Novel titanium-based tin oxide electrode, preparation method and application

Abstract

The invention relates to the technical field of electro-catalysis, in particular to a novel titanium-based tin oxide electrode, a preparation method and application. The titanium-based tin oxide electrode aims to solve the technical problems that a coating of a traditional titanium-based tin oxide electrode is easy to peel off, the catalytic activity is insufficient and the service life is short in electro-catalysis sewage treatment. Through an innovatively designed five-layer composite structure (TiC conductive layer / IrO2 transition layer / Sb-PtNi-SnO2 quantum dot active layer / ZrO2 nano coating layer / TiO2 self-cleaning layer), and in combination with gradient doping and atomic layer deposition processes, the functions of interface stress optimization, electron transport reinforcement and surface pollutant self-decomposition are realized, so that the service life of the electrode at the current density of 100 mA / cm < 2 > breaks through 138 hours, and the service life of the electrode is prolonged. Meanwhile, an intelligent control system is matched to realize dynamic optimization of reaction parameters, so that the industrial applicability of the sewage treatment system is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of electrocatalysis technology, and particularly to a novel titanium-based tin oxide electrode, a preparation method and an application. It is applicable to the field of water treatment, especially for the sewage treatment that efficiently degrades organic pollutants by electrocatalysis. Background Art

[0002] With the acceleration of the industrialization process, the content of organic pollutants in sewage is increasing continuously. Traditional physical and chemical methods (such as adsorption, flocculation) and biological methods often cannot efficiently degrade poorly soluble organic substances (such as polycyclic aromatic hydrocarbons, dyes, etc.). Due to its high oxidation ability, environmental compatibility and operation controllability, electrocatalysis technology has become a research hotspot in the field of water treatment. However, there are significant bottlenecks in the catalytic efficiency, stability, durability and cost-effectiveness of existing electrode materials, and there is an urgent need to develop new high-performance electrocatalytic electrode materials.

[0003] Titanium-based tin dioxide (Ti / SnO2) electrodes have been widely used in the electrocatalytic degradation of organic substances due to the high oxygen evolution potential of SnO2 and the strong ability to generate ·OH. However, traditional Ti / SnO2 electrodes have the following defects:

[0004] 1. Coating is prone to peeling: The difference in thermal expansion coefficients between SnO 2 and the titanium substrate leads to interfacial stress, and the coating is prone to cracking and peeling during long-term electrolysis;

[0005] 2. Insufficient catalytic activity: The electron mobility of single SnO 2 or Sb-doped electrodes is limited, and the active sites are easily covered by intermediate products;

[0006] 3. Short lifespan: In an acidic or high-salt wastewater environment, the corrosion of the electrode surface accelerates and the stability decreases significantly.

[0007] Therefore, there is an urgent need to develop a novel electrode and a supporting reaction system with high catalytic activity, long lifespan and self-repair function to meet the dual requirements of economy and stability for industrial wastewater treatment. Summary of the Invention

[0008] The present invention aims to solve the technical problems of easy peeling of the coating, insufficient catalytic activity and short lifespan existing in traditional titanium-based tin oxide electrodes in electrocatalytic sewage treatment. Through an innovatively designed five-layer composite structure (TiC conductive layer / IrO 2 transition layer / Sb-PtNi-SnO 2 quantum dot active layer / ZrO 2 nano-coating layer / TiO 2 self-cleaning layer), combined with gradient doping and atomic layer deposition processes, interface stress optimization, electron transport enhancement and surface pollutant self-decomposition functions are realized, enabling the electrode to reach 100 mA / cm 2The lifespan under the current density exceeds 138 hours. Meanwhile, a smart control system is equipped to achieve dynamic optimization of reaction parameters, significantly improving the industrial applicability of the sewage treatment system.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] The present invention provides a novel titanium-based tin oxide electrode, which is characterized in that it includes a Ti substrate, a TiC conductive enhancement layer, an IrO 2 transition layer, a doped SnO 2 active layer, a ZrO 2 nano-coating layer, and a TiO 2 self-cleaning coating layer, which are arranged in sequence.

[0011] The present invention also provides a preparation method of the novel titanium-based tin oxide electrode, including the following steps:

[0012] a) Deposit a TiC conductive enhancement layer on the Ti substrate with a thickness of 50 - 200 nm. It is prepared by physical vapor deposition with argon as the sputtering gas under a vacuum degree lower than 1×10 -6 Torr, the argon flow rate is 10 - 50 sccm, and the substrate is preheated to 200 - 400 °C;

[0013] b) Deposit an IrO 2 transition layer with a thickness of 80 - 300 nm on the TiC conductive enhancement layer. It is deposited by chemical vapor deposition at 400 - 500 °C and a pressure of 10 -3 -10 -5 Torr by reacting iridium chloride with oxygen in a molar ratio of 1∶1.5 - 1∶3 for deposition;

[0014] c) Prepare a doped SnO 2 active layer on the IrO 2 transition layer, which contains an Sb-doped SnO 2 quantum dot structure, where the Sb doping concentration is 1 - 5 at%, the quantum dot size is 2 - 10 nm, the active layer thickness is 300 - 500 nm. The quantum dots are synthesized by the sol-gel method and annealed at 350 - 450 °C for 1 - 3 hours, and then PtNi alloy doping is carried out to obtain a PtNi alloy-doped Sb-SnO 2 layer;

[0015] d) Prepare a ZrO 2 nano-coating layer with a thickness of 4 - 20 nm on the doped SnO 2 active layer. It is prepared by 100 cycles of atomic layer deposition at 200 - 350 °C;

[0016] e) Coat TiO 2 on the surface of the ZrO2 The self-cleaning coating, with a thickness of 10 - 50 nm, is formed by spin-coating a solution of tetra-isopropyl titanate and then annealing at 400 - 500 °C.

