A driving electrode with a wide potential window characteristic and a preparation method thereof

Abstract

The application discloses a driving electrode with a wide potential window characteristic and a preparation method thereof. The method comprises the following steps: firstly, a titanium mesh substrate is pretreated; then, tin, antimony and ruthenium metal salts are uniformly mixed with boric acid and carbon source powder by using a sol-gel method; synergies of carbon, boron and transition metals are utilized; the multi-element doped powder prepared through a ladder type heat treatment is loaded on the substrate through a tabletting process; and the stability is enhanced through fluorination treatment. Experimental results show that the potential window of the electrode prepared by the application can be widened to 3.0V (-1.15V~+1.85V), the side reaction in the electromotive repair process can be effectively inhibited, and the acid-base polarization can be significantly relieved. The application has low preparation cost and excellent performance, and has wide application prospects in the fields of environmental electrokinetics repair and wastewater advanced treatment.

Description

Technical Field

[0001] This invention relates to the field of electrode materials technology, specifically to a carbon, boron, and metal co-doped composite driving electrode with a wide potential window and low preparation cost, and its preparation method, which can be used as both an anode and a cathode in electrochemical reaction systems. Background Technology

[0002] Electrokinetic remediation technology is a highly efficient in-situ remediation technology for contaminated soil, groundwater, and sediments. With its advantages of no secondary pollution, high remediation efficiency, and in-situ implementation, it has become one of the core technologies in the field of environmental pollution control. Electrokinetic remediation technology is a highly efficient in-situ remediation technology that uses electrochemical methods. Its core principle is to construct a DC electric field at the contaminated site, and through electrochemical mechanisms such as electromigration, electroosmosis, and electrophoresis, to induce the directional movement of heavy metal ions, charged colloidal particles, and polar organic pollutants in the contaminated system towards the anode and cathode electrodes for enrichment and removal. However, in practical engineering applications, the performance defects of traditional driving electrodes have become a key bottleneck restricting its remediation efficiency: traditional electrodes have a narrow potential window, allowing hydrogen and oxygen evolution side reactions to occur in water at low potentials, directly triggering severe acid-base polarization. Furthermore, the anode region is prone to hydrogen and oxygen evolution side reactions due to the narrow potential window of traditional electrodes. + Rapid acidification due to large accumulation of OH groups in the cathode area — Enrichment tends towards alkalization; drastic fluctuations in pH not only alter the pore structure and permeability of soil and aquifers, leading to secondary precipitation of heavy metal ions and clogging of pores, significantly reducing the directional migration efficiency of pollutants, but also significantly deplete electric field energy, reducing the current efficiency of the electrodynamic system. Especially in composite remediation systems coupled with chemical oxidation such as persulfate activation, the narrow potential window of traditional driving electrodes triggers side reactions in water electrolysis, consuming large amounts of electrical energy while inhibiting the generation of reactive oxides such as sulfate free radicals, severely reducing the utilization efficiency of persulfate and significantly weakening the remediation effect of the composite system. Therefore, developing novel driving electrodes with a wide potential window that can effectively suppress side reactions in water electrolysis, breaking through the performance bottlenecks of traditional electrodes, has become a crucial technological need urgently needed to improve the efficiency of electrodynamic remediation technology and promote its large-scale engineering application.

[0003] Currently, commonly used electrodes for electrodynamic remediation mainly include graphite electrodes, stainless steel electrodes, noble metal electrodes, and transition metal oxide coated electrodes (such as DSA electrodes). Among them, transition metal oxide coated electrodes have attracted attention due to their moderate cost and good catalytic activity. Existing technologies typically employ single or binary transition metals to prepare them through Sn-Sb-Ru-CB composite doped oxide powders or thermal decomposition methods. However, single transition metal oxide coatings have limited tunability of electronic structure, weak suppression of hydrogen evolution / oxygen evolution reactions, and typically narrow potential windows (generally below 2.30V), making it difficult to effectively suppress water electrolysis side reactions. These shortcomings directly lead to problems such as high energy consumption, severe acid-base polarization, and short electrode life during electrodynamic remediation, limiting its large-scale engineering application.

[0004] This application addresses the aforementioned technical bottlenecks. By co-doping carbon, boron, and transition metals, and through the synergistic energy level modulation of C, B, and transition metals, the problem of narrow potential windows caused by single doping in traditional electrolytic electrodes is solved. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in existing electrodynamic repair technologies, such as the narrow potential window (typically below 2.30V) of the driving electrode, which easily leads to hydrogen and oxygen evolution side reactions, resulting in severe acid-base polarization near the electrode, high energy consumption, and low persulfate utilization. Simultaneously, addressing the drawback of the high cost of noble metal electrodes, this invention provides a carbon, boron, and metal multi-element co-doped composite driving electrode with a wide potential window (up to 2.70~3.00V), high conductivity, and low cost, as well as its preparation method.

[0006] The objective of this invention is achieved through the following technical solution: A method for fabricating a driving electrode with a wide potential window, the method comprising the following: Titanium mesh substrate pretreatment; Preparation of Sn-Sb-Ru-CB composite doped oxide powder: An organic chelating agent, anhydrous ethanol, and deionized water were mixed, and then tin salt, antimony salt, ruthenium salt, and boron source were added sequentially. The mixture was stirred until completely dissolved to obtain a main salt solution. The carbon source powder was ultrasonically dispersed and then added to the main salt solution, along with a crosslinking agent. The mixture was magnetically stirred in a water bath at 60-80°C to form a homogeneous sol. The sol was then dried in a forced-air drying oven at 75-80°C to obtain a dry gel. The obtained dry gel was ground into powder and placed in a tube furnace. Under a micro-oxidation atmosphere, the temperature was increased in a stepwise manner: First stage: 1~3℃ / min to 100~150℃, held for 0.5~1h; Second stage: 2~4℃ / min to 250~320℃, held for 1~2h; Third stage: 2~4℃ / min to 400~500℃, held for 2h; Fourth stage: 1~3℃ / min to 150~200℃, followed by natural cooling, to obtain Sn-Sb-Ru-CB composite doped oxide powder; the micro-oxidation atmosphere had an O2 volume content of 5~15% and a total flow rate of 75~90 mL / min. Electrode pressing: The Sn-Sb-Ru-CB composite doped oxide powder is mixed and ground with binder and dispersant, and then uniformly coated on the surface of the pretreated titanium mesh substrate. The active material is pressed into the titanium mesh under a pressure of 6-10MPa by a tablet press to obtain the formed electrode. Surface fluorination modification: The shaped electrode is immersed in ammonium fluoride solution for constant temperature water bath treatment, then taken out, rinsed and dried to obtain the final driving electrode with wide potential window characteristics.

