A hydro-photovoltaic cogeneration gel-based device and its preparation method and application

Abstract

The present application relates to a kind of cogeneration gel-based devices and its preparation method and application, belong to water treatment technical field.The cogeneration gel-based device of the present application, including two electrodes, and the electricity generation material contacted with two electrodes;The electricity generation material includes porous polymer matrix, and conductive carbon material and water-soluble metal salt dispersed in porous polymer matrix;The porous polymer matrix is mainly by three (hydroxymethyl) methyl glycine modified chitosan, acrylic acid and N,N'-methylene bisacrylamide by free radical polymerization into.The cogeneration gel-based device of the present application has excellent electricity generation performance and water purification capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a water and power cogeneration gel-based device and a preparation method and application thereof. Background Art

[0002] With the development of nanotechnology, people have begun to use nanomaterials to harvest energy from water waves, raindrops, moisture, or evaporation. Among the many avenues, research on the generation of electricity from nanomaterials during the mutual conversion of water vapor and liquid phases has attracted much attention. These are mainly divided into moisture-induced electricity generation (humidity-induced electricity generation developed by the adsorption of gaseous water) and evaporation electricity generation (evaporation-induced electricity generation developed by the evaporation of liquid water). Because the water vapor-liquid conversion process is less affected by temporal, spatial, geographical, or environmental factors, moisture-induced electricity generation and evaporation electricity generation offer new solutions to global energy challenges.

[0003] Compared to moisture-generated electricity, which has a smaller voltage / current signal and unstable pulse output, evaporation-generated electricity can achieve high-power density continuous output, and its power generation capacity can better meet the needs of practical applications. Evaporation-generated electricity devices are mainly divided into planar structures and sandwich structures. The planar structure consists of electrodes at both ends and a power-generating material in contact with the electrodes. This type of device can place one end in water or add water to one end to generate electricity. The key to its power generation performance lies in the power-generating material. However, the current power-generating materials mainly have a small contact area with water, which makes it difficult to effectively promote water diffusion and evaporation, poor photothermal conversion performance, and poor conductivity, which in turn leads to poor power generation performance of evaporation-generated electricity devices. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a hydropower cogeneration gel-based device and a preparation method and application thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a hydropower cogeneration gel-based device, comprising two electrodes at both ends and an electricity-generating material in electrolytic contact with the two ends; the electricity-generating material comprises a porous polymer matrix, and a conductive carbon material and a water-soluble metal salt dispersed in the porous polymer matrix;

[0007] The porous polymer matrix is ​​mainly prepared by free radical polymerization of chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and N,N'-methylenebisacrylamide.

[0008] The porous polymer matrix formed by free radical polymerization of chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and N,N'-methylenebisacrylamide can form water or ion transmission channels by utilizing the abundant loose porous three-dimensional structure. At the same time, tris(hydroxymethyl)methylglycine grafted on the side chain of chitosan is utilized to further enhance the hydrophilicity of chitosan to effectively promote the rapid transmission of water molecules to accelerate the diffusion and evaporation of water. The -COOH of some acrylic acid can also react with the -NH2 of chitosan to be grafted on the side chain of chitosan modified with tris(hydroxymethyl)methylglycine. The chitosan modified with tris(hydroxymethyl)methylglycine, the remaining part of the acrylic acid and the cross-linking agent N,N′-methylenebisacrylamide undergo free radical polymerization to form an interpenetrating network polymer structure, so that the power-generating material still maintains excellent mechanical properties after swelling with water during actual application; the conductive carbon material and water-soluble metal salt dispersed in the porous polymer matrix can enhance the conductivity, water absorption and photothermal properties of the power-generating material, while sharing a negative charge environment with the carboxyl-rich polymer chain segments in the porous polymer matrix, thereby improving the power generation performance of the hydropower cogeneration gel-based device.

