A preparation method of a ceramic-based double-sided evaporation desalination and power generation device based on a sandwich structure

Abstract

The application relates to a preparation method of a ceramic-based double-sided evaporation desalination and power generation device based on a sandwich structure, and relates to a double-sided evaporation desalination and power generation device preparation method. The application aims to solve the problem that the device or material used in the existing seawater desalination technology absorbs sunlight on one side, causing heat energy waste and reducing evaporation efficiency. The method comprises the following steps: 1, preparing a spinning solution; 2, electrospinning; 3, preparing an electrospinning porous ceramic film; 4, taking an ePTFE film as a sandwich layer, placing the ePTFE film between a graphene film with glue and the electrospinning porous ceramic film, and bonding the graphene film and the electrospinning porous ceramic film together by using the glue on the graphene film. Most of the existing offshore applications are independent, namely, seawater desalination and offshore power generation, and the application can ingeniously combine the two together, more fully utilize solar energy, and has good interface solar steam desalination compared with a traditional solar evaporation device.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a device for double-side evaporation desalination and driving power generation. BACKGROUND

[0002] Fresh water resource shortage is a big problem faced by human beings, and how to obtain drinking water at low cost and ingeniously is very urgent, in order to solve the problem, people have explored various technologies, and existing seawater desalination processes are divided into two types, namely thermal desalination and membrane technology, thermal desalination is divided into multi-stage flash evaporation and multi-effect distillation, and thermal desalination is the most widely used, thermal desalination is to evaporate contaminated water sources by heating, and the efficiency is very low, and even the cost is not worth the loss. With the addition of membrane technology seawater desalination, special membranes are made, pressure is applied to seawater, water passes through, and salt is left on the membrane surface, so that fresh water resources are obtained, and the pressure needs to be realized by a water pump, so that a large amount of electric energy is consumed, therefore, as the most abundant renewable energy in nature, solar energy is greater than the total of all non-renewable energies on the earth's surface every year, and as a clean energy, the solar energy has no harm to the environment, and the current seawater desalination technology generally absorbs sunlight on a single side, but the existing seawater desalination device does not leave the surface of bulk water, which causes a certain degree of heat energy waste, thereby reducing the evaporation efficiency. SUMMARY

[0003] The application aims to solve the problems that the device or material used in the existing seawater desalination technology absorbs sunlight on a single side, causes heat energy waste, and reduces the evaporation efficiency, and provides a preparation method of a ceramic-based double-side evaporation desalination and driving power generation device based on a sandwich structure.

[0004] A preparation method of a ceramic-based double-side evaporation desalination and driving power generation device based on a sandwich structure, and the method is completed according to the following steps:

[0005] I. Preparation of spinning solution

[0006] ①, polyvinyl butyral is dissolved in anhydrous ethanol to obtain a PVB solution;

[0007] ②, Al (NO3) 3 is added to deionized water, and stirring is carried out under water bath heating to obtain an Al (NO3) 3 solution;

[0008] ③, the PVB solution and the Al (NO3) 3 solution are mixed to obtain a spinning solution;

[0009] II. Electrospinning

[0010] The spinning solution is electrospun to obtain an electrospun film;

[0011] III. Preparation of electrospun porous ceramic film

[0012] ①, the electrostatic spinning film is pre-oxidized under the condition of air atmosphere and 190℃-210℃, and a pre-oxidized electrostatic spinning film is obtained;

[0013] ②, the pre-oxidized electrostatic spinning film is carbonized under the protection of inert atmosphere, and a electrostatic spinning porous ceramic film is obtained;

[0014] Four, the ePTFE film is used as a sandwich layer, which is arranged between the graphene film with glue and the electrostatic spinning porous ceramic film, the graphene film and the electrostatic spinning porous ceramic film are bonded together by the glue on the graphene film, and a ceramic-based double-layer water evaporator device with a Janus model is obtained, that is, a ceramic-based double-side evaporation desalination and power generation driving device based on a sandwich structure.

