Titanium dioxide nanotube interlayer cooperated with neodymium modified titanium-based lead dioxide hydrophobic electrode, preparation method and application thereof

Abstract

The embodiment of the application provides a titanium dioxide nanotube intermediate layer cooperated with neodymium modified titanium-based lead dioxide hydrophobic electrode and a preparation method and application thereof, and belongs to the technical field of electrocatalytic oxidation anode materials. The titanium-based lead dioxide hydrophobic electrode comprises a titanium base plate, a titanium dioxide nanotube intermediate layer formed on the surface of the titanium base plate, which is a vertically oriented nanotube array structure, and a neodymium modified lead dioxide surface active layer deposited on the surface of the titanium dioxide nanotube intermediate layer; wherein the neodymium modified lead dioxide surface active layer is a super-hydrophobic surface formed by regulating a hydrophobic agent, and the contact angle with water is greater than or equal to 140 degrees. The electrode prepared by the application solves the problems of easy falling off of the active layer and passivation of the titanium base, greatly prolongs the service life of the electrode, and enhances the catalytic activity and corrosion resistance, thereby improving the efficiency of wastewater advanced treatment and salt resource utilization.

Description

Technical Field

[0001] This invention relates to the technical field of electrocatalytic oxidation anode materials, and particularly to a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube intermediate layer synergistically modified with neodymium, its preparation method, and its application. Background Technology

[0002] With the rapid development of the coal chemical industry, the treatment of concentrated wastewater (ROC) generated by reverse osmosis (RO) membrane processes has become a major challenge in the water treatment field. ROC water accounts for approximately 15-40% of the influent and is characterized by high concentrations of recalcitrant organic matter, high total dissolved solids (TDS), and complex composition. Traditional technologies such as coagulation-adsorption, ozone oxidation, and membrane distillation generally suffer from problems such as high reagent costs, severe membrane fouling, low organic matter removal efficiency, and negative impacts on subsequent salt resource utilization when treating ROC.

[0003] In recent years, electrochemical oxidation technology has gradually gained attention in the water treatment field due to its advantages such as simple equipment, convenient operation, and green efficiency. When treating high-conductivity ROCs, it requires no additional electrolyte and can utilize the high concentration of Cl in wastewater. - and SO4 2- The generation of active chloride or sulfate radicals enhances the oxidation of organic matter. The anolyte material is the core of this electrochemical oxidation technology. Titanium-based lead dioxide electrodes are widely used due to their low cost and good stability, but they suffer from technical challenges such as insufficient electrocatalytic activity, easy shedding of the active layer, and short lifespan.

[0004] To improve the performance of titanium-based lead dioxide electrodes, there are currently two main approaches: one is to introduce an organic polymer interlayer (such as polyaniline or polypyrrole) to enhance interfacial bonding, but its structure is prone to deterioration under strong oxidation and high temperature environments, resulting in poor long-term stability; the other is to modify the PbO2 active layer by doping with metal ions (such as Fe, Mn, or Ce), but it will have problems such as valence state fluctuations, ion dissolution, and enhanced oxygen evolution side reactions at high potentials.

[0005] In view of this, a novel titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube intermediate layer synergistically modified with neodymium, its preparation method and application are proposed to solve all or part of the above problems. Summary of the Invention

[0006] To address at least one of the aforementioned problems and deficiencies in the prior art, embodiments of the present invention provide a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube interlayer synergistically modified with Nd, its preparation method, and its application. Through the synergistic design of a triple structure—a rigid TiO2 nanotube interlayer, stable rare-earth Nd doping, and a superhydrophobic surface—the electrode performance is significantly improved. The TiO2 nanotube interlayer is metallurgically bonded to the titanium substrate, fundamentally solving the problems of easy active layer detachment and titanium substrate passivation, thus greatly extending the electrode lifespan; Nd... 3+ By embedding the electrode in a stable valence state within the crystal lattice, catalytic activity and corrosion resistance are enhanced. The superhydrophobic surface effectively resists ion adsorption and scaling in high-salt wastewater, ensuring long-term, efficient, and stable operation of the electrode. Applying this electrode to treat concentrated wastewater from coal chemical reverse osmosis achieves efficient removal of organic matter without the need for additional reagents, providing an effective solution for advanced wastewater treatment and salt resource utilization. The technical solution is as follows:

[0007] According to one aspect of the present invention, a titanium-based lead dioxide hydrophobic electrode with a neodymium-modified intermediate layer in titanium dioxide nanotubes is provided. The titanium-based lead dioxide hydrophobic electrode comprises:

[0008] Titanium substrate;

[0009] A titanium dioxide nanotube interlayer is formed on the surface of a titanium substrate, wherein the titanium dioxide nanotube interlayer is a vertically oriented nanotube array structure; and

[0010] Neodymium-modified lead dioxide surface active layer deposited on the surface of the intermediate layer of titanium dioxide nanotubes; wherein the neodymium-modified lead dioxide surface active layer is a superhydrophobic surface formed by hydrophobic agent regulation, and the contact angle between the superhydrophobic surface and water is greater than or equal to 140°.

[0011] According to another aspect of the present invention, a method for preparing a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube interlayer synergistically modified with neodymium is provided. The preparation method includes:

[0012] S1: Pre-treatment of the titanium substrate by polishing, degreasing, and acid etching;

[0013] S2: The pretreated titanium substrate is subjected to the first anodic oxidation treatment in the first oxidation solution to oxidize the surface of the titanium substrate to generate a titanium dioxide nanotube array, thus obtaining a primary titanium dioxide substrate electrode.

[0014] S3: The primary titanium dioxide substrate electrode is subjected to a second anodic oxidation treatment in the second oxidation solution to control the pore expansion and wall thinning of the titanium dioxide nanotube array, thereby obtaining the secondary titanium dioxide substrate electrode.

[0015] S4: Anneal the secondary titanium dioxide substrate electrode to convert the amorphous titanium dioxide into anatase phase or mixed crystal phase, and obtain annealed titanium substrate electrode.

[0016] S5: An annealed titanium substrate electrode is subjected to electrochemical reduction treatment by applying a cathode current in a reducing solution to repair oxygen vacancies and increase carrier concentration, thereby obtaining a titanium-based titanium dioxide nanotube electrode.

[0017] S6: Anodic electrodeposition is performed on a titanium-based titanium dioxide nanotube electrode in an acidic electrodeposition solution containing lead salt, neodymium salt, fluoride, surfactant and hydrophobic agent. Neodymium ions are anchored in situ by supramolecular soft template and the electrocrystallization kinetic parameters are controlled to form a neodymium-modified lead dioxide surface active layer with a villous micro-nano structure on the surface of the intermediate layer of titanium dioxide nanotube, thus obtaining a titanium-based lead dioxide hydrophobic electrode.

