A composite material and its preparation method and application

Abstract

The present application proposes a composite material and its preparation method and application, wherein the composite material includes a decontamination layer and a catalytic layer, the decontamination layer is an organic-inorganic composite film having both hydrophobicity and oleophobicity; the catalytic layer is arranged on the outer surface of the decontamination layer, and the catalytic layer is a hydrogel loaded with a catalyst. The composite material of the present application, the decontamination layer has strong hydrophobicity and anti-fouling ability, can prevent impurities in water from entering the catalytic layer, and only allows water vapor to pass; the catalytic layer also plays a role in promoting water vapor to re-form liquid water, promoting water to pass through and photocatalytic in-situ reaction, and the large-area carrier increases the catalytic active surface area, thereby improving the efficiency of solar hydrogen production.

Description

Technical Field

[0001] The present application relates to the field of hydrogen energy technology, and in particular to a composite material and a preparation method and application thereof. Background Art

[0002] As the proportion of new energy in the future energy system continues to increase, the impact of fluctuating new energy on the power system has become an important problem facing the new power system. Renewable hydrogen production technology is a good solution to achieve new energy storage and solve the volatility problem of renewable energy such as wind and light.

[0003] Photocatalytic water splitting technology uses photocatalysts to decompose water to produce hydrogen, which can realize the direct use of solar energy, eliminating the conversion of solar energy to electricity and then to hydrogen energy. It is a renewable energy hydrogen production route with good prospects. However, the water source used for solar hydrogen production is often experimental grade pure water. In actual scenarios, it is difficult to obtain pure water in the three northern regions with abundant solar energy. The raw water often has a high contamination rate. The use of purification equipment to treat raw water has the problems of high energy consumption and unstable treatment effect. Direct use of untreated raw water or even industrial and domestic sewage for solar hydrogen production faces the problems of poor catalyst stability, reduced efficiency, and increased side reactions such as organic matter decomposition. Summary of the invention

[0004] In view of this, one purpose of the present application is to provide a composite material, in which the decontamination layer has strong hydrophobicity and anti-fouling ability, can prevent impurities in the water from entering the catalytic layer, and only allow water vapor to pass through; the catalytic layer also promotes the water vapor to reform into liquid water, promotes the passage of water and the photocatalytic in-situ reaction, and the large-area carrier increases the catalytic active surface area, thereby improving the efficiency of solar hydrogen production.

[0005] Another object of the present application is to provide a method for preparing a composite material.

[0006] Another object of the present application is to provide applications of the composite material.

[0007] Another object of the present application is to provide a device for producing hydrogen by photolysis of water.

[0008] Another object of the present application is to provide a method for producing hydrogen by photolysis of water.

[0009] To achieve the above-mentioned purpose, the composite material provided in the present application comprises:

[0010] A decontamination layer, wherein the decontamination layer is an organic-inorganic composite film having both hydrophobicity and oleophobicity;

[0011] The catalytic layer is arranged on the outer surface of the decontamination layer, and the catalytic layer is a hydrogel loaded with a catalyst.

[0012] Furthermore, in the organic-inorganic composite film, the inorganic substance is nanoparticles, and the organic substance is fluoride.

[0013] Furthermore, the nanoparticles include at least one of silicon dioxide, titanium dioxide, fluorinated silicon dioxide, and fluorinated titanium dioxide.

[0014] Furthermore, the fluoride includes at least one of perfluorooctyltrimethoxysilane, perfluorododecyltriethoxysilane, and a fluorocarbon surfactant.

[0015] Furthermore, the hydrogel is acrylamide hydrogel and / or sodium alginate hydrogel.

[0016] Furthermore, the porosity of the hydrogel is 80-90%, and the average pore size is 0.5-5 μm.

[0017] Furthermore, the catalyst includes at least one of metal oxides, metal sulfides, metal nitrides, metal oxysulfides, and metal oxynitrides; the metal includes d 10 Metal or 0 At least one of the metals.

[0018] Furthermore, the loading amount of the catalyst in the hydrogel is 3-10 wt %.

[0019] Furthermore, the decontamination layer has a first surface and a second surface which are arranged opposite to each other, the catalytic layer is arranged on the first surface, and the porous water-absorbing layer is arranged on the second surface.

[0020] Furthermore, the surface water contact angle and oil contact angle of the decontamination layer are both greater than 120°.

[0021] Furthermore, the decontamination layer has a thickness of 1-50 μm.

[0022] Furthermore, the porosity of the decontamination layer is 70-80%, and the average pore size is 0.2-1 μm.

[0023] Furthermore, the thickness of the catalytic layer is 0.1-0.5 mm.

[0024] Furthermore, the porous water-absorbing layer is a hydrophilic fiber.

[0025] Furthermore, the thickness of the porous water-absorbing layer is 1-5 mm.

[0026] The present application also relates to a method for preparing a composite material, comprising:

[0027] The decontamination layer was prepared by electrospinning;

[0028] The catalytic layer is synthesized on the surface of the decontamination layer by a brush coating method, and the catalyst is loaded in situ during the synthesis process.

[0029] The present application also relates to the application of the composite material of the present application in the field of photolysis of water to produce hydrogen.

[0030] Preferably, the water used for producing hydrogen by photolysis of water includes but is not limited to at least one of seawater and wastewater.

[0031] The present application also provides a photocatalytic water splitting hydrogen production device, comprising:

[0032] A cover plate, the cover plate is made of a transparent material and is provided with a first groove;

[0033] A base, wherein a second groove is provided on the base;

[0034] A functional material layer, wherein the functional material layer is arranged between the cover plate and the base, and the functional material layer and the first groove constitute a hydrogen collection space, and the functional material layer and the second groove constitute a water collection space, the functional material layer adopts the composite material of the present application, and the catalytic layer is adjacent to the cover plate.