[0009] As a preferred embodiment of the hydropower cogeneration gel-based device described herein, the power-generating material is prepared by the following preparation method: chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid, and water are mixed, a conductive carbon material and a water-soluble metal salt are added, and then N,N′-methylenebisacrylamide and an initiator are added to the mixture, and polymerization reaction is carried out at 50-80°C for 1-3 hours to obtain a gel matrix. The gel matrix is ​​then freeze-dried for 12-36 hours to obtain the power-generating material. Optionally, the polymerization reaction temperature can be 55°C, 60°C, 65°C, 70°C, or 75°C, and the reaction time can be 1.5 hours, 2 hours, or 2.5 hours; the freeze-drying time can be 15 hours, 20 hours, 25 hours, 30 hours, or 35 hours.

[0010] The initiator in the above preparation method is a free radical polymerization initiator, which can be an azo compound initiator, an organic peroxide initiator, an inorganic peroxide initiator, an oxidation-reduction initiator, etc., and can specifically be ammonium persulfate. The mass ratio of the tris(hydroxymethyl)methylglycine-modified chitosan to ammonium persulfate is 1:(0.5-1). Alternatively, the mass ratio of the tris(hydroxymethyl)methylglycine-modified chitosan to ammonium persulfate can specifically be 1:0.6, 1:0.7, 1:0.8, or 1:0.9.

[0011] In addition, during the mixing process of tris(hydroxymethyl)methylglycine-modified chitosan, acrylic acid and water, part of the -COOH in the acrylic acid reacts with the -NH2 of the chitosan and is grafted onto the side chain of the tris(hydroxymethyl)methylglycine-modified chitosan.

[0012] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the mass ratio of the tris(hydroxymethyl)glycine-modified chitosan to acrylic acid is 1:(10-30). Alternatively, the mass ratio of the tris(hydroxymethyl)glycine-modified chitosan to acrylic acid can be 1:12, 1:14, 1:16, 1:18, 1:20, 1:22, 1:24, 1:26, or 1:28.

[0013] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the mass ratio of the tris(hydroxymethyl)methylglycine-modified chitosan to N,N′-methylenebisacrylamide is 1:(0.01-0.02).

[0014] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the mass ratio of the tris(hydroxymethyl)glycine-modified chitosan to the conductive carbon material is 1:(0.1-0.8). Alternatively, the mass ratio of the tris(hydroxymethyl)glycine-modified chitosan to the conductive carbon material can be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, or 1:0.7.

[0015] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the mass ratio of the tris(hydroxymethyl)glycine-modified chitosan to the water-soluble metal salt is 1:(1-10). Alternatively, the mass ratio of the tris(hydroxymethyl)glycine-modified chitosan to the water-soluble metal salt can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, or 1:9.

[0016] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the conductive carbon material is at least one of carbon black, carbon nanotubes, and graphene; and / or the water-soluble metal salt is at least one of lithium chloride and calcium chloride.

[0017] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the tris(hydroxymethyl)methylglycine-modified chitosan is obtained by reacting tris(hydroxymethyl)methylglycine with chitosan, and the molar ratio of the repeating unit in the chitosan to tris(hydroxymethyl)methylglycine is 1:(0.1-0.5). Alternatively, the molar ratio of the repeating unit in the chitosan to tris(hydroxymethyl)methylglycine can be 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, or 1:0.45.

[0018] The reaction of tris(hydroxymethyl)methylglycine with chitosan refers to the reaction of the carboxyhydroxyl group (-COOH) in tris(hydroxymethyl)methylglycine with the amino group (-NH2) in chitosan to graft tris(hydroxymethyl)methylglycine onto the side chain of chitosan.

[0019] Specifically, the tris(hydroxymethyl)methylglycine-modified chitosan can be prepared according to existing technologies (e.g., “Multifunctional chitosan-based gel sponge with efficient antibacterial hemostasis and strong adhesion”), and can be prepared specifically according to the following preparation method:

[0020] Chitosan is dissolved in a glacial acetic acid solution (volume fraction of 0.5% to 2%, solvent is water), and tris(hydroxymethyl)methylglycine is added and stirred until completely dissolved. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and N-hydroxysuccinimide (NHS) are then added. The reaction is first carried out in an ice-water bath for 0.5 to 2 hours, then at room temperature (25°C) for 12 to 36 hours, and dialyzed (dialysis bag with a molecular weight cut-off of 200,000) for 3 to 5 days to remove unreacted tris(hydroxymethyl)methylglycine, EDC·HCl, NHS, etc. The pale yellow product obtained by lyophilization is tris(hydroxymethyl)methylglycine-modified chitosan; wherein the molar ratio of the repeating unit in the chitosan to EDC·HCl is 1:(1-2), and the molar ratio of EDC·HCl to NHS is 1:1.

