A phosphorus-doped iridium tantalum cerium bifunctional electrode, a preparation method and application thereof

Abstract

The application discloses a phosphorus-doped iridium tantalum cerium bifunctional electrode and a preparation method and application thereof. The preparation of the bifunctional electrode comprises the following steps: preparing a deposition solution containing a tin source, an antimony source and a carbon source, and preparing an outer layer precursor solution containing an iridium source, a tantalum source, a cerium source and a phosphorus-containing surfactant. First, a titanium substrate is taken as a cathode, and an anode is arranged as a counter electrode to perform electrodeposition in the deposition solution. After drying and calcining, the surface of the titanium substrate is brushed with the outer layer precursor solution, and then drying and calcining are performed again. The outer layer brushing, drying and calcining steps are repeated until the final active outer layer is obtained. The application realizes the synergistic effect of multiple components by optimizing the electronic structure through phosphorus doping and rare earth element regulation. The obtained electrode has excellent catalytic activity and stability in chlorine evolution reaction and hydrogen evolution reaction, and has high catalytic activity and long service life.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysis technology, specifically relating to a phosphorus-doped iridium-tantalum-cerium bifunctional electrode, its preparation method, and its application. Background Technology

[0002] Electrochemical chlorine evolution reaction (CER) and hydrogen evolution reaction (HER) have applications in various fields such as chlor-alkali industry, water electrolysis for hydrogen production, wastewater treatment, and resource utilization. CER primarily occurs at the anode, while HER occurs at the cathode; their synergy determines the overall energy efficiency and operational performance of the electrolysis system. These reactions typically proceed under harsh conditions such as strong acidity, high salt concentration, and high current density, placing extremely high demands on the catalytic activity, corrosion resistance, conductivity, and long-term structural stability of the electrode materials. Therefore, developing bifunctional catalysts with both high-efficiency chlorine and hydrogen evolution properties is beneficial for reducing energy consumption, improving system stability, and expanding application scenarios.

[0003] Currently, the electrode materials widely used in industry are mainly titanium-based coated electrodes, with anodes mainly composed of noble metal oxides such as RuO2 and IrO2, and cathodes mostly using Pt or other transition metal-based materials. Although these electrodes exhibit certain catalytic activity in their respective reactions, they still have the following limitations when constructing efficient bifunctional systems: (1) They are highly dependent on noble metals and are expensive, which limits their large-scale application; (2) Under strong acid and high potential / high current density conditions, the anode is prone to active component dissolution and structural degradation, and the cathode may also experience poisoning or deactivation, leading to overall performance degradation; (3) The anode and cathode material systems are independent of each other, and the interfacial synergistic effect is limited, making it difficult to further improve the overall electrolysis efficiency. Therefore, developing a bifunctional electrode material with high chlorine and hydrogen evolution activity, excellent stability, and good economy is beneficial to solving some of the technical problems existing in the current field of electrochemical catalysis.

[0004] To address the aforementioned issues, Chinese patent CN121344574A discloses a titanium-based iridium-tantalum oxide coated anode and its preparation method. The main steps include: brushing a tantalum source-containing solution onto a titanium substrate, followed by sintering; repeating this brush-coating-sintering process to obtain a tantalum-coated titanium substrate; and brushing an iridium-tantalum oxide coating solution onto the tantalum-coated titanium substrate, followed by sintering; repeating this brush-coating-sintering process to obtain the anode. A two-step brushing and thermal decomposition baking process is used to form an Ir-Ta oxide active layer on the titanium surface. However, this technical solution still has the following shortcomings: First, during multiple high-temperature thermal decomposition baking processes, due to the significant difference in thermal expansion coefficients between the oxide coating and the titanium substrate, large thermal stress is easily generated during repeated heating and cooling cycles, leading to the formation of typical "mud crack"-like microcracks on the coating surface. These cracks not only weaken the mechanical bonding between the coating and the substrate but also allow the electrolyte to seep into the interface region along the cracks, accelerating substrate corrosion and coating peeling, affecting the long-term stability of the electrode. Furthermore, this technology primarily optimizes chlorine evolution performance at the anode and does not involve the synergistic design of hydrogen evolution reaction at the cathode.

[0005] In practical electrolysis systems, HER, as the key cathode reaction corresponding to CER, directly affects the overall energy consumption and efficiency of the system. However, in existing technologies, anode and cathode materials are usually designed independently, lacking a unified structural control and interface synergy mechanism. This results in a lack of synergistic optimization between CER and HER in the electrolysis system, making it difficult to achieve efficient and stable bifunctional electrocatalytic processes.