[0007] Further, the organic chelating agent is at least one of citric acid, ethylenediaminetetraacetic acid, tartaric acid, malic acid, succinic acid, salicylic acid, EDTA, or triethanolamine; the crosslinking agent is at least one of ethylene glycol, glycerol, polyethylene glycol, propylene glycol, or pentaerythritol; the crosslinking agent reacts with the organic chelating agent to form a three-dimensional sol network.

[0008] The boron source is boric acid; The carbon source is at least one of the following: carbon black, graphene, carbon nanotubes, carbon nanofibers, acetylene black, activated carbon, mesoporous carbon, etc.

[0009] Furthermore, the micro-oxidation atmosphere is constructed from an inert gas and oxygen, with an oxygen volume fraction of 5-15%.

[0010] Further, the binder is at least one of PTFE, polyvinylidene fluoride, perfluoroethylene propylene, perfluorosulfonic acid resin (Nafion solution), or polyimide, preferably PTFE with a mass concentration of 60%; the dispersant is water or anhydrous ethanol.

[0011] Furthermore, the molar ratio of the effective coordinating groups in the organic chelating agent molecule to the total molar ratio of metal ions in the system is 4.5:1 to 8:1, ensuring sufficient chelation of metal ions without introducing excessive impurities. Taking citric acid as an example, its molar ratio to the total metal ions (Sn, Sb, Ru) is preferably 1.2:1 to 2:1. The organic chelating agent is dissolved in a mixed solvent, wherein the volume ratio of anhydrous ethanol to deionized water in the mixed solvent is (2.25~5):1.

[0012] The molar ratio of tin salt, antimony salt, ruthenium salt, boron source, and carbon source is: Sn : Sb : Ru : B : C = 1 : (0.05~0.09) : (0.025~0.045) : (0.15~0.25) : (0.95~1.56), and the number of moles of carbon source is converted according to carbon content.

[0013] Further, the organic chelating agent is citric acid, the carbon source is carbon black, and the crosslinking agent is ethylene glycol. The proportions of each component are as follows: citric acid 4.5~5.5g, anhydrous ethanol 18~25mL, deionized water 5~8mL, stannous chloride dihydrate 3.0~4.0g, antimony trichloride 0.2~0.3g, ruthenium trichloride 0.08~0.15g, boric acid 0.15~0.25g, and carbon black powder 0.2~0.25g; preferably, the proportions are as follows: citric acid 4.9g, anhydrous ethanol 20mL, deionized water 6mL, stannous chloride dihydrate 3.4g, antimony trichloride 0.24g, ruthenium trichloride 0.1g, boric acid 0.17g, and carbon black powder 0.22g. The molar ratio of citric acid to ethylene glycol is 0.1:1 to 0.2:1.

[0014] Furthermore, the mass of the binder is 5-15% of the mass of the dry gel after grinding. Too little binder results in poor electrode structural stability, while too much binder leads to plasticity after electrode pressing and cooling. During the electrode forming process, if the pressure is too low, the electrode is difficult to form and the structure is unstable; if the pressure is too high, the electrode is brittle.

[0015] The present invention also protects the driving electrode obtained by the preparation method, wherein the potential window of the driving electrode is not less than 2.70V, preferably 2.70V~3.00V.

[0016] Furthermore, the driving electrode can serve as both an anode to suppress oxygen evolution and a cathode to suppress hydrogen evolution.

[0017] The driving electrode described in this invention is used in the electrodynamic remediation of contaminated soil or groundwater. The specific remediation process is as follows: an electrodynamic remediation system is constructed, and the driving electrode is placed as the anode and cathode at the contaminated medium, respectively. Under the action of an electric field, the pollutants are directionally moved through electromigration and / or electroosmosis mechanisms. Since the electrode has a wide potential window of 2.7~3.0V, it can effectively suppress hydrogen evolution and oxygen evolution side reactions, alleviate acid-base polarization, and maintain the pH stability of the system during the remediation process, thereby achieving efficient removal of pollutants.

[0018] Compared with existing technologies, this invention, through the synergistic energy level modulation of C, B, and transition metals (Sn-Sb-Ru), combined with sol-gel molecular-level dispersion and compaction, and supplemented by surface fluorination passivation, breaks through the potential window limit of traditional electrodes while ensuring low cost. This results in a carbon, boron, and metal multi-element co-doped composite driving electrode with a wide potential window, exhibiting the following significant advantages: (1) Widening the potential window: This invention utilizes the synergistic effect of carbon (C), boron (B), and transition metal co-doping in electronic energy level regulation and reaction kinetic suppression to achieve an electrode potential window of 2.70~3.00V, significantly higher than that of ordinary DSA electrodes (2.30V). In particular, in the embodiments of this application, a higher potential window than that of noble metal Pt electrodes (2.70V) is obtained while ensuring low cost, solving the problem of electrolytic polarization in environmental remediation. Boron doping weakens the adsorption of intermediates by adjusting the electron cloud density, and the carbon source induces electronic structure rearrangement and enhances the hydrogen / oxygen evolution barrier. At the same time, the carbon source (such as carbon black) further optimizes the adsorption energy of water molecules through band modulation. This wide window characteristic can fundamentally suppress the side reactions of water electrolysis, alleviate acid-base polarization, and greatly improve the energy utilization efficiency of systems such as activated persulfate.

[0019] (2) Balancing high conductivity and physical stability: This invention utilizes carbon black to construct a highly efficient three-dimensional electron transport network, significantly reducing the interfacial charge transfer resistance. At the same time, the "pinning" effect of carbon black refines the grains. Combined with the pressing process (replacing the traditional method of coating the precursor onto the Ti (mesh / sheet) substrate, calcining, and multiple coatings) and surface fluorination treatment, it solves the defects of traditional coated electrodes that are easy to peel off and have poor durability, enhances the adhesion between the coating and the substrate, and ensures the long-term durability of the electrode under high current density.

[0020] (3) Significantly reduced production costs: By replacing some precious metals with low-cost carbon sources (such as carbon black) and boric acid, and with a relatively simple preparation process, the unit volume cost of the electrode of this invention is approximately RMB 10.08 / cm². 3 It accounts for less than 1% of the precious metal Pt electrode, giving it a strong competitive edge in industrial applications.

[0021] (4) Remediation efficiency adaptable to all scenarios: The wide window characteristics exhibited by this electrode make it suitable as both an anode to inhibit oxygen evolution and a cathode to inhibit hydrogen evolution, and it can be flexibly applied to various complex groundwater and soil electrodynamic remediation systems and wastewater treatment reactors.