[0035] Furthermore, a plurality of support members for supporting the functional material layer are provided in the hydrogen collection space, and the plurality of support members are arranged at intervals; one end of each of the plurality of support members is connected to the cover plate, and the other end is closely attached to the functional material layer;

[0036] Furthermore, the functional material layer and the cover plate, as well as the functional material layer and the base are sealed and connected.

[0037] Furthermore, the hydrogen collecting space and the water collecting space are arranged opposite to each other.

[0038] Furthermore, the depth of the first groove is 1-5 mm.

[0039] Furthermore, the light transmittance of the transparent material is above 80%.

[0040] Furthermore, the hydrogen collecting space is connected to at least one hydrogen collecting pipeline, and all of the hydrogen collecting pipelines are connected to the hydrogen storage tank.

[0041] Furthermore, a water inlet and a water outlet connected to the water collection space are provided on the base, and the water inlet is connected to a pressurized circulation pump, an ultrafiltration device and a water source in sequence at one end away from the water collection space.

[0042] Furthermore, the coverage rate of the plurality of support members on the cover plate is 10-30%.

[0043] Furthermore, a plurality of support members are evenly distributed in the hydrogen collecting space.

[0044] Furthermore, a plurality of support members are integrally formed with the cover plate.

[0045] The present application also provides a method for producing hydrogen by photolysis of water, comprising:

[0046] After the impurities are blocked by the functional material layer, the source water reforms into a liquid film in the form of water vapor and decomposes to generate hydrogen under the action of photocatalysis.

[0047] Furthermore, the flow rate of the source water is 0.005-0.015 m / s.

[0048] The composite material of the present application can at least bring the following beneficial effects:

[0049] 1. The decontamination layer has strong hydrophobicity and anti-fouling ability, which can prevent impurities in the water from entering the catalytic layer and only allow water vapor to pass through; the catalytic layer also promotes the re-formation of water vapor into liquid water, promotes the passage of water and the photocatalytic in-situ reaction. The large-area carrier increases the catalytic active surface area, thereby improving the efficiency of solar hydrogen production.

[0050] 2. The thickness of the catalytic layer and the decontamination layer has been carefully designed so that the catalytic layer can absorb the water vapor transmitted from the decontamination layer in time, thereby achieving efficient hydrogen production.

[0051] 3. It can block impurities in sewage through water absorption, spontaneous evaporation and condensation, avoid competition with hydrogen evolution photocatalytic reaction and corrosion of catalyst, which is beneficial to solve water use problems in sea areas and arid and water-scarce areas.

[0052] The photocatalytic water hydrogen production device and method of the present application not only has the beneficial effects of the photocatalytic water hydrogen production material of the present application, but also can bring at least the following beneficial effects:

[0053] 1. The main flat structure composed of the cover plate, functional material layer and base has a large effective exposed surface for hydrogen production by photolysis of water; the water vapor transmission path is short, and a faster lateral flushing speed can be achieved through a pressurized circulation pump, which reduces mass transfer resistance, produces hydrogen quickly and has a large output.

[0054] 2. The water permeability is controlled by adjusting the pressurized circulation pump, which can adapt to different hydrogen demands and achieve flexible regulation.

[0055] 3. By using the photolysis water hydrogen production device and method of the present application, condensed water is formed in situ after water vapor is transmitted and hydrogen is produced in situ through photocatalytic decomposition, eliminating the steps of water collection and transmission. The device is simple and has low energy consumption.

[0056] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0058] Figure 1 It is a schematic structural diagram of a composite material shown in an exemplary embodiment of the present application.

[0059] Figure 2 It is a schematic structural diagram of a composite material shown in another exemplary embodiment of the present application.

[0060] Figure 3 It is a schematic structural diagram of a photocatalytic water splitting hydrogen production device according to an exemplary embodiment of the present application.

[0061] Figure 4 for Figure 3 The schematic diagram of the photocatalytic hydrogen production device is shown.

[0062] Figure 5 This is a schematic diagram of the structure and principle of a photocatalytic water splitting hydrogen production device according to another exemplary embodiment of the present application.

[0063] Reference numerals:

[0064] 1-pollution removal layer; 2-catalytic layer; 3-cover plate; 301-first groove; 4-base; 401-second groove; 5-functional material layer; 6-hydrogen collection space; 7-water collection space; 8-support; 9-hydrogen collection pipeline; 10-pressurized circulation pump; 11-ultrafiltration device; 12-water source; 13-porous water absorption layer. DETAILED DESCRIPTION

[0065] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application.

[0066] Throughout the application, the disclosure of numerical ranges includes all values ​​within the entire range and disclosure of further subdivided ranges, including endpoints and subranges given within those ranges.

[0067] In the application, the raw materials, equipment, etc. involved, unless otherwise specified, are all raw materials and equipment that can be produced through commercial channels or known methods; the methods involved, unless otherwise specified, are all conventional methods.

[0068] A composite material, a device for producing hydrogen from water by photolysis, and a method for producing hydrogen from water by photolysis are described below with reference to the accompanying drawings.

[0069] Figure 1It is a schematic structural diagram of a composite material shown in an exemplary embodiment of the present application.

[0070] like Figure 1 As shown, the composite material of the present application includes a decontamination layer 1 and a catalytic layer 2.

[0071] The decontamination layer 1 is an organic-inorganic composite membrane having both hydrophobicity and oleophobicity. It has strong hydrophobicity and anti-fouling ability, can prevent impurities in water from entering the catalytic layer, and only allows water vapor to pass through.

[0072] The catalytic layer 2 is arranged on the outer surface of the decontamination layer 1. The catalytic layer 2 is a hydrogel loaded with a catalyst. The catalytic layer has a strong water vapor adsorption capacity. The adsorbed water vapor re-forms a liquid film on the surface of the catalytic layer and decomposes to generate hydrogen under the catalytic action.