[0018] According to another aspect of the present invention, an application is provided of a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube interlayer synergistically modified with neodymium in the treatment of reverse osmosis concentrate from coal chemical wastewater. This titanium-based lead dioxide hydrophobic electrode is either the titanium-based lead dioxide hydrophobic electrode described in the above-described aspect or a titanium-based lead dioxide hydrophobic electrode obtained according to the preparation method described in the above-described aspect.

[0019] The titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube interlayer synergistically modified with neodymium, the preparation method thereof, and its application provided by the embodiments of the present invention have at least one or a portion of the following advantages:

[0020] (1) A vertically oriented titanium dioxide nanotube array intermediate layer is formed on the surface of a titanium substrate by anodic oxidation. The intermediate layer forms a metallurgical bond with the titanium substrate, and the bonding force is much stronger than that of traditional organic polymer adsorption. This effectively solves the problem of easy detachment of the active layer. At the same time, the dense inorganic rigid structure can serve as a physical barrier layer, effectively inhibiting the formation of a high-resistance passivation film and blocking the diffusion of active oxygen into the substrate, thus significantly improving the structural stability and service life of the electrode.

[0021] (2) By doping the lead dioxide surface active layer with rare earth element neodymium (Nd), Nd 3+ It has a special f-electron orbital structure, which can be embedded in the PbO2 lattice in a stable +3 valence state to form a substitutional doping. It has no valence fluctuation in a strong oxidizing environment, avoiding lattice distortion and microcrack generation, thereby improving the corrosion resistance and long-term operational stability of the electrode.

[0022] (3) By introducing surfactants and hydrophobic agents (such as ODPA) during the preparation of the lead dioxide surface active layer, and through supramolecular soft template action and modification with low surface energy materials, a villous micro-nano structure superhydrophobic layer (contact angle ≥140°) with a lotus leaf-like effect was constructed on the electrode surface. This superhydrophobic layer can effectively repel Cl from high-salt wastewater. - F - The adsorption and scaling of corrosive ions and organic pollutants on the electrode surface solves the problem of traditional electrodes being easily contaminated and having their active sites covered, which leads to a decrease in efficiency and ensures long-term, low-energy operation of the electrode.

[0023] (4) Through the triple structure design of rigid nanotube array intermediate layer, Nd stable doping and superhydrophobic layer, a significant synergistic effect is generated: the nanotube array intermediate layer provides a stable substrate and efficient electron transport channel; Nd doping regulates the lattice and electronic structure of lead dioxide surface active layer, improving intrinsic catalytic activity and stability; the superhydrophobic layer endows the electrode with excellent anti-fouling and corrosion resistance; the overall performance of the electrode is comprehensively improved in terms of structure, performance and service life.

[0024] (5) By precisely controlling the process parameters of two-step anodizing, annealing, electrochemical reduction and composite electrodeposition, the morphology, crystal phase and Nd doping amount, microstructure and hydrophobicity of titanium dioxide nanotubes and PbO2 active layer are controllably adjustable, making the preparation method of the present invention stable and reproducible, providing a reliable technical path for the preparation of high-performance electrocatalytic anode electrode materials.

[0025] (6) By applying the electrode of the present invention to treat the reverse osmosis concentrate of coal chemical wastewater, it is possible to achieve efficient synergistic removal of COD and TOC without the need for additional chemical reagents (e.g., COD removal rate reached 88.0% and TOC removal rate reached 70.8% in Example 1), effectively solving the impact of organic matter in ROC on subsequent evaporation and crystallization processes, which is conducive to the resource recovery of by-product salts and achieving the environmental protection requirement of "near-zero emissions". Attached Figure Description

[0026] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 This is a physical appearance diagram of the titanium-based lead dioxide hydrophobic electrode according to Embodiment 1 of the present invention;

[0028] Figure 2 A flowchart illustrating the steps of a method for preparing a titanium-based lead dioxide hydrophobic electrode according to an embodiment of the present invention;

[0029] Figure 3Linear current-voltage curves of electrodes in Embodiment 1 and Comparative Examples 1-3 according to the present invention;

[0030] Figure 4 The graphs show the accelerated lifetime test results of electrodes in Embodiment 1 and Comparative Examples 1-3 according to the present invention.

[0031] Figure 5 The graphs show the cyclic degradation results of bisphenol A by electrodes of Examples 1 and 1-3 according to the present invention.

[0032] Figure 6a The contact angle of the electrode in Comparative Example 3 according to the present invention;

[0033] Figure 6b This refers to the contact angle of the electrode according to Embodiment 1 of the present invention. Detailed Implementation

[0034] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0035] This invention provides a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube interlayer synergistically modified with Nd and its preparation method. Through the synergistic design of a triple structure—a rigid TiO2 nanotube interlayer, stable rare-earth Nd doping, and a superhydrophobic surface—electrode performance is significantly improved. The TiO2 nanotube interlayer is metallurgically bonded to the titanium matrix, fundamentally solving the problems of easy active layer detachment and titanium matrix passivation, thus greatly extending the electrode lifespan; Nd... 3+ By embedding the electrode in a stable valence state within the crystal lattice, its catalytic activity and corrosion resistance are enhanced. The superhydrophobic surface effectively resists ion adsorption and scaling in high-salt wastewater, ensuring long-term, efficient, and stable operation. Applying this electrode to treat concentrated wastewater from coal chemical reverse osmosis achieves efficient removal of organic matter without the need for additional reagents, providing an effective solution for advanced wastewater treatment and salt resource utilization.

[0036] See Figure 1 The image shows a physical appearance of the titanium-based lead dioxide hydrophobic electrode of Embodiment 1 of the present invention.

[0037] The titanium-based lead dioxide hydrophobic electrode (hereinafter referred to as the electrode) comprises a titanium substrate, a titanium dioxide nanotube intermediate layer formed on the surface of the titanium substrate, and a neodymium-modified lead dioxide surfactant layer deposited on the surface of the titanium dioxide nanotube intermediate layer. The titanium dioxide nanotube intermediate layer is a vertically oriented nanotube array structure, metallurgically bonded to the titanium substrate; the neodymium-modified lead dioxide surfactant layer is modulated by a hydrophobic agent to form a superhydrophobic surface, the contact angle between this superhydrophobic surface and water being greater than or equal to 140°.

