Titanium-based tin oxide electrode, preparation method and application

Abstract

The present application relates to the technical field of electrocatalysis, in particular to a novel titanium-based tin oxide electrode, a preparation method and application thereof. The present application aims to solve the technical problems of easy peeling of the coating, insufficient catalytic activity and short service life of the traditional titanium-based tin oxide electrode in electrocatalytic wastewater treatment. Through the innovative design of a five-layer composite structure (TiC conductive layer / IrO2 transition layer / Sb-PtNi-SnO2 quantum dot active layer / ZrO2 nanometer coating layer / TiO2 self-cleaning layer), combined with gradient doping and atomic layer deposition process, the interface stress is optimized, the electron transmission is strengthened, and the surface pollutant self-decomposition function is realized, so that the service life of the electrode is broken through to 138 hours under the current density of 100 mA / cm 2 2, and the intelligent control system is matched to realize dynamic optimization of reaction parameters, thereby significantly improving the industrial applicability of the wastewater treatment system.

Description

Technical Field

[0001] This invention relates to the field of electrocatalysis technology, and in particular to a novel titanium-based tin oxide electrode, its preparation method, and its applications. It is suitable for water treatment, especially for wastewater treatment that utilizes electrocatalysis for the efficient degradation of organic pollutants. Background Technology

[0002] With the acceleration of industrialization, the content of organic pollutants in wastewater is constantly increasing. Traditional physicochemical methods (such as adsorption and flocculation) and biological methods are often unable to efficiently degrade insoluble organic compounds (such as polycyclic aromatic hydrocarbons and dyes). Electrocatalysis technology has become a research hotspot in the field of water treatment due to its high oxidation capacity, environmental compatibility, and operational controllability. However, existing electrode materials have significant bottlenecks in catalytic efficiency, stability, durability, and cost-effectiveness, necessitating the development of new high-performance electrocatalytic electrode materials.

[0003] Titanium-based tin dioxide (Ti / SnO2) electrodes are widely used in the electrocatalytic degradation of organic matter due to SnO2's high oxygen evolution potential and strong ·OH generation capability. However, traditional Ti / SnO2 electrodes have the following drawbacks:

[0004] 1. Coating is prone to peeling: The difference in thermal expansion coefficients between SnO2 and the titanium substrate leads to interfacial stress, and the coating is prone to cracking and peeling off during long-term electrolysis.

[0005] 2. Insufficient catalytic activity: The electron mobility of a single SnO2 or Sb-doped electrode is limited, and the active sites are easily covered by intermediate products;

[0006] 3. Short lifespan: In acidic or high-salt wastewater environments, the electrode surface corrodes faster, and its stability decreases significantly.

[0007] Therefore, there is an urgent need to develop a new type of electrode and matching reaction system that combines high catalytic activity, long lifespan, and self-healing function to meet the dual requirements of economic efficiency and stability in industrial wastewater treatment. Summary of the Invention

[0008] This invention aims to solve the technical problems of traditional titanium-based tin oxide electrodes in electrocatalytic wastewater treatment, such as easy coating peeling, insufficient catalytic activity, and short lifespan. 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), combined with gradient doping and atomic layer deposition processes, it achieves optimized interfacial stress, enhanced electron transport, and self-decomposition of surface contaminants, enabling the electrode to achieve a lifespan of 100 mA / cm². 2 With a lifespan exceeding 138 hours at current density, and equipped with an intelligent control system to dynamically optimize reaction parameters, the industrial applicability of the wastewater treatment system is significantly improved.

[0009] To achieve the above objectives, the present invention employs the following technical solution:

[0010] This invention provides a novel titanium-based tin oxide electrode, characterized in that it comprises a Ti substrate, a TiC conductive enhancement layer, an IrO2 transition layer, a SnO2 doped active layer, a ZrO2 nanocoating layer, and a TiO2 self-cleaning coating, arranged sequentially.

[0011] This invention also provides a method for preparing a novel titanium-based tin oxide electrode, comprising the following steps:

[0012] a) Deposit a TiC conductive reinforcement layer with a thickness of 50-200 nm on a Ti substrate using physical vapor deposition at a vacuum level below 1×10⁻⁶. -6 The substrate was prepared under Torr conditions using argon as the sputtering gas at a flow rate of 10-50 sccm and preheated to 200-400℃.