[0073] In some implementations, when the water contains pollutants, salts, etc., Figure 2 As shown, the composite material also includes a porous water-absorbing layer 13. The porous water-absorbing layer forms the first barrier to pollutants and salts in the water, protecting the decontamination layer and the catalytic layer from being damaged by large particle pollutants and salt crystals. The porous water-absorbing layer 13 is arranged on the surface of the decontamination layer 1, and the porous water-absorbing layer 13, the decontamination layer 1 and the catalytic layer 2 are arranged in sequence. That is, the decontamination layer 1 has a first surface and a second surface arranged opposite to each other, the first surface is provided with the catalytic layer 2, and the second surface is provided with the porous water-absorbing layer 13. Here, the first surface includes but is not limited to the upper surface, and the second surface includes but is not limited to the lower surface.

[0074] It should be noted that when the composite material also includes a porous water-absorbing layer, the water vapor adsorbed by the catalytic layer re-forms a liquid film on the surface of the catalytic layer and decomposes to generate hydrogen under the catalytic action, thereby forming a water vapor concentration difference, promoting the formation of water vapor on the surface of the porous water-absorbing layer and transmitting it through the decontamination layer.

[0075] In some embodiments, the connection methods of the dirt removal layer 1 and the catalytic layer 2, and the dirt removal layer 1 and the porous water absorption layer 13 include but are not limited to overlapping, hot pressing, ultrasonic welding, etc.

[0076] In some embodiments, in the organic-inorganic composite film as a decontamination layer, the inorganic substance is nanoparticles, including but not limited to at least one of silicon dioxide, titanium dioxide, fluorinated silicon dioxide, fluorinated titanium dioxide, and the like.

[0077] In some embodiments, in the organic-inorganic composite film as the decontamination layer, the organic matter is a fluoride, including but not limited to at least one of perfluorooctyltrimethoxysilane (PFTMS), perfluorododecyltriethoxysilane (FAS), fluorocarbon surfactant (FS), etc. The organic matter is used as a modification component, and is grafted and loaded on the surface of the inorganic base film by a method such as dip coating to form a modification layer.

[0078] In some embodiments, the hydrogel includes, but is not limited to, at least one of acrylamide hydrogel, sodium alginate hydrogel, and the like.

[0079] In some embodiments, the porosity of the hydrogel is 80-90%, and the average pore size is 0.5-5 μm. As a non-limiting example, the porosity of the hydrogel includes but is not limited to 80%, 83%, 85%, 88% or 90%, and the average pore size of the hydrogel includes but is not limited to 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm or 5 μm. If the porosity and pore size of the hydrogel are too large, the strength of the hydrogel layer will be reduced, resulting in a reduced service life, and the catalyst loading under the same volume will be reduced, resulting in a decrease in hydrogen production. If the porosity and pore size are too small, the water permeability effect will be reduced.

[0080] In some embodiments, the catalyst includes but is not limited to at least one of metal oxides, metal sulfides, metal nitrides, metal oxysulfides, and metal oxynitrides; the metal includes but is not limited to d 10 Metal or 0 At least one of the metals. 10 The metal includes but is not limited to at least one of Ga, Ge, In, Sb, Sn, Cd, etc. 0 Metals include but are not limited to Mo, Nb, Ta, Ti, W, Zr 4 At least one of the above.

[0081] In some embodiments, the catalyst loading in the hydrogel is 3-10wt%, including but not limited to 3wt%, 4wt%, 5wt%, 6%, 7%, 8%, 9% or 10%, etc. Too much catalyst loading will make it difficult to evenly disperse the catalyst, reducing the unit utilization rate of the catalyst; too little catalyst loading will reduce the total amount of hydrogen production active sites and reduce the actual hydrogen production.

[0082] In some embodiments, the surface water contact angle and oil contact angle of the dirt removal layer 1 are both greater than 120°, including but not limited to 121°, 130°, 140°, 150°, 160° or 170°, etc.

[0083] In some embodiments, the porosity of the decontamination layer 1 is 70-80%, and the average pore size is 0.2-1 μm. As a non-limiting example, the porosity of the decontamination layer 1 includes but is not limited to 70%, 73%, 75%, 78% or 80%, and the average pore size of the decontamination layer 1 includes but is not limited to 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm or 1 μm. Too small a porosity and average pore size of the decontamination layer will result in a reduced water vapor passage rate, and too large a porosity and average pore size will result in a poor pollutant blocking effect.

[0084] In some embodiments, the porous water-absorbing layer 13 is a hydrophilic fiber, including but not limited to hydrophilic non-woven fabrics, viscose fibers, etc. The porous water-absorbing layer can form the first barrier to pollutants and salts in the water, protecting the decontamination layer and the photocatalytic layer from being damaged by large particle pollutants and salt crystals.

[0085] In some embodiments, the thickness of the decontamination layer 1 is 1-50 μm, including but not limited to 1 μm, 10 μm, 20 μm, 30 μm, 40 μm or 50 μm, etc. Too large a thickness of the decontamination layer will reduce the water vapor passing rate, while too small a thickness will deteriorate the pollutant blocking effect.

[0086] In some embodiments, the thickness of the catalytic layer 2 is 0.1-0.5 mm, including but not limited to 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm, etc. If the thickness of the catalytic layer is too large, the water passing rate will be reduced, and if it is too small, the strength of the hydrogel layer will be reduced, resulting in a reduced service life, and the catalyst loading under the same volume will be reduced, resulting in a decrease in hydrogen production.

[0087] In some embodiments, the porous water-absorbing layer 13 has a thickness of 1-5 mm, including but not limited to 1 mm, 2 mm, 3 mm, 4 mm or 5 mm.

[0088] The composite material of the present application can at least bring the following beneficial effects:

[0089] 1. The decontamination layer has strong hydrophobicity and anti-fouling ability, which can prevent impurities in the water from entering the catalytic layer and only allow water vapor to pass through; the catalytic layer also promotes the re-formation of water vapor into liquid water, promotes the passage of water and the photocatalytic in-situ reaction. The large-area carrier increases the catalytic active surface area, thereby improving the efficiency of solar hydrogen production.