[0017] In the above solution, after the TiC conductive layer is deposited, it is annealed at 500 - 700 °C and cooled in an argon atmosphere.

[0018] In the above solution, in step b, the deposited IrO 2 coating is annealed under Ar gas, and the annealing temperature is 400 - 600 °C.

[0019] In the above solution, the Sb-doped SnO 2 active layer is prepared by the sol-gel method and is rapidly annealed under the condition of 350 °C - 450 °C for 1 - 2 hours, and the atmosphere is controlled to be air or nitrogen atmosphere to form a quantum dot structure.

[0020] In the above solution, it includes SnO 2 -Sb with a quantum dot structure and doped with PtNi alloy, and its crystal structure and stability are optimized by annealing treatment.

[0021] In the above solution, the TiO 2 self-cleaning coating is composed of photocatalytically active TiO 2 nanoparticles, which are uniformly coated on the surface of the active layer by spin-coating or dip-coating processes and annealed at 400 - 500 °C to form a crystallized structure for decomposing organic pollutants adsorbed on the electrode surface under light illumination and maintaining the electrocatalytic activity of the electrode.

[0022] In the above solution, the preparation method of the TiO 2 self-cleaning coating includes:

[0023] a) Dispersing a tetra-isopropyl titanate precursor in ethanol to form a uniform dispersion with a concentration of 0.5 - 1 mol / L;

[0024] b) Using the spin-coating method to coat the dispersion on the surface of the doped SnO 2 active layer, with a spin-coating speed of 1800 - 2000 r / min, and repeating the coating 5 - 10 times;

[0025] c) After the coating is completed, anneal in air or nitrogen atmosphere at 400 - 500 °C for 1 - 2 hours to form a crystallized TiO 2 self-cleaning coating.

[0026] The present invention also provides an electrocatalytic sewage degradation system, including the above-mentioned tin-based titanium oxide electrode as the anode, and:

[0027] An electrolytic cell, configured in a rectangular or cylindrical structure, is provided with fluid inlets and outlets;

[0028] A Pt cathode, disposed opposite to the anode to form a uniform electric field;

[0029] An intelligent control system, integrating current, voltage, and temperature sensors, adjusts the electrocatalytic reaction parameters in real time.

[0030] The tin-based titanium oxide electrode and its sewage degradation system provided by the present invention demonstrate significant technological progress and application value in the field of electrocatalytic degradation of organic pollutants through innovative material design, structural optimization, and device integration. Its beneficial effects are specifically reflected in the following aspects:

[0031] 1. The tin-based titanium oxide electrode designed by the present invention has high stability and can maintain stable electrocatalytic performance during long-term electrocatalytic reactions, solving the problem that existing electrode materials are prone to degradation during long-term use.

[0032] 2. Multilayer structure synergistic enhancement mechanism: Through the gradient design of the Ti substrate → TiC conductive layer → IrO 2 transition layer → Sb-SnO 2 active layer, the pain points of easy peeling and insufficient conductivity of the traditional tin-based electrode coating are solved. The TiC conductive layer forms a dense interface through PVD technology, reducing the resistance; the IrO 2 transition layer adopts a high-temperature CVD process, effectively alleviating the difference in thermal expansion coefficients between the substrate and the active layer, enhancing the interfacial bonding strength. At a current density of 100 mA / cm 2 the strengthening life can reach hours, and the coating peeling is not obvious.

[0033] 3. The design of the electrocatalytic sewage degradation device optimizes the electric field distribution and bubble generation, further improving the degradation efficiency and having strong industrial application potential.

[0034] 4. The electrocatalytic sewage degradation device of the present invention has a compact structure and is easy to maintain, with high economic benefits and practical value.

[0035] 5. Gradient doping and interface regulation: Through the synergistic effect of PtNi alloy doping and ZrO 2 coating, the oxygen evolution potential of the electrode is increased, effectively suppressing side reactions, optimizing the electron transport channels and catalytic active sites, enhancing the conductivity and electro-chemical reaction efficiency of the electrode, and providing a more efficient solution for the degradation of organic pollutants in wastewater treatment. The doping elements are uniformly introduced into the SnO 2 quantum dot structure coating through plasma treatment or ion implantation method, which can significantly improve the conductivity and catalytic activity of the electrode. This process also combines annealing treatment to optimize the distribution of doping elements and their roles in the coating, ensuring the structural stability and conductivity of the material. Description of the Drawings

[0036] Figure 1 This is the experimental flow chart of the present invention;

[0037] Figure 2 This is the electrocatalytic degradation device

[0038] Figure 3 This is the conductivity (change in carrier concentration) of Sb-doped SnO2

[0039] Figure 4 This is the change diagram of the coating layer before and after the stability test (the coating layer basically does not fall off before and after the 138-hour accelerated life test, and only a small amount of microcracks appear).

