A three-dimensional gas-favorable structure platinum-titanium electrode, a preparation method and application thereof, and a device for preparing hypochlorous acid by electrocatalytic ORR pairing

Abstract

The present application belongs to the technical field of marine biofouling prevention, and particularly relates to a three-dimensional gas-philic platinum-titanium electrode, a preparation method and application thereof, and a device for preparing hypochlorous acid by electrocatalytic ORR pairing. The present application prepares a three-dimensional titanium electrode from a titanium wire mesh, and the three-dimensional structure is conducive to increasing the contact area of the electrode with oxygen and prolonging the contact time. A nano platinum layer is pulse-electrodeposited on the surface of the three-dimensional titanium electrode to form a uniform nano platinum. The metal platinum is directly deposited on the three-dimensional titanium substrate to form a self-supporting electrode, and the platinum directly contacts the titanium substrate, which can increase the ORR activity and electrocatalytic performance. Then, the three-dimensional structure platinum-titanium electrode is subjected to polytetrafluoroethylene hydrophobic treatment, so that the electrode surface has gas-philic properties, the gas-liquid-solid three-phase interface is increased, the affinity of the electrode with oxygen is enhanced, the residence time of oxygen on the electrode surface is prolonged, the problem of limited oxygen solubility in an aqueous solution is overcome, the ORR reaction efficiency is conducive, and thus the effect of electrolysis for producing hypochlorous acid under the condition of no hydrogen production is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of marine biofouling prevention technology, specifically relating to a three-dimensional gas-loving platinum-titanium electrode and its preparation method and application, and an apparatus for electrocatalytic ORR pairing to prepare hypochlorous acid. Background Technology

[0002] With the continuous development of the marine industry, various marine equipment, such as ocean-going vessels, deep-sea equipment, aircraft carriers, and submarines, have made great progress. Among them, the power systems of many marine equipment require seawater cooling. After long-term service, a large amount of algae, barnacles, and other marine fouling organisms, as well as various shellfish in their later stages of growth, will adhere to the inner walls of the seawater cooling pipes and the drainage pipes at the bottom of the ship. This leads to problems such as blockage of the seawater cooling pipes and accelerated corrosion. Solving the problem of marine biofouling is urgent and has always been a global technical challenge.

[0003] Based on different antifouling principles, marine biofouling control can be divided into three main categories: physical control, biological control, and chemical control. Physical control refers to using physical methods to remove fouling organisms from marine equipment. However, physical control methods can harm other marine life and even workers, and often require shutdowns to clean the entire marine pipeline, resulting in significant resource waste and economic losses. Biological control uses biological means to manage marine pollution, such as studying the biomass composition or biological habits of fouling organisms to find corresponding methods to interfere with their nerve conduction or inhibit their attachment, thereby achieving the goal of antifouling. However, current biological control technologies are still immature and cannot be widely used. Chemical control methods refer to using relevant chemical antifouling agents to prevent the generation and attachment of fouling organisms, and are currently the most widely used method. Common methods include direct addition, electrolysis, and coating with chemical antifouling coatings.

[0004] Seawater electrolysis primarily relies on the generation of hypochlorous acid to eliminate fouling organisms. It is highly efficient, environmentally friendly, and low-cost, representing a dynamic antifouling method that "takes from the ocean and uses it back into the ocean," and is one of the most promising approaches to solving marine biofouling problems. However, seawater electrolysis technology generates hydrogen gas during the hydrogen evolution reaction (HER). Even with purging using hydrogen exhaust fans, the hydrogen gas cannot be completely removed, leaving residual hydrogen that poses a significant hazard to the power plants of ships, submarines, and other marine equipment. Furthermore, marine pipelines and the main bodies of warships and vessels are composed of metallic steel; trace amounts of hydrogen can easily induce hydrogen absorption in these materials and components, leading to hydrogen embrittlement and posing a substantial safety risk.

[0005] To suppress hydrogen production during seawater electrolysis for chlorination, the cathode oxygen reduction reaction (ORR) shows great promise as a paired reaction for hypochlorous acid production. ORR offers thermodynamic advantages over HER, effectively suppressing hydrogen production and reducing cell voltage and energy consumption. However, due to the extremely limited solubility of oxygen in seawater, commonly used ORR electrodes struggle to achieve practically meaningful current densities. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a three-dimensional gas-loving platinum-titanium electrode, its preparation method and application, and an apparatus for electrocatalytic ORR pairing to prepare hypochlorous acid. The three-dimensional gas-loving platinum-titanium electrode prepared by this invention can overcome the problem of limited oxygen solubility, has high mass transfer efficiency in the ORR reaction, and strong oxygen-consuming chlorine production capacity.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] This invention provides a method for preparing a three-dimensional gas-loving platinum-titanium electrode, comprising the following steps:

[0009] A three-dimensional titanium electrode is fabricated from titanium wire mesh and then subjected to pulse electrodeposition to obtain a three-dimensional platinum-titanium electrode; the electrolyte for pulse electrodeposition contains a platinum precursor in ionic form.