[0022] (5) Experimental results show that the electrode potential window prepared in this embodiment can reach -1.15V to +1.85V (3.00V), which is significantly better than that of the traditional DSA electrode (-1.05V to +1.25V (2.30V)) and the noble metal Pt electrode (-1.00V to +1.70V (2.70V)). This electrode can effectively suppress the side reaction of water electrolysis during the remediation process, alleviate acid-base polarization, and has extremely low preparation cost. It provides a novel driving electrode scheme with both high cost performance and wide potential window characteristics for large-scale, high-efficiency electrokinetic remediation and water treatment reaction systems. Attached Figure Description

[0023] Figure 1 Example 1: Cyclic voltammetry curve. Cyclic voltammetry curve in 0.5M Na2SO4 solution, scan rate: 100mV / s, x-axis potential (V), y-axis current (A). Example 1 has the widest potential window, ranging from -1.15V to +1.85V.

[0024] Figure 2 Example 2: Cyclic voltammetry curve. Cyclic voltammetry curve in 0.5M Na2SO4 solution, scan rate: 100mV / s, x-axis potential (V), y-axis current (A), potential window range of -1.16V to +1.74V in Example 2.

[0025] Figure 3 Example 3: Cyclic voltammetry curve. Cyclic voltammetry curve in 0.5M Na2SO4 solution, scan rate: 100mV / s, x-axis potential (V), y-axis current (A), potential window range of -1.14V to +1.75V in Example 3.

[0026] Figure 4 Example 4: Cyclic voltammetry curve. Cyclic voltammetry curve in 0.5M Na2SO4 solution, scan rate: 100mV / s, x-axis potential (V), y-axis current (A), potential window range of -1.05V to +1.65V in Example 4.

[0027] Figure 5 Comparative Example 1: Cyclic voltammetry curve in 0.5M Na2SO4 solution. Scan rate: 100mV / s. Abscissa: potential (V). ordinate: current (A). Potential window range for Comparative Example 1: -1.0V to +0.9V.

[0028] Figure 6Comparative Example 2: Cyclic voltammetry curves in 0.5M Na2SO4 solution. Scan rate: 100mV / s. Abscissa: potential (V). ordinate: current (A). Potential window range for Comparative Example 2: -1.05V to +1.05V.

[0029] Figure 7 Comparative Example 3: Cyclic voltammetry curves in 0.5M Na2SO4 solution. Scan rate: 100mV / s. Abscissa: potential (V). ordinate: current (A). Potential window range for Comparative Example 3: -1.05V to +1.60V.

[0030] Figure 8 Comparative Example 4: Cyclic voltammetry curves in 0.5M Na2SO4 solution. Scan rate: 100mV / s. Abscissa: potential (V). ordinate: current (A). Potential window range for Comparative Example 4: -0.60V to +1.40V.

[0031] Figure 9 Comparative Example 5 (DSA electrode) Cyclic voltammetry curves in 0.5M Na2SO4 solution, scan rate: 100mV / s, horizontal axis potential (V), vertical axis current (A), the potential window range of Comparative Example 5 is -1.05V to +1.25V.

[0032] Figure 10 Comparative Example 6 (Pt electrode) Cyclic voltammetry curve in 0.5M Na2SO4 solution, scan rate: 100mV / s, horizontal axis potential (V), vertical axis current (A), the potential window range of Comparative Example 6 is -1.00V to +1.70V.

[0033] Figure 11 Electrode cost comparison chart, comparing the costs of Example 1, DSA electrode, and Pt electrode in laboratory-scale settings. Detailed Implementation

[0034] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto. Unless otherwise specified, the experimental methods described in the present invention are conventional methods; the reagents and materials described, unless otherwise specified, are all commercially available.

[0035] In this invention, the micro-oxidation atmosphere is set as follows: a tubular furnace is used instead of a muffle furnace, sealed with flanges at both ends, and equipped with an inlet and an outlet to ensure a suitable micro-oxidation atmosphere. The atmosphere is adjusted using a gas cylinder and a mass flow controller. Insufficient oxygen content results in complete carbon retention but incomplete metal oxidation; excessive oxygen content leads to rapid carbon oxidation and loss of electrode conductivity. Complete carbon burn-off in an air atmosphere fails to achieve the desired doping effect. In the embodiments of this application, nitrogen and oxygen are used in a volume ratio to construct the micro-oxidation atmosphere. Other inert gases and oxygen, such as argon, can also be used to construct the micro-oxidation atmosphere.

[0036] Transition metals (such as tin, antimony, and ruthenium) typically exist in ionic form in polar aqueous solutions or inorganic salts, while high-performance carbon sources (such as graphene, carbon nanotubes, or organic precursors) often exhibit strong hydrophobic or nonpolar characteristics. Direct mixing leads to significant phase separation. Metal ions aggregate into clusters, while carbon components clump together individually, failing to form a uniform doped network at the atomic scale, resulting in extremely uneven distribution of active sites on the electrode surface. This invention employs a mixing strategy that involves first preparing a chelating agent ("mixing an organic chelating agent, anhydrous ethanol, and deionized water"), then sequentially adding "tin salt, antimony salt, ruthenium salt, and boron source" and stirring until completely dissolved. The carbon source powder undergoes "ultrasonic dispersion" before the addition of a "crosslinking agent." This pre-assembly utilizes the synergistic effect of functional groups to inhibit the migration and diffusion of metal ions, ensuring that C, B, and metal elements achieve a uniform molecular-level distribution before subsequent calcination. Furthermore, the water bath temperature should not exceed 60-80℃. If the temperature is too low, it will be difficult to form a precursor gel, and if the temperature is too high, the precursor will plasticize and lose its properties.

[0037] Furthermore, the fabrication of metal oxide electrodes typically requires a high-temperature oxidizing atmosphere (such as calcination in air), but carbon readily reacts with oxygen at high temperatures to generate CO2, thus "losing" away. Simultaneously, carbon has reducing properties, potentially reducing the already formed metal oxide to elemental metals, thus compromising the electrode's semiconductor properties. This invention employs stepped temperature control and a micro-oxidizing atmosphere for heat treatment, effectively balancing the "oxidation-reduction" contradiction. Simultaneously, boron atoms gain sufficient migration energy to diffuse into the interstitial spaces or substitution sites of the metal oxide lattice, achieving true co-doping. During the stepped heating process, the third stage ensures that tin, antimony, and ruthenium are fully oxidized and form a stable lattice. By precisely controlling the heating rate and time, the carbon component is partially oxidized and fixed rather than completely burned off. If the controlled temperature is too low, the precursor gel cannot be oxidized to metal oxide to form a stable lattice; if the temperature is too high, the doped carbon will be oxidized. Simultaneously, carbon can also act as a reducing agent to oxidize the metal oxide to a non-target valence state.

[0038] The preparation method of this invention introduces NH4F solution for fluorination treatment. Since multi-component doping can lead to lattice distortion, unstable active sites may exist on the electrode surface. Fluorination treatment can effectively repair surface micro-defects and form a chemically extremely stable "fluorine protective film." This not only solidifies the doping state of C and B but also further helps to suppress the adsorption of water molecules, thus helping to broaden the potential window.