[0013] b) Deposit an 80-300 nm thick IrO2 transition layer on the TiC conductive reinforcement layer via chemical vapor deposition at 400-500 °C and 10 °C. -3 -10 -5 Torr formed by the reaction of chloroiridic acid as a precursor with oxygen in a molar ratio of 1:1.5-1:3;

[0014] c) Prepare a SnO2 doped active layer on an IrO2 transition layer, comprising an Sb-doped SnO2 quantum dot structure, wherein the Sb doping concentration is 1-5 at%, the quantum dot size is 2-10 nm, and the active layer thickness is 300-500 nm. The quantum dots are synthesized by sol-gel method and annealed at 350-450℃ for 1-3 hours, and then PtNi alloy doping is performed to obtain a PtNi alloy doped Sb-SnO2 layer.

[0015] d) A ZrO2 nano-coating layer with a thickness of 4-20 nm was prepared on the SnO2 doped active layer by atomic layer deposition at 200-350 °C for 100 cycles.

[0016] e) A TiO2 self-cleaning coating with a thickness of 10-50 nm is applied to the surface of the ZrO2 coating layer. It is formed by spin-coating a tetraisopropyl titanate solution and then annealing at 400-500℃.

[0017] In the above scheme, the TiC conductive layer is annealed at 500-700℃ after deposition and cooled in an argon atmosphere.

[0018] In the above scheme, in step b, the deposited IrO2 coating is annealed under Ar gas at a temperature of 400-600℃.

[0019] In the above scheme, the Sb-doped SnO2 active layer is prepared by sol-gel method and subjected to rapid annealing at 350℃-450℃ for 1-2 hours, with the atmosphere controlled as air or nitrogen, in order to form a quantum dot structure.

[0020] The above schemes include SnO2-Sb with quantum dot structure and PtNi alloy doping, and their crystal structure and stability are optimized by annealing treatment.

[0021] In the above scheme, 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 process, and annealed at 400-500℃ to form a crystal structure, which is used to decompose organic pollutants adsorbed on the electrode surface under light conditions and maintain the electrocatalytic activity of the electrode.

[0022] The preparation method of the TiO2 self-cleaning coating in the above scheme includes:

[0023] a) Disperse the tetraisopropyl titanate precursor in ethanol to form a uniform dispersion with a concentration of 0.5-1 mol / L.

[0024] b) The dispersion was coated onto the surface of the SnO2 active layer by spin coating at a speed of 1800-2000 r / min, and the coating was repeated 5-10 times.

[0025] c) After coating, anneal at 400-500℃ in air or nitrogen atmosphere for 1-2 hours to form a crystallized TiO2 self-cleaning coating.

[0026] The present invention also provides an electrocatalytic wastewater degradation system, comprising the aforementioned titanium-based tin oxide electrode as the anode, and:

[0027] The electrolytic cell is configured as a rectangular or cylindrical structure and is equipped with a fluid inlet and an outlet;

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

[0029] The intelligent control system integrates current, voltage, and temperature sensors to adjust electrocatalytic reaction parameters in real time.

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

[0031] 1. The titanium-based tin oxide electrode designed in this invention has high stability and can maintain stable electrocatalytic performance during long-term electrocatalytic reactions, solving the problem of easy degradation of existing electrode materials during long-term use.

[0032] 2. Multilayer Structure Synergistic Enhancement Mechanism: A gradient design—Ti substrate → TiC conductive layer → IrO2 transition layer → Sb-SnO2 active layer—solves the problems of easy peeling and insufficient conductivity in traditional titanium-based electrode coatings. The TiC conductive layer forms a dense interface using PVD technology, reducing resistance; the IrO2 transition layer employs a high-temperature CVD process, effectively mitigating the difference in thermal expansion coefficients between the substrate and the active layer, improving interfacial bonding strength, and achieving an electrode conductivity of 100 mA / cm². 2 At current density, the enhanced lifespan can reach hours, and coating peeling is not obvious.

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

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

[0035] 5. Gradient Doping and Interface Control: Through the synergistic effect of PtNi alloy doping and ZrO2 coating, the oxygen evolution potential of the electrode is increased, effectively suppressing side reactions, optimizing electron transport channels and catalytic active sites, and improving the electrode's conductivity and electrochemical reaction efficiency, providing a more efficient solution for the degradation of organic pollutants in wastewater treatment. Dopant elements are uniformly introduced into the SnO2 quantum dot structure coating through plasma treatment or ion implantation, significantly improving the electrode's conductivity and catalytic activity. This process is also combined with annealing to optimize the distribution of dopant elements and their role in the coating, ensuring the material's structural stability and conductivity. Attached Figure Description

[0036] Figure 1 This is a flowchart of the experimental process of the present invention;

[0037] Figure 2 For electrocatalytic degradation device

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

[0039] Figure 4 The image shows the changes in the coating before and after the stability test (the coating showed almost no peeling after the 138-hour enhanced life test, with only a few microcracks appearing).

