Water and electricity co-production gel-based device as well as preparation method and application thereof

Abstract

The invention relates to a water and electricity co-production gel-based device and a preparation method and application thereof, and belongs to the technical field of water treatment. The water and electricity co-production gel-based device comprises electrodes at two ends and an electricity generation material in contact with the electrodes at the two ends, the electrogenesis material comprises a porous polymer matrix, and a conductive carbon material and a water-soluble metal salt which are dispersed in the porous polymer matrix; the porous polymer matrix is mainly prepared from chitosan modified by tris (hydroxymethyl) methylglycine, acrylic acid and N, N '-methylene bisacrylamide through free radical polymerization. The water and electricity co-production gel-based device disclosed by the invention has excellent electricity generation performance and water purification capability.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a water-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 collect energy from water waves, raindrops, moisture or evaporation. Among the many ways, the research on the generation of electricity by nanomaterials in the process of mutual transformation between gaseous water and liquid water has attracted much attention. It is mainly divided into moisture generation (moisture-induced electricity generation developed by adsorption of gaseous water) and evaporation generation (evaporation-induced electricity generation developed by evaporation of liquid water). Because the water vapor-liquid transformation process is less affected by time, space, geographical location or environmental factors, moisture generation and evaporation generation provide new solutions to global energy problems.

[0003] Compared with the smaller voltage / current signal and unstable pulse output of moisture power generation, evaporation power generation can achieve high power density continuous output, and the power generation capacity can better meet the needs of practical applications. Evaporation power generation devices are mainly divided into planar structures and sandwich structures. The planar structure is composed of electrodes at both ends and power generation materials in contact with the electrodes. This type of device can place one end in water or drip water at one end to achieve power generation. The key to its power generation performance lies in the power generation material. However, the current power generation 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 leads to the problem of poor power generation performance of evaporation power generation devices. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings 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 hydroelectric cogeneration gel-based device, which comprises two-terminal electrodes 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 formed by free radical polymerization of chitosan modified by tri(hydroxymethyl)methylglycine, acrylic acid and N,N'-methylenebisacrylamide.

[0008] The porous polymer matrix formed by free radical polymerization of chitosan modified with tri(hydroxymethyl)methylglycine, acrylic acid and N,N′-methylenebisacrylamide can form a water or ion transmission channel by utilizing a rich loose porous three-dimensional structure, and at the same time, tri(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; and the -COOH of part of acrylic acid can also react with -NH2 of chitosan to be grafted on the side chain of chitosan modified with tri(hydroxymethyl)methylglycine. The chitosan modified with tri(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 in contact 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 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 of the present invention, the power-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 to mix, and then N,N′-methylenebisacrylamide and an initiator are added to polymerize at 50 to 80°C for 1 to 3 hours to obtain a gel matrix, and then the gel matrix is ​​freeze-dried for 12 to 36 hours to obtain the power-generating material. Optionally, the polymerization temperature can be 55°C, 60°C, 65°C, 70°C, 75°C, and the time can be 1.5h, 2h, 2.5h; the freeze-drying time can be 15h, 20h, 25h, 30h, 35h.

[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 be ammonium persulfate in particular; the mass ratio of the chitosan modified by tris(hydroxymethyl)methylglycine to ammonium persulfate is 1:(0.5-1). Optionally, the mass ratio of the chitosan modified by tris(hydroxymethyl)methylglycine to ammonium persulfate can be 1:0.6, 1:0.7, 1:0.8, 1:0.9.

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

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

[0013] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the mass ratio of the chitosan modified by tris(hydroxymethyl)methylglycine 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 chitosan modified by tris(hydroxymethyl)methylglycine to the conductive carbon material is 1:(0.1-0.8). Optionally, the mass ratio of the chitosan modified by tris(hydroxymethyl)methylglycine to the conductive carbon material can be specifically 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7.

[0015] As a preferred embodiment of the hydropower cogeneration gel-based device of the present invention, the mass ratio of the chitosan modified by tris(hydroxymethyl)methylglycine to the water-soluble metal salt is 1:(1-10). Optionally, the mass ratio of the chitosan modified by tris(hydroxymethyl)methylglycine to the water-soluble metal salt can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 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 chitosan modified with tris(hydroxymethyl)methylglycine 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). Optionally, the molar ratio of the repeating unit in the chitosan to tris(hydroxymethyl)methylglycine can be specifically 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45.

[0018] The reaction of tris(hydroxymethyl)methylglycine with chitosan refers to the reaction of the carboxyl hydroxyl 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 the prior art (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), tri(hydroxymethyl)methylglycine is added, stirred until it is completely dissolved, then 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and N-hydroxysuccinimide (NHS) are added, first reacted in an ice water bath for 0.5 to 2 hours, then reacted at room temperature (25°C) for 12 to 36 hours, dialyzed (dialysis bag molecular weight cutoff 200000) for 3 to 5 days to remove unreacted tri(hydroxymethyl)methylglycine, EDC·HCl, NHS, etc., and freeze-dried to obtain a light yellow product, which is tri(hydroxymethyl)methylglycine-modified chitosan; wherein the molar ratio of the repeating unit in the chitosan to EDC·HCl is 1:(1 to 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 40000 to 60000. Optionally, the weight average molecular weight of the chitosan can be 45000, 50000, or 55000.