[0040] Figure 5 This is the stability comparison between the original electrode and the electrode described in the patent Detailed Embodiment

[0041] The embodiments of the present invention include the following steps:

[0042] Functional Design of the Anode Multilayer Structure

[0043] Based on the structural optimization of the coating material, the overall performance of the anode is improved through the multi-layer combination of different materials. The design of the multi-layer structure will consider factors such as coating thickness, interlayer transition, and surface morphology to optimize the electrocatalytic activity, durability, and conductivity of the electrode

[0044] 1. TiC Conductivity Enhancement Layer:

[0045] 1.1 Bottom Layer Design: Enhance the mechanical and electrical conductivity of the substrate

[0046] Ti is used as the support layer of the anode, which has excellent mechanical strength and corrosion resistance. However, due to its poor conductivity, the adhesion and current conduction efficiency of the coating material need to be improved. Therefore, the bottom layer can introduce a metal carbide (TiC) with better conductivity to form a conductivity enhancement layer, and it is designed as a thin and dense structure to reduce resistance and optimize current distribution

[0047] Specific preparation process: Deposit TiC with excellent conductivity on the Ti substrate to form a conductivity enhancement layer. This layer will be prepared by physical vapor deposition (PVD) technology, and the deposition parameters are optimized to ensure a thin and dense coating structure to reduce resistance and improve current distribution. By constructing nanostructures of metal carbides such as TiC or doping noble metals, the synergy between mechanical strength and conductivity is enhanced, and the overall performance of the electrode is improved

[0048] 1.1.1 Materials and Equipment

[0049] Substrate material: Ti substrate, usually a high-purity Ti substrate (such as Ti 6 Al 4 V alloy).

[0050] Target: TiC target for deposition, selecting high-purity titanium carbide (TiC) powder or target.

[0051] 1.1.2. Substrate pretreatment

[0052] First, mechanically polish the Ti substrate to remove surface roughness and improve the adhesion of the coating. The surface roughness after polishing should be controlled at the nanoscale (usually < 100 nm); then use an ultrasonic cleaning device to clean the substrate, successively using acetone, absolute ethanol, and deionized water for cleaning to remove surface oil and particulate matter; finally, dry it in an oven and blow it dry with argon for storage and standby.

[0053] 1.1.3 Deposition process

[0054] Fix the clean and dry Ti substrate on the sample holder of the PVD equipment, ensure that the distance between the substrate and the target is appropriate (usually 5 - 10 cm), and adjust the fixture and rotation mechanism of the sample to ensure that the substrate is evenly coated during deposition. Close the chamber and start pumping vacuum. The vacuum degree usually needs to reach below 10 -6 Torr to reduce the interference of impurity gases. Select the TiC target and install it in the target position to ensure that the surface of the target is smooth and pollution-free. In sputtering or laser deposition, the distance between the target and the substrate should be appropriate to ensure uniform coverage of sputtered ions. Inject working gas into the vacuum chamber, usually using high-purity argon (Ar) as the sputtering gas. The flow rate of Ar gas is controlled within an appropriate range, usually 10 - 50 sccm. Perform a preheating treatment on the Ti substrate, usually heating it to 200 - 400 °C to improve the adhesion between the coating and the substrate. Finally, use Ar ion bombardment to etch the surface of the substrate to remove residual contaminants and activate the substrate surface.

[0055] 1.1.4 Annealing and cooling

[0056] After deposition, perform subsequent annealing treatment on the substrate. Usually, the annealing temperature is 500 - 700 °C, aiming to improve the crystal structure and interfacial adhesion of TiC, and at the same time reduce defects and internal stress in the coating. Anneal in an argon environment to prevent oxidation. After annealing, gradually reduce the temperature of the vacuum chamber to cool the substrate slowly to room temperature. Rapid cooling may cause coating cracking or stress accumulation.

[0057] 2. Intermediate transition layer design: improving coating stability and adhesion

[0058] The main purpose of the transition layer is to reduce the interfacial stress, prevent the coating from peeling off during the electrolysis process, and extend the overall service life of the electrode. Using chemical vapor deposition (CVD) technology, an IrO 2 is introduced between the Ti substrate and the SnO 2 active layer to form a transition layer. Through the design of the interlayer transition material, the dual improvement of interfacial conductivity and stability is achieved, reducing the interfacial impedance in the electrochemical reaction. At the same time, it can reduce the interfacial stress, enhance the bonding force of the coating, and extend the service life of the electrode.

[0059] The specific experimental process is as follows:

[0060] 2.1. Materials and Equipment

[0061] A clean Ti substrate deposited with TiC, and a precursor of chloroiridic acid for IrO 2 deposition.