[0015] The use method of the ceramic-based double-side evaporation desalination and power generation driving device based on a sandwich structure is as follows:

[0016] The ceramic-based double-side evaporation desalination and power generation driving device based on a sandwich structure is placed obliquely, the bottom of the ceramic-based double-side evaporation desalination and power generation driving device based on a sandwich structure is immersed in seawater, the seawater is lifted in the device through the hydrophilic ability of the ePTFE film, and the seawater is evaporated at a high speed through the heat absorption ability of the graphene film and the electrostatic spinning porous ceramic film.

[0017] The distance that the bottom of the ceramic-based double-side evaporation desalination and power generation driving device based on a sandwich structure is immersed in seawater is 0.5 cm.

[0018] The use method of the ceramic-based double-side evaporation desalination and power generation driving device based on a sandwich structure is as follows:

[0019] The upper and lower parts of the ceramic-based double-side evaporation desalination and power generation driving device based on a sandwich structure are respectively clamped with copper electrodes, the lower copper electrode is immersed in seawater, the upper copper electrode is exposed to air, the seawater is absorbed by the ePTFE film, the seawater is lifted with a certain salt gradient change, so that a voltage is generated, power generation is carried out, and the seawater is evaporated at a high speed through the heat absorption ability of the graphene film and the electrostatic spinning porous ceramic film.

[0020] The distance that the lower copper electrode is immersed in seawater is 0.2 cm-0.3 cm.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] I, the present application utilizes electrospinning technology, through pre-oxidation, carbonization, to obtain carbon / ceramic composite porous material (electrospinning porous ceramic film), improve the light absorption of the membrane, and fix or wrap the carbonized PVB in the dense ceramic fiber, so as to prevent the loss of ceramic nanoparticles, and the carbon material has strong light absorption capacity, which can convert light energy into heat through lattice vibration and provide small energy to the outside, and the large number of electrons in the carbon material can be excited from P orbit to P* orbit, thereby enhancing the light absorption performance;

[0023] II, the electrospinning porous ceramic film prepared by combining carbon and ceramic in the present application enhances the mechanical strength and better faces the complex sea environment;

[0024] III, due to the hydrophobicity of carbon material and the hydrophilicity of sandwich ePTFE membrane, the Janus structure is formed, so that the water climbing effect in the hydrophilic membrane is good, so that the water transmission speed and the water evaporation speed can be ensured, and the salt resistance of the device can be improved;

[0025] IV, the existing evaporator is a single-sided light absorption device, while the device prepared by the present application is a double-sided light absorption water evaporator, which further improves the light absorption rate, and the device composite graphene film receives sunlight at a certain angle, away from the bulk water surface, which can realize double-sided light absorption and avoid heat energy waste, and can also achieve higher absorption by optimizing the angle;

[0026] V, most of the existing marine applications are independent, which are seawater desalination and marine power generation, while the present application can combine the two together, and make full use of clean energy solar energy;

[0027] VI, the device based on the sandwich structure of the present application is used to solve the problem of lack of fresh water resources, and utilizes the salt difference to generate electricity, and the bottom is immersed in water during work, and shows good stability, compared with the traditional solar evaporation device, the device has good interface solar steam desalination, and the evaporation efficiency under one sun can reach 14.07kg m -2 h -1 ;

[0028] VII, on the basis of utilizing clean energy, the device not only leaves the bulk water surface during work, but also utilizes the change of the salt gradient of seawater to generate electric energy, so as to make full use of solar energy, and has high performance in seawater desalination and wastewater treatment, which can reach the standard of drinking water, and provides a thought and method for solving the problem of water resource shortage. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1Preparation flowchart of the sandwich structure based ceramic dual-side evaporation desalination and power generation device prepared in Example 1;

