oleophobic modification, so that the oleophobic property of the material is increased. Super oleophobic property and high-efficiency salt resistance enable the solar steam desalination device to show excellent solar steam desalination performance. Through researches on application of the graphene oxide-based porous photo-thermal material, the graphene oxide-based porous photo-thermal material which can efficiently generate solar steam and has an alignment channel and oleophobic property is primarily considered to have higher solar energy conversion efficiency, excellent salt resistance and anti-fouling performance, and has a certain practical application value in the aspects of future sea water desalination and (oil-containing and dye-containing) wastewater purification treatment.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:
FIG. 1 is a schematic diagram of a preparation route for graphene oxide-based porous photothermal materials of the present invention that can efficiently generate solar vapor and have aligned channels and oleophobic properties.
In FIG. 2, a, d is an optical photograph of GO-1, and b, c, e, f are scanning electron microscopes of GO-1 and GO-2.
In FIG. 3, a is the mercury/extrusion plot for GO-1 and b is the large pore diameter distribution plot for GO-1.
FIG. 4 shows the wettability and contact angle of GO-1, GO-2 in pure water and the oleophobicity and contact angle in n-hexadecane containing red oil-O dye.
In FIG. 5, a is a graph of the mass change over time of GO-1 in pure water, GO-2 in 20% sodium chloride, GO-2 in 10% n-hexadecane oily water, GO-1 in 10% n-hexadecane oily water under one solar, pure water without photo-thermal material, b is the evaporation rate (+) and evaporation efficiency (+) of GO-1 in 10% n-hexadecane oily water, GO-1 in 20% sodium chloride, GO-2 in 10% n-hexadecane oily water under 1 solar, pure water without photo-thermal material.
FIG. 6 shows the evaporation efficiency test of GO-1 for 10 cycles in 1 sun.
FIG. 7 is a graph showing the comparison of GO-2 evaporation to simulate seawater ion concentration.
FIG. 8 is a graph showing the comparison of the ultraviolet absorption spectra of GO-2 vaporized methylene blue aqueous solutions.
Detailed Description
The following examples facilitate a better understanding of the present invention, but are not intended to limit the same. The experimental methods in the following examples are conventional methods unless otherwise specified. The test materials used in the examples described below are commercially available unless otherwise specified.
The preparation method of the graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam and having aligned channels and oleophobic property is shown in fig. 1.
FIG. 1 is a preparation route diagram of graphene oxide-based porous photothermal material capable of efficiently generating solar steam.
The preparation method of the graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam comprises the following steps of:
1. preparation of graphene oxide by hummers method
(1) Preoxidation of graphite
7.5mL of concentrated sulfuric acid, 1.5g of potassium peroxodisulfate and 1.5g of phosphorus pentoxide were taken in a 50mL three-necked flask, heated to 90℃and stirred for 15min before cooling to 80 ℃. To this was slowly added 1.8g of graphite powder, kept at 80℃and stirred for 4.5h to give a black precipitate mixture. After the reaction, the mixture was cooled to room temperature, diluted with 300mL of deionized water, left to stand overnight, the treated graphite was washed to neutrality with distilled water, and dried at room temperature for 24 hours to obtain preoxidized graphite.
Wherein, concentrated sulfuric acid and phosphorus pentoxide: an intercalating agent; potassium peroxodisulfate: an oxidizing agent. After pre-oxidation, the solubility of graphite in water increases.