[0062] 2.2. CVD Process

[0063] Fix the clean Ti substrate on the sample holder in the CVD chamber to ensure uniform heating. Close the chamber and start pumping to control the pressure within the range of 10 -3 to 10 -5 Torr. Load the chloroacetic acid precursor into the precursor supply system, control the temperature and pressure of the precursor vapor to ensure its stable flow into the reaction chamber. Use high-purity N 2 as the carrier gas to transport the vapor of the precursor to the CVD reaction zone. O 2 is used as the oxidant to convert Ir into IrO 2 and react with the Ir precursor during the CVD process to form an IrO 2 thin film. Heat the substrate in the reaction chamber to 400 - 500 °C, and this temperature range is suitable for the CVD deposition of IrO 2 . Temperature control is very important. Too low a temperature will cause IrO 2 to fail to form a crystalline phase, and too high a temperature may cause the film particles to become larger and the surface roughness to increase.

[0064] After the substrate heating is stable, start the gas flow control system, introduce N 2 and O 2 into the reaction zone to make the Ir precursor and oxygen react on the substrate surface to form an IrO 2 transition layer (ensure that N2 stably transports the precursor vapor to the reaction zone, and at the same time avoid uneven deposition caused by too fast air flow; the flow rate of O 2 must be precisely matched with the vapor flow rate of the precursor (1:1.5 - 1:3) to ensure that the Ir precursor can be fully oxidized to form IrO 2)。The thickness of the IrO thin film is controlled by adjusting the deposition time, and the target thickness is usually in the range of dozens to hundreds of nanometers. Then, the deposited IrO coating is annealed under Ar gas, and the annealing temperature is controlled at 400 - 600 °C to optimize the crystal structure and uniformity of the IrO coating. After the deposition is completed, the temperature in the CVD chamber is gradually reduced to allow the sample to cool naturally to room temperature. Rapid cooling may cause cracking or peeling of the thin film. 2 The thickness of the IrO thin film is controlled by adjusting the deposition time, and the target thickness is usually in the range of dozens to hundreds of nanometers. Then, the deposited IrO coating is annealed under Ar gas, and the annealing temperature is controlled at 400 - 600 °C to optimize the crystal structure and uniformity of the IrO coating. After the deposition is completed, the temperature in the CVD chamber is gradually reduced to allow the sample to cool naturally to room temperature. Rapid cooling may cause cracking or peeling of the thin film. 2 The thickness of the IrO thin film is controlled by adjusting the deposition time, and the target thickness is usually in the range of dozens to hundreds of nanometers. Then, the deposited IrO coating is annealed under Ar gas, and the annealing temperature is controlled at 400 - 600 °C to optimize the crystal structure and uniformity of the IrO coating. After the deposition is completed, the temperature in the CVD chamber is gradually reduced to allow the sample to cool naturally to room temperature. Rapid cooling may cause cracking or peeling of the thin film. 2 The thickness of the IrO thin film is controlled by adjusting the deposition time, and the target thickness is usually in the range of dozens to hundreds of nanometers. Then, the deposited IrO coating is annealed under Ar gas, and the annealing temperature is controlled at 400 - 600 °C to optimize the crystal structure and uniformity of the IrO coating. After the deposition is completed, the temperature in the CVD chamber is gradually reduced to allow the sample to cool naturally to room temperature. Rapid cooling may cause cracking or peeling of the thin film.

[0065] 3. Design of the active layer: Multilayer active coating structure

[0066] The active layer is the core working layer of the electrode material for electrochemical oxidation reactions. Through this, the composition and thickness of each layer are optimized according to catalytic activity and stability.

[0067] 3.1. Sb-doped SnO with quantum dot structure 2 Preparation of the active coating:

[0068] Preparation of the precursor solution:

[0069] SnO 2 Sol preparation: First, synthesize the SnO precursor by the sol-gel method. Dissolve SnCl₂·H₂O in a mixed solution of ethanol and deionized water, add a small amount of acid (such as hydrochloric acid) as a catalyst, stir and heat to a certain temperature to form a stable SnO sol. 2 SnO 2 ·H 2 ₂O in a mixed solution of ethanol and deionized water, add a small amount of acid (such as hydrochloric acid) as a catalyst, stir and heat to a certain temperature to form a stable SnO sol. 2 Sol preparation: First, synthesize the SnO precursor by the sol-gel method. Dissolve SnCl₂·H₂O in a mixed solution of ethanol and deionized water, add a small amount of acid (such as hydrochloric acid) as a catalyst, stir and heat to a certain temperature to form a stable SnO sol.

[0070] Sb-doped precursor solution: Dissolve SbCl₃ in ethanol to form an Sb-doped precursor, and the doping ratio is adjusted according to the research objective, usually in the range of 1% - 5% Sb doping concentration. 3 Sb-doped precursor solution: Dissolve SbCl₃ in ethanol to form an Sb-doped precursor, and the doping ratio is adjusted according to the research objective, usually in the range of 1% - 5% Sb doping concentration.

