A method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation

Abstract

A method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional manipulation of bubbles, which belongs to the field of new energy electrolytic hydrogen production and fluid transport technology. The present invention prints the electrode substrate and the gas manipulation grid based on surface projection micro-stereolithography printing technology, and uses nano-silicon dioxide to perform asymmetric wettability treatment on the gas manipulation grid on the top of the electrode, and uses its super-aerophilic properties to perform unidirectional manipulation of the bubbles; and uses chemical deposition to deposit a cobalt-nickel-phosphorus alloy catalyst on the bottom three-dimensional electrode surface, thereby achieving the functions of efficient hydrogen production by electrolysis of water and separation of hydrogen products. This three-dimensional hydrogen production functional electrode and its preparation method are simple to operate and have excellent hydrogen production performance. The three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional manipulation of bubbles prepared by the present invention has the characteristics of large-area stacking and splicing, which can enhance space utilization while accelerating electrolysis efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy electrolytic hydrogen production and fluid transportation, and specifically relates to a method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation. Background Art

[0002] As a clean energy carrier, hydrogen has the characteristics of zero carbon emissions. When it is burned or used to generate electricity through fuel cells, it only produces water vapor and does not release greenhouse gases or pollutants. As a clean and sustainable hydrogen production technology, hydrogen production by water electrolysis has far-reaching significance for promoting energy transformation and solving energy storage and transportation problems. Therefore, the design and development of functional electrodes with efficient water electrolysis hydrogen production and hydrogen transportation and collection will provide new research ideas for the development and transformation of hydrogen energy technology. Existing water electrolysis hydrogen production electrodes mainly rely on nickel foam and carbon paper with self-supporting structures as substrates, and the catalyst is attached to the substrate. However, due to the porous and multi-micro-nano structure of the electrode, the hydrogen bubbles in the water electrolysis hydrogen production process cannot escape by themselves, which in turn affects the reaction and performance testing. Intervention of the water electrolysis hydrogen production bubble behavior by external physical means cannot achieve the removal of hydrogen bubbles on the electrode surface, which ultimately affects the catalytic active sites of the electrode and reduces the electrode catalytic efficiency. The water electrolysis hydrogen production electrode designed using wettability engineering shows excellent performance in bubble control behavior. The electrode consists of a catalytic area and an asymmetric wettability bubble control area, which is equivalent to the catalytic area, limiting the rational use of the electrode catalytic area, resulting in poor overall electrode performance. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation.

[0004] The present invention provides a method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation, aiming to solve the bubble control problem of existing water electrolysis electrodes in hydrogen evolution reactions. The present invention makes full use of asymmetric wettability engineering and unidirectional bubble manipulation technology to perform ultra-fast directionally manipulate, transport and collect the hydrogen produced by water electrolysis to achieve "cleaning" of bubbles on the electrode surface and reconstruction of catalytic active sites. At the same time, the gas manipulation grid and the electrode substrate are assembled up and down without spatial interference, achieving perfect utilization of space and showing excellent performance in water electrolysis hydrogen production performance and bubble manipulation behavior; the top gas manipulation grid of the three-dimensional electrolytic hydrogen production functional electrode is treated with asymmetric wettability to form a Laplace pressure difference in the gas-liquid-solid three-phase, and the bubbles generated on the electrode surface are transported from bottom to top. The bubble manipulation grid is treated with asymmetric wettability, that is, the bottom of the grid is hydrophilic (contact angle less than 30°), and the top is treated with nano-silica spraying to form super-hydrophobicity (contact angle greater than 150°). Therefore, these two different wettability interfaces constitute the asymmetric wettability of the bubble manipulation grid. This longitudinally distributed three-dimensional electrolytic hydrogen production functional electrode that does not occupy the catalytic area can simultaneously meet excellent catalytic performance and bubble manipulation performance. In addition, the three-dimensional electrolytic hydrogen production functional electrode can rely on the bubble manipulation grid and the catalytic substrate to be assembled up and down to achieve reasonable space application, such as large-area splicing of the three-dimensional electrolytic hydrogen production functional electrode into the plane, or the stacking application of the three-dimensional electrolytic hydrogen production functional electrode in the space.