[0010] The three-dimensional platinum-titanium electrode was hydrophobically modified by mixing it with a polytetrafluoroethylene emulsion to obtain the three-dimensional gas-loving platinum-titanium electrode.

[0011] Preferably, the pH value of the electrolyte for pulse electrodeposition is 0.2 to 4.

[0012] Preferably, the parameters for the pulse electrodeposition include: a cathode pulse current density of 350–500 mA / cm². 2 The anode pulse current density is 0–10 mA / cm². 2 The cathode and anode pulse conduction times are independently 0.1–2 s, and the total electrodeposition time is 5–25 min.

[0013] Preferably, the polytetrafluoroethylene emulsion is obtained by mixing a concentrated polytetrafluoroethylene dispersion and an alcohol, wherein the volume ratio of the concentrated polytetrafluoroethylene dispersion to the alcohol is 1:1 to 20.

[0014] Preferably, the hydrophobic modification is performed by immersing the three-dimensional platinum-titanium electrode in a polytetrafluoroethylene emulsion for 24–72 hours.

[0015] The present invention also provides a three-dimensional gas-loving platinum-titanium electrode obtained by the preparation method described above. The three-dimensional gas-loving platinum-titanium electrode includes a three-dimensional platinum-titanium electrode and a polytetrafluoroethylene hydrophobic layer, wherein the polytetrafluoroethylene hydrophobic layer is loaded on the surface of the three-dimensional platinum-titanium electrode; the three-dimensional platinum-titanium electrode includes a three-dimensional titanium electrode and a nano-platinum layer, wherein the nano-platinum layer is loaded on the surface of the three-dimensional titanium electrode.

[0016] This invention also provides the application of the above-mentioned three-dimensional gas-loving platinum-titanium electrode in the electrocatalytic ORR pairing preparation of hypochlorous acid.

[0017] The present invention also provides an apparatus for the electrocatalytic ORR pairing to prepare hypochlorous acid, using the three-dimensional gas-loving platinum-titanium electrode described in the above technical solution as the cathode, the ruthenium-iridium-titanium mesh electrode as the anode, and the electrolyte as an aqueous solution containing sodium chloride.

[0018] Preferably, the electrolyte comprises seawater and / or sodium chloride solution, wherein the concentration of NaCl in the electrolyte is 3-4 wt%.

[0019] Preferably, the apparatus for preparing hypochlorous acid by electrocatalytic ORR pairing further includes an aeration head for introducing air.

[0020] This invention provides a method for preparing a three-dimensional gas-loving platinum-titanium electrode, comprising the following steps: forming a three-dimensional titanium electrode from a titanium wire mesh and then performing pulse electrodeposition to obtain a three-dimensional platinum-titanium electrode; the electrolyte of the pulse electrodeposition contains a platinum precursor in ionic form; and mixing the three-dimensional platinum-titanium electrode with a polytetrafluoroethylene emulsion for hydrophobic modification to obtain the three-dimensional gas-loving platinum-titanium electrode.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention fabricates a three-dimensional titanium electrode from titanium wire mesh. This three-dimensional structure increases the contact area between the electrode and oxygen. Then, a nano-platinum layer is pulse-electrodeposited onto the surface of the three-dimensional titanium electrode. Pulse electrodeposition prevents concentration polarization that could lead to grain growth, promoting the formation of porous, uniform, fine-grained platinum nanoparticles. Simultaneously, metallic platinum is directly deposited on the three-dimensional titanium substrate, forming a self-supporting electrode. Platinum atoms, acting as active centers for the electrocatalytic ORR reaction, are in direct contact with the titanium substrate. Compared to commonly used powder catalysts, this eliminates the need for binders, facilitating electron conduction, reducing the risk of peeling, ensuring electrode integrity and mechanical strength, improving electrode quality, and enhancing ORR activity and electrocatalytic performance. Furthermore, the three-dimensional platinum-titanium electrode is hydrophobically treated with polytetrafluoroethylene (PTFE), giving the electrode surface gas-loving properties. This increases the gas-liquid-solid three-phase interface and enhances the affinity between the electrode and oxygen, prolonging the residence time of oxygen on the electrode surface. This overcomes the limitation of oxygen solubility, improving mass transfer efficiency and reaction kinetics in the ORR reaction.