[0071] 3.2. Introduction of the quantum dot structure

[0072] Quantum dot treatment: Mix the SnO sol prepared by the sol-gel method with the Sb-doped solution and perform rapid annealing treatment at low temperature. This treatment can not only form an Sb-doped SnO structure but also promote the growth of SnO particles into a quantum dot structure at the nanoscale by controlling the annealing temperature and time. The quantum dot effect changes the electronic energy level structure of SnO, thus significantly improving its electrocatalytic performance. 2 Quantum dot treatment: Mix the SnO sol prepared by the sol-gel method with the Sb-doped solution and perform rapid annealing treatment at low temperature. This treatment can not only form an Sb-doped SnO structure but also promote the growth of SnO particles into a quantum dot structure at the nanoscale by controlling the annealing temperature and time. The quantum dot effect changes the electronic energy level structure of SnO, thus significantly improving its electrocatalytic performance. 2 Quantum dot treatment: Mix the SnO sol prepared by the sol-gel method with the Sb-doped solution and perform rapid annealing treatment at low temperature. This treatment can not only form an Sb-doped SnO structure but also promote the growth of SnO particles into a quantum dot structure at the nanoscale by controlling the annealing temperature and time. The quantum dot effect changes the electronic energy level structure of SnO, thus significantly improving its electrocatalytic performance. 2 Quantum dot treatment: Mix the SnO sol prepared by the sol-gel method with the Sb-doped solution and perform rapid annealing treatment at low temperature. This treatment can not only form an Sb-doped SnO structure but also promote the growth of SnO particles into a quantum dot structure at the nanoscale by controlling the annealing temperature and time. The quantum dot effect changes the electronic energy level structure of SnO, thus significantly improving its electrocatalytic performance. 2 Quantum dot treatment: Mix the SnO sol prepared by the sol-gel method with the Sb-doped solution and perform rapid annealing treatment at low temperature. This treatment can not only form an Sb-doped SnO structure but also promote the growth of SnO particles into a quantum dot structure at the nanoscale by controlling the annealing temperature and time. The quantum dot effect changes the electronic energy level structure of SnO, thus significantly improving its electrocatalytic performance.

[0073] Optimization of Quantum Dot Formation Conditions: Different annealing conditions (such as temperature 300 - 600 °C, time 1 - 1.5 h) are used to regulate the size and distribution of quantum dots (quantum dots with a size of 2 - 10 nm are evenly distributed), further optimizing the electrocatalytic performance and stability of the material.

[0074] Preferably, an annealing temperature in the range of 350 °C - 450 °C can most effectively promote the formation of Sb-doped SnO 2 quantum dots while ensuring their stability.

[0075] 3.3. Preparation of Multilayer Active Coating Structure

[0076] Sb-doped SnO with Quantum Dot Structure 2 Preparation of the Active Coating:

[0077] The Sb-doped SnO 2 quantum dot solution is uniformly coated on the treated IrO 2 transition layer surface by spin coating or dip coating. During spin coating, the coating thickness is controlled by adjusting the rotation speed and coating concentration to ensure that the quantum dots are evenly distributed on the coating surface. After the coating is naturally dried at room temperature, it enters the next annealing process.

[0078] High-Temperature Annealing: The coated electrode needs to be annealed at a certain temperature to enhance the adhesion between the coating and the substrate and further optimize the crystallinity of the quantum dots. The annealing temperature is generally controlled at 350 °C - 450 °C, the annealing time is 1 - 2 hours, and the atmosphere is controlled as air or nitrogen atmosphere.

[0079] Optimization of Doping Stability: During the annealing process, the stability of Sb ions and the uniformity of the doping concentration are further optimized, enabling the SnO 2 coating to have better long-term stability during the electrocatalytic reaction process.

[0080] 3.4. Doping Active Substances:

[0081] The introduction of doping elements is the key to improving the electrocatalytic performance of the SnO 2 -based coating. Through theoretical calculations (such as DFT) and literature research, PtNi alloy is determined to be the best dopant. Innovatively, highly active alloy elements and functional nanomaterials are doped into the electrode to optimize the electron transport channels and catalytic active sites, improving the conductivity and electrochemistry reaction efficiency of the electrode, and providing a more efficient solution for the degradation of organic pollutants in wastewater treatment. The doping elements are evenly introduced into the SnO 2 quantum dot structure coating by plasma treatment or ion implantation method, which can significantly improve the conductivity and catalytic activity of the electrode. This process is also combined with annealing treatment to optimize the distribution of doping elements and their roles in the coating, ensuring the structural stability and conductivity of the material.

[0082] The specific experimental process is as follows:

[0083] 3.4.1. Equipment preheating: Start the CVD equipment, set the reaction furnace temperature to 300 - 500 °C (adjust according to experimental requirements). Ensure that there are no impurities such as moisture and oxygen inside the reaction furnace, and fill it with hydrogen as the carrier gas.

[0084] 3.4.2. Gas flow control: Set up the gas flow control system, adjust the flow rate of the carrier gas hydrogen to be between 50 sccm - 1000 sccm, and ensure that the flow rate of the reaction gas is within an appropriate range.