[0039] The present invention discloses a method for fabricating a driving electrode with a wide potential window characteristic, the specific steps of which are as follows: S1: Titanium mesh substrate pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10%~15% oxalic acid solution and heat it at 85~95℃ for 1~2 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol, and dry it for later use.

[0040] S2: Preparation of Sn-Sb-Ru-CB composite doped oxide powder: Citric acid was weighed and dissolved in a mixed solvent of anhydrous ethanol and deionized water in a certain ratio. SnCl2·2H2O, SbCl3, RuCl3, and H3BO3 were added sequentially, and the mixture was magnetically stirred until completely dissolved to obtain the main salt solution. Carbon black powder was ultrasonically dispersed with anhydrous ethanol, and then the above main salt solution was added, followed by ethylene glycol. The mixture was continuously magnetically stirred in a water bath at 60~80℃ for 3~4 hours to form a homogeneous sol. The sol was dried in a forced-air drying oven at 75~80℃ to obtain a dry gel.

[0041] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. Under a micro-oxidizing atmosphere (N2 and O2 were mixed at a volume ratio of 9:1, and the total flow rate was controlled at 80 mL / min), the temperature was increased in a stepped manner: First stage: 1~3℃ / min to 100~150℃, held for 0.5~1h (dehydration); Second stage: 2~4℃ / min to 250~320℃, held for 1~2h (controlled decomposition of organic matter); Third stage: 2~4℃ / min to 400~500℃, held for 2h (lattice oxidation and CB co-doping); Fourth stage: 1~3℃ / min to 150~200℃, followed by natural cooling, to obtain dark gray Sn-Sb-Ru-CB composite doped oxide powder.

[0042] Stage 1: Objective To thoroughly remove physically adsorbed water and solvent residue. Too rapid heating leads to rapid dehydration, causing powder cracking and splattering; excessively high temperatures result in ethanol residue boiling and structural damage; too short a reaction time leads to incomplete dehydration, while too long a reaction time results in low efficiency. Stage 2: Objective To controllably decompose organic chelates to form amorphous metal oxide precursors. Too rapid heating causes violent decomposition of organic matter and excessive carbon loss; excessively high temperatures lead to premature carbon oxidation, while too low temperatures result in incomplete citric acid decomposition; too short a reaction time results in insufficient residual carbon formation, while too long a reaction time leads to excessive carbon oxidation. Stage 3: Objective To crystallize metal oxides, perform boron lattice doping, and fix carbon in situ. Too rapid heating leads to rapid grain growth and uneven boron diffusion; excessively high temperatures result in significant carbon loss; too short a reaction time results in insufficient boron doping depth, while too long a reaction time leads to grain coarsening. Stage 4: Objective To eliminate thermal stress, fix defect structures, and prevent lattice distortion relaxation. Too rapid heating leads to thermal stress cracking and defect relaxation.

[0043] S4: Electrode Forming: The Sn-Sb-Ru-CB composite doped oxide powder is ultrasonically dispersed, dried and ground with binder and dispersant to form a paste, which is then uniformly coated on the surface of the pretreated titanium mesh substrate (both sides). The paste is placed in a tableting mold and pressed under 6-10MPa pressure by a tableting machine to ensure that the active material is tightly bonded to the titanium mesh, thus obtaining the formed electrode. S5: Surface fluorination treatment. The shaped electrode is immersed in NH4F solution and treated in a water bath. After removal, it is rinsed with deionized water and dried to obtain the final driving electrode with a wide potential window.

[0044] The driving electrode prepared above is used in the electrodynamic remediation of contaminated soil or groundwater. The specific process involves constructing an electrodynamic remediation system and placing the driving electrode as both the anode and cathode at the contaminated medium. Under the influence of an electric field, pollutants move directionally through mechanisms such as electromigration and electroosmosis. Because the electrode has a wide potential window of 2.7–3.0 V, it can effectively suppress hydrogen and oxygen evolution side reactions, alleviate acid-base polarization, and maintain pH stability during the remediation process, thereby achieving efficient removal of pollutants.

[0045] Example 1 A method for fabricating a Sn-Sb-Ru-CB composite-doped driving electrode with a wide potential window is as follows: S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0046] Preparation of S2, Sn-Sb-Ru-CB composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. Then, 3.4 g SnCl2·2H2O, 0.24 g SbCl3, 0.1 g RuCl3, and 0.17 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.22 g of carbon black powder was ultrasonically dispersed in 20 mL ethanol, and the above main salt solution was added, followed by 10 mL ethylene glycol. The mixture was then continuously magnetically stirred in a 70°C water bath for 4 hours to form a homogeneous sol. The sol was dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0047] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. Stepped heating was carried out in a micro-oxidizing atmosphere (O2 volume content 10%, total flow rate controlled at 80 mL / min): First stage: 2℃ / min to 120℃, held for 1h (dehydration); Second stage: 3℃ / min to 280℃, held for 1.5h (controlled decomposition of organic matter); Third stage: 3℃ / min to 450℃, held for 2h (lattice oxidation and CB co-doping); Fourth stage: 2℃ / min to 200℃, followed by natural cooling, to obtain a dark gray-black Sn-Sb-Ru-CB composite doped oxide powder with a weak metallic luster.

[0048] S4. Electrode Forming: Mix 300mg of Sn-Sb-Ru-CB composite doped oxide powder with PTFE (60wt%) and 5mL of anhydrous ethanol, sonicate for 10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. The mass of PTFE is 10% of the mass of the dry gel after grinding. Place it into a tableting mold (13mm in diameter) and press at 8MPa for 2 minutes using a tablet press.

[0049] S5. Fluorination treatment: The pressed electrode is immersed in a 1wt% NH4F solution, treated in a 50℃ water bath for 30 minutes, rinsed with deionized water, and dried to obtain a Sn-Sb-Ru-CB composite doped driving electrode with a wide potential window.

[0050] S6. Performance Testing: Cyclic voltammetry (CV) was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100 mV / s. Figure 1 In the figure, the horizontal axis represents potential (V) and the vertical axis represents current (A). The electrode prepared in Example 1 has a hydrogen evolution potential of -1.15V and an oxygen evolution potential of +1.85V, with a potential window of 3.00V. Furthermore, its CV curve has a high slope, demonstrating the electrode's excellent conductivity.