[0006] Therefore, developing a bifunctional electrode material that maintains excellent chlorine evolution performance while possessing both high-efficiency hydrogen evolution activity and excellent structural stability is beneficial to improving the overall performance of the electrolysis system. Summary of the Invention

[0007] The purpose of this invention is to solve the aforementioned technical problems existing in the prior art and to provide a phosphorus-doped iridium-tantalum-cerium bifunctional electrode, its preparation method, and its application. This invention utilizes electrodeposition to load tin-antimony metal salts onto a titanium substrate and thermal decomposition to load iridium, tantalum, cerium, and phosphorus elements onto a tin-antimony-containing intermediate layer. This application successfully prepares a phosphorus-doped iridium-tantalum-cerium bifunctional electrode with high activity and high stability. By utilizing the regulatory effect of Ce and P on the electronic structure of the active centers of Ir and Ta, both catalytic activity and stability are improved. Using this electrode as an anode catalyst in electrolysis can enhance the activity of CER and HER.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode includes the following steps: Step 1: Clean and pre-treat the titanium substrate; Step 2: Add the tin source, antimony source, and carbon source sequentially to the deep eutectic solvent of choline chloride and ethylene glycol, and stir under oil bath heating to make them mix evenly, to obtain the intermediate layer electrodeposition solution; Step 3: Add the iridium source, tantalum source, cerium source and phosphorus-containing surfactant to the acidic solvent, and mix them evenly by ultrasonication to obtain the outer layer precursor solution; Step 4: Place the pretreated titanium substrate from Step 1 in the electrodeposition solution of the intermediate layer from Step 2 as the cathode, and set the anode as the electrode. Perform electrodeposition under oil bath heating, then dry it in an oven, and calcine it in a muffle furnace to obtain a titanium substrate containing a tin-antimony intermediate layer. Step 5: Apply the outer layer precursor solution from Step 3 evenly to the surface of the tin-antimony intermediate layer of the titanium substrate obtained in Step 4, ensuring the intermediate layer surface is fully wetted. Place it in an oven to dry, and then place it in a muffle furnace for calcination. Repeat the above steps of application, drying, and calcination 5-10 times to obtain the phosphorus-doped iridium-tantalum-cerium bifunctional electrode.

[0009] Further, the pretreatment step 1 is as follows: the titanium substrate is first rinsed with deionized water to remove surface impurities, then immersed in a strong alkaline solution and heated for alkaline treatment to remove surface grease; after rinsing with deionized water, it is immersed in an oxalic acid solution and heated for acid treatment to remove the oxide film on the surface; finally, it is thoroughly rinsed with deionized water, and the pretreatment is completed.

[0010] Furthermore, in the pretreatment step, the strong alkaline solution is NaOH or KOH solution with a mass fraction of 15-30%, and the oxalic acid solution has a mass fraction of 15-20%. The heating temperature for both the alkaline treatment and the acid treatment is 60-90℃. The purpose of the acid treatment in the pretreatment step is to roughen the surface of the titanium substrate, which helps to enhance the adhesion between the subsequent deposits and the titanium substrate, prevents coating peeling, improves the conductivity of the electrode, extends its service life, and removes surface oxides and impurities.

[0011] Further, in step 2, the carbon source is one of carbon nanotubes, graphene, diamond, or fullerene; the tin source is one of stannous sulfate, stannous chloride, stannous pyrophosphate, or stannous tetrachloride; and the antimony source is one of antimony trioxide, antimony trichloride, or antimony pentoxide. In this invention, the carbon source is uniformly dispersed in the solution as a suspension, and the solution is stirred evenly before electrodeposition. Doping with a carbon source can improve the surface roughness and interfacial bonding of the electrode coating in the electrocatalyst. This improvement provides advantages in terms of the electrocatalytic performance and stability of the electrode by increasing the electrode active area and delaying the shedding of the surface active layer.

[0012] Further, in the intermediate layer electrodeposition solution described in step 2, the final concentration of the tin source is 0.15-0.3 M, the final concentration of the antimony source is 0.01-0.04 M, and the final concentration of the carbon source is 0.1-0.5 g·L⁻¹.-1 Preferably, the final concentration of the tin source is 0.2-0.25 M, the final concentration of the antimony source is 0.02-0.03 M, and the final concentration of the carbon source is 0.15-0.2 g·L⁻¹. -1 .