[0085] 3.4.3. Gas delivery of the PtNi alloy precursor:

[0086] Introduce the metal precursors of Pt(CO) 6 and Ni(CO) 4 alloys into the reaction furnace, and set the PtNi atomic ratio to be between 1:3 - 1:5. Control the ratio of Pt and Ni, adjust the flow rate ratio, and ensure that the concentrations of Pt and Ni change according to the set gradient during the deposition process.

[0087] 3.4.4. Deposition process: By adjusting the temperature, gas flow rate, and time of the CVD reaction, deposit gradually to obtain the Sb - SnO 2 alloy film doped with PtNi alloy. To form a concentration gradient, a segmented deposition method can be used, that is, adjust the gas flow rate and the ratio of the PtNi precursor layer by layer:

[0088] Initial stage: Set a higher Pt flow rate (900 - 1000 sccm), first deposit more Pt on the surface of Sb - doped SnO 2 , and set the deposition time to 180 - 240 s.

[0089] Middle stage: Gradually reduce the Pt flow rate (600 - 800 sccm), increase the Ni flow rate (150 - 200 sccm), gradually increase the Ni doping ratio, and set the deposition time to 120 - 180 s.

[0090] Final stage: Further increase the flow rate of Ni (30 - 100 sccm), reduce the Pt flow rate (100 - 300 sccm), and finally form an active layer with a multi - layer gradient change, and set the deposition time to 60 - 120 s.

[0091] 3.4.5. Finally, take out the deposited sample from the reaction furnace, and carry out post - treatment such as cleaning and drying; then further carry out heat treatment (annealing at 600 - 900 °C for 1 - 2 h in a nitrogen atmosphere) to improve the crystal structure and stability of the PtNi alloy.

[0092] Oxide Coating: Coating a protective oxide film ZrO on the surface of the Sb-SnO layer doped with PtNi alloy 2 to enhance the corrosion resistance of the material and extend its lifespan in harsh electrochemical environments. 2

[0093] 4. Material Composite Design

[0094] Coating a protective oxide film, such as ZrO, on the surface of the active coating 2 to enhance the corrosion resistance of the material and extend its lifespan in harsh electrochemical environments, and to improve the electrocatalytic performance of the electrode (corrosion resistance, reducing the oxidation potential of the electrolyte, and increasing the catalytic efficiency) through synergistic effects. The specific experimental process is as follows: Using ZrCl as the Zr source and H2O as the oxygen source, and depositing ZrO layer by layer on the surface through the ALD technique in a cyclic manner. Each reaction deposits only one atomic layer, with very high precision and uniformity. The ALD cycle includes two steps: the pulse of ZrCl and the pulse of H2O, which are carried out in sequence. The ALD process generally needs to be carried out in the temperature range of 200°C - 350°C and in a nitrogen (N2) atmosphere. The N2 flow rate is set at 10 - 50 sccm, the pulse time is 2 seconds, the deposition pressure is set at 0.5 - 1 Torr, and the cyclic deposition is carried out 100 times (forming a ZrO film with a thickness of 4 - 20 nm). Finally, annealing is carried out in N2, and the annealing treatment is carried out at 500 - 600°C for 1 - 2 h 4 2 2 4 2 2 2 2 2

[0095] 5. Surface Modification of the Active Coating - Self-Cleaning Coating Design

[0096] During the sewage treatment process, the anode surface is prone to adsorption and contamination by pollutants or intermediate products, resulting in a decline in electrocatalytic performance. By introducing a self-cleaning material - photocatalytically active TiO2 on the coating surface, the organic matter attached to the surface is degraded by photocatalysis, thereby maintaining the surface activity of the electrode and extending its service life. 2

[0097] The specific operation is as follows:

[0098] 5.1. Material Preparation:

[0099] Photocatalytic Material: Select a highly efficient photocatalytic material such as TiO2 nanoparticles. 2

[0100] Solvent and Precursor: According to the selected TiO2 2Materials, prepare appropriate solvent ethanol and titanium tetraisopropoxide precursor.

[0101] 5.2. Preparation of self-cleaning coating:

[0102] TiO 2 Solution preparation: Add an appropriate amount of titanium tetraisopropoxide precursor to the solvent, and use ultrasonic treatment combined with magnetic stirring to make TiO 2 uniformly dispersed to form a stable solution. Adjust the solution concentration to 0.5 - 1 mol / l to ensure the thickness and photocatalytic activity of the coating.

[0103] Use the spin coating method to uniformly coat the TiO 2 solution on the surface of the prepared active electrode, set the rotation speed to 1800 - 2000 r / min, set the spin coating time to 0.5 - 1 min, then place it in an oven to dry for 3 - 5 min, take it out and repeat this process 5 - 10 times to form a uniform coating. Finally, place the coated electrode in an oven for heat treatment, usually anneal at a temperature of 400 - 500 °C to promote the crystallization process of TiO 2 and enhance its photocatalytic performance and improve the stability of the coating.

[0104] 5.3. Innovation in the preparation method of coating materials - Layer-by-Layer deposition technology

[0105] Adopt the Layer-by-Layer assembly (LbL) process to prepare a multi-layer structure, and precisely adjust the structural properties of the electrode material by controlling the thickness and composition of each layer. This method can achieve precise control of the interlayer transition, ensure the uniformity and denseness of the multi-layer coating, thereby enhancing the electrocatalytic performance and durability of the material.