[0023] Furthermore, the method for preparing the three-dimensional gas-loving platinum-titanium electrode provided by this invention is simple, efficient, highly flexible, and has low equipment requirements, which is conducive to large-scale production.

[0024] This invention also provides an apparatus for the electrocatalytic ORR pairing to prepare hypochlorous acid. The apparatus produces hypochlorous acid by electrolyzing a sodium chloride solution (salt water), which can solve the problem of marine biofouling and effectively kill marine bacteria and viruses. This invention introduces an aeration device into the electrolytic apparatus for preparing hypochlorous acid using ORR pairing. The aeration head is directly inserted into the electrolyte and close to the cathode electrode, which can efficiently deliver oxygen to the surface of the ORR electrode, increasing the oxygen concentration and contact area, and reducing the impact of oxygen mass transfer. Compared with gas diffusion electrodes with ultra-high gas mass transfer efficiency, this avoids the influence of Ca in seawater. 2+ Mg 2+ Ions deposit on the surface of the gas diffusion electrode, clogging the electrode. This invention provides a highly efficient, green, and low-cost electrocatalytic ORR pairing device for the preparation of hypochlorous acid. ORR pairing prevents the generation of hydrogen during electrolysis, avoiding the risks associated with hydrogen accumulation in the ship's hold. It also reduces energy consumption, saves costs, and has simple operating conditions, making it suitable for practical production to address marine biofouling problems and possessing broad application prospects. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a flowchart illustrating the preparation method of the three-dimensional gas-loving platinum-titanium electrode according to an embodiment of the present invention;

[0027] Figure 2 A diagram of an apparatus for preparing hypochlorous acid by pairing and electrolyzing brine with a three-dimensional gas-loving platinum-titanium electrode using ORR;

[0028] Figure 3 Linear voltammetry curves of a three-dimensional gas-loving platinum-titanium electrode in oxygen-containing and oxygen-free atmospheres;

[0029] Figure 4 The current variation curves for oxygen flow during electrolysis of 3.5 wt% NaCl solution using a three-dimensional aerophilic platinum-titanium electrode under a 2V cell pressure are shown.

[0030] Figure 5 The concentration of active chlorine was determined by electrolyzing a 3.5 wt% NaCl solution for 1 h in an oxygen atmosphere using a three-dimensional gas-loving platinum-titanium electrode under different constant cell pressures.

[0031] Figure 6 The current variation curves for oxygen flow during electrolysis of 3.5 wt% NaCl solution using a three-dimensional aerophilic platinum-titanium electrode and a commercial platinum-titanium plate electrode under a constant cell pressure of 2V are shown.

[0032] Figure 7 The concentration of active chlorine was determined by electrolyzing a 3.5 wt% NaCl solution for 1 h in an oxygen atmosphere using a three-dimensional gas-loving platinum-titanium electrode and a commercial platinum-titanium plate electrode under different cell pressures.

[0033] Figure 8 The concentration of active chlorine was determined by electrolyzing a 3.5 wt% NaCl solution with a platinum-titanium electrode with a three-dimensional aerophilic structure obtained by electrodeposition in oxygen atmosphere and solutions with different pH values ​​for 1 h.

[0034] Figure 9 The concentration of active chlorine in a three-dimensional oxyphilic platinum-titanium electrode obtained by electrodeposition under different cathode pulse conduction times in an oxygen atmosphere after electrolyzing a 3.5 wt% NaCl solution for 1 h.

[0035] Figure 10 The concentration of active chlorine was determined by electrolyzing 3.5 wt% NaCl solution with a three-dimensional gas-loving platinum-titanium electrode modified in polytetrafluoroethylene emulsions of different proportions in an oxygen atmosphere for 1 h. Detailed Implementation

[0036] This invention provides a method for preparing a three-dimensional gas-loving platinum-titanium electrode, comprising the following steps:

[0037] A three-dimensional titanium electrode is fabricated from titanium wire mesh and then subjected to pulse electrodeposition to obtain a three-dimensional platinum-titanium electrode; the electrolyte for pulse electrodeposition contains a platinum precursor in ionic form.

[0038] The three-dimensional platinum-titanium electrode was hydrophobically modified by mixing it with a polytetrafluoroethylene emulsion to obtain the three-dimensional gas-loving platinum-titanium electrode.

[0039] Unless otherwise specified, all materials and equipment used in this invention are commercially available products in the field.