(2) Preparation of graphene oxide
19mL of concentrated sulfuric acid was measured and added to a 250mL three-necked flask, and the flask was cooled to about 0℃with an ice-water bath. Adding the above materials under stirringAnd (3) rapidly stirring the pretreated graphite obtained in the step (1) until the graphite powder is fully dissolved. Slowly adding 9.0g of potassium permanganate, controlling the temperature to be not more than 10 ℃, and continuously stirring for 2 hours after adding, wherein the edge part of the graphene is curled, and the stage is a low-temperature reaction stage. The mixture was heated to 35 ℃ ± 3 ℃ and reacted for 2 hours, and as the reaction proceeded, the mixture became viscous and brown in color, which was a low temperature reaction stage. After the medium-temperature reaction is finished, 138mL of deionized water is slowly added into a three-neck flask, the temperature is greatly increased at the moment, the graphite oxide layer is separated into a single layer under the action of thermal tension, the dissociated sheet layer is repolymerized into a plurality of layers of carbon particles at high temperature, the GO yield is reduced, the temperature is required to be controlled to be not more than 60 ℃, a large number of bubbles are generated in the mixture along with the addition of distilled water, the color is deepened, the temperature is increased to 96+/-2 ℃ after the addition of the deionized water, the temperature is kept for 30min, and the stage is a high-temperature dehydration reaction stage. 420mL of deionized water and 7.5mL of hydrogen peroxide are added into the reaction system, and deionized water is added: the graphite is expanded. Hydrogen peroxide: excess potassium permanganate was removed, oxidation to 2-valent manganese ion was removed, the solution turned from brown to bright yellow, and the reacted mixture was allowed to stand overnight. Washing with 3% HCl solution to no SO 4 2- (with BaCl) 2 Solution detection), washing with distilled water to neutrality, pouring the washed colloid into a clean surface dish, drying at 55 ℃ for 48h, grinding, sealing and preserving to obtain graphene oxide, which is named GO.
Wherein, concentrated sulfuric acid: strong protonic acid enters between graphite layers; potassium permanganate: strong oxidant oxidation, enhancing the oxidizing property of concentrated sulfuric acid. The solubility of the obtained graphite oxide in water becomes large and the stability is increased.
2. Preparation of oriented graphene oxide-based porous photo-thermal material
Placing GO in deionized water, preparing into 8-12mg/mL dispersion by ultrasonic treatment, and mixing according to m GO :m PVA Polyvinyl alcohol (PVA, molecular weight 80000-120000, acting as a cross-linking agent) was weighed out in a mass ratio of =1:1, then dissolved in deionized water, and heated to 96 ℃ to completely dissolve the PVA. The polyvinyl alcohol solution was then cooled to room temperatureThe polyvinyl alcohol solution with the concentration of 8-12mg/mL is obtained. Adding GO dispersion to polyvinyl alcohol solution, wherein m GO :m PVA The solution was stirred rapidly to mix the GO dispersion and the polyvinyl alcohol solution uniformly and sonicated for 15min to remove bubbles. Then pouring the mixture into a glass bottle, slowly and vertically freezing in liquid nitrogen at a constant speed of 3-4mm/min, wherein the constant speed is for forming directional arrangement of holes, and the liquid nitrogen is used for forming freezing control holes which are directional arranged from bottom to top, so that the holes of the GO aerogel precursor are orderly and vertically arranged. After the solution is completely solidified, freeze-drying in a freeze dryer, such as freeze-drying at-48-52 ℃ for 3 days, taking out, standing at room temperature for 2min, and freeze-drying completely to obtain GO-1 precursor; ice crystals are formed in the material after freezing the liquid nitrogen, and freeze drying the material by a freeze dryer sublimates the ice crystals in the material, leaving pores in the material. Finally, the GO-1 precursor is heated to 200 ℃ for carbonization for 2 hours at a constant speed such as 2 ℃/min in a nitrogen atmosphere, and then cooled at a speed of 2 ℃/min, so as to obtain the oriented graphene oxide based porous photo-thermal material, which is named as GO-1. The GO-1 prepared was a directional porous black cylinder.
The carbonization of the GO-1 precursor in a nitrogen atmosphere is to darken the material and absorb light easily, and the graphitization degree is increased. The carbonization temperature is selected because the material is blackened to a large extent and has good light absorption properties.
The prepared oriented graphene oxide-based porous photo-thermal material is favorable for the transmission of water molecules, and the photo-thermal conversion efficiency of an interface evaporation system is improved.
The optimization process of the dosage ratio of polyvinyl alcohol and GO dispersion is as follows:
GO to PVA mass ratio 0.5: 1. 1:1. 1:1.5, according to the test result of a scanning electron microscope, the mass ratio of the two is 1:1, the pores of the resulting material are relatively dense.