[0013] Further, in step 2, the molar ratio of choline chloride to ethylene glycol is 0.5-2:1, preferably 0.8-1.2:1, and the oil bath heating temperature is 60-90℃, preferably 70-80℃.

[0014] Further, in step 3, the phosphorus-containing surfactant is one of diethyl phosphite, dipotassium cetyl phosphate, lecithin, or diethyl hydroxymethyl phosphate; the iridium source is one of chloroiridium acid, iridium trichloride, or iridium dioxide; the tantalum source is one of tantalum ethoxide, tantalum pentachloride, or tantalum pentoxide; and the cerium source is one of cerium nitrate, cerium chloride, cerium isopropoxide, or cerium hydroxide.

[0015] Further, in the outer precursor solution described in step 3, the final concentration of the iridium source is 0.03-0.07 M, the final concentration of the tantalum source is 0.01-0.03 M, the final concentration of the cerium source is 0.02-0.04 M, and the final concentration of the phosphorus-containing surfactant is 2-5 g·L. -1 Preferably, the final concentration of the iridium source is 0.04-0.05 M, the final concentration of the tantalum source is 0.015-0.02 M, the final concentration of the cerium source is 0.03-0.035 M, and the final concentration of the phosphorus-containing surfactant is 3-5 g·L. -1 .

[0016] Furthermore, in step 3, the acidic solvent is a mixture of n-butanol and concentrated hydrochloric acid with a mass concentration of 36-38% at a volume ratio of 10-15:1.

[0017] Furthermore, in step 4, the electrodeposition temperature is 80-100℃, the electrodeposition time is 10-60 min, and the current density is 10-20 mA·cm. -2 The muffle furnace roasting temperature is 400-800℃, and the roasting time is 1-6 h.

[0018] Furthermore, in step 4, the electrodeposition temperature is 80-90℃, the electrodeposition time is 25-40 min, and the current density is 15-20 mA·cm⁻¹. -2 The muffle furnace roasting temperature is 500-600℃, and the time is 2-4 hours.

[0019] Furthermore, in step 5, the muffle furnace roasting temperature is 400-700℃, the last roasting process takes 1-3 hours, and the remaining roasting processes take 10-30 minutes.

[0020] Furthermore, in step 5, the roasting temperature of the final roasting process is 450-500℃, and the roasting temperature of the remaining roasting processes is 400-450℃.

[0021] The present invention also discloses the application of the aforementioned phosphorus-doped iridium-tantalum-cerium bifunctional electrode in the electrocatalytic chlorine evolution reaction and / or hydrogen evolution reaction.

[0022] The application of the phosphorus-doped iridium-tantalum-cerium bifunctional electrode in the electrocatalytic chlorine evolution reaction includes the following steps: the current is controlled by a galvanometer, the reaction is carried out in a single electrolytic cell, a 0.8-2 M NaCl solution with pH = 1.5-3 is used as the electrolyte, the prepared phosphorus-doped iridium-tantalum-cerium bifunctional electrode is used as the anode working electrode, a platinum sheet is used as the cathode counter electrode, and the reaction current is controlled at 0.1-0.3 A to electrocatalyze the production of available chlorine.

[0023] To overcome the shortcomings of traditional ruthenium-iridium electrodes, this invention employs a multi-component synergistic regulation strategy to improve the structural stability of the electrode in chlorine-containing environments. Based on an iridium-tantalum electrode, the rare earth element Ce is introduced, utilizing its variable valence state to regulate the adsorption and desorption energy barriers of reaction intermediates, thereby optimizing the reaction pathway and enhancing electrocatalytic activity. Simultaneously, phosphorus is introduced and doped onto the catalyst surface in the form of phosphate. By coordinating with metal cations, it regulates the electronic structure, stabilizes active sites, and inhibits component dissolution at high potentials, enabling the electrode to continuously and efficiently generate active chlorine species. Furthermore, this invention maintains excellent CER performance while also exhibiting HER activity. Rare earth-induced oxygen vacancies and phosphorus doping synergistically promote water molecule activation, optimize hydrogen adsorption free energy, and reduce hydrogen evolution overpotential, thereby achieving synergistic enhancement of CER and HER, improving the energy utilization efficiency and operational stability of the electrolysis system.

[0024] By employing the above-described technology, the present invention offers the following advantages compared to existing ruthenium-iridium electrodes: (1) The bifunctional catalyst constructed in this invention has both high efficiency in chlorine and hydrogen evolution. Under the synergistic effect of multiple components, it achieves a significant improvement in catalytic activity, structural stability and energy utilization efficiency, effectively reduces electrolysis energy consumption, and significantly improves the service life of the electrode and the stability of system operation, thus avoiding the limitations of the single function of traditional catalysts.