[0040] This invention involves fabricating a three-dimensional titanium electrode from titanium wire mesh and then performing pulse electrodeposition to obtain a three-dimensional platinum-titanium electrode; the electrolyte for pulse electrodeposition contains a platinum precursor in ionic form.

[0041] In this invention, the specifications (length × width) of the titanium wire mesh preferably include 1cm × 2cm, 5cm × 5cm, 5cm × 10cm or 10cm × 20cm, more preferably 5cm × 10cm; the diameter of the titanium wire in the titanium wire mesh is preferably 10μm to 1mn, more preferably 50μm; the mesh count of the titanium wire mesh is preferably 50 to 600 meshes, more preferably 300 meshes.

[0042] In this invention, the titanium wire mesh is preferably further polished before use to remove oxides and contaminants from the surface of the titanium wire. The polishing preferably includes polishing with 200-grit and 1000-grit sandpaper in sequence.

[0043] In this invention, the shape of the three-dimensional titanium electrode preferably includes a cone, a sphere, a cube, or a cylinder, and the cone preferably includes a multi-layer cone structure, wherein the number of overlapping layers of the multi-layer cone structure is preferably 2 to 5.

[0044] In this invention, the platinum ion source in the electrolyte of the pulse electrodeposition preferably includes one or more of platinum dichloride, platinum tetrachloride, and chloroplatinic acid, and more preferably platinum tetrachloride.

[0045] In this invention, the concentration of platinum ions in the electrolyte for pulse electrodeposition is preferably 0.001 to 1 mol / L, more preferably 0.1 mol / L.

[0046] In this invention, the electrolyte for pulse electrodeposition is preferably an acidic electrolyte, and the pH value of the acidic electrolyte is preferably 0.2-4, more preferably 1-3. The hydrogen ion source in the acidic electrolyte preferably includes one or more of concentrated hydrochloric acid, concentrated nitric acid, concentrated sulfuric acid, and perchloric acid. This invention does not have a particular limitation on the concentration of the concentrated hydrochloric acid, concentrated nitric acid, concentrated sulfuric acid, and perchloric acid; concentrations well known to those skilled in the art can be used. By using the acidic electrolyte in this invention, during the pulse electrodeposition process, hydrogen ions can be reduced to form a large number of hydrogen bubbles on the cathode surface and occupy the space on the cathode surface, resulting in a porous structure in the platinum nanolayer obtained by pulse electrodeposition.

[0047] In the pulse electrodeposition process of this invention, a three-dimensional titanium electrode is used as the cathode. The counter electrode (anode) of the three-dimensional titanium electrode preferably includes one or more of platinum sheets, copper sheets, carbon rods, and graphite, more preferably platinum sheets. The dimensions of the platinum sheets are preferably 2cm × 2cm × 0.2cm. The pulse electrodeposition is preferably performed at a negative potential, which is preferably lower than the deposition potential of platinum ions, so as to obtain a three-dimensional platinum-titanium electrode with a uniform nano-platinum layer on its surface.

[0048] In this invention, the parameters of the pulse electrodeposition include: the cathode pulse current density is preferably 350-500 mA / cm². 2 The preferred anode pulse current density is 0–10 mA / cm². 2 More preferably 3mA / cm 2 The cathode and anode pulse conduction times are preferably 0.1–2 s, more preferably 0.5–1 s; the total electrodeposition time is preferably 5–25 min, more preferably 15 min. The cathode pulse conduction time described in this invention does not cause concentration polarization leading to grain growth; the anode pulse conduction time described in this invention does not result in excessively long non-deposition time, thus reducing deposition efficiency. The cathode and anode pulse conduction times described in this invention are beneficial for refining the platinum nanolayer grains, and the grain size of the platinum nanolayer obtained by this invention is preferably 5–100 nm. In the pulse electrodeposition process of this invention, the cathode pulse potential is lower than the reduction potential of hydrogen ions and platinum ions, and the anode pulse potential is higher than the cathode pulse potential.

[0049] In this invention, when the titanium wire mesh is preferably 5cm×10cm, the parameters of the pulse electrodeposition preferably include: cathode pulse conduction time of 0.5s, anode pulse conduction time of 1s, and total deposition time of 15min.

[0050] In this invention, the pulse electrodeposition temperature is preferably room temperature, and the pulse electrodeposition process is preferably accompanied by magnetic stirring.

[0051] In this invention, the pulse electrodeposition process preferably includes sequential washing and drying of the electrode. The washing solvent is preferably distilled water. This invention does not have special requirements for the drying method, such as natural air drying.

[0052] After obtaining the three-dimensional platinum-titanium electrode, the present invention mixes the three-dimensional platinum-titanium electrode with a polytetrafluoroethylene emulsion for hydrophobic modification to obtain the three-dimensional gas-loving platinum-titanium electrode.