[0038] In this embodiment of the invention, the titanium substrate serves as the conductive substrate and mechanical structural support for the electrodes. The titanium dioxide nanotube intermediate layer (TiO2-NTs / NTA) is a transition layer with a vertically oriented nanotube array structure, formed by self-growth on the surface of the titanium substrate through anodic oxidation. Its function is to enhance interfacial bonding, optimize electron transport, prevent the formation of passivation films, and block reactive oxygen corrosion.

[0039] Furthermore, the neodymium-modified lead dioxide surface active layer (PbO2-Nd) is a lead dioxide layer doped with the rare earth element neodymium, formed by electrodeposition on the intermediate layer of titanium dioxide nanotubes, and serves as the main body for electrocatalytic oxidation. Nd doping is used to stabilize the crystal lattice, regulate the electronic structure, and enhance catalytic activity and corrosion resistance.

[0040] Hydrophobic agents are used to reduce the surface energy of the electrodes, creating materials with superhydrophobic surfaces, such as octadecyl phosphate (ODPA). A superhydrophobic surface is a surface with a static contact angle with water greater than a certain angle (e.g., ≥140° as achieved in this invention). Such superhydrophobic surfaces possess self-cleaning and anti-fouling properties.

[0041] The metallurgical bond between the titanium dioxide nanotube intermediate layer's nanotube array structure and the titanium substrate refers to the interfacial bond formed through interatomic bonding forces. In this invention, the interfacial bond between the titanium matrix and the TiO2 nanotubes, formed through in-situ anodic oxidation growth, exhibits a strength far exceeding that of physical adsorption or adhesive bonding.

[0042] In one example, preferably, the thickness ratio of the titanium substrate to the titanium dioxide nanotube intermediate layer is 1:0.0025-0.025, more preferably 1:0.005-0.015. For example, when the thickness of the titanium substrate is 1 mm, the thickness of the titanium dioxide nanotube intermediate layer can be set between 2.5 μm and 25 μm, preferably between 5 and 15 μm.

[0043] In one example, preferably, the thickness ratio of the titanium dioxide nanotube intermediate layer to the neodymium-modified lead dioxide surfactant layer is 1:5-50, more preferably 1:10-20. For example, when the thickness of the titanium dioxide nanotube intermediate layer is 10 μm, the thickness of the neodymium-modified lead dioxide surfactant layer can be between 50-500 μm, preferably between 100-200 μm.

[0044] In one example, preferably, in the neodymium-modified lead dioxide surfactant layer, the molar ratio of neodymium to lead is 1:20-250, more preferably 1:60-120.

[0045] See Figure 2 The document illustrates the specific steps of a method for preparing a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube intermediate layer synergistically modified with neodymium, according to one embodiment.

[0046] Step S1: Pretreatment of titanium substrate.

[0047] Provide a titanium substrate (e.g., purity above 99%, size 50mm×50mm×1mm). First, use sandpaper of different grit sizes (e.g. 400#, 800#, 1500#) to polish the titanium substrate in sequence to remove the surface oxide layer and impurities until it presents a silvery-white metallic luster.

[0048] The polished titanium substrate was ultrasonically cleaned sequentially in acetone, ethanol, and ultrapure water for 15-25 minutes each time to remove oil and residue. Then, the cleaned titanium substrate was immersed in a 10 wt.% boiling oxalic acid solution for etching for 2-4 hours (preferably 3 hours) to remove residual stress layer from the polishing process and increase surface roughness. Finally, it was thoroughly rinsed with ultrapure water and then sealed in a 1 wt.% oxalic acid solution to prevent re-oxidation.

[0049] Step S2: First anodizing treatment.

[0050] The titanium substrate pretreated in step S1 is used as the anode, and an inert electrode such as stainless steel or graphite is used as the cathode to perform the first anodic oxidation treatment in the first oxidation solution.

[0051] The first oxidizing solution is an ethylene glycol solution containing ammonium fluoride and water. Specifically, the molar ratio of water, ammonium fluoride and ethylene glycol is (0.06-0.08):(0.08-0.1):1, and more preferably, the molar ratio of the three is (0.065-0.07):(0.085-0.095):1.

[0052] The conditions for the first anodizing treatment are: constant voltage 40-60V, temperature 15-30℃, anode-cathode spacing of 1.0-2.0cm, and time 3-5h. After step S2, an ordered but potentially somewhat disordered array of titanium dioxide nanotubes can be generated on the surface of the titanium substrate, thus obtaining a primary titanium dioxide substrate electrode.

[0053] Step S3: Second anodizing treatment.

[0054] The primary titanium dioxide substrate electrode obtained in step S2 is used as the anode, and an inert electrode such as stainless steel or graphite is used as the cathode, and a second anodic oxidation treatment is performed in the second oxidation solution.

[0055] The second oxidizing solution is a mixed solution of phosphoric acid and ethylene glycol. Specifically, the molar ratio of phosphoric acid to ethylene glycol is (0.02-0.05):1, and more preferably (0.03-0.04):1.

[0056] The conditions for the second anodizing treatment are: constant voltage 40-60V, temperature 15-30℃, anode-cathode spacing of 1.0-2.0cm, and time 70-120s. After step S3, the disordered surface layer formed after the first anodizing treatment can be peeled off, and the titanium dioxide nanotubes can be enlarged and their walls thinned to make the titanium dioxide nanotube array more regular and the tube diameter more uniform, thus obtaining a secondary titanium dioxide substrate electrode.

[0057] Step S4: Annealing.

[0058] The secondary titanium dioxide substrate electrode obtained in step S3 is placed in a muffle furnace for annealing. The annealing conditions are: heating to 420-480℃ at a heating rate of 1-3℃ / min and holding at that temperature for 1.5-2.5h. This step transforms the amorphous titanium dioxide into anatase or anatase / rutile mixed crystal phase to improve its conductivity and stability, thereby obtaining an annealed titanium substrate electrode.

[0059] Step S5: Electrochemical reduction treatment.

[0060] The annealed titanium substrate electrode obtained in step S4 is used as the cathode, and stainless steel or graphite is used as the anode for electrochemical reduction treatment in a reducing solution.

[0061] The reducing solution is an ammonium sulfate solution with a molar concentration of 0.5-1.5 mol / L (preferably 1.0-1.2 mol / L). The reduction conditions are: current density 1-5 mA / cm². 2 Temperature 15-30℃, anode-cathode spacing 1.0-2.0cm, processing time 10-20min.

[0062] After electrochemical reduction treatment, the electrode is rinsed with deionized water and dried at 50-70℃ for 1.5-3.0h (preferably at 60℃ for 2h). This step S5 introduces oxygen vacancies into the titanium dioxide nanotubes through cathodic reduction, increasing the carrier concentration and further improving its conductivity, thus obtaining a titanium-based titanium dioxide nanotube electrode (Ti / TiO2-NTs).