[0106] 6. New laboratory electrolytic cell degradation device

[0107] The present invention designs a new type of high-efficiency electrocatalytic degradation device: a modular system with a multi-layer Ti / SnO 2 -Sb anode structure, which further improves the sewage degradation effect. The device integrates doping elements to improve conductivity and oxidation reaction performance. The device adopts a transparent hierarchical design, showing the gradient concentration structure of the electrode. The overall design is modern and has a sense of industrial application. The water flow channel is integrated with multiple electrode arrays, optimizing the contact efficiency with pollutants in water. The design of the device takes into account factors such as fluid fluidity, temperature control, and electrode stability, and can maintain stable operation under different operating conditions. Through the intelligent control system, it can real-time monitor parameters such as current, voltage, and temperature during the reaction process, and optimize the reaction conditions according to the real-time data, thereby improving the degradation efficiency.

[0108] The specific structure is described as follows:

[0109] 6.1. Electrolytic cell design:

[0110] The shape of the electrolytic cell can be designed as rectangular or cylindrical. The cell can accommodate the sewage to be treated to ensure fluid mobility. There are fluid inlets and outlets on the sides for the inflow and outflow of sewage, ensuring that the water flow can flow evenly in the electrolytic cell and avoiding dead ends.

[0111] 6.2. Electrode configuration:

[0112] Anode: The target electrode serves as the anode and is installed above or below the electrolytic cell to form the main reaction area in the electrolytic cell.

[0113] Cathode: The Pt electrode is usually placed in the part opposite to the anode to form an electric field distribution. The distance between the two electrodes should ensure a uniform electric field.

[0114] 6.3. Fluid mobility:

[0115] Flow guiding devices (turbine flow devices) can be designed in the cell to enhance fluid flow, enabling the water flow to fully contact the electrode surface and improving the reaction efficiency.

[0116] 6.4. Temperature control system:

[0117] A temperature control device, such as a heater or a cooling system, is set around the electrolytic cell to keep the temperature within the range required for the experiment.

[0118] 6.5. Intelligent control system:

[0119] Sensors: Install sensors for current, voltage, temperature, etc. to monitor the reaction conditions in the electrolytic cell in real time.

[0120] Control panel: Connect various sensors through an intelligent control panel to achieve real-time data acquisition, and adjust parameters such as current, voltage, and temperature through algorithms to ensure the efficiency of the degradation process.

[0121] Optimized design of doped tin oxide coating: Multiple elements are doped to enhance the electrocatalytic performance of the tin oxide electrode and improve its application effect in sewage treatment.

[0122] Multilayer structure design: Optimize the thickness of the SnO 2 coating (control the thickness at 300 - 500 nm through layer-by-layer deposition) and the surface structure to increase the specific surface area and conductivity, thereby improving the electrocatalytic efficiency.

[0123] New electrolytic cell degradation device: A highly efficient and stable electrolytic cell system is designed, optimizing the electrode configuration and reaction conditions, enhancing the reliability and commercial feasibility of the experimental process.

[0124] Stability and long-term performance: The electrode material has high stability and can maintain good electrocatalytic performance during long-term operation, reducing the frequency of equipment maintenance and replacement.

[0125] Example 1

[0126] 1. Preparation of TiC conductive enhancement layer

[0127] The Ti substrate (purity 99.6%) was mechanically polished to a surface roughness <50 nm, ultrasonically cleaned successively with acetone, ethanol, and deionized water, and then dried and placed in a physical vapor deposition (PVD) apparatus.

[0128] The vacuum was pumped to 5×10 -7 Torr, argon gas was introduced (flow rate 20 sccm), and the substrate was preheated to 300 °C.

[0129] Using a TiC target, magnetron sputtering was carried out in an argon atmosphere to deposit a TiC layer with a thickness of 50 nm.

[0130] After deposition, annealing was carried out at 700 °C for 1 hour in an argon atmosphere, and then slowly cooled to room temperature.

[0131] 2. Preparation of IrO 2 Intermediate layer

[0132] The substrate deposited with TiC was placed in a chemical vapor deposition (CVD) apparatus, and the vacuum was pumped to 5×10 -4 Torr.

[0133] Using chloroiridic acid (H 2 IrCl 6 ) as the precursor, mixed with oxygen in a molar ratio of 1:2, the substrate was heated to 450 °C, the reaction pressure was 5×10 -4 Torr, and an IrO 2 layer with a thickness of 80 nm was deposited.

[0134] Annealing treatment was carried out at 550 °C for 1 hour in Ar gas and then naturally cooled.

[0135] 3. Preparation of Sb-PtNi-SnO 2 Active layer

[0136] Synthesis of Sb-SnO 2 Quantum dots by sol-gel method: Weigh 3.3848 g of SnCl 2 ·H 2 0 and 0.1711 g of SbCl 3 Dissolve in an ethanol solution and stir for 24 hours to form a sol.