[0053] In this invention, the polytetrafluoroethylene emulsion is preferably obtained by mixing a concentrated polytetrafluoroethylene dispersion with an alcohol, wherein the alcohol preferably includes one or more of methanol, ethanol, isopropanol, and glycerol, and the volume ratio of the concentrated polytetrafluoroethylene dispersion to the alcohol is preferably 1:1 to 20, more preferably 1:5 to 10; in a specific embodiment of this invention, the manufacturer and model of the concentrated polytetrafluoroethylene dispersion is Maclean P816262, and the concentration is 60wt%.

[0054] In this invention, the preferred method of hydrophobic modification is to immerse the three-dimensional platinum-titanium electrode in a polytetrafluoroethylene emulsion for a preferred immersion time of 24 to 72 hours.

[0055] In this invention, the hydrophobic modification preferably includes room temperature air drying, and the room temperature air drying time is preferably 12 to 24 hours.

[0056] The present invention also provides a three-dimensional gas-loving platinum-titanium electrode obtained by the preparation method described above. The three-dimensional gas-loving platinum-titanium electrode includes a three-dimensional platinum-titanium electrode and a polytetrafluoroethylene hydrophobic layer, wherein the polytetrafluoroethylene hydrophobic layer is loaded on the surface of the three-dimensional platinum-titanium electrode; the three-dimensional platinum-titanium electrode includes a three-dimensional titanium electrode and a nano-platinum layer, wherein the nano-platinum layer is loaded on the surface of the three-dimensional titanium electrode.

[0057] This invention also provides the application of the above-mentioned three-dimensional gas-loving platinum-titanium electrode in the electrocatalytic ORR pairing preparation of hypochlorous acid.

[0058] The present invention also provides an apparatus for the electrocatalytic ORR pairing to prepare hypochlorous acid, using the three-dimensional gas-loving platinum-titanium electrode described in the above technical solution as the cathode, the ruthenium-iridium-titanium mesh electrode as the anode, and the electrolyte as an aqueous solution containing sodium chloride.

[0059] In this invention, the preferred size of the ruthenium-iridium titanium mesh electrode is 2cm × 2cm, and there are no special requirements for the source of the ruthenium-iridium titanium mesh electrode.

[0060] In this invention, the electrolyte preferably comprises seawater and / or sodium chloride solution, and the concentration of NaCl in the electrolyte is preferably 3-4 wt%, more preferably 3.5 wt%.

[0061] In this invention, the apparatus for preparing hypochlorous acid by electrocatalytic ORR pairing preferably further includes an aeration head for introducing air, such as... Figure 2 As shown, the aeration head is equipped with an air pump, and the air flow rate of the air pump is preferably 2 to 16 L / min, more preferably 4 L / min. The air flow rate is related to the electrode area. The air flow rate of the aeration head of the present invention can meet the pairing requirements of the chlorine production reaction.

[0062] In this invention, the aeration head is preferably a spherical aeration head, and the diameter of the spherical aeration head is preferably 30 mm. The aeration head of this invention can refine the bubbles, and the bubble diameter is preferably 3 mm.

[0063] To further illustrate the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, describes the three-dimensional gas-loving platinum-titanium electrode of the present invention, its preparation method and application, and the apparatus for electrocatalytic ORR pairing to prepare hypochlorous acid. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0064] Example 1

[0065] The fabrication process of the three-dimensional gas-loving platinum-titanium electrode is as follows: Figure 1 As shown, the specific steps include:

[0066] Step 1: First, sand the titanium wire mesh with 200-grit sandpaper, then polish it with 1000-grit sandpaper to completely remove surface oxides and contaminants. Then, weave the polished 5cm x 10cm titanium wire mesh (50μm diameter, 300 mesh) into a three-dimensional, multi-layered cone structure. The cone's base diameter is approximately 3cm, and its height is approximately 4cm. Figure 1 As shown.

[0067] Step 2: Prepare an acidic mixed solution containing platinum ions and hydrogen ions: Weigh 5.053g of platinum tetrachloride and add it to 150mL of deionized water. Stir at a constant speed until the platinum salt is fully dissolved to form an aqueous solution of metal ions. Add concentrated hydrochloric acid dropwise to the above solution to adjust the pH value of the solution to 1. Stir evenly for 20min to form a mixed solution.