[0021] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the weight average molecular weight of the chitosan is 40,000 to 60,000. Alternatively, the weight average molecular weight of the chitosan can be 45,000, 50,000, or 55,000.

[0022] In a second aspect, the present invention provides a method for preparing the above-mentioned hydropower cogeneration gel-based device, which specifically comprises the following steps:

[0023] S1. Tris(hydroxymethyl)methylglycine-modified chitosan, acrylic acid, and water are mixed uniformly, and then a conductive carbon material and a water-soluble metal salt are added and mixed uniformly, and then N,N′-methylenebisacrylamide and an initiator are added and mixed uniformly to form a precursor solution;

[0024] S2. Place the precursor solution in S1 into a mold, insert the end electrode, polymerize at 50-80° C. for 1-3 hours, and then freeze-dry for 12-36 hours to obtain a hydropower cogeneration gel-based device.

[0025] In a third aspect, the present invention provides the use of the above-mentioned hydropower cogeneration gel-based device in the preparation of power generation devices or water purification devices.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The hydropower cogeneration gel-based device of the present invention includes electrodes at both ends and an electricity-generating material in electrolytic contact with the two ends; the electricity-generating material includes a porous polymer matrix, a conductive carbon material and a water-soluble metal salt dispersed in the porous polymer matrix, and a porous polymer matrix formed by free radical polymerization of chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and N,N′-methylenebisacrylamide. The porous polymer matrix can utilize a rich loose porous three-dimensional structure to form a water or ion transmission channel, and at the same time utilize tris(hydroxymethyl)methylglycine grafted on the side chain of chitosan to further enhance the hydrophilicity of chitosan to effectively promote water molecules. Rapid transmission to accelerate the diffusion and evaporation of water; and the interpenetrating network polymer structure formed by tris(hydroxymethyl)methylglycine-modified chitosan, acrylic acid and cross-linker N,N′-methylenebisacrylamide can enable the power-generating material to maintain excellent mechanical properties after swelling in contact with water during actual application; and the conductive carbon material and water-soluble metal salt dispersed in the porous polymer matrix can enhance the conductivity, water absorption and photothermal properties of the power-generating material, while sharing a negative charge environment with the carboxyl-rich polymer chain segments in the porous polymer matrix, thereby improving the power generation performance of the hydropower cogeneration gel-based device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of a hydropower cogeneration gel-based device according to the present invention;

[0029] Figure 2 The structural formula and H-NMR spectrum of tris(hydroxymethyl)methylglycine-modified chitosan of the present invention are shown below:

[0030] Figure 3 4 is a Fourier transform infrared spectrum of chitosan and chitosan modified with tris(hydroxymethyl)methylglycine of the present invention;

[0031] Figure 4 This is a scanning electron microscope image of the electricity-generating material in Example 1;

[0032] Figure 5 Graph showing the open circuit voltage of the hydropower cogeneration gel-based device over time in Example 1;

[0033] Figure 6 Graph showing the change in open circuit voltage of the hydropower cogeneration gel-based device as a function of the number of devices in Example 1;

[0034] Figure 7 Graph showing the open circuit voltage of the hydropower cogeneration gel-based device in Example 1 in deionized water and sodium chloride solution over time;

[0035] Figure 8 This is a graph showing the relationship between voltage and time when the voltage is reversed after the wires contacted by the upper and lower electrodes of the hydropower cogeneration gel-based device in Example 1 are exchanged multiple times;

[0036] Figure 9 Schematic diagram of a circuit for lighting up a light-emitting diode in a closed loop of the hydropower cogeneration gel-based device in multiple embodiments 1;

[0037] Figure 10 The graph is a graph showing the mass change of the solution with and without the hydropower cogeneration gel-based device in Example 1 in a closed system over time;

[0038] Figure 11 1 is a graph showing the ultraviolet absorption spectra of a methylene blue solution and a methylene blue solution treated with the hydropower cogeneration gel-based device in Example 1. DETAILED DESCRIPTION

[0039] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0040] Unless otherwise specified, other materials and reagents used in the examples can be obtained from commercial sources.