[0005] A method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation, characterized in that the preparation method is specifically completed according to the following steps:

[0006] 1. Using 3D modeling software, establish a 3D model of a 3D electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation; the 3D electrolytic hydrogen production functional electrode comprises an electrode substrate and a gas manipulation grid;

[0007] The electrode substrate described in step 1 is an irregular three-dimensional surface;

[0008] The gas manipulation grid described in step 1 is composed of polygonal through holes and polygonal cross sections, and the polygonal through holes are connected by polygonal cross sections to form an integral grid structure;

[0009] 2. Use the corresponding slicing software to slice the 3D model and transfer the sliced ​​model to the control system of the light-curing 3D printer;

[0010] 3. Use a light-curing 3D printer to print layer by layer to obtain the electrode substrate and gas manipulation grid required for the three-dimensional electrolysis hydrogen production functional electrode;

[0011] 4. Irradiate the printed electrode substrate and gas manipulation grid with a 405nm UV lamp for a period of time to obtain a cured electrode substrate and gas manipulation grid;

[0012] 5. depositing a cobalt-nickel-phosphorus alloy catalyst on the solidified electrode substrate by chemical plating to obtain an electrode substrate on which the cobalt-nickel-phosphorus alloy catalyst is deposited;

[0013] 6. Soaking the solidified gas manipulation grid in hydrochloric acid for a period of time and using ultrasonic vibration, then taking it out and drying it to obtain a hydrochloric acid-treated gas manipulation grid;

[0014] 7. Fix the hydrochloric acid-treated gas manipulation grid on a glass slide, then evenly spray a hydrophobic material composed mainly of nano-silica particles on the upper surface and sidewalls of the hydrochloric acid-treated gas manipulation grid, and then dry it to obtain a gas manipulation grid with an asymmetric wettability gradient;

[0015] 8. Assemble the electrode substrate deposited with the cobalt-nickel-phosphorus alloy catalyst and the gas manipulation grid with an asymmetric wettability gradient, so that the gas manipulation grid with an asymmetric wettability gradient is set on the electrode substrate deposited with the cobalt-nickel-phosphorus alloy catalyst, to obtain a three-dimensional electrolysis hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation.

[0016] The gas manipulation grid with an asymmetric wettability gradient obtained in step seven of the present invention exhibits an air-repellent property at the bottom, and a super-air-philic property at the sidewalls and the top.

[0017] The three-dimensional electrolytic hydrogen production functional electrode prepared by the present invention based on wettability gradient and unidirectional bubble manipulation can, while ensuring extremely high catalytic efficiency, utilize the Laplace pressure difference formed by the asymmetric wettability of the bubble manipulation grid to actively detach the bubbles generated and accumulated on the catalyst surface from bottom to top, alleviate the obstruction of the catalytic area, accelerate the ion exchange rate, and promote the progress of the catalytic reaction.

[0018] The working process of the three-dimensional electrolysis hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation in the present invention is as follows:

[0019] The three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and bubble unidirectional control prepared by the present invention is placed in a three-electrode electrolytic hydrogen production acidic electrolytic cell, and the three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and bubble unidirectional control prepared by the present invention is used as a working electrode, graphite is used as a counter electrode, and silver / silver chloride is used as a reference electrode; after power is applied, hydrogen bubbles nucleate, aggregate, and grow on the surface of the cobalt-nickel-phosphorus alloy catalyst of the three-dimensional electrolytic hydrogen production functional electrode. When the volume of the hydrogen bubbles expands to the point where they touch the gas with asymmetric wettability gradient at the top, the hydrogen bubbles grow. After manipulating the grid, under the action of the combined force, the bubbles will be rapidly adsorbed from the electrode surface to the top of the grid, undergoing an ultra-fast unidirectional detachment process from bottom to top, thereby completing the transport of hydrogen bubbles; during hydrogen production and bubble manipulation, the asymmetric wettability gradient is manifested at the top and bottom of the grid, that is, the top is super-hydrophobic and the bottom is hydrophilic; in this asymmetric interfacial wettability, a dominant Laplace pressure difference will be generated in the gas-liquid-solid three-phase system, which can transport bubbles unidirectionally from the catalyst interface to the top.

[0020] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0021] 1. The three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble control prepared by the present invention has higher hydrogen production efficiency and bubble control efficiency than the one-dimensional planar electrolytic hydrogen production functional electrode;

[0022] Second, the three-dimensional electrolytic hydrogen production functional electrode prepared by the present invention based on wettability gradient and unidirectional bubble control can control the active detachment of a single bubble from the bottom to the top of the catalytic electrode surface within 20 milliseconds and has good stability.