[0030] Figure 2 SEM image of the electrospun porous ceramic film prepared in step three ② of Example 1;

[0031] Figure 3 Contact angle test image of the sandwich structure based ceramic dual-side evaporation desalination and power generation device prepared in step four of Example 1;

[0032] Figure 4 Infrared image of the sandwich structure based ceramic dual-side evaporation desalination and power generation device prepared in step four of Example 1 under one sunlight. DETAILED DESCRIPTION

[0033] Detailed implementation one: a preparation method of a sandwich structure based ceramic dual-side evaporation desalination and power generation device, which is specifically completed according to the following steps:

[0034] I. Preparation of the spinning solution:

[0035] ①, dissolve polyvinyl butyral in anhydrous ethanol to obtain a PVB solution;

[0036] ②, add Al(NO3)3 to deionized water, and then stir under water bath heating to obtain an Al(NO3)3 solution;

[0037] ③, mix the PVB solution with the Al(NO3)3 solution to obtain a spinning solution;

[0038] II. Electrospinning:

[0039] Electrospinning is performed on the spinning solution to obtain an electrospun film;

[0040] III. Preparation of the electrospun porous ceramic film:

[0041] ①, pre-oxidize the electrospun film in an air atmosphere at 190℃-210℃ to obtain a pre-oxidized electrospun film;

[0042] ②, carbonize the pre-oxidized electrospun film under the protection of an inert atmosphere to obtain an electrospun porous ceramic film;

[0043] IV. Take the ePTFE film as the interlayer, place it between the graphene film with glue and the electrospun porous ceramic film, and use the glue on the graphene film to bond the graphene film and the electrospun porous ceramic film together to obtain a ceramic-based double-layer water evaporator device with a Janus model, i.e., a sandwich structure based ceramic dual-side evaporation desalination and power generation device.

[0044] Specific embodiment two: the difference between this embodiment and specific embodiment one is that the mass fraction of the PVB solution in step one ① is 10% to 12%. The other steps are the same as specific embodiment one.

[0045] Specific embodiment three: the difference between this embodiment and one of specific embodiment one or two is that in step one ②, Al(NO3)3 is added to deionized water, and then stirred under water bath heating at 40℃ to 50℃ for 1h to 3h to obtain an Al(NO3)3 solution; the mass fraction of the Al(NO3)3 solution in step one ② is 35% to 45%. The other steps are the same as specific embodiment one or two.

[0046] Specific embodiment four: the difference between this embodiment and one of specific embodiment one to three is that the volume ratio of the PVB solution to the Al(NO3)3 solution in step one ③ is 2:1. The other steps are the same as specific embodiment one to three.

[0047] Specific embodiment five: the difference between this embodiment and one of specific embodiment one to four is that the process parameters of electrospinning in step two are as follows: the applied voltage is 18kv, the distance between the needle and the receiver is 10cm, the advancing speed of the needle is 1mL / h, the type of electrospinning is 20G, the collector in electrospinning is a rotating shaft type collector, the rotating speed of the collector is 50rpm, and the working time of electrospinning is 6h to 12h. The other steps are the same as specific embodiment one to four.

[0048] Specific embodiment six: the difference between this embodiment and one of specific embodiment one to five is that the pre-oxidation time in step three ① is 2h to 3h. The other steps are the same as specific embodiment one to five.

[0049] Specific embodiment seven: the difference between this embodiment and one of specific embodiment one to six is that the carbonization temperature in step three ② is 900℃, and the carbonization time is 2h. The other steps are the same as specific embodiment one to six.

[0050] Specific embodiment eight: the difference between this embodiment and one of specific embodiment one to seven is that the thickness of the ePTFE film in step four is 0.25mm; the thickness of the graphene film with adhesive in step four is 0.3mm; the thickness of the electrospun porous ceramic film in step four is 0.2mm to 0.4mm. The other steps are the same as specific embodiment one to seven.