[0041] Chitosan was purchased from Shanghai Yien Chemical Technology Co., Ltd. with a weight-average molecular weight of 50,000.

[0042] Tris(hydroxymethyl)methylglycine-modified chitosan can be prepared by the following preparation method:

[0043] 1 g of chitosan (weight-average molecular weight of 50,000) was dissolved in an aqueous solution of glacial acetic acid (1 mL of glacial acetic acid + 100 mL of deionized water), and then 0.33 g of tris(hydroxymethyl)methylglycine was added and stirred until completely dissolved. Subsequently, 10.0 mmol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and 10.0 mmol of N-hydroxysuccinimide (NHS) were added. The mixture was reacted in an ice-water bath for 2 h, then at room temperature (25°C) for 24 h. Unreacted tris(hydroxymethyl)methylglycine, EDC·HCl, NHS, etc. were removed by dialysis (dialysis bag with a molecular weight cut-off of 200,000). The pale yellow product obtained by lyophilization was tris(hydroxymethyl)methylglycine-modified chitosan.

[0044] The chitosan modified with tris(hydroxymethyl)methylglycine was dissolved in a 1% acetic acid heavy water solution and subjected to nuclear magnetic resonance spectroscopy at 600 MHz. The test results are as follows: Figure 2 As shown. Figure 2 It can be seen that the chemical shift of 3.87 ppm corresponds to the characteristic peak of tris(hydroxymethyl)methylglycine, and the chemical shifts of 2.75 ppm-3.75 ppm are all characteristic peaks of chitosan. The appearance of the characteristic peak of chemical shift 3.87 pmm fully proves the successful synthesis of tris(hydroxymethyl)methylglycine-modified chitosan.

[0045] At the same time, the above-mentioned tris (hydroxymethyl) methylglycine modified chitosan and chitosan were tested by Fourier transform infrared spectroscopy. The test results are as follows Figure 3 As shown. Figure 3 It can be seen that compared with the hydroxyl absorption peak of chitosan, the hydroxyl absorption peak of chitosan modified with tris(hydroxymethyl)methylglycine shifts to a lower wave number (from 3362 cm -1 Move to 3360cm -1 ) and becomes wider in an asymmetric shape, indicating that the molecular chain of tris(hydroxymethyl)methylglycine-modified chitosan contains more hydroxyl groups, which indicates that tris(hydroxymethyl)methylglycine-modified chitosan is successfully synthesized.

[0046] Example 1

[0047] An embodiment of the hydropower cogeneration gel-based device of the present invention, the hydropower cogeneration gel-based device of this embodiment (such as Figure 1 As shown), it includes two-end electrodes (carbon rod electrodes) and an electricity-generating material (hydrogel) in electrolytic contact with the two ends; the electricity-generating material includes a porous polymer matrix, a conductive carbon material (carbon black) and a water-soluble metal salt (lithium chloride) dispersed in the porous polymer matrix; the porous polymer matrix is ​​formed by free radical polymerization of chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and N,N′-methylenebisacrylamide;

[0048] Among them, the mass volume ratio of the above-mentioned tris(hydroxymethyl)methylglycine-modified chitosan and acrylic acid is 1:15 g / mL; the mass ratio of tris(hydroxymethyl)methylglycine-modified chitosan and N,N′-methylenebisacrylamide is 1:0.25; the mass ratio of tris(hydroxymethyl)methylglycine-modified chitosan, conductive carbon material and water-soluble metal salt is 1:0.5:7.5.