[0023] 3. The chemically deposited cobalt-nickel-phosphorus alloy catalyst exhibits a low overpotential, and its electrode catalytic performance does not decay during long-term hydrogen electrolysis experiments;

[0024] 4. The three-dimensional electrolysis hydrogen production functional electrode prepared by the present invention based on wettability gradient and unidirectional bubble control has the characteristics of large-area stacking and splicing, which can enhance space utilization while accelerating electrolysis efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation in Example 1. In the figure, 1 is a nano-silica coating, 2 is a gas manipulation grid, 3 is a cobalt-nickel-phosphorus alloy catalyst, and 4 is an electrode substrate;

[0026] Figure 2 This is a magnified scanning electron microscope image of the nano-silica coating on the gas manipulation grid in step 7 of Example 1;

[0027] Figure 3This is a magnified scanning electron microscope image of the cobalt-nickel-phosphorus alloy catalyst on the electrode substrate in step 5 of Example 1;

[0028] Figure 4 A photo of a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation prepared in Example 1;

[0029] Figure 5 A diagram illustrating the experimental process of electrolytic hydrogen production and bubble manipulation using a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation prepared in Example 1;

[0030] Figure 6 Current density performance images of 1D, 2D, and 3D electrodes. DETAILED DESCRIPTION

[0031] Specific embodiment 1: This embodiment provides a method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation, which is specifically completed in the following steps:

[0032] 1. Using 3D modeling software, establish a 3D model of a 3D electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation; the 3D electrolytic hydrogen production functional electrode comprises an electrode substrate and a gas manipulation grid;

[0033] The electrode substrate described in step 1 is an irregular three-dimensional surface;

[0034] The gas manipulation grid described in step 1 is composed of polygonal through holes and polygonal cross sections, and the polygonal through holes are connected by polygonal cross sections to form an integral grid structure;

[0035] 2. Use the corresponding slicing software to slice the 3D model and transfer the sliced ​​model to the control system of the light-curing 3D printer;

[0036] 3. Use a light-curing 3D printer to print layer by layer to obtain the electrode substrate and gas manipulation grid required for the three-dimensional electrolysis hydrogen production functional electrode;

[0037] 4. Irradiate the printed electrode substrate and gas manipulation grid with a 405nm UV lamp for a period of time to obtain a cured electrode substrate and gas manipulation grid;

[0038] 5. depositing a cobalt-nickel-phosphorus alloy catalyst on the solidified electrode substrate by chemical plating to obtain an electrode substrate on which the cobalt-nickel-phosphorus alloy catalyst is deposited;

[0039] 6. Soaking the solidified gas manipulation grid in hydrochloric acid for a period of time and using ultrasonic vibration, then taking it out and drying it to obtain a hydrochloric acid-treated gas manipulation grid;

[0040] 7. Fix the hydrochloric acid-treated gas manipulation grid on a glass slide, then evenly spray a hydrophobic material composed mainly of nano-silica particles on the upper surface and sidewalls of the hydrochloric acid-treated gas manipulation grid, and then dry it to obtain a gas manipulation grid with an asymmetric wettability gradient;

[0041] 8. Assemble the electrode substrate deposited with the cobalt-nickel-phosphorus alloy catalyst and the gas manipulation grid with an asymmetric wettability gradient, so that the gas manipulation grid with an asymmetric wettability gradient is set on the electrode substrate deposited with the cobalt-nickel-phosphorus alloy catalyst, to obtain a three-dimensional electrolysis hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation.

[0042] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the irregular three-dimensional surface described in step 1 is a parabolic curvature surface or a double parabolic curvature surface. The other steps are the same as those in specific embodiment 1.

[0043] Specific embodiment 3: This embodiment differs from specific embodiments 1 or 2 in that the polygonal through-hole described in step 1 is rectangular, circular, triangular, or pentagonal; the aperture of the polygonal through-hole is in the range of 100 μm to 600 μm; and the polygonal cross-section described in step 1 is circular or rectangular. Other steps are the same as those in specific embodiments 1 or 2.

[0044] Specific Embodiment 4: This embodiment differs from Specific Embodiments 1 to 3 in that the electrode substrate required for the three-dimensional electrolytic hydrogen production electrode in step 3 is made of a polymer light-curing resin; the gas manipulation grid required for the three-dimensional electrolytic hydrogen production electrode in step 3 is also made of a polymer light-curing resin; this polymer light-curing resin is purchased from Chongqing Mofang Precision Technology Co., Ltd. and is designated HTL (high-temperature resistant resin). The remaining steps are the same as Specific Embodiments 1 to 3.