[0051] Example 2 A method for fabricating a Sn-Sb-Ru-CB composite-doped driving electrode with a wide potential window is as follows: S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0052] Preparation of S2, Sn-Sb-Ru-CB composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixture of 20 mL ethanol and 6 mL water. Then, 3.6 g SnCl2·2H2O, 0.26 g SbCl3, 0.12 g RuCl3, and 0.22 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.24 g of carbon black powder was ultrasonically dispersed in 20 mL ethanol, and the above main salt solution was added, followed by 10 mL ethylene glycol. The mixture was then continuously magnetically stirred in an 80°C water bath for 4 hours to form a homogeneous sol. The sol was dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0053] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. Stepped heating was carried out in a micro-oxidizing atmosphere (O2 content 7%, total flow rate controlled at 80 mL / min): First stage: 2℃ / min to 120℃, held for 1h (dehydration); Second stage: 3℃ / min to 280℃, held for 1.5h (controlled decomposition of organic matter); Third stage: 2℃ / min to 480℃, held for 2h (lattice oxidation and CB co-doping); Fourth stage: 2℃ / min to 200℃, followed by natural cooling, to obtain a dark gray-black Sn-Sb-Ru-CB composite doped oxide powder with a weak metallic luster.

[0054] S4. Electrode Forming for Tableting: Mix 300 mg of the above Sn-Sb-Ru-CB composite doped oxide powder with PTFE (60 wt%) and 5 ml of ethanol, sonicate for 10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. Place it into a tableting mold (13 mm in diameter) and press at 8 MPa for 2 minutes using a tablet press. The mass of PTFE is 12% of the mass of the dry gel after grinding.

[0055] S5. Fluorination treatment: The pressed electrode is immersed in a 1.2wt% NH4F solution, treated in a 50℃ water bath for 30 minutes, rinsed with deionized water, and dried to obtain a Sn-Sb-Ru-CB composite doped driving electrode with a wide potential window.

[0056] S6. Performance Testing: Cyclic voltammetry (CV) was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100 mV / s. Figure 2 This indicates that the electrode prepared in Example 2 has a hydrogen evolution potential of -1.16V, an oxygen evolution potential of +1.74V, and a potential window of 2.90V.

[0057] Example 3 A method for fabricating a Sn-Sb-Ru-CB composite doped driving electrode with a wide potential window is as follows: S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0058] Preparation of S2, Sn-Sb-Ru-CB composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. Then, 3.4 g SnCl2·2H2O, 0.24 g SbCl3, 0.1 g RuCl3, and 0.20 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.23 g of carbon black powder was ultrasonically dispersed in 20 mL ethanol, and the above main salt solution was added, followed by 10 mL ethylene glycol. The mixture was then continuously magnetically stirred in a 75°C water bath for 4 hours to form a homogeneous sol. The sol was dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0059] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. The temperature was increased in a stepwise manner under a micro-oxidizing atmosphere (O2 content 15%, total flow rate controlled at 80 mL / min): First stage: 3℃ / min to 120℃, held for 1h (dehydration); Second stage: 4℃ / min to 280℃, held for 2h (controlled decomposition of organic matter); Third stage: 3℃ / min to 500℃, held for 2h (lattice oxidation and CB co-doping); Fourth stage: 2℃ / min to 200℃, followed by natural cooling, to obtain a dark gray-black Sn-Sb-Ru-CB composite doped oxide powder with a weak metallic luster.

[0060] S4. Electrode Forming for Tableting: Mix 300 mg of the above powder with PTFE (60 wt% emulsion) and 5 mL of anhydrous ethanol, sonicate for 10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. Place it into a tableting mold (13 mm in diameter) and pressurize at 8 MPa for 2 minutes. The mass of PTFE is 15% of the mass of the dry gel after grinding.

[0061] S5. Fluorination treatment: The pressed electrode is immersed in a 1wt% NH4F solution, treated in a 60℃ water bath for 30 minutes, rinsed with deionized water, and dried to obtain a Sn-Sb-Ru-CB composite doped driving electrode with a wide potential window.

[0062] S6. Performance Testing: Cyclic voltammetry (CV) was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100 mV / s. Figure 3 This indicates that the electrode prepared in Example 3 has a hydrogen evolution potential of -1.14V, an oxygen evolution potential of +1.74V, and a potential window of 2.88V.

[0063] Example 4 A method for fabricating a Sn-Sb-Ru-CB composite-doped driving electrode with a wide potential window is as follows: S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0064] Preparation of S2, Sn-Sb-Ru-CB composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. Then, 3.0 g SnCl2·2H2O, 0.20 g SbCl3, 0.08 g RuCl3, and 0.15 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.2 g of carbon black powder was ultrasonically dispersed in 20 mL ethanol, and the above main salt solution was added, followed by 12 mL ethylene glycol. The mixture was then continuously magnetically stirred in a 60°C water bath for 3 hours to form a homogeneous sol. The sol was dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0065] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. The temperature was increased in a stepwise manner under a micro-oxidizing atmosphere (O2 content 5%, total flow rate controlled at 80 mL / min): First stage: 1℃ / min to 100℃, held for 0.5h (dehydration); Second stage: 2℃ / min to 250℃, held for 1h (controllable decomposition of organic matter); Third stage: 2℃ / min to 400℃, held for 2h (lattice oxidation and CB co-doping); Fourth stage: 1℃ / min to 200℃, followed by natural cooling, to obtain a dark gray-black Sn-Sb-Ru-CB composite doped oxide powder with a weak metallic luster.

[0066] S4. Tableting Preparation: Mix 300 mg of the above powder with PTFE (60%) and 5 ml of anhydrous ethanol, sonicate for 10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. Place it into a tableting mold (13 mm in diameter) and press at 6 MPa for 1 minute using a tablet press. The mass of PTFE is 5% of the mass of the dry gel after grinding.

[0067] S5. Fluorination treatment: The pressed electrode is immersed in 0.05wt% NH4F solution, treated in a 40℃ water bath for 20 minutes, rinsed with deionized water, and dried to obtain a Sn-Sb-Ru-CB composite doped driving electrode with a wide potential window.

[0068] S6. Performance Testing: Cyclic voltammetry (CV) was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100 mV / s. Figure 4 This indicates that the electrode prepared in Example 4 has a hydrogen evolution potential of -1.05V, an oxygen evolution potential of +1.65V, and a potential window of 2.70V.

[0069] Example 5 S1. Pretreatment of titanium mesh substrate: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 85℃ for 2 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol, and dry it for later use.

[0070] Preparation of S2, Sn-Sb-Ru-CB composite doped oxide powder: Weigh 4.5-5.5 g of citric acid and dissolve it in a mixed solvent of 18-25 mL ethanol and 5-8 mL water. Add 3.0-4.0 g SnCl2·2H2O, 0.2-0.3 g SbCl3, 0.08-0.15 g RuCl3, and 0.15-0.25 g H3BO3 sequentially, stirring for 10 minutes until completely dissolved. Separately, ultrasonically disperse 0.2-0.25 g of carbon black powder in 20 mL ethanol, add the above main salt solution, followed by 8-12 mL ethylene glycol. Then, continuously stir magnetically in a water bath at 60-80℃ for 3-4 hours to form a homogeneous sol. Dry the sol in a forced-air drying oven at 75-80℃ for 10-12 hours to obtain a dry gel.