[0049] The preparation method of the hydropower cogeneration gel-based device comprises the following steps:

[0050] S1. Tris(hydroxymethyl)methylglycine-modified chitosan (0.4 g), acrylic acid (6 mL) and deionized water (30 mL) were fully mixed and reacted for 30 min, and then a conductive carbon material (carbon black, 0.2 g) and a water-soluble metal salt (lithium chloride, 3 g) were added and stirred for 30 min. Then, N,N′-methylenebisacrylamide (0.01 g) and an initiator (ammonium persulfate, 0.3 g) were added and stirred for 30 min to form a precursor solution;

[0051] S2. Place the precursor solution in S1 in a mold (rectangular mold: 30 mm long × 10 mm wide × 20 mm high), and fix two carbon rods (the length of the long carbon rod is 20 mm, the diameter is 1 mm, and the insertion depth of the carbon rod is about 10 mm) as end electrodes at both ends of the length direction about 2 cm away from the mold wall. After free radical polymerization reaction at 60°C for 2 hours, place it in a refrigerator and freeze it for 12 hours, and then freeze-dry it for 24 hours to obtain a hydropower cogeneration gel-based device.

[0052] Example 2

[0053] A comparative example of the hydropower cogeneration gel-based device of the present invention is that the hydropower cogeneration gel-based device described in this embodiment is basically the same as that in Example 1, except that the mass volume ratio of tris(hydroxymethyl)methylglycine-modified chitosan to acrylic acid is 1:10 g / mL.

[0054] The preparation method of the above-mentioned hydropower cogeneration gel-based device is the same as that in Example 1.

[0055] Example 3

[0056] A comparative example of the hydropower cogeneration gel-based device of the present invention is that the hydropower cogeneration gel-based device described in this embodiment is basically the same as that in Example 1, except that the mass volume ratio of tris(hydroxymethyl)methylglycine-modified chitosan to acrylic acid is 1:30 g / mL.

[0057] The preparation method of the above-mentioned hydropower cogeneration gel-based device is the same as that in Example 1.

[0058] Comparative Example 1

[0059] A comparative example of the hydropower cogeneration gel-based device of the present invention. The hydropower cogeneration gel-based device described in this embodiment is basically the same as that in Example 1, with the only difference being that the power-generating material includes a porous polymer matrix and lithium chloride (without carbon black added) dispersed in the porous polymer matrix.

[0060] The preparation method of the above-mentioned hydropower cogeneration gel-based device is the same as that in Example 1.

[0061] Comparative Example 2

[0062] A comparative example of the hydropower cogeneration gel-based device of the present invention. The hydropower cogeneration gel-based device described in this embodiment is basically the same as that in Example 1, with the only difference being that the power-generating material includes a porous polymer matrix and carbon black (without lithium chloride added) dispersed in the porous polymer matrix.

[0063] The preparation method of the above-mentioned hydropower cogeneration gel-based device is the same as that in Example 1.

[0064] Comparative Example 3

[0065] A comparative example of the water-electricity cogeneration gel-based device, the water-electricity cogeneration gel-based device of the present example is basically the same as that of Example 1, with the difference that the porous polymer matrix is formed by radical polymerization of chitosan, acrylic acid and N,N'-methylenebisacrylamide.

[0066] The preparation method of the water-electricity cogeneration gel-based device includes the following steps:

[0067] S1, chitosan (0.4 g), acrylic acid (6 mL) and deionized water (30 mL) were mixed and reacted for 30 min, then conductive carbon material (carbon black, 0.2 g) and water-soluble metal salt (lithium chloride, 3 g) were added and stirred for 30 min, then N,N'-methylenebisacrylamide (0.01 g) and initiator (ammonium persulfate, 0.3 g) were added and stirred for 30 min to form a precursor solution;

[0068] S2, the precursor solution in S1 was placed in a mold (cuboid mold: length 30 mm x width 10 mm x height 20 mm), two carbon rods (length of carbon rod is 20 mm, diameter is 1 mm, and the insertion depth of carbon rod is about 10 mm) were fixed at a distance of about 2 cm from the wall of the mold at both ends in the length direction as end electrodes, and then the mold was placed in a 60℃ oven for 2h of radical polymerization reaction, then placed in a refrigerator for 12h of freezing, and then freeze-dried for 24h to obtain the water-electricity cogeneration gel-based device.

[0069] Comparative Example 4

[0070] A comparative example of the water-electricity cogeneration gel-based device, the water-electricity cogeneration gel-based device of the present example is basically the same as that of Example 1, with the difference that the porous polymer matrix is formed by radical polymerization of chitosan, acrylic acid and N,N'-methylenebisacrylamide.