[0051] Specific embodiment nine: the use method of the ceramic-based double-sided evaporation desalination and power generation device based on the sandwich structure is as follows:

[0052] The sandwich structure-based ceramic-based double-side evaporation desalination and power generation device is placed obliquely, the bottom of the sandwich structure-based ceramic-based double-side evaporation desalination and power generation device is immersed in seawater, seawater rises in the device through the hydrophilic ability of the ePTFE film, and seawater is evaporated at high speed through the heat absorption ability of the graphene film and the electrospun porous ceramic film.

[0053] The distance of the bottom of the sandwich structure-based ceramic-based double-side evaporation desalination and power generation device immersed in seawater is 0.5 cm.

[0054] Specific embodiment ten: the use method of the sandwich structure-based ceramic-based double-side evaporation desalination and power generation device is as follows:

[0055] The upper and lower parts of the sandwich structure-based ceramic-based double-side evaporation desalination and power generation device are respectively clamped with copper electrodes, the lower copper electrode is immersed in seawater, the upper copper electrode is exposed to air, seawater is absorbed by the ePTFE film, the rising of seawater has a certain salt gradient change, thereby generating voltage, and power generation is carried out, and seawater is evaporated at high speed through the heat absorption ability of the graphene film and the electrospun porous ceramic film.

[0056] The distance of the lower copper electrode immersed in seawater is 0.2 cm to 0.3 cm.

[0057] The beneficial effects of the present application are verified by the following examples:

[0058] Example 1: A preparation method of a sandwich structure-based ceramic-based double-side evaporation desalination and power generation device, specifically completed according to the following steps:

[0059] I. Preparation of spinning solution:

[0060] ①, polyvinyl butyral is dissolved in anhydrous ethanol to obtain solution I;

[0061] The mass fraction of solution I in step one ① is 11%;

[0062] ②, Al(NO3)3 is added to deionized water, stirred under water bath heating at 40℃ for 2h to obtain an Al(NO3)3 solution;

[0063] The mass fraction of the Al(NO3)3 solution in step one ② is 40%;

[0064] ③, solution I and the Al(NO3)3 solution are mixed to obtain a spinning solution;

[0065] The volume ratio of solution I to the Al(NO3)3 solution in step one ③ is 2:1;

[0066] II. Electrospinning:

[0067] Electrospinning the spinning solution to obtain an electrospun film;

[0068] The process parameters of electrospinning in step two are as follows: the applied voltage is 18kv, the distance between the needle and the receiver is 10cm, the advancing speed of the needle is 1mL / h, the type of electrospinning is 20G, the rotating speed of the rotating collector in the electrospinning is 50rpm, and the working time of electrospinning is 9h;

[0069] III. Preparation of electrospun porous ceramic film:

[0070] ①. Pre-oxidizing the electrospun film under the condition of air atmosphere and 200℃ for 2h to obtain a pre-oxidized electrospun film;

[0071] ②. Carbonizing the pre-oxidized electrospun film under the protection of inert atmosphere to obtain an electrospun porous ceramic film;

[0072] The carbonization temperature in step three ② is 900℃, and the carbonization time is 2h;

[0073] IV. Placing the ePTFE film as a sandwich between the graphene film with adhesive and the electrospun porous ceramic film, and using the adhesive on the graphene film to bond the graphene film and the electrospun porous ceramic film together to obtain a ceramic-based double-layer water evaporator device with Janus model, i.e. a ceramic-based double-sided evaporation desalination and power generation device based on sandwich structure;

[0074] The thickness of the ePTFE film in step four is 0.25mm, which is purchased from Guangzhou Polyfluorine New Material Technology Co., Ltd.;

[0075] The thickness of the graphene film with adhesive in step four is 0.3mm, which is purchased from Dongguan Junfa Electronic Material Co., Ltd.;

[0076] The thickness of the electrospun porous ceramic film in step four is 0.2-0.4mm.