[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, mixing chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and water evenly, adding conductive carbon material and water-soluble metal salt and mixing evenly, and then adding N,N′-methylenebisacrylamide and initiator and mixing evenly to form a precursor solution;

[0024] S2. Place the precursor solution in S1 in a mold, insert the terminal 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 comprises electrodes at two ends and an electricity-generating material in electrolytic contact with the two ends; the electricity-generating material comprises 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 tri(hydroxymethyl)methylglycine, acrylic acid and N,N′-methylenebisacrylamide, which can form a water or ion transmission channel by utilizing a rich loose porous three-dimensional structure, and at the same time utilizes tri(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 tri(hydroxymethyl)methylglycine-modified chitosan, acrylic acid and cross-linking agent N,N′-methylenebisacrylamide can enable the power-generating material to maintain excellent mechanical properties after swelling in contact with water during actual application; while 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 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 It is a schematic diagram of the structure of the hydropower cogeneration gel-based device of the present invention;

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

[0030] Figure 3 Fourier transform infrared spectra of chitosan and chitosan modified by 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 is a graph showing the open circuit voltage of the hydropower cogeneration gel-based device in Example 1 as a function of time;

[0033] Figure 6 The open circuit voltage of the hydropower cogeneration gel-based device in Example 1 varies with the number of devices;

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

[0035] Figure 8 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] Fig. 9 A schematic diagram of a circuit for lighting up a light-emitting diode in a closed loop of a hydropower cogeneration gel-based device in multiple embodiments 1;

[0037] Fig.10 is a graph showing the mass variation of the solution with and without the water-power cogeneration gel-based device in Example 1 in a closed system over time;

[0038] Fig.11 The ultraviolet absorption spectra of the methyl blue solution and the methyl blue solution treated by the hydropower cogeneration gel-based device in Example 1 are shown. 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, reagents, etc. 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] Chitosan modified with tri(hydroxymethyl)methylglycine 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 it was completely dissolved. Then, 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, and then at room temperature (25°C) for 24 h. Unreacted tris(hydroxymethyl)methylglycine, EDC·HCl, NHS, etc. were removed by dialysis (dialysis bag molecular weight cutoff 200,000), and the light 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 a nuclear magnetic resonance hydrogen spectrum test at 600 MHz. The test results are as follows: Figure 2 As shown. Figure 2 It can be seen that the chemical shift of 3.87ppm corresponds to the characteristic peak of tri(hydroxymethyl)methylglycine, and the chemical shifts of 2.75ppm-3.75ppm are all characteristic peaks of chitosan. The appearance of the characteristic peak of chemical shift 3.87ppm fully proves the successful synthesis of chitosan modified with tri(hydroxymethyl)methylglycine.

[0045] At the same time, the chitosan and chitosan modified with tris(hydroxymethyl)methylglycine 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 by tri(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 electrodes at both ends (carbon rod electrodes) and an electricity-generating material (hydrogel) in electrolytic contact with both 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 by tris(hydroxymethyl)methylglycine, acrylic acid and N,N′-methylenebisacrylamide;

[0048] Among them, the mass volume ratio of the above-mentioned tri(hydroxymethyl)methylglycine-modified chitosan and acrylic acid is 1:15 g / mL; the mass ratio of tri(hydroxymethyl)methylglycine-modified chitosan and N,N′-methylenebisacrylamide is 1:0.25; the mass ratio of tri(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, and 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), 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) at both ends of the length direction about 2 cm away from the mold wall as end electrodes, and 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, the hydropower cogeneration gel-based device described in this embodiment is basically the same as Example 1, the only difference is 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, the hydropower cogeneration gel-based device described in this embodiment is basically the same as Example 1, the only difference is 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 Example 1, the only difference is that the power generating material includes a porous polymer matrix and lithium chloride (without adding carbon black) 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 Example 1, the only difference is that the power generation 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 hydropower cogeneration gel-based device of the present invention, the hydropower cogeneration gel-based device described in this embodiment is basically the same as Example 1, the only difference is that the porous polymer matrix is ​​formed by free radical polymerization of chitosan, acrylic acid and N,N′-methylenebisacrylamide.

[0066] The preparation method of the hydropower cogeneration gel-based device comprises the following steps:

[0067] S1. 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, and 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;

[0068] S2. Place the precursor solution in S1 in a mold (rectangular mold: 30 mm long × 10 mm wide × 20 mm high), 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) at both ends of the length direction about 2 cm away from the mold wall as end electrodes, and 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.

[0069] Comparative Example 4

[0070] 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 Example 1, the only difference is that the porous polymer matrix is ​​mainly formed by free radical polymerization of chitosan modified by tris(hydroxymethyl)methylglycine and acrylic acid.