[0071] The preparation method of the water-electricity cogeneration gel-based device includes the following steps:

[0072] S1, chitosan (0.4 g), acrylic acid (6 mL) and deionized water (30 mL) were mixed and reacted for 30 min, then conductive carbon material (carbon black, 0.2 g) and water-soluble metal salt (lithium chloride, 3 g) were added and stirred for 30 min, then N,N'-methylenebisacrylamide (0.01 g) and initiator (ammonium persulfate, 0.3 g) were added and stirred for 30 min to form a precursor solution;

[0073] S2, the precursor solution in S1 is placed in a mold (cuboid mold: length 30 mm x width 10 mm x height 20 mm), two carbon rods (length of long carbon rod is 20 mm, diameter is 1 mm, and the insertion depth of the carbon rod is about 10 mm) are fixed at the both ends of the length direction at a distance of about 2 cm from the mold wall as end electrodes, after free radical polymerization reaction at 60℃ for 2h, it is placed in a refrigerator for freezing for 12h, and then freeze-drying for 24h, to obtain the cogeneration gel-based device.

[0074] Comparative Example 5

[0075] The cogeneration gel-based device of the present application is basically the same as that of Example 1, the difference is only that the porous polymer matrix is formed by free radical polymerization of tris (hydroxymethyl) methyl glycine modified chitosan and N, N'-methylene bisacrylamide.

[0076] The preparation method of the above-mentioned cogeneration gel-based device comprises the following steps:

[0077] S1, tris (hydroxymethyl) methyl glycine modified chitosan (0.4g) and deionized water (30mL) are mixed and reacted for 30min, then conductive carbon material (carbon black, 0.2g) and water-soluble metal salt (lithium chloride, 3g) are added and stirred for 30min, then N, N'-methylene bisacrylamide (0.01g) and initiator (ammonium persulfate, 0.3g) are added and stirred for 30min to form a precursor solution;

[0078] S2, the precursor solution in S1 is placed in a mold (cuboid mold: length 30 mm x width 10 mm x height 20 mm), two carbon rods (length of long carbon rod is 20 mm, diameter is 1 mm, and the insertion depth of the carbon rod is about 10 mm) are fixed at the both ends of the length direction at a distance of about 2 cm from the mold wall as end electrodes, after free radical polymerization reaction at 60℃ for 2h, it is placed in a refrigerator for freezing for 12h, and then freeze-drying for 24h, to obtain the cogeneration gel-based device.

[0079] Performance test

[0080] 1, scanning electron microscope (SEM) test

[0081] Figure 4 The SEM image of the power generation material in the cogeneration gel-based device prepared in Example 1 is shown in Figure 1. Figure 4 It can be seen that there is a porous structure inside the device, which fully shows that ions and water can be transported inside the device.

[0082] 2, power generation performance test

[0083] 1) Take a 20mm×20mm×15mm uncovered plastic box and use a punch to punch a circular hole with a diameter of 1mm about 2mm from the bottom. Then place the hydropower cogeneration gel-based device in Example 1 in the uncovered plastic box so that one end electrode of the hydropower cogeneration gel-based device extends out of the circular hole. At the same time, add 5g of deionized water to the uncovered plastic box. Measure the open circuit voltage between the two end electrodes of the hydropower cogeneration gel-based device to evaluate its power generation performance. The test results are shown as follows: Figure 5 Then four hydropower cogeneration gel-based devices (the same as in Example 1) were sequentially connected in series with the above hydropower cogeneration gel-based device, and the open circuit voltage after each addition of a hydropower cogeneration gel-based device was tested. The test results were as follows Figure 6 shown.

[0084] according to Figure 5 It can be seen that the open circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device shows a trend of first increasing and then remaining unchanged with the increase of time; from 0 to 10 minutes, the open circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device rapidly increases from 0V to 0.4V; from 10 to 70 minutes, the open circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device continues to increase from 0.4V to 0.6V; from 70 to 80 minutes, the open circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device basically remains at 0.6V, indicating that the device has the ability to stabilize the output voltage after a certain stabilization time.