[0090] 2. The thickness of the catalytic layer and the decontamination layer has been carefully designed so that the catalytic layer can absorb the water vapor transmitted from the decontamination layer in time, thereby achieving efficient hydrogen production.

[0091] 3. It can block impurities in sewage through water absorption, spontaneous evaporation and condensation, avoid competition with hydrogen evolution photocatalytic reaction and corrosion of catalyst, which is beneficial to solve water use problems in sea areas and arid and water-scarce areas.

[0092] The method for preparing the composite material of the embodiment of the present application comprises the following steps:

[0093] S1. Prepare the decontamination layer by electrospinning.

[0094] In some embodiments of the present application, the decontamination layer is prepared by an electrospinning method, comprising the following steps:

[0095] (1) adding nanoparticles to a crosslinking agent aqueous solution and stirring thoroughly to obtain a dispersion;

[0096] (2) adding H3PO4 to a TEOS aqueous solution under sufficient stirring to obtain a silica sol;

[0097] (3) mixing the dispersion obtained in step (1) with the silica sol obtained in step (2), and subjecting the mixture to electrospinning to form a film;

[0098] (4) The membrane obtained in step (3) is calcined to remove the cross-linking agent, and then immersed in an organic solution of fluoride, and then taken out and dried to obtain a decontamination membrane.

[0099] In some embodiments, in step (1), the crosslinking agent includes but is not limited to at least one of polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinyl acetate (PVAc), etc., and the content of the crosslinking agent in the crosslinking agent aqueous solution is 8-12wt%, preferably 10wt%.

[0100] In some embodiments, in step (1), the content of nanoparticles in the dispersion is 8-12 wt%, including but not limited to 8 wt%, 9 wt%, 10 wt%, 11 wt% or 12 wt%, etc.

[0101] In some embodiments, in step (2), the molar ratio of ethyl silicate (TEOS) to water in the ethyl silicate (TEOS) aqueous solution is 1:(9-13), including but not limited to 1:9, 1:10, 1:11, 1:12 or 1:13, etc.

[0102] In some embodiments, in step (2), H3PO4 is added to the TEOS aqueous solution dropwise.

[0103] In some embodiments, in step (2), H3PO4 is an H3PO4 aqueous solution with a H3PO4 mass fraction of 85%.

[0104] In some embodiments, in step (2), the molar ratio of H3PO4 to tetraethyl orthosilicate (TEOS) is 1:95-105, including but not limited to 1:95, 1:98, 1:100, 1:102 or 1:105, etc.

[0105] In some embodiments, in step (3), the mass ratio of the dispersion to the silica sol is (0.8-1.2):(0.8-1.2), including but not limited to 0.8:1.2, 0.8:1, 1:1, 1.2:0.8 or 1.2:1, etc.

[0106] In some embodiments, in step (4), the calcination temperature is 750-850°C, including but not limited to 750°C, 800°C or 950°C, etc.; the calcination time is 1.5-2.5h, including but not limited to 1.5h, 2h or 2.5h, etc.

[0107] In some embodiments, in step (4), the content of fluoride in the organic solution of fluoride is 1.5-4.5wt%, including but not limited to 1.5wt%, 2wt%, 3wt%, 4wt% or 4.5wt%, etc., and the organic solvent includes but is not limited to at least one of hexane, propane, toluene, etc.

[0108] In some embodiments, in step (4), the soaking time is 20-28 hours, including but not limited to 20 hours, 24 hours or 28 hours.

[0109] S2. The catalytic layer is synthesized on the surface of the decontamination layer by a brush coating method, and the catalyst is loaded in situ during the synthesis process.

[0110] In some embodiments, the catalytic layer is synthesized on the surface of the decontamination layer by a brush coating method and the catalyst is in situ loaded during the synthesis process, comprising the following steps:

[0111] 1) Dissolve sodium alginate in pure water to form solution A;

[0112] 2) dissolving polyacrylate in pure water to form solution B;

[0113] 3) Solution A and solution B are thoroughly mixed to form solution C;

[0114] 4) adding methylenebisacrylamide, ammonium persulfate and catalyst nanoparticles to solution C and mixing them uniformly to obtain solution D;

[0115] 5) Repeatedly apply solution D on the surface of the decontamination layer, then dry it at room temperature overnight.

[0116] In some embodiments, the content of sodium alginate in solution A in step 1) is 5-8wt%, including but not limited to 5wt%, 6wt%, 6.8wt%, 7wt% or 8wt%, etc.

[0117] In some embodiments, the content of polyacrylate in solution B in step 2) is 20-30 wt %, including but not limited to 20 wt %, 25 wt % or 8 wt %.

[0118] In some embodiments, the mass ratio of sodium alginate, polyacrylate, methylene bisacrylamide and ammonium persulfate is 11:29:1:1.

[0119] In some embodiments, the catalyst loading in the catalyst layer is 5-10 mg / cm 2, including but not limited to 5mg / cm 2 , 6mg / cm 2 , 7mg / cm 2 , 8mg / cm 2 , 9mg / cm 2 or 10mg / cm 2 wait.

[0120] In some embodiments, the drying temperature in step 5) is 70-90°C, including but not limited to 70°C, 80°C or 90°C, etc.; the drying time is 15-25min, including but not limited to 15min, 20min or 25min, etc.

[0121] It should be noted that in the embodiments of the present application, the order of step 1) and step 2) can be interchanged.

[0122] like Figure 3 As shown, the photocatalytic water splitting hydrogen production device of the embodiment of the present application comprises:

[0123] The photocatalytic water splitting hydrogen production device of the embodiment of the present application includes a cover plate 3 , a base 4 and a functional material layer 5 .

[0124] The cover plate 3 is made of a transparent material, including but not limited to transparent plastic with high light transmittance, such as transparent plastic with a light transmittance of more than 80%, including but not limited to polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymer (ABS), etc. A first groove 301 is formed on the cover plate 3.

[0125] The base 4 is provided with a second groove 401 .