[0063] Step S6: Composite electrodeposition treatment.

[0064] Using the Ti / TiO2-NTs electrode obtained in step S5 as the anode and stainless steel as the cathode, anodic electrodeposition is performed in an acidic electrodeposition solution containing lead salt, neodymium salt, fluoride, surfactant and hydrophobic agent to form a neodymium-modified lead dioxide surface active layer on the surface of the titanium dioxide nanotube intermediate layer, while achieving hydrophobic regulation.

[0065] The electrodeposition solution is a mixed solution containing metal salts, fluorides, and surfactants (including hydrophobic agents).

[0066] In one example, the metal salt includes lead nitrate Pb(NO3)2 as the main salt at a concentration of 0.3-0.7 mol (preferably 0.4-0.5 mol), and at least one neodymium salt, such as neodymium nitrate Nd(NO3)3 at a concentration of 4-7 mol (preferably 5.5-6.5 mol).

[0067] In one example, to further optimize electrode performance, the metal salt may also contain other metal salts, such as at least one of cerium nitrate, samarium nitrate, and copper nitrate, or any combination thereof.

[0068] In one example, when the metal salt contains copper nitrate, the concentration of copper nitrate is 0.01-0.2 mol, preferably 0.08-0.1 mol.

[0069] In one example, the fluoride is at least one of sodium fluoride (NaF), ammonium fluoride (NH4F), or potassium fluoride (KF), or any combination thereof, and the fluoride concentration is 0.002-0.05 mol, preferably 0.006-0.01 mol. The role of the fluoride is to optimize the crystal quality of the electrode coating and enhance the adhesion.

[0070] In one example, the surfactant is any one or any combination of sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), sodium hexadecylbenzenesulfonate, hexadecyltrimethylammonium bromide (CTAB), or sodium carboxymethyl cellulose (CMC), and the concentration of the surfactant is 0.1-0.5 mmol, preferably 0.2-0.4 mmol. The surfactant acts as a supramolecular soft template to regulate the electrocrystallization kinetics of the electrode, induce the formation of villous micro / nanostructures, and assist in anchoring metal ions.

[0071] In one example, the hydrophobic agent is octadecyl phosphate (ODPA). ODPA has a synergistic effect with the surfactant during electrodeposition, co-adsorbing or embedding into the neodymium-modified lead dioxide surface active layer, thus imparting low surface energy properties to the electrode surface.

[0072] In one example, the pH of the electrodeposition solution was adjusted to 1.0-2.5, preferably 1.5-2.0, using 1 mol of nitric acid. The electrodeposition conditions were: a current density of 5-30 mA / cm². 2 Temperature 65-75℃, pH 1.0-2.0, anode-cathode spacing 1.0-2.0cm, electrodeposition time 60-180min.

[0073] After electrodeposition, the electrode is removed, repeatedly washed with deionized water, and dried at 50-70℃ for 10-15 hours (preferably at 60℃ for 12 hours) to finally obtain a titanium-based lead dioxide hydrophobic electrode (Ti / TiO2-NTs / PbO2-Nd-ODPA) with a titanium dioxide nanotube intermediate layer and neodymium modification.

[0074] The Ti / TiO2-NTs / PbO2-Nd-ODPA electrode obtained by the above preparation method has the following structural characteristics and mechanism of action:

[0075] ① It possesses a stable interlayer structure: The titanium dioxide nanotube interlayer forms a metallurgical bond with the titanium substrate (titanium matrix) through anodic oxidation self-growth, exhibiting strong interfacial adhesion, far superior to the molecular chain adsorption of traditional organic polymer interlayers. Its vertically oriented nanotube array provides a highly efficient electron transport channel, reducing electron scattering and improving current efficiency. Simultaneously, the dense nanotube walls act as a physical barrier layer, effectively suppressing the formation of a high-resistivity TiO2 passivation film on the titanium substrate surface and blocking reactive oxygen species (such as ·O, O2) generated during electrochemical reactions. 2- The diffusion of Pb into the titanium matrix achieves a dual oxygen barrier effect of physical inhibition and chemical inertness, resulting in resistance to strong oxidation, high temperatures, and extreme pH environments. Furthermore, the porous structure of the nanotubes can also trap Pb. 2+This guides PbO2 to grow directionally inside and outside the pipe, forming a strong "anchoring" structure and achieving a "selective transport" effect, taking into account both oxygen barrier and mass transfer.

[0076] ② Highly efficient and stable active layer: doped Nd 3+ The ionic radius has a high degree of matching with the lattice interstices of TiO2 and PbO2, and can be uniformly embedded in the lattice to form substitutional doping. 3+ The unique f-electron orbital structure and stable +3 valence state (without valence fluctuations in strong oxidizing environments) can alter the microcurrent structure on the electrode surface, improve catalytic activity, stabilize the crystal lattice, avoid lattice distortion and microcrack formation, and significantly enhance the electrode's corrosion resistance.

[0077] During electrodeposition, Nd 3+ Ions are in situ embedded into the growing PbO2 lattice, forming substitutional doping. Because their ionic radius matches the PbO2 lattice and has a high degree of matching with the TiO2 interstitial structure, and their +3 valence state is extremely stable under strong oxidation potentials, they can firmly exist in the lattice and are not easily dissolved. This doping not only introduces additional active sites through lattice strain, optimizing the electronic structure and enhancing catalytic activity (e.g., ... Figure 3 As shown in the linear voltammetry curve, it increases the oxygen evolution potential. More importantly, it stabilizes the PbO2 lattice, suppressing microcracks caused by lattice distortion in high-potential cycling or strongly corrosive media, thereby significantly enhancing the mechanical stability and corrosion resistance life of the electrode (e.g., Figure 4 Accelerated life testing showed that lifespan was significantly extended.

[0078] ③ Superhydrophobic antifouling surface: The supramolecular soft template formed by surfactants (such as CTAB) in the electrodeposition solution can anchor Nd in situ. 3+ Furthermore, the electrocrystallization kinetics of PbO2 were modulated to prevent particle aggregation and induce preferential grain growth, forming a villous micro / nano array structure. This micro / nano array structure, combined with the low surface energy modification of the hydrophobic agent ODPA, produced a synergistic effect, constructing a dense, lotus-leaf-like hydrophobic isolation layer on the electrode surface. This caused the electrode contact angle to jump from a hydrophilic state (approximately 83°) to a superhydrophobic state (≥140°). This hydrophobic layer effectively repels Cl- from high-salt wastewater. - F - The adsorption and deposition of corrosive ions and organic pollutants on the electrode surface solves the key problems of electrode scaling and pollution and the covering of active sites.