[0045] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the illumination time in step 4 is 3 to 5 minutes. The other steps are the same as those in specific embodiments 1 to 4.

[0046] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that: in step 5, the cobalt-nickel-phosphorus alloy catalyst is deposited on the electrode substrate using chemical plating, which is specifically completed by the following steps:

[0047] ① Immerse the cured electrode substrate in anhydrous ethanol and ultrasonically treat for 10 minutes. Repeat the above operation twice to remove oxides and impurities on the surface of the electrode substrate to obtain a cleaned electrode substrate. Immerse the cleaned electrode substrate in a mixture of 39.6 mL of water, 400 μL of 37% dilute hydrochloric acid, and 0.426 g of SnCl2 at a temperature of 45°C for 10 minutes. The electrode is sensitized in this step to obtain a sensitized electrode substrate.

[0048] ② Rinse the sensitized electrode substrate 3 to 5 times with deionized water, then dry it, and then place it in a mixture of 40 mL of water, 100 μL of 37% dilute hydrochloric acid, and 0.005 g of PdCl2 at 45°C for 20 minutes to complete the activation process and obtain the activated electrode substrate;

[0049] ③. Add 0.657 g NiSO4·6H2O and 0.703 g CoSO4·7H2O to 80 mL deionized water and stir evenly with a magnetic stirrer. Then add 2.94 g C6H5Na3O7 and 3.45 g C4H4Na2O6 and continue stirring. Then add 6.6 g (NH4)2SO4 and 2.12 g NaH2PO2 to the solution. Finally, add NaOH to adjust the pH value of the solution to 8.0-9.0. After stirring evenly, add deionized water to a beaker with a graduated cylinder, dilute to 100 mL, and heat the solution to 70°C for 10 min to obtain a deposition solution.

[0050] ④ Immerse the activated electrode substrate in the deposition solution for 3 to 5 minutes, remove it and dry it to obtain an electrode substrate with a cobalt-nickel-phosphorus alloy catalyst deposited thereon. The other steps are the same as those in the first to fifth embodiments.

[0051] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the thickness of the cobalt-nickel-phosphorus alloy catalyst on the surface of the electrode substrate in step 5 is 50 nm to 200 nm. The other steps are the same as specific embodiments 1 to 6.

[0052] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that the concentration of the hydrochloric acid in step six is ​​0.1 mol / L; and the soaking time in step six is ​​10 min to 15 min.

[0053] The other steps are the same as those in Specific Embodiments 1 to 7.

[0054] Specific Embodiment 9: This embodiment differs from Specific Embodiments 1 to 8 in that the hydrophobic material described in step 7, whose main component is nano-silica particles, is NeverWet produced by Rust-Oleum; the thickness of the nano-silica on the surface of the gas manipulation grid in step 7 is 500 nm to 1000 nm; and the drying temperature in step 7 is 60°C to 70°C, and the drying time is 10 to 12 hours. The other steps are the same as Specific Embodiments 1 to 8.

[0055] Specific Embodiment 10: This embodiment differs from Specific Embodiments 1 to 9 in that the distance between the surface of the electrode substrate on which the cobalt-nickel-phosphorus alloy catalyst is deposited and the gas manipulation grid with the asymmetric wettability gradient described in step 8 is 200 μm to 600 μm. The remaining steps are the same as Specific Embodiments 1 to 9.

[0056] In this embodiment, the fixing and assembly are performed by ultra-thin double-sided tape or resin curing.

[0057] The following examples are used to verify the beneficial effects of the present invention:

[0058] Example 1: Combination Figures 1 to 5 This embodiment describes a method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation, which is specifically completed by the following steps:

[0059] 1. Using 3D modeling software, establish a 3D model of a 3D electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation; the 3D electrolytic hydrogen production functional electrode comprises an electrode substrate and a gas manipulation grid;

[0060] The electrode substrate described in step 1 is a double parabola curvature surface;

[0061] The gas manipulation grid described in step 1 is composed of polygonal through holes and polygonal cross sections, and the polygonal through holes are connected by polygonal cross sections to form an integral grid structure; the polygonal through holes described in step 1 are rectangular; the aperture of the polygonal through holes is a rectangle with a side length of 400 μm; the polygonal cross section described in step 1 is a rectangular cross section;