[0068] Step 3: Using a high-power regulated voltage source, with the three-dimensional titanium electrode obtained in Step 1 as the cathode, a 2cm × 2cm platinum sheet (0.2cm thick) as the anode, and the mixed solution from Step 2 as the electrolyte, the cathode pulse current density is 500mA / cm. 2 The anode pulse current density is 3 mA / cm². 2 The cathode and anode pulse conduction times were both 1s, and the total electrodeposition time was 15min, resulting in a three-dimensional platinum-titanium electrode with a uniformly coated nano-platinum layer on its surface.

[0069] Step 4: The three-dimensional platinum-titanium electrode obtained in Step 3 is immersed in a polytetrafluoroethylene emulsion for hydrophobic modification: the polytetrafluoroethylene emulsion is obtained by mixing a concentrated polytetrafluoroethylene dispersion and methanol in a volume ratio of 1:10. The three-dimensional platinum-titanium electrode is completely immersed in the polytetrafluoroethylene emulsion for 72 hours. After being removed, it is naturally air-dried at room temperature for 24 hours to obtain a three-dimensional gas-loving platinum-titanium electrode.

[0070] Application Example 1

[0071] The three-dimensional gas-loving platinum-titanium electrode obtained in Example 1 was applied to a device for producing hypochlorous acid by electrolyzing brine, as follows:

[0072] Using a DC electrolytic cell, the three-dimensional aerophilic platinum-titanium electrode obtained in Example 1 was used as the cathode, and a 2cm × 2cm commercial ruthenium-iridium-titanium mesh was used as the anode. 3.5g of sodium chloride was weighed and added to 100mL of deionized water, stirred until all the sodium chloride was dissolved, forming a 3.5wt% sodium chloride solution as the electrolyte. The electrolytic cell contained a 30mm diameter spherical aerator, and the aeration pump rate was adjusted to 4L / min. This aerator could refine the bubbles to a diameter of 3mm. The above apparatus was used for ORR pairing to produce hypochlorous acid. A simplified diagram of the apparatus is shown below. Figure 2 As shown.

[0073] Figure 3 These are the linear voltammetric curves of a three-dimensional oxyphilic platinum-titanium electrode in oxygen-containing and oxygen-free atmospheres. Before testing in an oxygen-free atmosphere, high-purity argon gas is continuously introduced into the electrolyte solution for 30 minutes to remove oxygen and create an argon-saturated electrolyte solution. The linear voltammetric curves are obtained at a scan rate of 5 mV / s. It can be seen that the current is significantly higher in the presence of oxygen than in the absence of oxygen. This is mainly due to the ORR reaction occurring at the cathode, which enhances the kinetics of the entire reaction and thus increases the current. Without O2, the critical cell voltage for HER is around 2V, at which point the current is almost zero; while with O2, due to the ORR reaction at the cathode, the current is 136.8 mA at a cell voltage of 2V.

[0074] Figure 4 The figures show the current variation curves when oxygen is introduced / deactivated during the electrolysis of a 3.5 wt% NaCl solution at a cell voltage of 2V. It can be seen that under a cell voltage of 2V, the current changes with O2 introduction / deactivation. When O2 is not introduced, the current is almost 0 mA, while the current increases to approximately 90 mA instantaneously upon introducing O2, and then gradually decreases to near 0 mA upon deactivation. This indicates that in the presence of oxygen, the ORR reaction occurs at the cathode, enhancing the overall system kinetics, increasing electrode activity and current density, and reducing the cell voltage.

[0075] Figure 5 This represents the concentration of active chlorine after electrolyzing a 3.5 wt% NaCl solution for 1 hour under different constant voltages in an oxygen atmosphere. For the same electrolysis time, the concentration of active chlorine increases with increasing voltage. At 2.0V, no hydrogen gas is produced. Using the ORR reaction, the paired electrolysis of brine can produce 479.25 mg / L of hypochlorous acid per hour.

[0076] Application Comparative Example 1

[0077] The cathode in Application Example 1 was replaced with a commercial platinum titanium plate electrode of the same area, while all other test conditions remained unchanged.

[0078] Figure 6 The figures show the current variation curves when oxygen is introduced and removed during the electrolysis of 3.5 wt% NaCl solution using a three-dimensional gas-loving platinum-titanium electrode and a commercial platinum-titanium plate electrode under a constant cell voltage of 2V. It can be seen that when O2 is not introduced, the current of both electrodes is almost 0 mA, while the current increases instantaneously due to the ORR reaction when O2 is introduced. The current of the three-dimensional gas-loving platinum-titanium electrode increases to approximately 90 mA, while that of the commercial platinum-titanium plate electrode only increases to approximately 20 mA. This indicates that the three-dimensional platinum-titanium electrode of this invention has superior ORR performance compared to the commercial platinum-titanium plate electrode, increasing current density and reducing cell voltage. The superior performance of the three-dimensional gas-loving platinum-titanium electrode is attributed to its three-dimensional structure, which increases the contact area with oxygen and the residence time of oxygen on the electrode surface, reducing the mass transfer effect of oxygen and thus being more conducive to the ORR reaction.