[0079] Furthermore, the TiO2 nanotube intermediate layer forms an n-type heterojunction with the outer PbO2 layer, accelerating electron transfer and increasing the generation rate of ·OH free radicals (e.g., Figure 3As shown in the LSV curve, the electrode of this invention exhibits a higher oxygen evolution potential. Simultaneously, the high specific surface area of ​​the nanotubes provides abundant active sites for PbO2 deposition and refines the grain size, resulting in a denser and more uniform active layer. Ultimately, through the synergistic effect of the triple structure of "rigid nanotube intermediate layer," "stable Nd doping," and "superhydrophobic surface," a comprehensive improvement in electrode structural stability, electrocatalytic activity, and corrosion / fouling resistance is achieved, effectively solving the core problems of traditional electrodes such as easy detachment of the active layer, short lifespan, low efficiency, and high energy consumption. (For example...) Figure 4 Accelerated life testing and Figure 5 The results of the cyclic degradation test show that the electrode life of the present invention is nearly 7 times that of the conventional electrode, and its performance is stable.

[0080] The Ti / TiO2-NTs / PbO2-Nd-ODPA electrode of this invention can be effectively applied to the treatment of reverse osmosis concentrate from coal chemical wastewater. Using the Ti / TiO2-NTs / PbO2-Nd-ODPA electrode of this invention as the anode and stainless steel or other suitable materials as the cathode, the reverse osmosis concentrate from coal chemical wastewater is subjected to electrochemical oxidation treatment.

[0081] Typical treatment conditions are: initial pH of wastewater: 6-9; TDS concentration of wastewater: 10-15 g / L; current density: 15-30 mA / cm³. 2 Processing time: 100-150 minutes.

[0082] Without the addition of any other chemical agents, it can achieve efficient and synergistic removal of COD and TOC from the wastewater, while providing high-quality feed water for subsequent processes such as membrane distillation and evaporation crystallization, and ensuring the resource recovery of by-product salts.

[0083] The technical solution and effects of the present invention will be further illustrated below through specific embodiments.

[0084] Example 1

[0085] The specific fabrication process of the Ti / TiO2-NTs / PbO2-Nd-ODPA electrode is as follows:

[0086] Step (1), Titanium substrate pretreatment: Provide a titanium plate (50mm×50mm×1mm, 99% purity), and polish it sequentially with 400#, 800#, and 1500# sandpaper until the surface has a silvery-white luster. Clean the polished titanium plate sequentially with acetone, ethanol, and ultrapure water, each for 20 minutes. After cleaning, etch the titanium plate in a 10wt.% boiling oxalic acid solution for 3 hours. After etching, rinse thoroughly with ultrapure water and immerse in a 1wt.% oxalic acid solution for sealed storage for later use.

[0087] Step (2), preparation of Ti / TiO2-NTs electrode:

[0088] First anodizing: Using a pretreated titanium plate as the anode and stainless steel as the cathode, the reaction was carried out for 4 hours in an ethylene glycol electrolyte containing 2 vol% H2O and 5 wt% NH4F at a constant voltage of 50 V and a temperature of 25 °C.

[0089] Second anodizing: Remove the electrode after the first anodizing and immediately place it in an ethylene glycol electrolyte containing 5wt% H3PO4, and react for 90s at a constant voltage of 50V and a temperature of 25℃.

[0090] Annealing treatment: The electrode after secondary anodizing is placed in a muffle furnace and heated to 450°C at a heating rate of 2°C / min, and held for 2 hours.

[0091] Electrochemical reduction: Using an annealed electrode as the cathode and stainless steel as the anode, in a 1 mol / L (NH4)2SO4 solution, at a current of 0.05 A (current density approximately 2 mA / cm²). 2 The electrode was reduced at 25℃ for 15 min. After removal, it was rinsed with deionized water and dried at 60℃ for 2 h to obtain the Ti / TiO2-NTs electrode. The thickness of the TiO2 nanotube intermediate layer was measured to be approximately 0.01 mm.

[0092] Step (3), preparation of Ti / TiO2-NTs / PbO2-Nd-ODPA electrode:

[0093] Preparation of electrodeposition solution: Prepare 1 L of electrodeposition solution containing 6 mmol Nd(NO3)3, 0.01 mol NaF, 0.5 mol Pb(NO3)2, 0.1 mol Cu(NO3)2, and 0.3 mmol CTAB. Adjust the pH of the solution to 1.5 using 1 mol HNO3.

[0094] Hydrophobic agent treatment: Dissolve an appropriate amount of ODPA in a solvent containing a small amount of ethanol, heat and sonicate for 60 minutes until completely dissolved, with no flocculation or precipitation.

[0095] Electrodeposition: First, using the electrodeposition solution prepared above (excluding ODPA), with a Ti / TiO2-NTs electrode as the anode and stainless steel as the cathode, at a current density of 20 mA / cm²... 2 Electrodeposition was performed at 65℃ and pH=1.5 for 90 min to obtain a Ti / TiO2-NTs / PbO2-Nd electrode.

[0096] Then, the completely dissolved ODPA solution was slowly added to the new electrodeposition solution and mixed evenly. Using the Ti / TiO2-NTs / PbO2-Nd electrode prepared above as the anode, electrodeposition was continued for 15 min under the same conditions.

[0097] After deposition, the electrode was repeatedly washed with deionized water and dried in a 60°C oven for 12 hours to finally obtain the Ti / TiO2-NTs / PbO2-Nd-ODPA electrode. The total thickness of the PbO2 surface active layer was measured to be approximately 0.15 mm (see photograph of the electrode surface in Example 1). Figure 1 (As shown).

[0098] Using the Ti / TiO2-NTs / PbO2-Nd-ODPA electrode obtained in Example 1 as the anode and a pre-polished stainless steel sheet as the cathode, bisphenol A was degraded with an initial concentration of 100 mg / L, pH = 9.0, an anode-cathode spacing of 1.5 cm, an electrolyte sodium sulfate concentration of 10 g / L, a reaction time of 120 min, and a current density of 20 mA / cm². 2 The removal rate was 99.26%.

[0099] Using the Ti / TiO2-NTs / PbO2-Nd-ODPA electrode obtained in Example 1 as the anode and a pre-polished stainless steel sheet as the cathode, the reverse osmosis concentrate from a coking plant in Hebei Province was degraded. The COD of the coking reverse osmosis concentrate was 235 mg / L, the TOC was 43 mg / L, and the pH was 6.0. The anode-cathode spacing was 1.5 cm, the reaction time was 120 min, and the current density was 20 mA / cm². 2 The COD removal rate was 88.0%, and the TOC removal rate was 70.8%.