[0062] 2. Use the corresponding slicing software to slice the 3D model and transfer the sliced ​​model to the control system of the light-curing 3D printer;

[0063] The material of the electrode substrate required for the three-dimensional electrolytic hydrogen production functional electrode in step 3 is a polymer light-curing resin; the polymer light-curing resin is purchased from Chongqing Mofang Precision Technology Co., Ltd., and the model is HTL (high temperature resistant resin);

[0064] The material of the gas manipulation grid required for the three-dimensional electrolysis hydrogen production functional electrode described in step 3 is a polymer light-curing resin; the polymer light-curing resin is purchased from Chongqing Mofang Precision Technology Co., Ltd. and the model is HTL (high temperature resistant resin);

[0065] 3. Use a light-curing 3D printer to print layer by layer to obtain the electrode substrate and gas manipulation grid required for the three-dimensional electrolysis hydrogen production functional electrode;

[0066] 4. Irradiate the printed electrode substrate and gas manipulation grid with a 405nm UV lamp for a period of time to obtain a cured electrode substrate and gas manipulation grid;

[0067] The illumination time described in step 4 is 5 minutes;

[0068] 5. depositing a cobalt-nickel-phosphorus alloy catalyst on the solidified electrode substrate by chemical plating to obtain an electrode substrate on which the cobalt-nickel-phosphorus alloy catalyst is deposited;

[0069] 6. Soak the solidified gas manipulation grid in hydrochloric acid for 1 hour and use ultrasonic vibration, then take it out and dry it to obtain a hydrochloric acid-treated gas manipulation grid;

[0070] The concentration of hydrochloric acid in step 6 is 0.1 mol / L;

[0071] 7. Fix the hydrochloric acid-treated gas manipulation grid on a glass slide, then evenly spray a hydrophobic material composed mainly of nano-silica particles on the upper surface and sidewalls of the hydrochloric acid-treated gas manipulation grid, and then dry it to obtain a gas manipulation grid with an asymmetric wettability gradient;

[0072] The hydrophobic material described in step 7, whose main component is nano-silica particles, is NeverWet produced by Rust-Oleum;

[0073] In step 7, the thickness of the nano-silicon dioxide on the surface of the gas manipulation grid is 500 nm to 800 nm;

[0074] The drying temperature in step 7 is 60°C and the drying time is 12 hours;

[0075] 8. Assembling an electrode substrate deposited with a cobalt-nickel-phosphorus alloy catalyst and a gas manipulation grid with an asymmetric wettability gradient, so that the gas manipulation grid with an asymmetric wettability gradient is disposed on the electrode substrate deposited with the cobalt-nickel-phosphorus alloy catalyst, to obtain a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation;

[0076] The distance between the surface of the electrode substrate on which the cobalt-nickel-phosphorus alloy catalyst is deposited and the gas manipulation grid with the asymmetric wettability gradient described in step eight is 400 μm.

[0077] In step 5 of Example 1, the cobalt-nickel-phosphorus alloy catalyst is deposited on the electrode substrate using chemical plating, which is specifically completed by the following steps:

[0078] ① Immerse the cured electrode substrate in anhydrous ethanol and ultrasonically treat for 10 minutes. Repeat the above operation twice to remove oxides and impurities on the surface of the electrode substrate to obtain a cleaned electrode substrate. Immerse the cleaned electrode substrate in a mixture of 39.6 mL of water, 400 μL of 37% dilute hydrochloric acid, and 0.426 g of SnCl2 at a temperature of 45°C for 10 minutes. The electrode is sensitized in this step to obtain a sensitized electrode substrate.

[0079] ② Rinse the sensitized electrode substrate five times with deionized water, dry it, and then place it in a mixture of 40 mL of water, 100 μL of 37% dilute hydrochloric acid, and 0.005 g of PdCl2 at 45°C for 20 minutes to complete the activation process and obtain the activated electrode substrate;

[0080] ③. Add 0.657 g NiSO4·6H2O and 0.703 g CoSO4·7H2O to 80 mL deionized water and stir evenly with a magnetic stirrer. Then add 2.94 g C6H5Na3O7 and 3.45 g C4H4Na2O6 and continue stirring. Then add 6.6 g (NH4)2SO4 and 2.12 g NaH2PO2 to the solution. Finally, add NaOH to adjust the pH value of the solution to 8.0-9.0. After stirring evenly, add deionized water to a beaker with a graduated cylinder, dilute to 100 mL, and heat the solution to 70°C for 10 min to obtain a deposition solution.