3. Preparation of hydrophilic oleophobic graphene oxide based porous photo-thermal material
Immersing GO-1 into polydiallyl dimethyl ammonium chloride (PDDA, 1.0 mg/L) solution for 18-22min to make the surface positively charged,PDDA modified GO-1 is obtained. Then PDDA modified GO-1 is soaked in sodium alginate salt solution (0.4 wt%) for 2min, and then soaked in calcium chloride solution (0.1M) for 18-22min to obtain Ca 2+ Alginate hydrogel coating. Then, ca is added to 2 + Immersing the surface of the alginate hydrogel coating in PDDA solution (1.0 mg/L) for 2min, immersing in sodium perfluorooctanoate (PFO, 0.1M) solution for 18-22min, and drying at room temperature to obtain the hydrophilic oleophobic graphene oxide-based porous photo-thermal material named GO-2.
Wherein, PDDA: positively charging the GO-1 surface; sodium alginate and calcium chloride: the calcium ions are crosslinked with sodium alginate to form a hydrogel coating, so that the GO-1 material is hydrophilic; PFO: and (5) oleophobic modification.
Example 1 preparation of oriented graphene oxide-based porous photothermal Material
1. Preparation of graphene oxide by hummers method
(1) Preoxidation of graphite
7.5mL of concentrated sulfuric acid, 1.5g of potassium peroxodisulfate and 1.5g of phosphorus pentoxide were taken in a 50mL three-necked flask, heated to 90℃and stirred for 15min before cooling to 80 ℃. To this was slowly added 1.8g of graphite powder, kept at 80℃and stirred for 4.5h to give a black precipitate mixture. After the reaction, the mixture was cooled to room temperature, diluted with 300mL of deionized water, left to stand overnight, the treated graphite was washed to neutrality with distilled water, and dried at room temperature for 24 hours to obtain preoxidized graphite.
(2) Preparation of graphene oxide
19mL of concentrated sulfuric acid was measured and added to a 250mL three-necked flask, and the flask was cooled to about 0℃with an ice-water bath. Adding the graphite subjected to the pre-oxidation treatment in the step (1) under stirring, and rapidly stirring until the graphite powder is fully dissolved. Slowly adding 9.0g of potassium permanganate, controlling the temperature to be not more than 10 ℃, and continuously stirring for 2 hours after adding, wherein the edge part of the graphene is curled, and the stage is a low-temperature reaction stage. The mixture was heated to 35 ℃ and reacted for 2 hours, and as the reaction proceeded, the mixture became viscous and brown in color, which was a medium temperature reaction stage. After the medium-temperature reaction is finished, 138mL of deionized water is slowly added into a three-neck flask, and the temperature is greatly increased at the moment due to the oxidized stoneThe ink layer is separated into a single layer under the action of thermal tension, the dissociated sheet layer is polymerized into a plurality of layers of carbon particles at high temperature, the GO yield is reduced, so that the temperature is required to be controlled to be not higher than 60 ℃, a large number of bubbles can be generated in the mixture along with the addition of distilled water, the color is deepened, the temperature is increased to 96+/-2 ℃ after the addition of deionized water, and the temperature is kept for 30min, and the stage is a high-temperature dehydration reaction stage. 420mL of deionized water and 7.5mL of hydrogen peroxide were added to the reaction system, the solution turned from brown to bright yellow, and the reacted mixture was allowed to stand overnight. Washing with 3% HCl solution to no SO 4 2- (with BaCl) 2 Solution detection), washing with distilled water to neutrality, pouring the washed colloid into a clean surface dish, drying at 55 ℃ for 48h, grinding, sealing and preserving to obtain graphene oxide, which is named GO.