[0071] S3. Stepped heat treatment: The obtained dry gel is ground into powder and placed in a tube furnace. Under a micro-oxidizing atmosphere (O2 content 5~15%, total flow rate controlled at 80 mL / min), the temperature is increased in a stepped manner: First stage: 1~3℃ / min to 100~150℃, held for 0.5~1h (dehydration); Second stage: 2~4℃ / min to 250~320℃, held for 1~2h (controlled decomposition of organic matter); Third stage: 2~4℃ / min to 400~500℃, held for 2h (lattice oxidation and CB co-doping); Fourth stage: 1~3℃ / min to 150~200℃, followed by natural cooling, to obtain a dark gray-black Sn-Sb-Ru-CB composite doped oxide powder with a weak metallic luster.

[0072] S4. Electrode Forming: Mix 300mg of the above powder with 60wt% poly(fluoroethylene propylene) emulsion and 5ml of anhydrous ethanol, sonicate for 5-10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. Place it into a tableting mold (13mm in diameter) and press at 6-10MPa for 1-3 minutes. The binder should be 5-15% of the powder mass.

[0073] S5. Fluorination treatment: Immerse the pressed electrode in 0.5~2wt% NH4F solution, treat in a water bath at 40~60℃ for 20~40 minutes, rinse with deionized water, and dry to obtain a Sn-Sb-Ru-CB composite doped driving electrode with a wide potential window.

[0074] Example 6 In this embodiment, the Sn-Sb-Ru-CB composite doped oxide powder was prepared as follows: 3.8 g of tartaric acid (or 3.4 g of malic acid) was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. Then, 3.4 g of SnCl2·2H2O, 0.24 g of SbCl3, 0.1 g of RuCl3, and 0.17 g of H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.22 g of carbon black powder was ultrasonically dispersed in 20 mL of ethanol, and the above main salt solution was added, followed by 10 mL of ethylene glycol. The mixture was then continuously magnetically stirred in a 70°C water bath for 4 hours to form a homogeneous sol. The sol was then dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0075] The remaining steps are the same as in Example 1. Cyclic voltammetry testing using an electrochemical workstation showed that replacing the chelating agent could achieve a potential window of 2.73~2.94V, which meets the intended potential window of 2.7V~3.0V.

[0076] Example 7 In this embodiment, the Sn-Sb-Ru-CB composite doped oxide powder was prepared as follows: 4.9 g of citric acid was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. Then, 3.4 g SnCl2·2H2O, 0.24 g SbCl3, 0.1 g RuCl3, and 0.17 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.22 g of carbon black powder was ultrasonically dispersed in 20 mL ethanol, and the above main salt solution was added, followed by 9.9 mL glycerol (or 15 mL PEG400). The mixture was then continuously magnetically stirred in a 70°C water bath for 4 hours to form a homogeneous sol. The sol was then dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0077] The remaining steps are the same as in Example 1. Cyclic voltammetry testing using an electrochemical workstation showed that replacing the crosslinking agent could achieve a potential window of 2.72~2.87V, which meets the intended potential window of 2.7V~3.0V.

[0078] Example 8 In this embodiment, the Sn-Sb-Ru-CB composite doped oxide powder was prepared as follows: 4.9 g of citric acid was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. Then, 3.4 g SnCl2·2H2O, 0.24 g SbCl3, 0.1 g RuCl3, and 0.17 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.23 g of carbon nanotubes (or 0.23 g of carbon nanofibers or 0.17 g of graphene oxide) was ground into powder, ultrasonically dispersed in 20 mL of ethanol, and the above main salt solution was added. Subsequently, 10 mL of ethylene glycol was added, and the mixture was continuously magnetically stirred in a 70°C water bath for 4 hours to form a homogeneous sol. The sol was then dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0079] The remaining steps are the same as in Example 1. Cyclic voltammetry testing using an electrochemical workstation showed that replacing the carbon source could achieve a potential window of 2.75~2.93V, which meets the intended potential window of 2.7V~3.0V.

[0080] Comparative Example 1 Same as Example 1, but omitting carbon black and H3BO3, and using only SnCl2·2H2O, SbCl3, and RuCl3.

[0081] S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0082] Preparation of S2, Sn-Sb-Ru composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixture of 20 mL ethanol and 6 mL water. Then, 3.4 g SnCl2·2H2O, 0.24 g SbCl3, and 0.1 g RuCl3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Next, 10 mL of ethylene glycol was added, and the mixture was continuously magnetically stirred in a 70°C water bath for 4 hours to form a homogeneous sol. The sol was then dried in an 80°C oven for 12 hours to obtain a dry gel.

[0083] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. The temperature was increased in a stepwise manner under a micro-oxidizing atmosphere (O2 content 10%, total flow rate controlled at 80 mL / min): First stage: 2℃ / min to 120℃, held for 1h; Second stage: 3℃ / min to 280℃, held for 1.5h; Third stage: 3℃ / min to 450℃, held for 2h; Fourth stage: 2℃ / min to 200℃, followed by natural cooling, to obtain a dark blue-gray Sn-Sb-Ru composite doped oxide powder with obvious metallic luster.

[0084] S4. Electrode Forming for Tableting: Mix 300mg of the above powder with PTFE (60wt%) and 5ml of anhydrous ethanol, sonicate for 10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. Place it into a tableting mold (13mm in diameter) and press at 8MPa for 2 minutes using a tablet press. The mass of PTFE is 10% of the mass of the dry gel after grinding.

[0085] S5. Fluorination treatment: Immerse the pressed electrode in a 1wt% NH4F solution, treat it in a 50℃ water bath for 30 minutes, rinse with deionized water, and dry it.

[0086] S6. Performance Testing: Cyclic voltammetry was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100mV / s. Figure 5 This indicates that the electrode prepared in Comparative Example 1 has a hydrogen evolution potential of -1.00V, an oxygen evolution potential of +0.90V, and a total potential window of 1.90V. Comparative Example 2 Same as Example 1, but carbon black is omitted and H3BO3 is retained.

[0087] S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0088] Preparation of S2, Sn-Sb-Ru-B composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixture of 20 mL ethanol and 6 mL water. Then, 3.4 g SnCl2·2H2O, 0.24 g SbCl3, 0.1 g RuCl3, and 0.17 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Subsequently, 10 mL of ethylene glycol was added, and the mixture was continuously magnetically stirred in a 70°C water bath for 4 hours to form a homogeneous sol. The sol was then dried in an 80°C oven for 12 hours to obtain a dry gel.