[0100] Example 2

[0101] The difference between Example 2 and Example 1 is that the first anodic oxidation treatment in step (2) lasted for 3 hours and the constant voltage was 60V. In the electrode prepared in Example 2, the thickness of the TiO2 nanotube intermediate layer was about 0.007 mm and the thickness of the PbO2 active layer was about 0.15 mm.

[0102] When applied to degrade BPA, the removal rate is 98.7%; when degrading coking reverse osmosis concentrate, the COD removal rate is 85.4% and the TOC removal rate is 65.6%.

[0103] Example 3

[0104] The difference between Example 3 and Example 1 is that the electrodeposition current density in step (3) is 30 mA / cm². 2 The deposition time was 90 min. In the electrode prepared in Example 3, the thickness of the TiO2 nanotube intermediate layer was approximately 0.01 mm, and the thickness of the PbO2 active layer was approximately 0.18 mm.

[0105] When applied to degrade BPA, the removal rate is 97.5%; when degrading coking reverse osmosis concentrate, the COD removal rate is 83.6% and the TOC removal rate is 62.0%.

[0106] Example 4

[0107] The difference between Example 4 and Example 1 is that the neodymium nitrate concentration in the electrodeposition solution in step (3) is 12 mmol, and no ODPA is added for hydrophobic modification during the electrodeposition process, ultimately yielding a Ti / TiO2-NTs / PbO2-Nd-ODPA electrode. In the electrode prepared in Example 4, the thickness of the TiO2 nanotube intermediate layer is approximately 0.01 mm, and the thickness of the PbO2 active layer is approximately 0.15 mm.

[0108] When applied to degrade BPA, the removal rate is 98.4%; when degrading coking reverse osmosis concentrate, the COD removal rate is 85.5% and the TOC removal rate is 64.5%.

[0109] Comparative Example 1

[0110] The difference between Comparative Example 1 and Example 1 is that neodymium nitrate was not added to the electrodeposition solution in step (3), resulting in a Ti / TiO2-NTs / PbO2 electrode without Nd modification.

[0111] When applied to degrade BPA, the removal rate is 92.6%; when degrading coking reverse osmosis concentrate, the COD removal rate is 78.6% and the TOC removal rate is 59.5%.

[0112] Comparative Example 2

[0113] Comparative Example 2 uses a conventional Ti / PbO2 electrode (i.e., without TiO2 nanotube interlayer, without Nd doping, and without hydrophobic modification).

[0114] When applied to degrade BPA, the removal rate was 85.5%; when degrading coking reverse osmosis concentrate, the COD removal rate was 58.5%, and the TOC removal rate was 45.3%. It exhibited the worst performance among all examples and comparative examples.

[0115] Comparative Example 3

[0116] The difference between Comparative Example 3 and Example 1 is that ODPA hydrophobic modification was not performed in step (3), that is, the prepared electrode is Ti / TiO2-NTs / PbO2-Nd.

[0117] When applied to degrade BPA, the removal rate was 99.24%, comparable to Example 1; when degrading coking reverse osmosis concentrate, the COD removal rate was 88.0%, and the TOC removal rate was 70.8%, comparable to Example 1. However, its contact angle of 83° was much lower than that of Example 1 (147°), indicating that its surface is hydrophilic. In terms of long-term antifouling and stability, Example 1 is more advantageous.

[0118] Furthermore, the performance of the electrodes of Example 1 and Comparative Examples 1-3 was tested respectively.

[0119] See Figure 3 The linear voltammetry curves of the electrodes in Example 1 and Comparative Examples 1-3 are shown.

[0120] See Figure 4 The accelerated lifetime test of the electrodes of Example 1 and Comparative Examples 1-3 is shown.

[0121] See Figure 5 The results of the cyclic degradation test of bisphenol A by the electrodes of Example 1 and Comparative Examples 1-3 are shown.

[0122] See Figure 6a and Figure 6b The contact angles of the electrodes in Comparative Example 3 and Example 1 are shown respectively.

[0123] like Figure 3 As shown, linear voltammetry (LSV) curves were performed on the electrodes of Example 1 and Comparative Examples 1-3. The results show that the electrode of Example 1 has the highest oxygen evolution potential, indicating that it has the strongest electrocatalytic activity.

[0124] Electrode linear voltammetry curves are core evidence for evaluating the electrocatalytic activity of electrodes. The figure shows the current-potential response relationship of different electrodes under the same test conditions. At a constant scanning potential, a higher current density indicates a higher oxygen evolution overpotential of the electrode, meaning that more current is used to generate highly oxidizing hydroxyl radicals (·OH) to degrade organic matter, rather than being wasted on oxygen evolution side reactions. Therefore, the electrocatalytic activity is stronger, the treatment efficiency is higher, and the energy consumption is lower.

[0125] Compared to Ti / PbO2 in Comparative Example 2 and Ti / TiO2-NTs / PbO2 in Comparative Example 1, the curves for Ti / TiO2-NTs / PbO2-Nd-ODPA in Example 1 and Ti / TiO2-NTs / PbO2-Nd in Comparative Example 3 are positioned higher, indicating that they possess higher oxygen evolution potentials and stronger electrocatalytic activity. This is due to the heterojunction effect of the titanium dioxide nanotube interlayer and the Nd... 3+ The combined effect of doping and lattice regulation promotes electron transfer and increases the generation rate of hydroxyl radicals (·OH).

[0126] like Figure 4 As shown, accelerated lifetime tests were conducted in a 1 mol H2SO4 solution at high current density. The accelerated lifetime of the electrode in Example 1 was approximately 3675 hours, which is nearly 7 times that of the conventional Ti / PbO2 electrode in Comparative Example 2 (approximately 533 hours), and significantly better than Comparative Example 1 and Comparative Example 3.

[0127] This accelerated life test accelerates electrode failure by applying a current far exceeding normal operating conditions, thereby predicting the actual service life of the electrode. Constant current electrolysis is performed in a strongly acidic electrolyte and at high current density until the electrode potential rises sharply (typically by 5V), which is considered failure. The recorded time is the accelerated life test.

[0128] The accelerated lifetime of the Ti / PbO2 electrode in Comparative Example 2 was approximately 533 hours. The accelerated lifetime of the Ti / TiO2-NTs / PbO2 electrode in Comparative Example 1 was extended to 2383 hours. The accelerated lifetime of the Ti / TiO2-NTs / PbO2-Nd electrode in Comparative Example 3 was further improved to approximately 2850 hours. The Ti / TiO2-NTs / PbO2-Nd-ODPA electrode of Example 1, as a preferred embodiment of the present invention, has its accelerated lifetime significantly improved to approximately 3675 hours, which is nearly 7 times that of the conventional Ti / PbO2 electrode.