[0025] (2) By comparison, the phosphorus-doped iridium-tantalum-cerium bifunctional electrode prepared in this invention did not show significant attenuation of its electrocatalytic activity after long-term continuous operation. The above results indicate that the introduction of cerium helps to enhance structural stability and corrosion resistance, while the doping of phosphorus optimizes the electronic structure of the active components. The synergistic effect of the two significantly improves the stability of the electrode during the chlorine evolution reaction, which is an effective technical means to improve the long-term durability of electrocatalysis.

[0026] (3) Under the same test conditions, compared with the Faradaic efficiency (91.2%) of the conventional DSA electrode reported in the literature in the electrocatalytic chlorine evolution reaction, the phosphorus-doped iridium-tantalum-cerium bifunctional electrode prepared in this invention has a higher Faradaic efficiency (97.0%). This result indicates that the electrode of this invention has higher electron utilization efficiency in the electrocatalytic chlorine evolution reaction, and side reactions are effectively suppressed, thereby improving the effective chlorine generation efficiency and product concentration, demonstrating superior catalytic activity and energy utilization efficiency.

[0027] (4) Under the same test conditions, compared with the comparative example, the phosphorus-doped iridium-tantalum-cerium bifunctional electrode prepared in this invention exhibits a lower hydrogen evolution overpotential, indicating that it can effectively reduce the reaction energy barrier and accelerate the charge transfer process, thereby significantly improving the hydrogen evolution performance.

[0028] The electrode of this invention possesses excellent activity in both the chlorine evolution reaction (CER) and the hydrogen evolution reaction (HER): during the CER process, it can significantly promote the reaction of Cl-. - →ClO - This dual-function synergistic catalytic system enhances the conversion of active chlorine and increases the yield of active chlorine. During the HER process, it effectively reduces the hydrogen evolution overpotential and accelerates the hydrogen generation rate. This system endows the electrode with significant advantages such as high activity, low energy consumption, and excellent stability. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the P-IrTaCe / CNT-ATO electrode prepared in Example 1 under a scanning electron microscope at 50 μm. Figure 2 This is a scanning electron microscope image of the P-IrTaCe / CNT-ATO electrode prepared in Example 1 at 10 μm. Figure 3 This is a cross-sectional image of the P-IrTaCe / CNT-ATO electrode prepared in Example 1 at 100 nm using a scanning electron microscope. Figure 4 This is a transmission electron microscope image of the P-IrTaCe / CNT-ATO electrode prepared in Example 1 at 20 nm. Figure 5 The Faraday efficiency of the P-IrTaCe / CNT-ATO electrode prepared in Example 1 was obtained by electrolysis for 2 min at different current densities in 1 M NaCl (pH=2) solution. Figure 6 The electrodes of Example 1 and Comparative Example 1 were used in a 1 M NaCl solution (pH=2) at 500 mA·cm⁻¹. -2 Lifetime test results at current density; Figure 7For Examples 1-5, electrodes were tested under simulated tap water conditions at 50 mA·cm. -2 Current density represents the concentration of available chlorine and reactive oxygen species produced by electrocatalysis. Figure 8 The electrodes of Example 1 and Comparative Examples 1-4 were prepared in 1 M NaCl (pH=2) solution at 50 mA·cm⁻¹. -2 A comparison of Faraday efficiency after 2 minutes of electrolysis at different current densities.

[0030] Figure 9 Linear voltammetric scan curves of the electrode in Example 1 and the electrodes in Comparative Examples 1-4 in 1 M NaCl (pH=2) solution for CER testing.

[0031] Figure 10 Linear voltammetric scan curves of the electrode in Example 1 and the electrodes in Comparative Examples 1-4 in 0.5 M H2SO4 solution for HER testing.