2. Preparation of oriented graphene oxide-based porous photo-thermal material (GO-1)
GO is placed in deionized water, and is prepared into a dispersion with the concentration of 10mg/mL by ultrasonic treatment according to m GO :m PVA Polyvinyl alcohol (PVA, molecular weight 100000, acting as a cross-linking agent) was weighed in a mass ratio of 1:1, then dissolved in deionized water and heated to 96 ℃ to completely dissolve the PVA. The polyvinyl alcohol solution was then cooled to room temperature to give a polyvinyl alcohol solution having a concentration of 10 mg/mL. Adding the GO dispersion with the same volume into the polyvinyl alcohol solution, rapidly stirring the solution, uniformly mixing the GO dispersion and the polyvinyl alcohol solution, and removing bubbles in ultrasonic for 15 min. Then pouring the mixture into a glass bottle, slowly putting the glass bottle into liquid nitrogen at a speed of 4mm/min for freezing, and forming freezing control holes which are arranged in a direction from bottom to top through the liquid nitrogen so that the pores of the GO aerogel precursor are orderly and vertically arranged. And after the solution is completely solidified, freeze-drying the solution in a freeze dryer at the temperature of minus 50 ℃ for 3 days, taking out the solution, standing the solution at room temperature for 2 minutes, and obtaining the GO-1 precursor after no water drops appear. Finally, the GO-1 precursor is heated to 200 ℃ at a speed of 2 ℃/min in nitrogen atmosphere for carbonization for 2 hours, and then cooled at a speed of 2 ℃/min, so that the oriented graphene oxide-based porous photo-thermal material is obtained and named as GO-1.
The prepared GO-1 is an oriented porous black cylinder, and has the height of 1cm and the diameter of 2.3cm.
In FIG. 2, a, d is an optical photograph of GO-1, and b, c, e, f are scanning electron microscopes of GO-1 and GO-2.
As shown in FIG. 2b, which is a scanning electron microscope image of a cross section of GO-1, it can be seen that GO-1 has a dense pore structure of uniform size and shape.
As shown in FIGS. 2e-f, scanning electron microscopy of a longitudinal section of GO-1, the oriented ordered pores can be seen. The structure is more favorable for the transmission of water molecules and improves the photo-thermal conversion efficiency of the interface evaporation system.
The pore size of GO-1 and the pore size distribution of mesopores and macropores were tested using Mercury Intrusion (MIP), the specific test method being: the point measurement was performed using an Autopore9520 high performance fully automatic mercury porosimeter, a company of America microphone, computer program controlled. Cleavage of several 1cm from different regions on GO-1 3 The cut pieces were placed in a vacuum oven and heated to 110 c for 4 hours. Then it is placed in a clean, dry volume of 1cm 3 And (3) carrying out the test by vacuumizing in the sample dilatometer. The test results are shown in FIG. 3.
In FIG. 3, a is the mercury/extrusion plot for GO-1 and b is the large pore diameter distribution plot for GO-1.
As shown in FIGS. 3a-b, the pore size of GO-1 and the pore size distribution of mesopores and macropores were tested using mercury intrusion Method (MIP), and when the pore size was around 300nm, the mercury intrusion volume was smoothed, the porosity was 84.2%, and the average pore size was 338.5nm, indicating that GO-1 consisted mainly of macropores.
Example 2 preparation of hydrophilic oleophobic graphene oxide based porous photothermal Material
(1) Preparation of oriented graphene oxide-based porous photo-thermal material (GO-1): as in example 1.
(2) Immersing GO-1 in polydiallyl dimethyl ammonium chloride (PDDA, 1.0 mg/L) solution for 20min to make the surface positively charged, immersing PDDA modified GO-1 in sodium alginate salt solution (0.4 wt%) for 2min, immersing in calcium chloride solution (0.1M) for 20min to obtain Ca 2+ Alginate hydrogel coating. Finally, ca is 2+ The surface covered by alginate hydrogel is immersed in PDDA solution (1.0 mg/L) for 2min, then immersed in sodium perfluorooctanoate (PFO, 0.1M) solution for 20min, and dried at room temperature to obtain the hydrophilic oleophobic graphene oxide based porous photo-thermal material, which is named as GO-2.
As shown in FIG. 2c, which is a scanning electron micrograph of a GO-2 cross section, the pore structure becomes more dense than that of GO-1.