[0129] In the electrode of Example 1, the titanium dioxide nanotube intermediate layer is metallurgically bonded to the titanium matrix, exhibiting high mechanical strength and effectively preventing the diffusion of active oxygen into the titanium matrix, thus preventing the formation of the TiO2 passivation film and the peeling off of the active layer. Neodymium (Nd) doping stabilizes the lead dioxide lattice and enhances corrosion resistance. The hydrophobic layer (ODPA modification) reduces direct contact between the electrolyte and the electrode surface and scale formation. The synergistic effect of these three elements greatly improves the structural stability and corrosion resistance life of the electrode under harsh operating conditions.

[0130] like Figure 5 As shown, in the cyclic degradation test of bisphenol A (BPA), the electrodes prepared in Example 1 and Comparative Examples 1-3 were used as anodes, and stainless steel was used as cathodes. The degradation of a BPA solution with an initial concentration of 100 mg / L (pH=9.0, electrolyte Na2SO4 concentration 10 g / L, anode-cathode spacing 1.5 cm) was carried out at a current density of 20 mA / cm². 2 The reaction was carried out for 120 min, and the degradation effect was tested after multiple cycles to evaluate the stability and long-term reliability of the electrode's electrocatalytic performance in actual operation. The electrode in Example 1 achieved a BPA degradation rate of up to 99.26%, and maintained high efficiency and stability throughout multiple cycles.

[0131] The degradation rate of the target pollutant bisphenol A (BPA) by different electrodes and the changes in the working voltage of the electrolytic cell were recorded during the test in multiple repeated experimental cycles.

[0132] For BPA-simulated wastewater, the Ti / TiO2-NTs / PbO2-Nd-ODPA electrode in Example 1 achieved a degradation rate of up to 99.26% within 120 minutes, significantly outperforming comparative examples 1-3. In the cyclic test, this electrode not only maintained a high and stable BPA removal efficiency over a long period, but also exhibited a small voltage rise, indicating that the internal resistance increased slowly during long-term use, the active layer did not show significant passivation or failure, and the structure remained stable.

[0133] like Figure 6a and Figure 6b As shown, contact angle tests were performed on the electrodes of Comparative Example 3 and Example 1, respectively. The contact angle of Comparative Example 3 (without ODPA) was 83°, while the contact angle of Example 1 (with ODPA) was 147°, reaching the level of superhydrophobicity.

[0134] Based on the performance test results and removal efficiency analysis above, this invention, through the synergistic effect of constructing a TiO2 nanotube intermediate layer, rare earth Nd doping modification, and constructing a superhydrophobic lead dioxide surface active layer, prepared a high-performance, long-life Ti / TiO2-NTs / PbO2-Nd-ODPA electrode. This electrode significantly outperforms traditional process electrodes in terms of electrocatalytic activity, stability, corrosion resistance, and antifouling ability, and exhibits significant synergistic removal effects in treating high-salt, recalcitrant organic wastewater such as coal chemical reverse osmosis concentrate, demonstrating good application potential.

[0135] The titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube interlayer synergistically modified with neodymium, the preparation method thereof, and its application provided by the embodiments of the present invention have at least one or a portion of the following advantages:

[0136] (1) A vertically oriented titanium dioxide nanotube array intermediate layer is formed on the surface of a titanium substrate by anodic oxidation. The intermediate layer forms a metallurgical bond with the titanium substrate, and the bonding force is much stronger than that of traditional organic polymer adsorption. This effectively solves the problem of easy detachment of the active layer. At the same time, the dense inorganic rigid structure can serve as a physical barrier layer, effectively inhibiting the formation of a high-resistance passivation film and blocking the diffusion of active oxygen into the substrate, thus significantly improving the structural stability and service life of the electrode.

[0137] (2) By doping the lead dioxide surface active layer with rare earth element neodymium (Nd), Nd 3+ It has a special f-electron orbital structure, which can be embedded in the PbO2 lattice in a stable +3 valence state to form a substitutional doping. It has no valence fluctuation in a strong oxidizing environment, avoiding lattice distortion and microcrack generation, thereby improving the corrosion resistance and long-term operational stability of the electrode.

[0138] (3) By introducing surfactants and hydrophobic agents (such as ODPA) during the preparation of the lead dioxide surface active layer, and through supramolecular soft template action and modification with low surface energy materials, a villous micro-nano structure superhydrophobic layer (contact angle ≥140°) with a lotus leaf-like effect was constructed on the electrode surface. This superhydrophobic layer can effectively repel Cl from high-salt wastewater. - F - The adsorption and scaling of corrosive ions and organic pollutants on the electrode surface solves the problem of traditional electrodes being easily contaminated and having their active sites covered, which leads to a decrease in efficiency and ensures long-term, low-energy operation of the electrode.

[0139] (4) Through the triple structure design of rigid nanotube array intermediate layer, Nd stable doping and superhydrophobic layer, a significant synergistic effect is generated: the nanotube array intermediate layer provides a stable substrate and efficient electron transport channel; Nd doping regulates the lattice and electronic structure of lead dioxide surface active layer, improving intrinsic catalytic activity and stability; the superhydrophobic layer endows the electrode with excellent anti-fouling and corrosion resistance; the overall performance of the electrode is comprehensively improved in terms of structure, performance and service life.

[0140] (5) By precisely controlling the process parameters of two-step anodizing, annealing, electrochemical reduction and composite electrodeposition, the morphology, crystal phase and Nd doping amount, microstructure and hydrophobicity of titanium dioxide nanotubes and PbO2 active layer are controllably adjustable, making the preparation method of the present invention stable and reproducible, providing a reliable technical path for the preparation of high-performance electrocatalytic anode electrode materials.

[0141] (6) By applying the electrode of the present invention to treat the reverse osmosis concentrate of coal chemical wastewater, it is possible to achieve efficient synergistic removal of COD and TOC without the need for additional chemical reagents (e.g., COD removal rate reached 88.0% and TOC removal rate reached 70.8% in Example 1), effectively solving the impact of organic matter in ROC on subsequent evaporation and crystallization processes, which is conducive to the resource recovery of by-product salts and achieving the environmental protection requirement of "near-zero emissions".

[0142] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube interlayer synergistically modified with neodymium, characterized in that, The titanium-based lead dioxide hydrophobic electrode comprises: Titanium substrate; A titanium dioxide nanotube intermediate layer is formed on the surface of the titanium substrate, wherein the titanium dioxide nanotube intermediate layer is a vertically oriented nanotube array structure; and A neodymium-modified lead dioxide surfactant layer deposited on the surface of the intermediate layer of the titanium dioxide nanotubes; wherein The neodymium-modified lead dioxide surface active layer is a superhydrophobic surface formed by a hydrophobic agent, and the contact angle between the superhydrophobic surface and water is greater than or equal to 140°.