[0032] Figure 11 This is a comparison of the polarization curves of the electrode in Example 1 before and after 1000 cycles of CV testing in a 0.5 M H2SO4 solution. Detailed Implementation

[0033] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0034] Example 1: Preparation of a P-IrTaCe / CNT-ATO bifunctional electrode, including the following steps: (1) Titanium substrate pretreatment: The titanium substrate was cut into 2×2 cm pieces and rinsed with deionized water to remove surface impurities. The cut titanium substrate was completely immersed in 200 mL of 20% NaOH solution and then placed in an 80℃ oil bath for 2 h to remove grease from the substrate surface. After removing the titanium substrate, it was rinsed with deionized water until the NaOH on the surface was completely washed away. The alkaline-washed titanium substrate was then placed in a 15% oxalic acid solution and treated in an 80℃ oil bath for 2 h to remove the oxide film on the substrate surface. After removing the titanium substrate, the excess oxalic acid solution on the surface was rinsed away with a large amount of deionized water, repeated 3 times, until the washing deionized water changed from yellow to clear.

[0035] (2) Preparation of intermediate layer electrodeposition solution: Take 40 mL of a deep eutectic solvent in which choline chloride and ethylene glycol are mixed in a molar ratio of 1:2, and add 0.25 mol·L⁻¹ to the deep eutectic solvent. -1 Stannous chloride, final concentration 0.026 mol·L⁻¹ -1 Antimony trichloride, final concentration 0.15 g·L -1Carbon nanotubes were stirred for 30 minutes under an oil bath at 80°C to ensure thorough mixing, thus obtaining an intermediate layer electrodeposition solution.

[0036] (3) Preparation of outer layer precursor solution: In a mixed solution of 3.7 mL n-butanol and 0.3 mL concentrated hydrochloric acid with a mass concentration of 38%, add the solution to a final concentration of 0.049 mol·L⁻¹. -1 Chloroirilic acid, final concentration 0.015 mol·L⁻¹ -1 Tantalum ethanol, final concentration 0.029 mol·L⁻¹ -1 Cerium isopropoxide and final concentration 4 g·L -1 Dipotassium cetyl phosphate was used to treat the mixed solution in an ultrasonic instrument for 30 minutes to obtain a uniformly mixed outer layer precursor solution.

[0037] (4) Electrodeposition: The titanium substrate pretreated in step (1) is placed in the intermediate layer electrodeposition solution of step (2), with the titanium substrate as the cathode and two graphite plates as the anodes. The cathode is placed between the two anodes. The electrodeposition is carried out in an oil bath at a temperature of 80°C and a current density of 15 mA·cm. -2 Under certain conditions, electrodeposition was performed for 30 min, followed by drying in an oven. After drying, the material was calcined in a muffle furnace at 550°C for 2 h to obtain a titanium matrix containing a tin-antimony interlayer.

[0038] (5) Thermal decomposition: The outer layer precursor liquid of step (3) is uniformly brushed onto the surface of the tin-antimony intermediate layer of the titanium matrix obtained in step (4) to fully wet the surface of the intermediate layer. It is then placed in an 80°C oven to dry for 20 min, and then placed in a 400°C muffle furnace for calcination for 20 min. The above brushing, drying and calcination process is repeated 8 times. The last calcination process is carried out in a 500°C muffle furnace for 2 h and then taken out. The phosphorus-doped iridium-tantalum-cerium bifunctional electrode is finally marked as P-IrTaCe / CNT-ATO electrode.

[0039] A schematic diagram of the P-IrTaCe / CNT-ATO electrode prepared in Example 1 under a scanning electron microscope at 50 μm is shown below. Figure 1 As shown, a schematic diagram of a scanning electron microscope at 10 μm is as follows. Figure 2 As shown, P-IrTaCe / CNT-ATO was successfully loaded onto a titanium substrate, and the coating was uniformly distributed. Figure 3 This is a schematic diagram of the cross-section of the P-IrTaCe / CNT-ATO electrode under a scanning electron microscope at 100 nm, showing a distinct intermediate and outer layer. Figure 4 This is a schematic diagram of the P-IrTaCe / CNT-ATO electrode under a transmission electron microscope at 20 nm. The catalyst particles are tightly bound together, which is beneficial to improving structural stability.

[0040] The P-IrTaCe / CNT-ATO bifunctional electrode from Example 1 was used in electrocatalysis experiments, including the following experiments: ① Chlorine evolution reaction experiment: Current and voltage were controlled by a galvanometer, and the reaction was carried out in an H-type electrolytic cell using Nafion 117 as a proton exchange membrane, separating the cathode and anode. P-IrTaCe / CNT-ATO from Example 1 was used as the working anode electrode, and a platinum sheet was used as the cathode electrode. The electrolyte was a 1 M NaCl solution, adjusted to pH = 2 with concentrated sulfuric acid. During the current efficiency test, 100 mL of electrolyte was used for electrolysis each time, with a reaction time of 2 min. After electrolysis, 5 mL of sample was taken from the system for subsequent efficiency analysis. The effective chlorine concentration and Faradaic efficiency were measured at different current densities. The Faradaic efficiencies for producing effective chlorine concentrations after 2 min of electrolysis at different current densities are shown below. Figure 5 As shown, at 50 mA·cm -2 At the given current density, the Faradaic efficiency of the electrode electrocatalytic chlorine evolution in Example 1 reached 97.0% (see [reference needed]). Figure 8 ).