[0089] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. The temperature was increased in a stepwise manner under a micro-oxidizing atmosphere (O2 content 10%, total flow rate controlled at 80 mL / min): First stage: 2℃ / min to 120℃, held for 1h; Second stage: 3℃ / min to 280℃, held for 1.5h; Third stage: 3℃ / min to 450℃, held for 2h; Fourth stage: 2℃ / min to 200℃, followed by natural cooling, to obtain gray-blue Sn-Sb-Ru-B composite doped oxide powder with metallic luster.

[0090] S4. Tableting Preparation: Mix 300 mg of the above powder with PTFE (60%) and 5 ml of anhydrous ethanol, sonicate for 10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. Place it into a tableting mold (13 mm in diameter) and pressurize at 8 MPa for 2 minutes. The mass of PTFE is 10% of the mass of the dry gel after grinding.

[0091] S5. Fluorination treatment: Immerse the pressed electrode in a 1wt% NH4F solution, treat it in a 50℃ water bath for 30 minutes, rinse with deionized water, and dry it.

[0092] S6. Performance Testing: Cyclic voltammetry was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100mV / s. Figure 6 This indicates that the electrode prepared in Comparative Example 2 has a hydrogen evolution potential of -1.05V, an oxygen evolution potential of +1.05V, and a potential window of 2.10V.

[0093] Comparative Example 3: Same as Example 1, but H3BO3 is omitted and carbon black is retained.

[0094] S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0095] Preparation of S2, Sn-Sb-Ru-C composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. 3.4 g SnCl2·2H2O, 0.24 g SbCl3, and 0.1 g RuCl3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.22 g of carbon black powder was ultrasonically dispersed in 20 mL ethanol, and the above main salt solution was added, followed by 10 mL ethylene glycol. The mixture was then continuously magnetically stirred in a 70°C water bath for 4 hours to form a homogeneous sol. The sol was dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0096] S3. Stepped heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. The temperature was increased in a stepwise manner under a micro-oxidizing atmosphere (O2 content 10%, total flow rate controlled at 80 mL / min): First stage: 2℃ / min to 120℃, held for 1h; Second stage: 3℃ / min to 280℃, held for 1.5h; Third stage: 3℃ / min to 450℃, held for 2h; Fourth stage: 2℃ / min to 200℃, followed by natural cooling, to obtain black Sn-Sb-Ru-C composite doped oxide powder with no metallic luster.

[0097] S4. Tableting Preparation: Take 300mg of the above powder, mix it with 10% PTFE (60%) and 5ml anhydrous ethanol, sonicate for 10 minutes, dry and grind it into a paste, and then evenly coat it on both sides of the pretreated titanium mesh. Place it into a tableting mold (13mm in diameter) and press it at 8MPa for 2 minutes using a tableting machine.

[0098] S5. Fluorination treatment: Immerse the pressed electrode in a 1wt% NH4F solution, treat it in a 50℃ water bath for 30 minutes, rinse with deionized water, and dry it.

[0099] S6. Performance Testing: Cyclic voltammetry was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100mV / s. Figure 7 The results show that the electrode prepared in Comparative Example 3 has a hydrogen evolution potential of -1.05V, an oxygen evolution potential of +1.60V, and a potential window of 2.65V.

[0100] Comparative Example 4 Same as Example 1, but the parameters and conditions are outside the scope of the present invention: S1. Titanium mesh pretreatment: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10% oxalic acid solution and heat it at 90℃ for 1.5 hours to etch. After the surface turns rough gray-black, take it out; rinse it with deionized water and ultrasonically clean it with anhydrous ethanol for 5 minutes, and dry it for later use.

[0101] Preparation of S2, Sn-Sb-Ru-CB composite doped oxide powder: 4.9 g of citric acid was dissolved in a mixed solvent of 20 mL ethanol and 6 mL water. 5 g SnCl2·2H2O, 0.4 g SbCl3, 0.1 g RuCl3, and 0.30 g H3BO3 were added sequentially, and the mixture was stirred for 10 minutes until completely dissolved. Separately, 0.1 g of carbon black powder was ultrasonically dispersed in 20 mL ethanol, and the above main salt solution was added, followed by 15 mL ethylene glycol. The mixture was then continuously magnetically stirred in a 90°C water bath for 4 hours to form a homogeneous sol. The sol was dried in an 80°C forced-air drying oven for 12 hours to obtain a dry gel.

[0102] S3. Heat treatment: The obtained dry gel was ground into powder and placed in a tube furnace. It was directly heated in air atmosphere: 3℃ / min to 550℃ and held for 2h. Then it was naturally cooled to obtain gray-blue Sn-Sb-Ru-CB composite doped oxide powder with metallic luster.

[0103] S4. Electrode Forming for Tableting: Mix 300 mg of the above powder with PTFE (60%) and 5 mL of anhydrous ethanol, sonicate for 10 minutes, dry and grind into a paste, and then evenly coat both sides of the pretreated titanium mesh. Place it into a tableting mold (13 mm in diameter) and press at 4 MPa for 2 minutes. The mass of PTFE is 10% of the mass of the dry gel after grinding.

[0104] S5. Fluorination treatment: Immerse the pressed electrode in a 1wt% NH4F solution, treat it in a 50℃ water bath for 30 minutes, rinse with deionized water, and dry to obtain the driving electrode.

[0105] S6. Performance Testing: Cyclic voltammetry (CV) was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100 mV / s. Figure 5 This indicates that the electrode prepared in Example 5 has a hydrogen evolution potential of -0.60V, an oxygen evolution potential of +1.40V, and a potential window of 2.00V.

[0106] Comparative Example 4, although the doping elements are the same as in Example 1, the reaction parameters are not within the range of the experimental objectives, and the stepped temperature control and "micro-oxidation" atmosphere adjustment are not guaranteed. The resulting electrode potential window is 2.0V.

[0107] Comparative Example 5 S1. Take a commercially available DSA electrode (ruthenium-iridium coating), first use sandpaper to polish the surface to remove the oxide layer, then rinse with deionized water, ultrasonically clean with anhydrous ethanol for 5 minutes, and dry. Use it directly as a comparative example to measure its potential window.

[0108] S2. Performance Testing: Cyclic voltammetry was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100mV / s. Figure 9 The results show that the hydrogen evolution potential of the comparative 5DSA electrode is -1.05V, the oxygen evolution potential is +1.25V, and the total potential window reaches 2.30V. Furthermore, its CV curve has a high slope, demonstrating the electrode's excellent conductivity.

[0109] Comparative Example 6 S1. Take a commercial Pt electrode, first use sandpaper to polish the surface to remove the oxide layer, then rinse with deionized water, ultrasonically clean with anhydrous ethanol for 5 minutes, and dry. Use it directly as a comparative example to measure its potential window.