2. The titanium-based lead dioxide hydrophobic electrode according to claim 1, characterized in that, The titanium dioxide nanotube intermediate layer is metallurgically bonded to the titanium substrate through anodizing self-growth to form a physical barrier layer. This physical barrier layer inhibits the formation of a high-resistivity passivation film on the surface of the titanium substrate and blocks the diffusion of active oxygen into the titanium substrate.

3. The titanium-based lead dioxide hydrophobic electrode according to claim 1, characterized in that, In the neodymium-modified lead dioxide surfactant layer, neodymium is expressed as Nd. 3+ It exists in the form of substitutional doping, which is formed by embedding the +3 valence stable state and f electron orbital structure into the lead dioxide lattice to stabilize the lattice in a strong oxidizing environment and suppress lattice distortion and / or suppress the generation of microcracks in the lattice.

4. The titanium-based lead dioxide hydrophobic electrode according to claim 1, characterized in that, The superhydrophobic surface has a villous micro / nano structure induced by a surfactant. The villous micro / nano structure and the low surface energy modification of the hydrophobic agent form a hydrophobic isolation layer with a lotus leaf effect. The hydrophobic isolation layer repels the adsorption and scaling of ions in high-salt wastewater on the surface of the titanium-based lead dioxide hydrophobic electrode.

5. The titanium-based lead dioxide hydrophobic electrode according to any one of claims 1-4, characterized in that, The thickness ratio of the titanium substrate to the titanium dioxide nanotube intermediate layer is 1:0.0025-0.025; The thickness ratio of the titanium dioxide nanotube intermediate layer to the neodymium-modified lead dioxide surface active layer is 1:5-50; In the neodymium-modified lead dioxide surfactant layer, the molar ratio of neodymium to lead is 1:20-250.

6. A method for preparing a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube intermediate layer synergistically modified with neodymium, used to prepare a titanium-based lead dioxide hydrophobic electrode according to any one of claims 1-5, characterized in that, The preparation method includes: S1: Pre-treatment of the titanium substrate by polishing, degreasing, and acid etching; S2: The pretreated titanium substrate is subjected to a first anodic oxidation treatment in the first oxidation solution to oxidize the surface of the titanium substrate to generate a titanium dioxide nanotube array, thereby obtaining a primary titanium dioxide substrate electrode. S3: The primary titanium dioxide substrate electrode is subjected to a second anodic oxidation treatment in the second oxidation solution, and the titanium dioxide nanotube array is subjected to pore expansion and tube wall thinning control to obtain a secondary titanium dioxide substrate electrode. S4: Anneal the secondary titanium dioxide substrate electrode to convert the amorphous titanium dioxide into anatase phase or mixed phase, and obtain annealed titanium substrate electrode. S5: The annealed titanium substrate electrode is subjected to electrochemical reduction treatment by applying a cathode current in a reduction solution to repair oxygen vacancies and increase carrier concentration, thereby obtaining a titanium-based titanium dioxide nanotube electrode. S6: The titanium-based titanium dioxide nanotube electrode is subjected to anodic electrodeposition in an acidic electrodeposition solution containing lead salt, neodymium salt, fluoride, surfactant and hydrophobic agent. Neodymium ions are anchored in situ by supramolecular soft template and the electrocrystallization kinetic parameters are controlled to form a neodymium-modified lead dioxide surface active layer with a villous micro-nano structure on the surface of the intermediate layer of the titanium dioxide nanotube, thereby obtaining a titanium-based lead dioxide hydrophobic electrode.

7. The preparation method according to claim 6, characterized in that, The first oxidation solution is a mixed solution of water, ammonium fluoride and ethylene glycol, wherein the molar ratio of water, ammonium fluoride and ethylene glycol is (0.06-0.08):(0.08-0.1):

1. The conditions for the first anodizing treatment are a constant voltage of 40-60V, a temperature of 15-30℃ and a time of 3-5h, in order to form an ordered nanotube array substrate. The second oxidation solution is a mixture of phosphoric acid and ethylene glycol, wherein the molar ratio of phosphoric acid to ethylene glycol is (0.02-0.05):

1. The conditions for the second anodizing treatment are a constant voltage of 40-60V, a temperature of 15-30℃, and a time of 70-120s, in order to peel off the disordered layer on the surface of the ordered nanotube array substrate and optimize the nanotube diameter.

8. The preparation method according to claim 6, characterized in that, The annealing conditions are as follows: heating to 420-480℃ at a heating rate of 1-3℃ / min and holding for 1.5-2.5h to transform the crystal form of titanium dioxide and enhance its conductivity. The reducing solution is an ammonium sulfate solution with a molar concentration of 0.5-1.5 mol / L, and the reduction treatment conditions are a current density of 1-5 mA / cm². 2 The time is 10-20 minutes to introduce oxygen vacancies into titanium dioxide nanotubes and improve their electronic conductivity.

9. The preparation method according to any one of claims 6-8, characterized in that, The electrodeposition solution comprises: Lead salt, wherein the lead salt is lead nitrate, and the concentration is 0.3-0.7 mol; Neodymium salt, wherein the neodymium salt is neodymium nitrate, and the concentration is 4-7 mmol; Fluoride, wherein the fluoride is any one or any combination of sodium fluoride, ammonium fluoride and potassium fluoride, and the concentration is 0.002-0.05 mol; The surfactant is any one or any combination of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium hexadecylbenzene sulfonate, hexadecyltrimethylammonium bromide and sodium carboxymethyl cellulose, with a concentration of 0.1-0.5 mmol. Hydrophobic agent, wherein the hydrophobic agent is octadecyl phosphate; The electrodeposition conditions were: current density 5-30 mA / cm². 2 The temperature was 65-75℃, the pH value was 1.0-2.0, and the electrodeposition time was 60-180 min, in order to form a dense, uniform neodymium-modified lead dioxide surface active layer with a villous micro-nano structure.

10. The application of a titanium-based lead dioxide hydrophobic electrode with a titanium dioxide nanotube intermediate layer synergistically modified with neodymium in the treatment of reverse osmosis concentrate from coal chemical wastewater, characterized in that... The titanium-based lead dioxide hydrophobic electrode is the titanium-based lead dioxide hydrophobic electrode according to any one of claims 1-5 or the titanium-based lead dioxide hydrophobic electrode obtained by the preparation method according to any one of claims 6-9.

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