[0126] The functional material layer 5 is arranged between the cover plate 3 and the base 4, and the functional material layer 5 and the first groove 301 constitute a hydrogen collection space 6, and the functional material layer 5 and the second groove 401 constitute a water collection space 7. The functional material layer 5 adopts the composite material of the embodiment of the present application, and the catalytic layer 2 is adjacent to the cover plate 3, which is convenient for photolysis of water to produce hydrogen under the action of the photocatalyst.

[0127] In some embodiments, in order to prevent water from leaking into the hydrogen collection space, the functional material layer 5 is supported between the cover plate 3 and the base 4 to form a tight seal. Specifically, the functional material layer 5 and the cover plate 3, and the functional material layer 5 and the base 4 are all sealed and connected, and the sealing connection method includes but is not limited to using a sealing ring seal, a labyrinth seal, etc.

[0128] In some embodiments, a plurality of support members 8 for supporting the functional material layer 5 are provided in the hydrogen collection space 6, and the plurality of support members 8 are arranged at intervals; one end of each of the plurality of support members 8 is connected to the cover plate 3, and the other end is close to the functional material layer 5. It should be noted that the connection method between the plurality of support members and the cover plate 3 can be integrated molding, ultrasonic wave welding, threaded sealing connection, etc.

[0129] In some embodiments, the coverage of the plurality of support members 8 on the cover plate 3 is 10-30%, including but not limited to 10%, 15%, 20%, 25% or 30%, etc. It should be noted that the coverage here refers to the ratio of the area of ​​the cover plate covered by all support members to the total surface area of ​​the cover plate on one side connected to the support members.

[0130] In some embodiments, the shape of the support member 8 is not limited, as long as it is easy to process. As a non-limiting example, the shape of the support member 8 includes but is not limited to a cylinder, a cube, a cuboid, etc.

[0131] As an optional example, a plurality of support members 8 are evenly distributed in the hydrogen collecting space 6 , and the plurality of support members 8 are cylindrical protrusions integrally formed on the cover plate 3 .

[0132] In some embodiments, in order to allow the water that passes through the functional material layer to be exposed to as much sunlight as possible as quickly as possible and then participate in the catalytic photolysis reaction, the hydrogen collection space 6 and the water collection space 7 are arranged opposite each other. For example, when the hydrogen collection space 6 is located above the water collection space 7, the upper and lower positions of the two are arranged correspondingly.

[0133] In some embodiments, the depth of the first groove 301 is 1-5 mm, including but not limited to 1 mm, 2.5 mm or 5 mm, etc. The shapes of the first groove and the second groove are not limited, and can be a cube, a cuboid, a cylinder, etc.

[0134] In some embodiments, the hydrogen collection space 6 is connected to at least one hydrogen collection pipeline 9, and all hydrogen collection pipelines 9 are connected to the hydrogen storage tank. It should be noted that the hydrogen collection pipeline can be set on the upper cover plate, and when multiple hydrogen collection pipelines are set, the multiple hydrogen collection pipelines are connected to the hydrogen storage tank after being collected.

[0135] In some embodiments, Figure 3As shown, the base 4 is provided with a water inlet and a water outlet connected to the water collection space 7, and the water inlet is connected to the pressurized circulation pump 10, the ultrafiltration device 11 and the water source 12 in sequence away from the end of the water collection space 7. The source water enters the ultrafiltration device through a pipeline to remove micron-level pollutants such as particulate matter, dust, and microorganisms in the water, and then enters the water collection space after pressurized circulation. The pressurized circulation causes the source water to move at a certain speed in the reactor composed of the cover plate, the functional material layer and the base in a direction parallel to the functional material layer, thereby eliminating the boundary layer mass transfer resistance from the source water to the porous water-absorbing layer in the functional material layer. The flow rate of the source water is preferably 0.005-0.015m / s, including but not limited to 0.005m / s, 0.008m / s, 0.01m / s, 0.013m / s or 0.015m / s, etc. When the flow rate is too low, the source water forms a thicker boundary layer on one side of the porous water-absorbing layer, which is not conducive to water transfer; when the flow rate is too high, pollutants can easily pass through the water-absorbing layer and the decontamination layer by forced convection, and easily damage the material.

[0136] The ultrafiltration device, pressurized circulation pump, etc. in the embodiments of the present application are all existing equipment, and the specific structure will not be repeated here.

[0137] The composite material of the embodiment of the present application can be widely used in the field of photolysis of water to produce hydrogen.

[0138] It should be noted that the composite materials of the embodiments of the present application can be used not only in the field of photolysis of water to produce hydrogen, but also in any field that requires the functions of the composite materials of the present application.

[0139] The method for producing hydrogen by photolysis of water using the photolysis of water hydrogen production device of the embodiment of the present application comprises the following steps:

[0140] After the impurities are blocked by the functional material layer, the source water reforms into a liquid film in the form of water vapor and decomposes to generate hydrogen under the action of photocatalysis.

[0141] The source water includes but is not limited to at least one of seawater, industrial sewage, domestic sewage, and untreated raw water.

[0142] In some embodiments, the method for producing hydrogen by photolysis of water further comprises the step of sending the source water into the water collection space through pressurized circulation after ultrafiltration treatment. The purpose of ultrafiltration treatment is to remove particles, micelles and other substances larger than 0.01 microns in the water to prevent physical damage to materials such as the base, functional material layer, and cover plate.

[0143] In some embodiments, the flow rate of the source water is 0.005-0.015 m / s, including but not limited to 0.005 m / s, 0.008 m / s, 0.01 m / s, 0.013 m / s or 0.015 m / s, etc. When the flow rate is too low, the source water forms a thick boundary layer on one side of the porous water-absorbing layer, which is not conducive to water transfer; when the flow rate is too high, it is easy for pollutants to pass through the water-absorbing layer and the decontamination layer in a forced convection manner, and it is easy to damage the material.