[0041] ② Catalytic stability experiment: A single-tank reaction was conducted, using P-IrTaCe / CNT-ATO from Example 1 as the anolyte working electrode, a platinum sheet as the cathode counter electrode, and a 1 M NaCl solution (adjusted to pH = 2 with concentrated sulfuric acid) at 500 mA·cm⁻¹. -2 The results of accelerated lifetime testing at current density are as follows: Figure 6 As shown, the catalyst exhibits good stability, with little voltage change after 770 h of operation.

[0042] ③ Experiments were conducted to determine the effective chlorine concentration and reactive oxygen species concentration under simulated tap water conditions: Simulated tap water (TDS concentration of 250 mg·L⁻¹) -1 The preparation process involves adding 303.6 mg sodium bicarbonate, 169.5 mg magnesium sulfate, and 56 mg calcium chloride to 1 L of deionized water to adjust the TDS concentration to 250 mg·L⁻¹. -1 The reaction was carried out in a single tank, with P-IrTaCe / CNT-ATO from Example 1 as the working anode and a platinum sheet as the cathode counter electrode. The electrolyte used was 150 mL of simulated tap water (TDS concentration of 250 mg·L⁻¹). -1 The electrolysis time was 2 min, and the current density was set to 50 mA·cm⁻¹. -2After the reaction was complete, approximately 70 mL of electrolyte was taken, and the total concentration of reactive oxygen species and available chlorine was determined by iodometric titration. Subsequently, the remaining electrolyte was heated in a 30°C water bath for 90 min, assuming that the reactive oxygen species had completely decomposed during this period, leaving only available chlorine. The same titration method was then used again for analysis. The difference between the two titration results was used to estimate the concentration of reactive oxygen species. Following the above experimental procedure, P-IrTaCe / CNT-ATO from Example 1 was used as the anolyte working electrode, at 50 mA·cm⁻¹. -2 The results of the concentrations of available chlorine and reactive oxygen species produced by electrocatalysis for 2 min at the current density are shown in [the table below]. Figure 7 .

[0043] ④ CER testing experiment: A three-electrode system was used, with P-IrTaCe / CNT-ATO from Example 1 as the working anode, a platinum sheet as the cathode, and Ag / AgCl as the reference electrode. The electrolyte was a 1 M NaCl solution (adjusted to pH = 2 with concentrated sulfuric acid). The results of the linear voltammetric scan are shown below. Figure 9 .

[0044] ⑤HER testing experiment: A three-electrode system was used, with P-IrTaCe / CNT-ATO from Example 1 as the cathode working electrode, a graphite rod as the anode counter electrode, and a saturated calomel electrode as the reference electrode. The electrolyte was 0.5 M H2SO4 solution. The results of the linear voltammetric scan are shown below. Figure 10 .

[0045] Example 2: The preparation method of the bifunctional electrode in Example 2 is the same as that in Example 1, except that "in the outer layer precursor solution of step (3), cerium isopropoxide is replaced with lanthanum nitrate of the same molar concentration", and the other conditions remain unchanged. The bifunctional electrode obtained is labeled as P-IrTaLa / CNT-ATO electrode.

[0046] Example 3: The preparation method of the bifunctional electrode in Example 3 is the same as that in Example 1, except that "in the outer precursor solution of step (3), cerium isopropoxide is replaced with praseodymium nitrate of the same molar concentration", and the other conditions remain unchanged. The bifunctional electrode obtained is labeled as P-IrTaPr / CNT-ATO electrode.

[0047] Example 4: The preparation method of the bifunctional electrode in Example 4 is the same as that in Example 1, except that "in the outer precursor solution of step (3), cerium isopropoxide is replaced with neodymium nitrate of the same molar concentration", and the other conditions remain unchanged. The bifunctional electrode obtained is labeled as P-IrTaNd / CNT-ATO electrode.