[0085] according to Figure 6 It can be seen that the open-circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device increases linearly with the increase in the number of hydropower cogeneration gel-based devices connected in series, indicating that the voltages generated by multiple devices can be superimposed and have development prospects.

[0086] 2) Take two uncovered plastic boxes of 20mm×20mm×15mm, and use a punch to punch a circular hole with a diameter of 1mm at a distance of about 2mm from the bottom of each box. Then, place the two hydropower cogeneration gel-based devices in Example 1 in the above-mentioned uncovered plastic boxes respectively, and make one end electrode of the hydropower cogeneration gel-based device extend from the above-mentioned circular hole; then add 5g of deionized water to one uncovered plastic box and add a sodium chloride aqueous solution with a mass fraction of 10% to the other uncovered plastic box. After evaporation for 120 minutes (the evaporation difference at both ends of the hydropower cogeneration gel-based device reaches equilibrium), measure the open circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device. The test results are as follows: Figure 7 As shown. Figure 7 It can be seen that using sodium chloride aqueous solution makes the device generate a larger voltage, indicating that the conductivity of the liquid has an impact on the output capacity of the device, thus showing that the device can play a greater role in liquids such as seawater.

[0087] 3) Take a 20mm×20mm×15mm uncovered plastic box and use a punch to punch a circular hole with a diameter of 1mm at a distance of about 2mm from the bottom. Then place the hydropower cogeneration gel-based device in Example 1 in the above-mentioned uncovered plastic box so that one end electrode of the hydropower cogeneration gel-based device extends out from the above-mentioned circular hole. At the same time, add 5g of deionized water to the uncovered plastic box. After evaporation for more than 60 minutes (the evaporation difference at both ends of the hydropower cogeneration gel-based device reaches equilibrium), measure the open circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device, and exchange the wires contacting the two end electrodes of the hydropower cogeneration gel-based device every 20 seconds (a total of 3 exchanges). The test results are as follows: Figure 8 As shown. Figure 8 It can be seen that the voltage across the device is positive and negative, indicating that the device is indeed generating voltage and outputting it.

[0088] 4) Take a 20mm×20mm×15mm uncovered plastic box and use a punch to punch a circular hole with a diameter of 1mm at a distance of about 2mm from the bottom. Then place the hydropower cogeneration gel-based device in Example 1 in the above-mentioned uncovered plastic box so that one end electrode of the hydropower cogeneration gel-based device extends out of the above-mentioned circular hole. At the same time, add 5g of deionized water to the uncovered plastic box and wait for 2h to evaporate (the evaporation difference at both ends of the hydropower cogeneration gel-based device reaches equilibrium); then connect the above four hydropower cogeneration gel-based devices in series and connect them to a light-emitting diode with a rated voltage of 1.5V to form a closed circuit (such as Figure 9 As shown). Figure 9 It can be found that the device can generate a larger voltage and light up the diode by connecting in series, indicating that the device has broad application prospects and the generated energy can indeed be used.

[0089] 5) Experimental Group: The hydropower cogeneration gel-based device from Example 1 was fixed to the side wall of a 100 mL beaker (with the length of the hydropower cogeneration gel-based device perpendicular to the bottom of the beaker). 50 mL of deionized water was then added to the beaker, submerging half of the hydropower cogeneration gel-based device in the deionized water. The electrodes at both ends of the hydropower cogeneration gel-based device were then connected to an electrochemical workstation.

[0090] Control group: Add 50 mL of deionized water to a 100 mL beaker;

[0091] The experimental group and control group were placed on different balance scales, and a transparent glass cover was added to each to form a closed system. Then, the voltage and mass changes of the experimental group and the mass change of the control group were measured under the same xenon lamp. The test results are as follows: Figure 10 As shown. Figure 10It can be seen that in the test with samples, the mass change rate is faster than that without samples, and during this process, the device has been continuously outputting voltage, indicating that the device can absorb light and heat and purify water while outputting voltage.