[0144] The photocatalytic water hydrogen production device and method of the present application not only has the beneficial effects of the photocatalytic water hydrogen production material of the present application, but also can bring at least the following beneficial effects:

[0145] 1. The main flat structure composed of the cover plate, functional material layer and base has a large effective exposed surface for hydrogen production by photolysis of water; the water vapor transmission path is short, and a faster lateral flushing speed can be achieved through a pressurized circulation pump, which reduces mass transfer resistance, produces hydrogen quickly and has a large output.

[0146] 2. The water permeability is controlled by adjusting the pressurized circulation pump, which can adapt to different hydrogen demands and achieve flexible regulation.

[0147] 3. By using the photolysis water hydrogen production device and method of the present application, condensed water is formed in situ after water vapor is transmitted and hydrogen is produced in situ through photocatalytic decomposition, eliminating the steps of water collection and transmission. The device is simple and has low energy consumption.

[0148] Certain features of the present technology are further illustrated in the following non-limiting examples.

[0149] 1. Examples and Comparative Examples

[0150] Example 1

[0151] like Figure 2 As shown, the composite material of this embodiment includes a catalytic layer 2, a decontamination layer 1 and a porous water-absorbing layer 13.

[0152] The dirt removal layer 1 is an organic-inorganic composite membrane with both hydrophobicity and oleophobicity, wherein the inorganic substance is a silica fiber membrane (fiber diameter is 200-500nm), and the organic substance is perfluorododecyltriethoxysilane (FAS), and FAS is located on the surface of the silica fiber membrane to form a fluorinated modification; the average pore size of the dirt removal layer is 0.84μm, the porosity is 70-80%, the contact angles to water and mineral oil are 150° and 149° respectively, and the thickness is 20μm.

[0153] The catalytic layer 2 is arranged on the upper surface of the decontamination layer 1, and the catalytic layer 2 is a hydrogel loaded with a catalyst. The hydrogel is a sodium alginate-acrylamide hydrogel, the porosity of the hydrogel is 80%, and the average pore size is 1 μm; the thickness of the catalytic layer is 100 μm; the catalyst is cadmium sulfide (CdS) particles, and the particle size of the cadmium sulfide (CdS) nanoparticles is 10-20 nm; the loading amount of the catalyst in the hydrogel is 10 wt%.

[0154] The porous water-absorbing layer 13 is arranged on the lower surface of the decontamination layer 1 . The porous water-absorbing layer is a hydrophilic polyester non-woven fabric, which can be purchased commercially. The thickness of the porous water-absorbing layer is 2.5 mm.

[0155] The method for preparing the composite material of this embodiment comprises the following steps:

[0156] S1. Prepare the decontamination layer by electrospinning.

[0157] SiO2 nanoparticles were added to a PVA aqueous solution (10wt%) so that the mass ratio of SiO2 in the mixture was 10%, and the mixture was fully stirred to obtain a dispersion; H3PO4 (85wt%) was dropwise added to a TEOS aqueous solution (TEOS:H2O molar ratio of 1:11) under full stirring so that the H3PO4:TEOS molar ratio reached 1:100 to obtain a silica sol; the dispersion and the silica sol were then mixed in a mass ratio of 1:1, and the mixture was subsequently processed into a film by a commercial electrospinning machine; the obtained film layer was calcined at 800°C for 2h to remove the PVA cross-linking agent, and then transferred to a 3wt% FAS hexane solution for immersion for 24h, and then the obtained film layer was dried to obtain a decontamination layer.

[0158] S2. Synthesizing a catalytic layer on the decontamination layer by a brush coating method, and in-situ loading a catalyst during the synthesis process.

[0159] Sodium alginate is dissolved in pure water to form solution A with a concentration of 0.07 g / mL; acrylamide is dissolved in pure water to form solution B with a concentration of 0.33 g / ml; solution A and solution B are fully mixed at a volume ratio of 12:7 to form solution C; methylenebisacrylamide and ammonium persulfate are added to solution C (the concentrations of methylenebisacrylamide and ammonium persulfate are 4.2 g / L and 4.2 g / L, respectively), and then catalyst CdS nanoparticles are added to solution C, mixed evenly, to obtain solution D; solution D is repeatedly brushed on the upper surface of the decontamination layer, and then dried at 80°C for 20 minutes, and then left at room temperature overnight to obtain a decontamination layer-catalytic layer composite layer.

[0160] S3. Placing the decontamination layer-catalytic layer composite layer on the porous water-absorbing layer so that the lower surface of the decontamination layer is in close contact with the upper surface of the porous water-absorbing layer to form the composite material of this embodiment.

[0161] The photocatalytic water splitting hydrogen production device of the present embodiment includes a cover plate 3 , a base 4 , a functional material layer 5 , a pressurized circulation pump 10 , an ultrafiltration device 11 and a water source 12 .

[0162] The cover plate 3 is a rectangular parallelepiped polyethylene terephthalate (PET) plate, and a rectangular parallelepiped first groove 301 is provided on its lower surface. The depth of the first groove 301 is 3 mm, and a plurality of spaced support members 8 are integrally formed on the lower surface of the first groove 301; the plurality of support members 8 are evenly distributed in the first groove 301, and their coverage rate on the cover plate 3 is 20%; the support member 8 is a cylindrical protrusion. Three hydrogen collection pipes 9 are provided on the cover plate 3, and the three hydrogen collection pipes 9 are evenly distributed, and one end of each is connected to the first groove 301, and the other end is connected to the hydrogen storage tank.

[0163] The base 4 is arranged below the cover plate 3, and a second groove 401 is provided on the upper surface of the base 4, and the second groove 401 is arranged opposite to the first groove 301 in the upper and lower positions; a water inlet is provided on the left side of the base 4, and a water outlet is provided on the right side, and one end of the water inlet and the water outlet are connected to the second groove 401.