[0137] Spin-coat the sol on IrO 2The layer surface (rotation speed 2000 r / min), rapid annealing at 350 °C for 1 hour (in air atmosphere), to form Sb-SnO 2 Quantum dots (size 3-5 nm), the thickness of the active layer is 300 nm.

[0138] PtNi alloy doping: Using the CVD method, with Pt(CO) 6 and Ni(CO) 4 as precursors, Pt∶Ni = 1∶3, deposition temperature 400 °C, to form a gradient doping layer, and then annealed in N 2 at 600 °C for 1.5 hours.

[0139] 4. Preparation of the ZrO2 nanocoating layer

[0140] Using atomic layer deposition (ALD), with ZrCl 4 and H 2 O as precursors, substrate temperature 250 °C, 100 cycles, deposition thickness 8 nm.

[0141] Annealed in N 2 at 500 °C for 1 hour.

[0142] 5. Preparation of the TiO 2 self-cleaning coating

[0143] Dissolve tetra-isopropyl titanate in ethanol (concentration 0.8 mol / L), spin-coat (rotation speed 1900 r / min, repeat 8 times), anneal at 500 °C for 1.5 hours (in air atmosphere), to form a 30-nm crystallized TiO 2 layer.

Claims

1. A novel titanium-based tin oxide electrode, characterized in that: It includes a Ti substrate, a TiC conductive enhancement layer, an IrO2 transition layer and a doped SnO2 active layer, a ZrO2 nano-coating layer and a TiO2 self-cleaning coating which are arranged in sequence.

2. A method for preparing a novel titanium-based tin oxide electrode, characterized in that: The following steps are involved: a) Depositing a TiC conductive enhancement layer with a thickness of 50-200 nm on a Ti substrate by physical vapor deposition in a vacuum of less than 1×10 -6 The substrate was prepared with argon as the sputtering gas at 200-400°C under 400-500°C conditions. b) Depositing an IrO2 transition layer with a thickness of 80-300 nm on the TiC conductive enhancement layer by chemical vapor deposition at 400-500°C and a pressure of 10 -3 -10 -5 It is formed by reaction deposition with chloroiridic acid as a precursor and oxygen in a molar ratio of 1:1.5-1:3 at 1:2 to 2:

1. c) preparing a doped SnO2 active layer on the IrO2 transition layer, comprising a Sb-doped SnO2 quantum dot structure, wherein the Sb doping concentration is 1-5at%, the quantum dot size is 2-10nm, and the active layer thickness is 300-500nm, wherein the quantum dots are synthesized by a sol-gel method and annealed at 350-450°C for 1-3 hours, and then PtNi alloy doping is performed to obtain a PtNi alloy-doped Sb-SnO2 layer; d) preparing a ZrO2 nanocoating layer on the doped SnO2 active layer with a thickness of 4-20 nm by atomic layer deposition at 200-350°C for 100 cycles; e) The TiO2 self-cleaning coating coated on the surface of the ZrO2 coating layer has a thickness of 10-50 nm and is formed by spin coating a tetraisopropyl titanate solution and annealing at 400-500°C.

3. The method according to claim 2, characterized in that After the TiC conductive layer is deposited, it is annealed at 500-700° C. and cooled in an argon atmosphere.

4. The method according to claim 2, characterized in that: In step b, the deposited IrO2 coating is annealed in Ar gas at a temperature of 400-600°C.

5. The method according to claim 2, characterized in that: The Sb-doped SnO2 active layer is prepared by a sol-gel method and subjected to rapid annealing treatment at a temperature of 350°C-450°C for 1-2 hours in an atmosphere controlled to be air or nitrogen to form a quantum dot structure.

6. The method according to claim 2, characterized in that It includes SnO2-Sb and PtNi alloy doped with quantum dot structure, and its crystal structure and stability are optimized through annealing treatment.

7. The method according to claim 2, characterized in that The TiO2 self-cleaning coating is composed of photocatalytically active TiO2 nanoparticles, which are uniformly coated on the surface of the active layer by spin coating or dip coating, and annealed at 400-500°C to form a crystallized structure, which is used to decompose organic pollutants adsorbed on the electrode surface under light conditions and maintain the electrocatalytic activity of the electrode.

8. The method according to claim 7, characterized in that The preparation method of the TiO2 self-cleaning coating comprises: a) dispersing tetraisopropyl titanate precursor in ethanol to form a uniform dispersion with a concentration of 0.5-1 mol / L; b) applying the dispersion onto the surface of the doped SnO2 active layer by spin coating at a speed of 1800-2000 r / min, and repeating the coating 5-10 times; c) After coating, annealing is performed at 400-500°C in air or nitrogen atmosphere for 1-2 hours to form a crystallized TiO2 self-cleaning coating.

9. An electrocatalytic wastewater degradation system, characterized in that: The titanium-based tin oxide electrode according to claim 1 is used as an anode, and: An electrolytic cell configured as a rectangular or cylindrical structure having a fluid inlet and an outlet; A Pt cathode, arranged opposite to the anode to form a uniform electric field; Intelligent control system, integrating current, voltage and temperature sensors, to adjust electrocatalytic reaction parameters in real time.

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