[0077] Example 2: The difference between this example and Example 1 is that the working time of electrospinning in step two is 6h. The other steps and parameters are the same as those in Example 1.

[0078] Example 3: The difference between this example and Example 1 is that the working time of electrospinning in step two is 12h. The other steps and parameters are the same as those in Example 1.

[0079] Application Example 1:

[0080] The use method of a sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device prepared in Example 1 is as follows:

[0081] The sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device is placed obliquely, the bottom of the sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device is immersed in seawater, the seawater rises in the device through the hydrophilic ability of the ePTFE film, and then the seawater is evaporated at high speed through the heat absorption ability of the graphene film and the electrospun porous ceramic film.

[0082] The distance of the bottom of the sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device immersed in seawater is 0.5 cm.

[0083] Application Example 2:

[0084] The use method of a sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device prepared in Example 2 is as follows:

[0085] The sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device is placed obliquely, the bottom of the sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device is immersed in seawater, the seawater rises in the device through the hydrophilic ability of the ePTFE film, and then the seawater is evaporated at high speed through the heat absorption ability of the graphene film and the electrospun porous ceramic film.

[0086] The distance of the bottom of the sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device immersed in seawater is 0.5 cm.

[0087] Application Example 3:

[0088] The use method of a sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device prepared in Example 3 is as follows:

[0089] The sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device is placed obliquely, the bottom of the sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device is immersed in seawater, the seawater rises in the device through the hydrophilic ability of the ePTFE film, and then the seawater is evaporated at high speed through the heat absorption ability of the graphene film and the electrospun porous ceramic film.

[0090] The distance of the bottom of the sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device immersed in seawater is 0.5 cm.

[0091] The evaporation efficiency of the sandwich structure based ceramic based double-sided evaporation desalination and power generation driving device prepared in Example 1 under one sun can reach 14.07 kg m -2 h-1 .

[0092] The device prepared in Example 2, based on a sandwich structure and using a ceramic matrix for double-sided evaporation desalination and power generation, achieved an evaporation efficiency of 12.36 kg m³ under one sun. -2 h -1 .

[0093] The device prepared in Example 3, based on a sandwich structure and using a ceramic matrix for double-sided evaporation desalination and power generation, achieved an evaporation efficiency of 13.67 g / m² under one sun. -2 h -1 .

[0094] Figure 2 The image shows the SEM image of the electrospun porous ceramic film prepared in step 3② of Example 1.

[0095] from Figure 2 It can be seen that the formed porous structure is conducive to water evaporation. Due to the formation of the porous structure, the specific surface area of ​​the device is increased, the light absorption area of ​​the device is expanded, and the photothermal conversion efficiency is improved.

[0096] Figure 3 The contact angle test diagram is shown for the sandwich-structured ceramic-based double-sided evaporation desalination and power generation device prepared in step four of Example 1.

[0097] from Figure 3 It is known that the superhydrophobicity of the electrospun porous ceramic film and the hydrophilicity of the ePTFE hydrophilic film will form a Janus structure, which increases the salt resistance of the device and allows it to be repeatedly recycled.

[0098] Figure 4 The infrared image of the sandwich-structured ceramic-based double-sided evaporation desalination and power generation device prepared in step four of Example 1 under sunlight;

[0099] from Figure 4 It can be seen that: by using an infrared thermal imager to study the surface temperature of the device under sunlight intensity, the temperature rises to 38.8℃ after 1 minute of illumination, and it can be seen that the highest surface temperature is around 45℃. After 30 minutes, the temperature is maintained at 44℃, indicating that the evaporator heats up rapidly and has strong heat preservation ability.