[0164] The functional material layer 5 is a composite material of this embodiment, which is clamped between the cover plate 3 and the base 4, and forms a tight seal with both of them (the sealing connection is a sealing ring seal). The upper surface of the functional material layer 5 (the side surface where the catalytic layer is located) is close to the bottom of the multiple support members 8, and the upper surface of the functional material layer 5 and the first groove 301 form a hydrogen collection space 6, and the lower surface and the second groove form a water collection space 7.

[0165] The water inlet of the pressurized circulating pump 10 is connected to the water outlet of the ultrafiltration device 11, and the water outlet of the pressurized circulating pump 10 is connected to the water inlet of the base. The ultrafiltration device 11 is an existing ultrafiltration device, and its water inlet is connected to a water source 12, which is a seawater storage tank storing seawater.

[0166] The method for producing hydrogen by photolysis of water using the photolysis of water hydrogen production device of the embodiment of the present application comprises the following steps:

[0167] SS1, source water simulated organic wastewater is treated by ultrafiltration and then pressurized and circulated into the water collection space at a flow rate of 0.01m / s.

[0168] SS2. The simulated organic wastewater entering the water collection space is blocked by the functional material layer 5 for impurities and then reforms into a liquid film in the form of water vapor, and decomposes to generate hydrogen under the action of photocatalysis.

[0169] The composition of the simulated organic wastewater is fulvic acid, with a concentration of 1000 mg / L. The porous water-absorbing layer in the functional material layer 5 forms the first barrier to pollutants and salts in the water, protecting the decontamination layer and the catalytic layer from being damaged by large particle pollutants and salt crystals; the decontamination layer can prevent impurities in the water from entering the photocatalytic film, and only allows water vapor to pass through; the catalytic layer has a strong water vapor adsorption capacity, and the adsorbed water vapor re-forms a liquid film on the surface of the catalytic layer, and decomposes to generate hydrogen under the action of photocatalysis, thereby forming a water vapor concentration difference, which promotes the formation of water vapor on the surface of the porous water-absorbing layer and transfers through the decontamination layer.

[0170] Example 2 (Influence of the material of the decontamination layer and the double-repellent performance)

[0171] This embodiment is basically the same as Embodiment 1, except that:

[0172] In the composite material, the inorganic substance in the decontamination layer is fluorinated titanium dioxide nanoparticles, and the organic substance is Zonyl@8867L fluorocarbon surfactant. The contact angles of the decontamination layer to water and mineral oil are 160° and 150°, respectively, and the thickness is 50 μm.

[0173] Example 3 (Effects on Hydrogel Performance)

[0174] This embodiment is basically the same as Embodiment 1, except that:

[0175] In the composite material, the porosity of the hydrogel in the catalytic layer is 90% and the average pore size is 5 μm.

[0176] Example 4 (Catalyst Effect)

[0177] This embodiment is basically the same as Embodiment 1, except that:

[0178] In the composite material, the loading amount of the catalyst in the hydrogel is 5wt%.

[0179] Example 5 (Thickness Effect)

[0180] This embodiment is basically the same as Embodiment 1, except that:

[0181] In the composite material, the thickness of the decontamination layer is 50 μm, the thickness of the catalytic layer is 200 μm, and the thickness of the porous water-absorbing layer is 2.5 mm.

[0182] Example 6 (effect of flow rate)

[0183] This embodiment is basically the same as Embodiment 1, except that:

[0184] The source water flow rate is 0.005m / s.

[0185] Comparative Example 1

[0186] This comparative example is basically the same as Example 1, except that:

[0187] The composite material does not contain a decontamination layer.

[0188] 2. Performance Test

[0189] 1. Test methods

[0190] (1) Barrier effect on pollutants

[0191] Under the condition of not containing a catalytic layer, a photocatalytic water splitting hydrogen production device is assembled; the valve at the water inlet on the base of the photocatalytic water splitting hydrogen production device of each embodiment and comparative example is opened, and the source water simulated organic wastewater is introduced into each water collection space, so that the simulated organic wastewater (the simulated organic wastewater in Example 1) circulates in each water collection space at the source water circulation flow rate involved in each embodiment and comparative example; pure water is filled in the hydrogen collection space, and the content of pollutants (fulvic acid) on the pure water side is detected after an interval of 48 hours, and the detection method is ICP-MS with a detection sensitivity of 10ppm. According to the pollutant content on the pure water side after a certain period of time and the pollutant content in the initial wastewater, the pollutant blocking rate is calculated according to formula (1).

[0192] The pollutant blocking rate is calculated as follows:

[0193] d=(V t c t -V0c0) / V y c y Formula (1)

[0194] In formula (1):

[0195] d——pollutant blocking rate, %;

[0196] V t ——Total volume of pure water side at time t, L;

[0197] c t ——Contaminant content on the pure water side at time t, mg / L;

[0198] V0——total volume of pure water side at the initial moment, L;

[0199] c t ——Content of pollutants on the pure water side at the initial moment, mg / L;

[0200] V y ——Total volume of initial source water, L;

[0201] c y ——Content of pollutants in initial source water, mg / L.

[0202] (2) Photocatalytic hydrogen production rate

[0203] Under the laboratory simulated sunlight (full spectrum light intensity of 1W / cm 2 ), assemble a photocatalytic water hydrogen production device; open the valve at the water inlet on the base of the photocatalytic water hydrogen production device of each embodiment and comparative example, and introduce water source water simulating organic wastewater into each water collection space, so that the simulated organic wastewater circulates in each water collection space at the water source water circulation flow rate involved in each embodiment and comparative example; fill the hydrogen collection space with pure water, use the simulated organic wastewater as the water source water, use the photocatalytic water hydrogen production device of the embodiment and comparative example to perform photocatalytic water hydrogen production, and examine the hydrogen production rate,

[0204] 2. Test results

[0205] Table 1 Performance test results of embodiments and comparative examples

[0206]

[0207] As can be seen from Table 1, due to the presence of the decontamination layer in this application, the pollutant barrier rate is relatively high, so that a relatively high hydrogen production rate is maintained when the simulated organic wastewater is used as the source water. Within the parameter range set in this application, the hydrogen production rate remains basically unchanged within 48 hours, indicating that the water flow rate does not change much, and the water flow rate can meet the hydrogen production demand.