[0110] S2. Performance Testing: Cyclic voltammetry was performed using an electrochemical workstation in a 0.5M Na2SO4 electrolyte. This electrode served as the working electrode, the counter electrode as a graphite electrode, and the reference electrode as an Ag / AgCl electrode. The scan rate was 100mV / s. Figure 10 The results show that the hydrogen evolution potential of the Pt electrode in Comparative Example 6 is -1.00V, the oxygen evolution potential is +1.70V, and the total potential window reaches 2.70V. Furthermore, its high CV curve slope demonstrates the electrode's excellent conductivity.

[0111] In summary, this invention addresses the challenges of narrow potential windows in traditional electrodynamic remediation technologies, the susceptibility to hydrogen and oxygen evolution side reactions leading to severe acid-base polarization, and high energy consumption. This invention creatively introduces carbon as a conductive framework and bandgap regulating phase into the Sn-Sb-Ru system, supplemented by deep microscopic doping with boron (B). Through stepped heat treatment, electrode pressing, and surface fluorination, this invention achieves precise control over the electronic structure and adsorption energy of active sites on the electrode surface. Experimental results show that the electrode prepared by this invention has a potential window spanning 2.70–3.00 V, approximately 30% higher than traditional DSA electrodes and about 11% higher than noble metal Pt electrodes; simultaneously, its production cost is significantly reduced to about 1% of that of Pt electrodes. This invention not only resolves the contradiction between "high performance" and "low cost" in electrode materials but also solves the pH fluctuation problem in electrodynamic remediation through deep suppression of side reactions, demonstrating broad industrial application prospects in the in-situ remediation of contaminated soil and groundwater.

[0112] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A method for fabricating a driving electrode with a wide potential window, characterized in that, The method includes the following: Titanium mesh substrate pretreatment; Preparation of Sn-Sb-Ru-CB composite doped oxide powder: An organic chelating agent, anhydrous ethanol, and deionized water were mixed, and then tin salt, antimony salt, ruthenium salt, and boron source were added sequentially. The mixture was stirred until completely dissolved to obtain a main salt solution. The carbon source powder was ultrasonically dispersed and then added to the main salt solution, along with a crosslinking agent. The mixture was magnetically stirred in a water bath at 60-80°C to form a homogeneous sol. The sol was then dried in a forced-air drying oven at 75-80°C to obtain a dry gel. The obtained dry gel was ground into powder and placed in a tube furnace. Under a micro-oxidation atmosphere, the temperature was increased in a stepwise manner: First stage: 1~3℃ / min to 100~150℃, held for 0.5~1h; Second stage: 2~4℃ / min to 250~320℃, held for 1~2h; Third stage: 2~4℃ / min to 400~500℃, held for 2h; Fourth stage: 1~3℃ / min to 150~200℃, followed by natural cooling, to obtain Sn-Sb-Ru-CB composite doped oxide powder; the micro-oxidation atmosphere had an O2 volume content of 5~15% and a total flow rate of 75~90 mL / min. Electrode pressing: The Sn-Sb-Ru-CB composite doped oxide powder is mixed and ground with binder and dispersant, and then uniformly coated on the surface of the pretreated titanium mesh substrate. The active material is pressed into the titanium mesh under a pressure of 6-10MPa by a tablet press to obtain the formed electrode. Surface fluorination modification: The shaped electrode is immersed in ammonium fluoride solution for constant temperature water bath treatment, then taken out, rinsed and dried to obtain the final driving electrode with wide potential window characteristics.

2. The preparation method according to claim 1, characterized in that, The organic chelating agent is at least one selected from citric acid, ethylenediaminetetraacetic acid, tartaric acid, malic acid, succinic acid, salicylic acid, or triethanolamine; the crosslinking agent is at least one selected from ethylene glycol, glycerol, polyethylene glycol, propylene glycol, or pentaerythritol; and the boron source is boric acid. The carbon source is at least one of carbon black, graphene, carbon nanotubes, carbon nanofibers, acetylene black, activated carbon, and mesoporous carbon. The micro-oxidation atmosphere is constructed from inert gas and oxygen, with an oxygen volume fraction of 5-15%.

3. The preparation method according to claim 1, characterized in that, The binder is at least one of PTFE, polyvinylidene fluoride, perfluoroethylene propylene, perfluorosulfonic acid resin or polyimide; the dispersant is water or anhydrous ethanol.

4. The preparation method according to claim 1, characterized in that, The ratio of the molar amount of the effective coordinating group in the organic chelating agent molecule to the molar amount of the total metal ions in the system is 4.5:1 to 8:1; The molar ratio of tin salt, antimony salt, ruthenium salt, boron source, and carbon source is: Sn : Sb : Ru : B : C = 1 : (0.05~0.09) : (0.025~0.045) : (0.15~0.25) : (0.95~1.56), and the number of moles of carbon source is converted according to carbon content.

5. The preparation method according to claim 1, characterized in that, The organic chelating agent is citric acid, the carbon source is carbon black, and the crosslinking agent is ethylene glycol. The proportions of each component are as follows: citric acid 4.5~5.5g, anhydrous ethanol 18~25mL, deionized water 5~8mL, stannous chloride dihydrate 3.0~4.0g, antimony trichloride 0.2~0.3g, ruthenium trichloride 0.08~0.15g, boric acid 0.15~0.25g, and carbon black powder 0.2~0.25g. The molar ratio of citric acid to ethylene glycol is 0.1:1 to 0.2:

1.

6. The preparation method according to claim 1, characterized in that, The mass of the binder is 5-15% of the mass of the dry gel after grinding; the mass concentration of the ammonium fluoride solution is 0.5-2 wt%.

7. The preparation method according to claim 1, characterized in that, The pretreatment process of the titanium mesh substrate is as follows: Select industrial pure titanium mesh, first use sandpaper to polish the surface to remove the oxide layer; then immerse it in a 10%~15% oxalic acid solution and heat it at 85~95℃ for 1~2 hours to etch it. Take it out after the surface turns rough gray-black. Rinse with deionized water, ultrasonically clean with anhydrous ethanol, and dry for later use.

8. A driving electrode obtained by the preparation method according to any one of claims 1-7, characterized in that, The potential window of the driving electrode is not less than 2.70V, and preferably the potential window is 2.70V~3.00V.

9. The driving electrode according to claim 8, characterized in that, The driving electrode can act as both an anode to suppress oxygen evolution and a cathode to suppress hydrogen evolution.

10. The driving electrode of claim 8 is used in the electrodynamic remediation of contaminated soil or groundwater, characterized in that, The specific remediation process is as follows: Construct an electrodynamic remediation system, place the driving electrodes as anode and cathode respectively at the contaminated medium, and under the action of the electric field, promote the directional movement of pollutants through electromigration and / or electroosmosis mechanisms; Because the electrode has a wide potential window of 2.7~3.0V, it can effectively suppress hydrogen evolution and oxygen evolution side reactions during the remediation process, alleviate acid-base polarization, maintain pH stability of the system, and thus achieve efficient removal of pollutants.

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