[0092] 3. Water purification capacity test

[0093] Take a 20mm×20mm×15mm uncovered plastic box, and use a punch to punch a circular hole with a diameter of 1mm at a distance of about 2mm from the bottom. Then, place the two hydropower cogeneration gel-based devices in Example 1 in the above-mentioned uncovered plastic box respectively, and make one end electrode of the hydropower cogeneration gel-based device extend from the above-mentioned circular hole. At the same time, add 5g of methyl blue solution (mass fraction of 0.1%) to the uncovered plastic box, and install a transparent glass cover on the outside of the entire device to form a closed system. After 120 minutes of evaporation (the evaporation difference at both ends of the hydropower cogeneration gel-based device reaches equilibrium), collect the water condensed on the glass cover, and use an ultraviolet spectrophotometer to test its absorbance. The test results are as follows: Figure 11 As shown. Figure 11 It can be seen that the ultraviolet absorbance of the methylene blue solution changed greatly before and after the sample treatment, indicating that the sample has the ability to purify sewage.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A hydropower cogeneration gel-based device, characterized in that: The invention comprises two electrodes at both ends and an electricity-generating material in contact with the two electrodes; the electricity-generating material comprises a porous polymer matrix, and a conductive carbon material and a water-soluble metal salt dispersed in the porous polymer matrix; The porous polymer matrix is ​​mainly formed by free radical polymerization of chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and N,N′-methylenebisacrylamide; The tris(hydroxymethyl)methylglycine-modified chitosan is obtained by reacting tris(hydroxymethyl)methylglycine with chitosan, and the molar ratio of the repeating unit in the chitosan to the tris(hydroxymethyl)methylglycine is 1:(0.1-0.5); The reaction of tris(hydroxymethyl)methylglycine with chitosan refers to the reaction of the carboxyl group (-COOH) in tris(hydroxymethyl)methylglycine with the amino group (-NH2) in chitosan to graft tris(hydroxymethyl)methylglycine onto the side chain of chitosan.

2. The hydropower cogeneration gel-based device according to claim 1, characterized in that: The electricity-generating material is prepared by the following preparation method: Chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and water are mixed, and then a conductive carbon material and a water-soluble metal salt are added and mixed. Then, N,N′-methylenebisacrylamide and an initiator are added to carry out polymerization reaction at 50-80°C for 1-3 hours to obtain a gel matrix. The gel matrix is ​​then freeze-dried for 12-36 hours to obtain an electricity-generating material.

3. The hydropower cogeneration gel-based device according to claim 1, characterized in that: The mass volume ratio of the tris(hydroxymethyl)methylglycine-modified chitosan to acrylic acid is 1:(10-30) in g / mL.

4. The hydropower cogeneration gel-based device according to claim 1, wherein: The mass ratio of the tris(hydroxymethyl)methylglycine-modified chitosan to N,N′-methylenebisacrylamide is 1:(0.01-0.02).

5. The hydropower cogeneration gel-based device according to claim 1, characterized in that: The mass ratio of the tris(hydroxymethyl)methylglycine-modified chitosan to the conductive carbon material is 1:(0.1-0.8); And / or, the mass ratio of the tris(hydroxymethyl)methylglycine-modified chitosan to the water-soluble metal salt is 1:(1-10).

6. The hydropower cogeneration gel-based device according to claim 1, wherein: The conductive carbon material is at least one of carbon black, carbon nanotubes, and graphene; And / or, the water-soluble metal salt is at least one of lithium chloride and calcium chloride.

7. The hydropower cogeneration gel-based device according to claim 1, wherein: The weight average molecular weight of the chitosan is 40,000-60,000.

8. The method for preparing the hydropower cogeneration gel-based device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Tris(hydroxymethyl)methylglycine-modified chitosan, acrylic acid, and water are mixed uniformly, and then a conductive carbon material and a water-soluble metal salt are added and mixed uniformly, and then N,N′-methylenebisacrylamide and an initiator are added and mixed uniformly to form a precursor solution; S2. Place the precursor solution in S1 into a mold, insert the end electrode, polymerize at 50-80°C for 1-3 hours, and then freeze-dry for 12-36 hours to obtain a hydropower cogeneration gel-based device.

9. Use of the hydropower cogeneration gel-based device according to any one of claims 1 to 7 in the preparation of power generation devices or water purification devices.

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