[0079] Figure 7 The concentration of active chlorine was measured after electrolyzing a 3.5 wt% NaCl solution for 1 hour in an oxygen atmosphere using a three-dimensional oxyphilic platinum-titanium electrode and a commercial platinum-titanium plate electrode under different cell pressures. Under the same electrolysis time and cell pressure, the active chlorine concentration increased with increasing voltage. At different cell pressures, the three-dimensional oxyphilic platinum-titanium electrode produced a higher concentration of hypochlorous acid per hour than the commercial platinum-titanium plate electrode. Specifically, at 2.0V, the three-dimensional oxyphilic platinum-titanium electrode produced 479.25 mg / L of hypochlorous acid per hour, while the commercial platinum-titanium plate electrode produced only 90.43 mg / L. This demonstrates that the three-dimensional oxyphilic platinum-titanium electrode of this invention can increase oxygen-consuming chlorine production capacity, improve energy efficiency, reduce cell pressure, and lower chlorine production costs.

[0080] Example 2

[0081] The only difference between Example 2 and Example 1 is that the pH value of the mixed solution is different in step 2. All other conditions remain the same. In Example 2, the pH value of the solution is adjusted to 3.

[0082] Comparative Example 1

[0083] The only difference between Comparative Example 1 and Example 1 is the pH value of the mixed solution in step 2. All other conditions remain the same. The pH value of the solution in Comparative Example 1 is adjusted to 5.

[0084] Application Example 2

[0085] Following the test conditions of Application Example 1, the three-dimensional gas-loving platinum-titanium electrodes obtained in Example 2 and Comparative Example 1 were applied to devices for producing hypochlorous acid by electrolyzing brine.

[0086] Figure 8This study describes the concentration of active chlorine produced by electrodepositing three-dimensional oxyphilic platinum-titanium electrodes at different pH values ​​in an oxygen atmosphere after electrolyzing a 3.5 wt% NaCl solution for 1 hour. Under the same cell pressure, the concentration of hypochlorous acid produced by the three-dimensional oxyphilic platinum-titanium electrodes at different pH values ​​varied. Specifically, at 2.0 V, with increasing pH, the hypochlorous acid production per hour by the three-dimensional oxyphilic platinum-titanium electrode decreased from 479.25 mg / L (pH=1) to 402.74 mg / L (pH=5). It can be seen that the pH value of the electrodeposition solution in this invention affects the preparation of the three-dimensional oxyphilic platinum-titanium electrode, thereby affecting its oxygen-consuming chlorine production capacity. A more optimal electrodeposition pH value can reduce the cell pressure and improve the chlorine production capacity.

[0087] Comparative Example 2

[0088] The only difference between Comparative Example 2 and Example 1 is that the cathode pulse conduction time in step 3 is 10s, while all other conditions remain the same.

[0089] Application Example 3

[0090] Following the test conditions of Application Example 1, the three-dimensional gas-loving platinum-titanium electrode obtained in Comparative Example 2 was applied to a device for producing hypochlorous acid by electrolyzing brine.

[0091] Figure 9 This study describes the concentration of active chlorine obtained by electrodeposition of a three-dimensional oxyphilic platinum-titanium electrode with different cathode pulse conduction times in an oxygen atmosphere after electrolyzing a 3.5 wt% NaCl solution for 1 hour. Under the same cell voltage, the concentration of hypochlorous acid produced by the electrodeposition of the three-dimensional oxyphilic platinum-titanium electrode with different cathode pulse conduction times varied. Specifically, at 2.0 V, with increasing cathode pulse conduction time, the hypochlorous acid production per hour by the three-dimensional oxyphilic platinum-titanium electrode decreased from 479.25 mg / L (t = 1 s) to 325.56 mg / L (t = 10 s). It can be seen that different cathode pulse conduction times affect the preparation of the three-dimensional oxyphilic platinum-titanium electrode, thus affecting its oxygen-consuming chlorine production capacity. Excessively long cathode pulse conduction times lead to concentration polarization, affecting the growth of the platinum layer on the titanium surface. The three-dimensional oxyphilic platinum-titanium electrode obtained with shorter cathode pulse conduction times exhibits superior performance, reduces cell voltage, and improves chlorine production capacity.