Claims

1. A method for fabricating a ceramic-based double-sided evaporation desalination and power generation device based on a sandwich structure, characterized in that... The preparation method is specifically carried out according to the following steps: I. Preparation of spinning solution: ① Dissolve polyvinyl butyral in anhydrous ethanol to obtain a PVB solution; ② Add Al(NO3)3 to deionized water, and then stir while heating in a water bath to obtain an Al(NO3)3 solution; ③ Mix the PVB solution with the Al(NO3)3 solution to obtain the spinning solution; II. Electrospinning: Electrospinning was performed on the spinning solution to obtain an electrospun film; III. Preparation of electrospun porous ceramic thin films: ① The electrospun film is pre-oxidized in air atmosphere and at 190℃~210℃ to obtain the pre-oxidized electrospun film. ② The pre-oxidized electrospun film is carbonized under an inert atmosphere to obtain an electrospun porous ceramic film. Fourth, using an ePTFE membrane as a sandwich layer, it is placed between an adhesive-coated graphene membrane and an electrospun porous ceramic membrane. The adhesive on the graphene membrane is used to bond the graphene membrane and the electrospun porous ceramic membrane together, resulting in a ceramic-based double-layer water evaporator device with a Janus model. This device is a ceramic-based double-sided evaporation desalination and power generation device based on a sandwich structure.

2. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... The mass fraction of the PVB solution mentioned in step 1① is 10% to 12%.

3. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... In step 1②, Al(NO3)3 is added to deionized water, and then stirred for 1 to 3 hours under water bath heating at 40℃~50℃ to obtain an Al(NO3)3 solution; the mass fraction of the Al(NO3)3 solution in step 1② is 35%~45%.

4. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... The volume ratio of the PVB solution to the Al(NO3)3 solution mentioned in step 1③ is 2:

1.

5. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... The electrospinning process parameters described in step two are as follows: the applied voltage is 18kV, the distance between the needle and the receiver is 10cm, the needle advance speed is 1mL / h, the electrospinning type is 20G, the collector in the electrospinning is a rotating shaft collector with a rotation speed of 50rpm, and the working time of electrospinning is 6h to 12h.

6. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... The pre-oxidation time mentioned in step 3① is 2h to 3h.

7. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... The carbonization temperature described in step 3② is 900℃, and the carbonization time is 2 hours.

8. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... The thickness of the ePTFE membrane mentioned in step four is 0.25 mm; the thickness of the graphene membrane with adhesive mentioned in step four is 0.3 mm; and the thickness of the electrospun porous ceramic film mentioned in step four is 0.2 mm to 0.4 mm.

9. The method for fabricating a ceramic-based double-sided evaporation desalination and power generation device based on a sandwich structure according to claim 1, wherein the method of using the ceramic-based double-sided evaporation desalination and power generation device based on a sandwich structure is as follows: The device, which uses a sandwich structure-based ceramic double-sided evaporation desalination and power generation, is placed at an angle. The bottom of the device is immersed in seawater. The seawater rises in the device through the hydrophilicity of the ePTFE membrane, and then evaporates rapidly through the heat absorption capacity of the graphene membrane and the electrospun porous ceramic film. The bottom of the device based on a sandwich structure and double-sided evaporation desalination and power generation is immersed in seawater at a distance of 0.5 cm.

10. The method for fabricating a device based on a sandwich structure for double-sided evaporation desalination and power generation on a ceramic substrate, as described in claim 1, is characterized in that... The method of using the aforementioned ceramic-based double-sided evaporation desalination and power generation device with a sandwich structure is as follows: The upper and lower parts of the device based on a sandwich structure ceramic double-sided evaporation desalination and power generation are sandwiched with copper electrodes. The lower copper electrode is immersed in seawater, while the upper copper electrode is exposed to air. The seawater is absorbed by the ePTFE membrane, and the rising seawater creates a certain salt gradient change, thereby generating voltage and generating electricity. The seawater is then rapidly evaporated through the heat absorption capacity of the graphene membrane and the electrospun porous ceramic film. The lower copper electrode is immersed in seawater at a distance of 0.2cm to 0.3cm.

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