[0048] Example 5: The preparation method of the bifunctional electrode in Example 5 is the same as that in Example 1, except that "in the outer precursor solution of step (3), cerium isopropoxide is replaced with samarium nitrate of the same molar concentration", and the other conditions remain unchanged. The bifunctional electrode obtained is labeled as P-IrTaSm / CNT-ATO electrode.

[0049] The preparation method of the bifunctional electrode of Comparative Example 1 was the same as that of Example 1, except that "cerium isopropoxide and dipotassium cetyl phosphate were not added to the outer precursor solution in step (3)", and the other conditions remained unchanged. The bifunctional electrode obtained was labeled as IrTa / CNT-ATO electrode.

[0050] Catalytic stability experiments were conducted on the electrode of Comparative Example 1. The specific experimental testing procedures were the same as step ② of Example 1. The electrode of Comparative Example 1 was used as the anolyte working electrode, and the electrolyte was 1 M NaCl solution (pH = 2) at 500 mA·cm⁻¹. -2 The results of accelerated lifetime testing at current density are as follows: Figure 6 As shown.

[0051] Comparative Example 2 and Comparative Example 2 are prepared by repeating the method of Example 1, except that "cerium isopropoxide is not added to the outer layer precursor solution in step (3)", and the other conditions remain unchanged. The resulting bifunctional electrode is labeled as P-IrTa / CNT-ATO electrode.

[0052] The preparation method of the bifunctional electrode of Comparative Example 3 was the same as that of Example 1, except that "dicarbyl phosphate dipotassium was not added to the outer precursor solution in step (3)", and the other conditions remained unchanged. The bifunctional electrode obtained was labeled as IrTaCe / CNT-ATO electrode.

[0053] The preparation method of the bifunctional electrode of Comparative Example 4 is the same as that of Example 1, except that "carbon nanotubes are not added to the intermediate layer electrodeposition solution in step (2)", and the other conditions remain unchanged. The bifunctional electrode obtained is labeled as P-IrTaCe / ATO electrode.

[0054] Examples 1-5 were used to determine the effective chlorine concentration and reactive oxygen species concentration under simulated tap water conditions. The specific experimental test steps were the same as step ③ in Example 1. The electrodes of Examples 1-5 were used as the anode working electrodes in simulated tap water (TDS concentration of 250 mg·L⁻¹). -1 A comparison chart of effective chlorine concentration and reactive oxygen concentration determined by electrolysis for 2 minutes is shown below. Figure 7 As shown, compared with the electrodes of Examples 2-5, the effective chlorine concentration and the total concentration of effective chlorine and reactive oxygen species under the catalysis of the electrode of Example 1 are significantly improved.

[0055] The chlorine evolution reaction was carried out using the electrode of Example 1 and the electrodes of Comparative Examples 1-4, respectively. The specific experimental test steps were the same as step ① of Example 1. The electrodes of Example 1 and Comparative Examples 1-4 were used as the working anode electrodes, respectively, at 50 mA·cm -2 The comparison results of Faraday efficiency under the current density for 2 min of electrolysis are shown in the figure. Figure 8 .from Figure 8 It can be seen that, compared with the electrodes of Comparative Examples 1-4, the Faraday efficiency of the electrochemical chlorine evolution reaction of the electrode of Example 1 is improved to a certain extent, indicating that the prepared bifunctional electrode can improve the performance of the electrochemical chlorine evolution reaction, and at the same time enhance the electrocatalytic activity of the electrode through the synergistic effect of multiple components.

[0056] CER tests were performed on the electrode of Example 1 and the electrodes of Comparative Examples 1-4, respectively. The specific experimental test steps were the same as step ④ of Example 1. The electrodes of Example 1 and Comparative Examples 1-4 were used as the working anode electrodes. The results of the linear voltammetric scan in 1 M NaCl (pH=2) solution are shown below. Figure 9 , Figure 9 This reflects the chlorine evolution performance catalyzed by different electrodes. Example 1 only requires 1.45 V vs. RHE to achieve 10 mA·cm⁻¹. -2 The current density is lower than that of Comparative Examples 1-3, indicating that it can effectively reduce the reaction energy barrier and accelerate the charge transfer process, thereby significantly improving the kinetic performance of the chlorine evolution reaction.