[0092] Examples 3-4

[0093] The only difference between Examples 3 and 4 and Example 1 is that the volume ratio of polytetrafluoroethylene concentrated dispersion to methanol in step 4 is different. All other conditions remain the same. In Example 3, the volume ratio of polytetrafluoroethylene concentrated dispersion to methanol is 1:5, and in Example 4, the volume ratio of polytetrafluoroethylene concentrated dispersion to methanol is 1:20.

[0094] Application Example 4

[0095] According to the test conditions of Application Example 1, the three-dimensional gas-loving platinum-titanium electrodes obtained in Examples 3 and 4 were applied to devices for producing hypochlorous acid by electrolyzing seawater.

[0096] Figure 10 This study investigated the concentration of active chlorine in a 3D oxyphilic platinum-titanium electrode modified with different proportions of polytetrafluoroethylene (PTFE) emulsion after electrolysis of a 3.5 wt% NaCl solution for 1 hour in an oxygen atmosphere. Under the same cell pressure, the concentration of hypochlorous acid produced by the 3D oxyphilic platinum-titanium electrode modified with different proportions of PTFE emulsion varied. The PTFE-methanol volume ratio of 1:10 showed superior hypochlorous acid production. This is mainly because a higher ratio (e.g., 1:5) increases the relative concentration of PTFE, leading to greater surface modification, increased hydrophobicity and oxyphilicity, and thus a larger gas-solid interface and a smaller solid-liquid interface. Conversely, a lower ratio (e.g., 1:20) decreases the relative concentration of PTFE, resulting in less surface modification, reduced hydrophobicity and oxyphilicity, and a smaller gas-solid interface and a larger solid-liquid interface. Therefore, controlling the degree of hydrophobicity and oxyphilicity modification of the electrode by the PTFE emulsion to achieve the optimal balance of the gas-solid-liquid three-phase interface is crucial.

[0097] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on the present invention without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a three-dimensional gas-loving platinum-titanium electrode, characterized in that, Includes the following steps: A three-dimensional titanium electrode is fabricated from titanium wire mesh and then subjected to pulse electrodeposition to obtain a three-dimensional platinum-titanium electrode; the electrolyte for pulse electrodeposition is an acidic mixed solution containing platinum ions and hydrogen ions. The three-dimensional platinum-titanium electrode was mixed with polytetrafluoroethylene emulsion and hydrophobically modified to obtain the three-dimensional gas-loving platinum-titanium electrode. The pH value of the electrolyte used in the pulse electrodeposition is 0.2~4; The parameters for the pulsed electrodeposition include: a cathode pulse current density of 350~500 mA / cm². 2 The anode pulse current density is 0~10 mA / cm². 2 The cathode and anode pulse conduction times are independently 0.1~2s, and the total electrodeposition time is 5~25min.

2. The preparation method according to claim 1, characterized in that, The polytetrafluoroethylene emulsion is obtained by mixing a concentrated polytetrafluoroethylene dispersion with an alcohol, wherein the volume ratio of the concentrated polytetrafluoroethylene dispersion to the alcohol is 1:1 to 20.

3. The preparation method according to claim 2, characterized in that, The hydrophobic modification method involves immersing the three-dimensional platinum-titanium electrode in a polytetrafluoroethylene emulsion for 24-72 hours.

4. The three-dimensional aerophilic platinum-titanium electrode obtained by the preparation method according to any one of claims 1 to 3, characterized in that, The three-dimensional gas-loving platinum-titanium electrode comprises a three-dimensional platinum-titanium electrode and a polytetrafluoroethylene hydrophobic layer, wherein the polytetrafluoroethylene hydrophobic layer is loaded on the surface of the three-dimensional platinum-titanium electrode; the three-dimensional platinum-titanium electrode comprises a three-dimensional titanium electrode and a nano-platinum layer, wherein the nano-platinum layer is loaded on the surface of the three-dimensional titanium electrode.

5. The application of the three-dimensional gas-loving platinum-titanium electrode of claim 4 in the electrocatalytic ORR pairing preparation of hypochlorous acid.

6. An apparatus for the electrocatalytic ORR pairing to prepare hypochlorous acid, characterized in that, The three-dimensional aerophilic platinum-titanium electrode of claim 4 is used as the cathode, and the ruthenium-iridium-titanium mesh electrode is used as the anode. The electrolyte is an aqueous solution containing sodium chloride.

7. The apparatus according to claim 6, characterized in that, The electrolyte includes seawater and / or sodium chloride solution, wherein the concentration of NaCl in the electrolyte is 3-4 wt%.

8. The apparatus according to claim 6, characterized in that, It also includes aeration heads that allow air to pass through.

Images