[0071] The preparation method of the hydropower cogeneration gel-based device comprises the following steps:

[0072] 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, and then an initiator (ammonium persulfate, 0.3 g) was added and stirred for 30 min to form a precursor solution;

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

[0074] Comparative Example 5

[0075] 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 Example 1, the only difference is that: the porous polymer matrix is ​​formed by free radical polymerization of chitosan modified by tris(hydroxymethyl)methylglycine and N,N′-methylenebisacrylamide.

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

[0077] S1. Tris(hydroxymethyl)methylglycine-modified chitosan (0.4 g) 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, and 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;

[0078] S2. Place the precursor solution in S1 in a mold (rectangular mold: 30 mm long × 10 mm wide × 20 mm high), 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) at both ends of the length direction about 2 cm away from the mold wall as end electrodes, and 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.

[0079] Performance Testing

[0080] 1. Scanning electron microscope (SEM) test

[0081] Figure 4 This is a SEM image of the electricity-generating material in the hydropower cogeneration gel-based device prepared in Example 1. Figure 4 It can be seen that there is a porous structure inside the device, which fully demonstrates 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, 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 uncovered plastic box and make one end electrode of the hydropower cogeneration gel-based device extend out of the circular hole, and at the same time add 5g of deionized water to the uncovered plastic box, measure the open circuit voltage between the electrodes at both ends of the hydropower cogeneration gel-based device to evaluate its power generation performance, and the test results are as follows: Figure 5 Then four hydropower cogeneration gel-based devices (the same as in Example 1) are 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 is tested. The test results are 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 20mm×20mm×15mm uncovered plastic boxes, use a puncher to punch a circular hole with a diameter of 1mm at a distance of about 2mm from the bottom, and then place the two hydropower cogeneration gel-based devices in Example 1 in the above-mentioned uncovered plastic boxes respectively so that one end electrode of the hydropower cogeneration gel-based device extends out of 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 the voltage generated by the device is greater when sodium chloride aqueous solution is used, 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, 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 and make one end electrode of the hydropower cogeneration gel-based device extend out of the above-mentioned circular hole, and at the same time add 5g of deionized water to the uncovered plastic box. After evaporation for more than 60min (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 20s (exchange 3 times in total). 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, 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 and make one end electrode of the hydropower cogeneration gel-based device extend out of the above-mentioned circular hole, and at the same time add 5g of deionized water to the uncovered plastic box, and wait for 2h of evaporation (the evaporation difference at both ends of the hydropower cogeneration gel-based device reaches equilibrium); then connect the above-mentioned 4 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 loop (such as Fig. 9 ). Fig. 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 in Example 1 was fixed on the side wall of a beaker with a capacity of 100 mL (the length direction of the hydropower cogeneration gel-based device was perpendicular to the bottom of the beaker), and then 50 mL of deionized water was added to the beaker so that half of the hydropower cogeneration gel-based device was immersed in the deionized water, and then the electrodes at both ends of the hydropower cogeneration gel-based device were connected to the electrochemical workstation;

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

[0091] The experimental group and control group were placed on different balance scales and equipped with a transparent glass cover 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: Fig.10 As shown. Fig.10It can be seen that in the test with samples, the mass change rate is faster than that without samples, and in 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, use a puncher 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 out of the above-mentioned circular hole, and 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: Fig.11 As shown. Fig.11 It can be seen that the ultraviolet absorbance of the methylene blue solution before and after the sample treatment has changed greatly, 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 solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A hydropower cogeneration gel-based device, characterized in that: It includes two electrodes at both ends and an electricity-generating material in contact with the two electrodes; the electricity-generating material includes 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 by tri(hydroxymethyl)methylglycine, acrylic acid and N,N'-methylenebisacrylamide.

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 tri(hydroxymethyl)methylglycine, acrylic acid and water are mixed, and then a conductive carbon material and a water-soluble metal salt are added and mixed, and then N,N′-methylenebisacrylamide and an initiator are added to polymerize at 50 to 80°C for 1 to 3 hours to obtain a gel matrix, and then the gel matrix is ​​freeze-dried for 12 to 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) g / mL.

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

6. The hydropower cogeneration gel-based device according to claim 1, characterized in that: 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, characterized in that: The tri(hydroxymethyl)methylglycine-modified chitosan is obtained by reacting tri(hydroxymethyl)methylglycine with chitosan, and the molar ratio of the repeating unit in the chitosan to the tri(hydroxymethyl)methylglycine is 1:(0.1-0.5).

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

9. The method for preparing the hydropower cogeneration gel-based device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, mixing chitosan modified with tris(hydroxymethyl)methylglycine, acrylic acid and water evenly, adding conductive carbon material and water-soluble metal salt and mixing evenly, and then adding N,N′-methylenebisacrylamide and initiator and mixing evenly to form a precursor solution; S2. Place the precursor solution in S1 in a mold, insert the terminal 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.

10. Use of the hydropower cogeneration gel-based device according to any one of claims 1 to 8 in the preparation of power generation devices or water purification devices.

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