[0057] HER testing experiments were conducted on the electrode of Example 1 and the electrodes of Comparative Examples 1-4, respectively. The specific experimental test procedures were as described in step ⑤ of Example 1. The electrodes of Example 1 and Comparative Examples 1-4 were used as cathode working electrodes. The experimental results of linear voltammetry scans in 0.5 M H2SO4 solution are shown below. Figure 10 , Figure 10 This reflects the hydrogen evolution performance catalyzed by different electrodes, and also shows a lower overpotential, indicating that it has superior hydrogen evolution catalytic activity. Figure 11 The polarization curves of the electrode in Example 1 before and after 1000 cycles of CV in 0.5 M H2SO4 solution are compared. It can be seen that the polarization curve of Example 1 decays very little before and after 1000 cycles, indicating that the bifunctional catalyst has good HER stability.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode, characterized in that, Includes the following steps: Step 1: Clean and pre-treat the titanium substrate; Step 2: Add the tin source, antimony source, and carbon source sequentially to the deep eutectic solvent of choline chloride and ethylene glycol, mix thoroughly and evenly to obtain the intermediate layer electrodeposition solution; Step 3: Add the iridium source, tantalum source, cerium source and phosphorus-containing surfactant to the acidic solvent and mix thoroughly to obtain the outer layer precursor solution; Step 4: Place the pretreated titanium substrate from Step 1 into the electrodeposition solution of the intermediate layer from Step 2 as the cathode, and set the anode as the electrode. Electrodeposition is performed under heating, followed by drying and calcination to obtain a titanium substrate containing a tin-antimony intermediate layer. Step 5: Apply the outer layer precursor solution from Step 3 evenly to the surface of the tin-antimony intermediate layer of the titanium substrate obtained in Step 4, ensuring the intermediate layer surface is fully wetted, dried, and then calcined. Repeat the above steps of application, drying, and calcination several times to obtain the phosphorus-doped iridium-tantalum-cerium bifunctional electrode.

2. The method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode according to claim 1, characterized in that, The specific steps of the pretreatment process in step 1 are as follows: First, the titanium substrate is rinsed to remove surface impurities. Then, it is immersed in a strong alkaline solution and heated for alkaline treatment to remove surface grease. After rinsing, it is immersed in an oxalic acid solution and heated for acid treatment to remove the oxide film on the surface. Finally, it is rinsed thoroughly, and the pretreatment is completed.

3. The method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode according to claim 2, characterized in that, In the pretreatment step, the strong alkali solution is NaOH or KOH solution with a mass fraction of 15-30%, and the oxalic acid solution has a mass fraction of 15-20%. The heating temperature for both the alkali treatment and the acid treatment is 60-90℃.

4. The method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode according to claim 1, characterized in that, In step 2, the carbon source is one of carbon nanotubes, graphene, diamond, or fullerene. In the intermediate layer electrodeposition solution described in step 2, the final concentration of the tin source is 0.15-0.3 M, the final concentration of the antimony source is 0.01-0.04 M, and the final concentration of the carbon source is 0.1-0.5 g·L⁻¹. -1 .

5. The method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode according to claim 1, characterized in that, In step 2, the molar ratio of choline chloride to ethylene glycol is 0.5-2:

1.

6. The method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode according to claim 1, characterized in that, In step 3, the phosphorus-containing surfactant is one of diethyl phosphite, dipotassium cetyl phosphate, lecithin, or diethyl hydroxymethyl phosphate. In the outer precursor solution described in step 3, the final concentrations of the iridium source are 0.03-0.07 M, the tantalum source is 0.01-0.03 M, the cerium source is 0.02-0.04 M, and the phosphorus-containing surfactant is 2-5 g·L. -1 ; In step 3, the acidic solvent is a mixture of n-butanol and concentrated hydrochloric acid with a mass concentration of 36-38% at a volume ratio of 10-15:

1.

7. The method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode according to claim 1, characterized in that, In step 4, the electrodeposition temperature is 80-100℃, the electrodeposition time is 10-60 min, and the current density is 10-20 mA·cm. -2 The roasting is carried out in a muffle furnace at a temperature of 400-800℃ for 1-6 hours.

8. The method for preparing a phosphorus-doped iridium-tantalum-cerium bifunctional electrode according to claim 1, characterized in that, In step 5, the process of brushing, drying and firing is repeated 5-10 times. Firing is carried out in a muffle furnace at a temperature of 400-700℃. The last firing process takes 1-3 hours, and the remaining firing processes take 10-30 minutes.

9. A phosphorus-doped iridium-tantalum-cerium bifunctional electrode prepared by the method described in any one of claims 1-8.

10. The application of the phosphorus-doped iridium-tantalum-cerium bifunctional electrode as described in claim 9 in the electrocatalytic chlorine evolution reaction and / or hydrogen evolution reaction.

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