[0081] ④. Immerse the activated electrode substrate in the deposition solution for 5 minutes, take it out and dry it to obtain an electrode substrate with a cobalt-nickel-phosphorus alloy catalyst deposited thereon.

[0082] Figure 4 A photo of a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation prepared in Example 1;

[0083] Figure 5 This is a diagram of the experimental process of electrolytic hydrogen production and bubble manipulation using a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation prepared in Example 1.

[0084] from Figure 4-Figure 5 It can be seen that a three-dimensional electrolysis hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation can produce hydrogen.

[0085] Hydrogen production by water electrolysis I:

[0086] The three-dimensional electrolytic hydrogen production functional electrode (3D electrode) based on wettability gradient and unidirectional bubble manipulation prepared in Example 1 was placed in a three-electrode electrolytic hydrogen production acidic electrolyzer, and a 0.1 mol / L sulfuric acid solution was added to the electrolyzer. The three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation prepared in the present invention was used as a working electrode, graphite was used as a counter electrode, and silver / silver chloride was used as a reference electrode. After a constant voltage of 2 V was applied, hydrogen bubbles nucleated, aggregated, and grew on the surface of the cobalt-nickel-phosphorus alloy catalyst of the three-dimensional electrolytic hydrogen production functional electrode. When the volume of the hydrogen bubbles expanded, the hydrogen bubbles formed a hydrogen bubble. After expanding to contact the gas manipulation grid with an asymmetric wettability gradient at the top, the bubbles will be rapidly adsorbed from the electrode surface to the top of the grid under the action of the combined force, thus undergoing an ultra-fast unidirectional detachment process from bottom to top, thereby completing the transport of hydrogen bubbles; during the hydrogen production and bubble manipulation process, the asymmetric wettability gradient is manifested at the top and bottom of the grid, that is, the top is super-hydrophobic and the bottom is hydrophilic; in this asymmetric interfacial wettability, a dominant Laplace pressure difference will be generated in the gas-liquid-solid three-phase system, which can transport bubbles unidirectionally from the catalyst interface to the top.

[0087] Electrolysis of Water to Hydrogen II: A one-dimensional common flat electrode (1D electrode) was used to replace the three-dimensional electrolysis hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation prepared in Example 1. The other steps and parameters were the same as those of Electrolysis of Water to Hydrogen I.

[0088] Electrolysis of Water to Hydrogen III: A two-dimensional electrode (2D electrode) was used to replace the three-dimensional electrolysis hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation prepared in Example 1. The other steps and parameters were the same as those of Electrolysis of Water to Hydrogen I.

[0089] Figure 6 Current density performance images of 1D, 2D, and 3D electrodes;

[0090] from Figure 6 It can be seen that: under the same voltage and experimental conditions, the current density of the three-dimensional electrolysis hydrogen production functional electrode (3D electrode) based on wettability gradient and unidirectional bubble manipulation prepared in Example 1 is 2.5 times higher than that of the two-dimensional electrode (2D electrode), and 8 times higher than that of the one-dimensional ordinary flat plate electrode (1D electrode) with the same catalytic surface area.

Claims

1. A method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation, characterized in that The preparation method is specifically completed according to the following steps:

1. Using 3D modeling software, establish a 3D model of a 3D electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation; the 3D electrolytic hydrogen production functional electrode comprises an electrode substrate and a gas manipulation grid; The electrode substrate described in step 1 is an irregular three-dimensional surface; The gas manipulation grid described in step 1 is composed of polygonal through holes and polygonal cross sections, and the polygonal through holes are connected by polygonal cross sections to form an integral grid structure; 2. Use the corresponding slicing software to slice the 3D model and transfer the sliced ​​model to the control system of the light-curing 3D printer; 3. Use a light-curing 3D printer to print layer by layer to obtain the electrode substrate and gas manipulation grid required for the three-dimensional electrolysis hydrogen production functional electrode; 4. Irradiate the printed electrode substrate and gas manipulation grid with a 405nm UV lamp for a period of time to obtain a cured electrode substrate and gas manipulation grid; 5. depositing a cobalt-nickel-phosphorus alloy catalyst on the solidified electrode substrate by chemical plating to obtain an electrode substrate on which the cobalt-nickel-phosphorus alloy catalyst is deposited; 6. Soaking the solidified gas manipulation grid in hydrochloric acid for a period of time and using ultrasonic vibration, then taking it out and drying it to obtain a hydrochloric acid-treated gas manipulation grid; 7. Fix the hydrochloric acid-treated gas manipulation grid on a glass slide, then evenly spray a hydrophobic material composed mainly of nano-silica particles on the upper surface and sidewalls of the hydrochloric acid-treated gas manipulation grid, and then dry it to obtain a gas manipulation grid with an asymmetric wettability gradient; 8. Assemble the electrode substrate deposited with the cobalt-nickel-phosphorus alloy catalyst and the gas manipulation grid with an asymmetric wettability gradient, so that the gas manipulation grid with an asymmetric wettability gradient is set on the electrode substrate deposited with the cobalt-nickel-phosphorus alloy catalyst, to obtain a three-dimensional electrolysis hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation.

2. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that The irregular three-dimensional surface described in step 1 is a parabola curvature surface or a double parabola curvature surface.

3. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that The polygonal through hole described in step 1 is rectangular, circular, triangular or pentagonal; the aperture range of the polygonal through hole is 100 μm to 600 μm; the polygonal cross section described in step 1 is a circular cross section or a rectangular cross section.

4. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that The material of the electrode substrate required for the three-dimensional electrolytic hydrogen production functional electrode described in step three is a polymer photocurable resin; the material of the gas control grid required for the three-dimensional electrolytic hydrogen production functional electrode described in step three is a polymer photocurable resin.

5. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that The illumination time described in step 4 is 3 minutes to 5 minutes.

6. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that In step five, the cobalt-nickel-phosphorus alloy catalyst is deposited on the electrode substrate using electroless plating, which is accomplished by the following steps: ① Immerse the cured electrode substrate in anhydrous ethanol and ultrasonically treat for 10 minutes. Repeat the above operation twice to remove oxides and impurities on the surface of the electrode substrate to obtain a cleaned electrode substrate. Immerse the cleaned electrode substrate in a mixture of 39.6 mL of water, 400 μL of 37% dilute hydrochloric acid, and 0.426 g of SnCl2 at a temperature of 45°C for 10 minutes. The electrode is sensitized in this step to obtain a sensitized electrode substrate. ② Rinse the sensitized electrode substrate 3 to 5 times with deionized water, then dry it, and then place it in a mixture of 40 mL of water, 100 μL of 37% dilute hydrochloric acid, and 0.005 g of PdCl2 at 45°C for 20 minutes to complete the activation process and obtain the activated electrode substrate; ③. Add 0.657 g NiSO4·6H2O and 0.703 g CoSO4·7H2O to 80 mL deionized water and stir evenly with a magnetic stirrer. Then add 2.94 g C6H5Na3O7 and 3.45 g C4H4Na2O6 and continue stirring. Then add 6.6 g (NH4)2SO4 and 2.12 g NaH2PO2 to the solution. Finally, add NaOH to adjust the pH value of the solution to 8.0-9.

0. After stirring evenly, add deionized water to a beaker with a graduated cylinder, dilute to 100 mL, and heat the solution to 70°C for 10 min to obtain a deposition solution. ④. Immerse the activated electrode substrate in the deposition solution for 3 to 5 minutes, take it out and dry it to obtain an electrode substrate with the cobalt-nickel-phosphorus alloy catalyst deposited thereon.

7. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that In step 5, the thickness of the cobalt-nickel-phosphorus alloy catalyst on the surface of the electrode substrate is 50 nm to 200 nm.

8. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that The concentration of the hydrochloric acid in step 6 is 0.1 mol / L; the soaking time in step 6 is 10 min to 15 min.

9. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that The thickness of the nano-silicon dioxide on the surface of the gas manipulation grid in step seven is 500 nm to 1000 nm; the drying temperature in step seven is 60° C. to 70° C., and the drying time is 10 h to 12 h.

10. The method for preparing a three-dimensional electrolytic hydrogen production functional electrode based on wettability gradient and unidirectional bubble manipulation according to claim 1, characterized in that The distance between the surface of the electrode substrate on which the cobalt-nickel-phosphorus alloy catalyst is deposited and the gas manipulation grid with an asymmetric wettability gradient described in step eight is 200 μm to 600 μm.

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