The wettability of GO-1 and GO-2 in pure water and oleophobicity in n-hexadecane containing red oil-O dye were tested as follows:
two toilet papers were placed on dried GO-1 and GO-2, respectively, and then put into pure water to test wettability, and the two toilet papers were completely penetrated at 28s and 180s, respectively. And respectively placing the two pieces of toilet paper on the dried GO-1 and GO-2, integrally placing the two pieces of toilet paper into n-hexadecane containing the red oil-O dye for oleophobic test, wherein the toilet paper on the GO-1 is completely infiltrated by the n-hexadecane within 58 seconds, and the GO-2 can float on the liquid due to oleophobicity, and can still be kept dry after 5 minutes.
FIG. 4 shows the wettability and contact angle of GO-1, GO-2 in pure water and the oleophobicity and contact angle in n-hexadecane containing red oil-O dye.
As shown in fig. 4 a, the contact angle of GO-1 prepared in example 1 with pure water was 0 °. As shown in FIG. 4 b, the GO-2 prepared in example 2 has a contact angle of less than 30 DEG with pure water, and this result is because the GOP-2 has a PFO-containing hydrogel coating attached to its surface, which has reduced hydrophilicity and thus has a slightly longer soaking time. As shown in fig. 4 c, the contact angle of GO-1 prepared in example 1 with n-hexadecane of the red oil-O-containing dye is 0 °, and as shown in fig. 4 d, the contact angle of GO-2 prepared in example 2 with n-hexadecane of the red oil-O-containing dye is 105 °, greater than 90 °, indicating that: the oleophobic modified GO-2 exhibits excellent oil resistance.
Example 3 the graphene oxide-based porous photothermal material of the invention, which can efficiently generate solar steam and has aligned channels and oleophobic properties, was applied to simulate sea water desalination and (oil-containing, dye-containing) wastewater purification treatments.
1. The GO-1 prepared in example 1 and the GO-2 prepared in example 2 were placed in different environments (pure water,20% NaCl and 10% hexadecane oily water) in 1 sun (1 kW/m) 2 ) The irradiation was performed for 5 minutes, 30 minutes and 60 minutes, respectively. The evaporation performance of the solar heat collector is tested by using a laboratory simulated solar test device system. The system is characterized in that the mass change of water in the system is monitored in real time through an electronic analytical balance, and the temperature change of the top of the material is monitored by utilizing an infrared photography technology. The evaporation rate and evaporation efficiency of the GO-SSG can be obtained according to the slope of the mass-versus-time curve. And GO-1 was subjected to 10 evaporation efficiency tests in one sun.
In FIG. 5, a is a graph of the mass change over time of GO-1 in pure water, GO-2 in 20% sodium chloride, GO-2 in 10% n-hexadecane oily water, GO-1 in 10% n-hexadecane oily water under one solar, pure water without photo-thermal material, b is the evaporation rate (#) and evaporation efficiency (#) of GO-1 in 10% n-hexadecane oily water, GO-1 in 20% sodium chloride, GO-2 in 10% n-hexadecane oily water under 1 solar, pure water without photo-thermal material.
As shown in FIGS. 5 a-b, after 60 minutes of solar irradiation, the surface temperature of GO-1 in pure water was increased from 21.9℃to 45.1℃and the surface temperature of GO-2 in 20% sodium chloride solution was increased from 19.5℃to 40.5℃and the surface temperature of GO-2 in 10% n-hexadecane oily water was increased from 20.0℃to 40.2 ℃. The evaporation rate of GO-1 in pure water was 1.63kw/m 2 And/h, the evaporation efficiency is 92%; and the evaporation rate of pure water without photothermal material was 0.4114kW/m 2 And/h, evaporation efficiency is 8.197%. The value of the solar energy conversion device is far smaller than that of the GO-1 under the same illumination, which indicates that the directional arrangement channel of the GO-1 is beneficial to the transmission of water molecules and has high-efficiency solar energy conversion performance.
The evaporation rate of GO-2 in 10% of n-hexadecane oily water is 1.48kw/m 2 And/h, the evaporation efficiency is 84%. The evaporation rate of GO-1 in 10% of n-hexadecane oily water is 1.10kw/m 2 And/h, the evaporation efficiency is 55%, which indicates that GO-2 has excellent oleophobic performance and good evaporation efficiency in oily wastewater. The evaporation rate of GO-2 in 20% sodium chloride solution is 1.52kw/m2/h, the evaporation efficiency is 86%, which shows that GO-2 has good salt tolerance.