[0208] By comparing Example 1 and Example 2, it can be seen that when the decontamination layer has stronger hydrophobicity and oleophobicity and a greater thickness, the barrier rate for pollutants is higher, and the hydrogen production rate can be maintained at a higher level after a longer period of time.

[0209] By comparing Example 1 and Example 3, it can be seen that when the porosity and pore size of the hydrogel are larger, there is no effect on the barrier rate of pollutants, but there is a slight difference in the photocatalytic hydrogen production rate, which may be due to the fact that the dispersion of the catalyst in the hydrogel is affected to a certain extent (the increase in pore size causes catalyst agglomeration in some parts).

[0210] By comparing Example 1 and Example 4, it can be seen that within a certain range of catalyst loading, the photocatalytic effect of the catalyst per unit mass is basically the same.

[0211] By comparing Example 1 and Example 5, it can be seen that when the thickness of the decontamination layer and the catalytic layer are increased at the same time, the water flux requirement for the photocatalytic reaction is still met, so the catalytic reaction rate remains substantially unchanged.

[0212] By comparing Example 1 and Example 6, it can be seen that when the water flow rate decreases, the catalytic reaction rate decreases to a certain extent due to the thickening of the boundary layer and the obstruction of mass transfer.

[0213] By comparing Example 1 with Comparative Example 1, it can be seen that the decontamination layer plays a decisive role in maintaining a relatively high photocatalytic reaction rate.

[0214] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0215] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A composite material, characterized in that: The invention comprises a decontamination layer, a catalytic layer and a porous water-absorbing layer, wherein the decontamination layer is an organic-inorganic composite membrane having both hydrophobicity and oleophobicity, wherein the inorganic substance in the organic-inorganic composite membrane is nanoparticles, the organic substance is fluoride, and the fluoride is at least one of perfluorooctyltrimethoxysilane, perfluorododecyltriethoxysilane and a fluorocarbon surfactant; the decontamination layer comprises a first surface and a second surface arranged opposite to each other, wherein the catalytic layer is arranged on the first surface, the catalytic layer is a hydrogel loaded with a catalyst, and the porous water-absorbing layer is arranged on the second surface.

2. The composite material according to claim 1, characterized in that The nanoparticles include at least one of silicon dioxide, titanium dioxide, fluorinated silicon dioxide and fluorinated titanium dioxide.

3. The composite material according to claim 1, characterized in that The hydrogel is acrylamide hydrogel and / or sodium alginate hydrogel; and / or, the hydrogel has a porosity of 80-90% and an average pore size of 0.5-5 μm; And / or, the catalyst comprises at least one of metal oxide, metal sulfide, metal nitride, metal oxysulfide and metal oxynitride; the metal comprises d 10 Metal or 0 At least one of the metals; And / or, the catalyst is loaded in the hydrogel in an amount of 3-10 wt %.

4. The composite material according to claim 1, characterized in that The surface water contact angle and oil contact angle of the decontamination layer are both greater than 120°; And / or, the decontamination layer has a thickness of 1-50 μm; and / or, the porosity of the decontamination layer is 70-80% and the average pore size is 0.2-1 μm; And / or, the thickness of the catalytic layer is 0.1-0.5 mm; And / or, the porous water-absorbing layer is a hydrophilic fiber; And / or, the thickness of the porous water-absorbing layer is 1-5 mm.

5. A method for preparing a composite material according to any one of claims 1 to 4, characterized in that: include: The decontamination layer was prepared by electrospinning; The catalytic layer is synthesized on the surface of the decontamination layer by a brush coating method, and the catalyst is loaded in situ during the synthesis process.

6. Use of the composite material according to any one of claims 1 to 4 in the field of hydrogen production by photolysis of water.

7. A photocatalytic water splitting hydrogen production device, characterized in that: include: A cover plate, the cover plate is made of a transparent material and is provided with a first groove; A base, wherein a second groove is provided on the base; A functional material layer, wherein the functional material layer is arranged between the cover plate and the base, and the functional material layer and the first groove constitute a hydrogen collection space, and the functional material layer and the second groove constitute a water collection space, the functional material layer adopts the composite material according to any one of claims 1 to 4, and the catalytic layer is adjacent to the cover plate.

8. The photocatalytic water hydrogen production device according to claim 7, characterized in that: A plurality of support members for supporting the functional material layer are arranged in the hydrogen collection space, and the plurality of support members are arranged at intervals; one end of each of the plurality of support members is connected to the cover plate, and the other end is closely attached to the functional material layer; And / or, the functional material layer and the cover plate, and the functional material layer and the base are all sealed and connected; And / or, the hydrogen collection space and the water collection space are arranged opposite to each other; And / or, the depth of the first groove is 1-5 mm; And / or, the light transmittance of the transparent material is above 80%; And / or, the hydrogen collection space is connected to at least one hydrogen collection pipeline, and all of the hydrogen collection pipelines are connected to the hydrogen storage tank; And / or, a water inlet and a water outlet connected to the water collection space are provided on the base, and the water inlet is connected to a pressurized circulation pump, an ultrafiltration device and a water source in sequence at one end away from the water collection space.

9. The photocatalytic water hydrogen production device according to claim 8, characterized in that: The coverage rate of the plurality of support members on the cover plate is 10-30%; and / or, a plurality of support members are evenly distributed in the hydrogen collecting space; And / or, a plurality of support members are integrally formed with the cover plate.

10. A method for producing hydrogen by photolysis of water using the photolysis of water hydrogen production device according to any one of claims 7 to 9, characterized in that: include: After the impurities are blocked by the functional material layer, the source water reforms into a liquid film in the form of water vapor and decomposes to generate hydrogen under the action of photocatalysis.

11. The method for producing hydrogen by photolysis of water according to claim 10, characterized in that: The flow rate of the source water is 0.005-0.015 m / s.

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