FIG. 6 shows the evaporation efficiency test of GO-1 for 10 cycles in pure water under 1 sun.
As shown in fig. 6, GO-1 was subjected to evaporation efficiency test of 10 cycles under 1 sun irradiation, with an average efficiency of 92%.
2. And (3) putting the GO-2 into simulated seawater, heating and evaporating, and collecting evaporated condensate for ion concentration testing. The ions existing in the simulated seawater and the initial concentration thereof are respectively Na + (10473.6mg/L),Mg 2+ (6723.2mg/L),Ca 2+ (396.4mg/L),K + (382.7mg/L)。
FIG. 7 is a graph showing the comparison of GO-2 evaporation to simulate seawater ion concentration.
As shown in FIG. 7, GO-2 is heated and evaporated in simulated seawater, and the condensate obtained by evaporation is collected for ion concentration test, wherein the ions and initial concentration thereof in simulated seawater are respectively Na + (10473.6mg/L),Mg 2+ (6723.2mg/L),Ca 2+ (396.4mg/L),K + (382.7 mg/L); the ions in the evaporated water and the concentration thereof are respectively Na + (25.199mg/L),Mg 2+ (6.814mg/L),Ca 2+ (1.462mg/L),K + (1.401 mg/L). The GO-2 has obvious filtration effect, and the concentration of each ion is lower than the value of membrane or distilled seawater desalination and far lower than the standard value of drinking water.
3. And (3) putting the GO-2 into a methylene blue aqueous solution, heating and evaporating, collecting evaporated condensed water, and detecting whether a high-intensity peak of the methylene blue exists or not by using an ultraviolet-visible spectrophotometer.
FIG. 8 is a graph showing the comparison of the ultraviolet absorption spectra of GO-2 vaporized methylene blue aqueous solutions.
As shown in FIG. 8, GO-2 was placed in an aqueous methylene blue solution, heated to evaporate, and the evaporated condensate was collected, so that the liquid was clearly seen to evaporate from blue and filter into a colorless transparent liquid, which was detected by an ultraviolet-visible spectrophotometer, the aqueous methylene blue solution measured a high intensity peak at 660nm, and the high intensity peak measured by evaporating water disappeared, demonstrating that GO-2 successfully filtered methylene blue, indicating that GO-2 can filter colored dye.
Finally, it should be noted that: the foregoing description is only a preferred embodiment of the present invention, and the present invention is not limited thereto, but it is to be understood that modifications and equivalents of some of the technical features described in the foregoing embodiments may be made by those skilled in the art, although the present invention has been described in detail with reference to the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. The preparation method of the graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam is characterized by comprising the following steps of: the method comprises the following steps:
s1, preparing graphene oxide by a hummers method;
s2, preparing a graphene oxide-based porous photo-thermal material in a directional arrangement mode: dispersing or dissolving graphene oxide and polyvinyl alcohol with deionized water respectively, uniformly mixing, wherein the mass ratio of the graphene oxide to the polyvinyl alcohol is 0.5-1.5:1, removing bubbles by adopting an ultrasonic method, slowly and vertically putting the mixture into liquid nitrogen at a constant speed for freezing at a speed of 3-5mm/min to obtain a solidified product, freeze-drying the solidified product in a freeze dryer to obtain a graphene oxide precursor, and heating the graphene oxide precursor to 200 ℃ in a nitrogen atmosphere for carbonization to obtain the oriented graphene oxide porous photo-thermal material named as GO-1;
s3, preparing a hydrophilic oleophobic graphene oxide based porous photo-thermal material: immersing GO-1 into polydiallyl dimethyl ammonium chloride solution to obtain PDDA modified GO-1; soaking PDDA modified GO-1 in sodium alginate salt solution and calcium chloride solution to obtain Ca 2+ Alginate hydrogel coating; then Ca is added 2+ And (3) immersing the surface of the alginate hydrogel coating into polydiallyl dimethyl ammonium chloride, immersing into sodium perfluoro octoate to perform oleophobic modification, taking out and drying to obtain the hydrophilic oleophobic graphene oxide-based porous photothermal material.
2. The method of manufacturing according to claim 1, characterized in that: in the step S2, the mass ratio of the graphene oxide to the polyvinyl alcohol is 1:1.
3. The method of manufacturing according to claim 1, characterized in that: in step S2, the freeze drying specifically includes: freeze-drying at-50℃for 3 days.
4. The method of manufacturing according to claim 1, characterized in that: in step S2, the carbonization specifically includes: the graphene oxide precursor was uniformly warmed to 200 ℃ and carbonized 2h, and then uniformly cooled.
5. The method of manufacturing according to claim 1, characterized in that: in step S2, the carbonization specifically includes: the graphene oxide precursor was carbonized 2h by uniformly heating to 200 ℃ at a rate of 2 ℃/min, and then cooled at a uniform rate of 2 ℃/min.
6. A graphene oxide-based porous photothermal material capable of efficiently generating solar steam, which is prepared by the method of any one of claims 1 to 5.
7. The application of the graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam in sea water desalination or purification treatment of oily dye-containing wastewater in claim 6.
8. The use according to claim 7, characterized in that: the graphene oxide-based porous photo-thermal material capable of efficiently generating solar steam is placed in seawater or oily dye-containing wastewater for sunlight irradiation.
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CN114479171B (en) * 2021-12-29 2023-02-28 东华大学 Porphyrin-based conjugated microporous polymer photothermal conversion sponge and preparation and application thereof
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109081331A (en) * 2018-10-17 2018-12-25 青岛科技大学 It is a kind of with the graphene-based aeroge of asymmetric wetability, preparation method and applications
CN110025985A (en) * 2019-04-25 2019-07-19 南昌航空大学 It is a kind of to prepare oil-water separation filter paper super hydrophilic oleophobic treatment agent and its application method
CN110090603A (en) * 2019-04-12 2019-08-06 湖北大学 A kind of MXene and graphene oxide composite aerogel and its preparation method and application
CN111423246A (en) * 2020-05-27 2020-07-17 山东科技大学 Preparation method of ecological porous concrete for oily sewage treatment

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2928500B1 (en) * 2012-12-04 2019-03-06 Phosphorex Inc. Microparticles and nanoparticles having negative surface charges
WO2017031403A1 (en) * 2015-08-20 2017-02-23 University Of Virginia Patent Foundation Method of forming graphene/metal-oxide hybrid reinforced composites and product thereof
US10576421B2 (en) * 2016-11-30 2020-03-03 Dalian University Of Technology Method of water purification using hydrophilic and compressible aerogel as draw agent in forward osmosis

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109081331A (en) * 2018-10-17 2018-12-25 青岛科技大学 It is a kind of with the graphene-based aeroge of asymmetric wetability, preparation method and applications
CN110090603A (en) * 2019-04-12 2019-08-06 湖北大学 A kind of MXene and graphene oxide composite aerogel and its preparation method and application
CN110025985A (en) * 2019-04-25 2019-07-19 南昌航空大学 It is a kind of to prepare oil-water separation filter paper super hydrophilic oleophobic treatment agent and its application method
CN111423246A (en) * 2020-05-27 2020-07-17 山东科技大学 Preparation method of ecological porous concrete for oily sewage treatment

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Lihua Chen et al.Superhydrophilic and oleophobic porous architectures based on basalt fibers as oil-repellent photothermal materials for solar steam generation.《CHEMSUSCHEM》.2019,第13卷(第3期),第493、496、498页. *
李坚 ; 张明 ; 强添刚 ; .特殊润湿性油水分离材料的研究进展.《森林与环境学报》.2016,(第03期),第257-265页. *
超亲水超疏油聚合物膜处理含油废水的研究进展;沈舒苏;张干伟;杨晶晶;周晓吉;白仁碧;;《功能材料》(第04期);第4018-4024+4032 *

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