[0040] Figure 5 This is a comparison of the stability of the original electrode and the electrode described in the patent. Detailed Implementation

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

[0042] Functional design of anode multilayer structure

[0043] Based on the structural optimization of coating materials, the overall performance of the anode is improved through multilayer combinations of different materials. The design of the multilayer structure will take into account factors such as coating thickness, interlayer transition, and surface morphology to optimize the electrocatalytic activity, durability, and conductivity of the electrode.

[0044] 1. TiC conductive reinforcement layer:

[0045] 1.1 Substrate Design: Enhance the mechanical and electrical conductivity of the substrate.

[0046] Ti, as a support layer for the anode, possesses excellent mechanical strength and corrosion resistance. However, due to its poor electrical conductivity, the adhesion and current conduction efficiency of the coating material need improvement. Therefore, the bottom layer can be formed by introducing a metal carbide (TiC) with better conductivity to create a conductive reinforcement layer, designed as a thin and dense structure to reduce resistance and optimize current distribution.

[0047] Specific preparation process: Highly conductive TiC is deposited on a Ti substrate to form a conductivity enhancement layer. This layer is prepared using physical vapor deposition (PVD) technology. Optimized deposition parameters ensure a thin and dense coating structure, reducing resistance and improving current distribution. By constructing metal carbides such as TiC or nanostructures doped with noble metals, a synergistic enhancement of mechanical strength and conductivity is achieved, improving the overall performance of the electrode.

[0048] 1.1.1 Materials and Equipment

[0049] Substrate material: Ti substrate, usually high-purity Ti substrate (such as Ti6Al4V alloy) is selected.

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

[0051] 1.1.2. Substrate Pretreatment

[0052] First, the Ti substrate is mechanically polished to remove surface roughness and improve coating adhesion. The surface roughness after polishing should be controlled at the nanoscale (typically <100nm). Then, the substrate is cleaned using an ultrasonic cleaner, followed by cleaning with acetone, anhydrous ethanol, and deionized water in sequence to remove surface oil and particulate matter. Finally, it is dried in an oven and then purged with argon gas for storage.

[0053] 1.1.3 Deposition process

[0054] Secure the clean, dry Ti substrate onto the sample holder of the PVD equipment, ensuring a proper distance between the substrate and the target (typically 5-10 cm). Adjust the sample clamps and rotation mechanism to ensure uniform deposition of the substrate during the deposition process. Close the chamber and begin evacuation; the vacuum level typically needs to reach 10. -6 To minimize interference from impurity gases, the target should be positioned below the specified torque (Tor). A TiC target should be selected and mounted on the target site, ensuring a smooth and contamination-free surface. During sputtering or laser deposition, the distance between the target and the substrate should be appropriate to ensure uniform coverage of sputtered ions. A working gas, typically high-purity argon (Ar), should be injected into the vacuum chamber. The Ar gas flow rate should be controlled within an appropriate range, typically 10-50 sccm. The Ti substrate should be preheated, usually to 200-400°C, to improve the adhesion between the coating and the substrate. Finally, the substrate surface should be etched using Ar ion bombardment to remove residual contaminants and activate the substrate surface.

[0055] 1.1.4 Annealing and Cooling

[0056] After deposition, the substrate undergoes subsequent annealing. The annealing temperature is typically 500-700℃ to improve the crystal structure and interfacial adhesion of TiC, while reducing defects and internal stress in the coating. Annealing is performed in an argon atmosphere to prevent oxidation. After annealing, the vacuum chamber temperature is gradually reduced, allowing the substrate to cool slowly to room temperature. Rapid cooling may cause coating cracking or stress accumulation.

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

[0058] The main purpose of the transition layer is to reduce interfacial stress, prevent coating peeling during electrolysis, and improve the overall lifespan of the electrode. IrO2 is introduced between the Ti substrate and the SnO2 active layer using chemical vapor deposition (CVD) technology to form a transition layer. Through the design of the interlayer transition material, both interfacial conductivity and stability are improved, reducing interfacial impedance in electrochemical reactions. Simultaneously, it reduces interfacial stress, enhances coating adhesion, and extends the electrode's lifespan.

[0059] The specific experimental procedure is as follows:

[0060] 2.1. Materials and Equipment

[0061] A clean Ti substrate with deposited TiC and a chloroiridium acid precursor for IrO2 deposition.

[0062] 2.2. CVD Process

[0063] Secure the cleaned Ti substrate to the sample holder inside the CVD chamber, ensuring uniform heating. Close the chamber and begin evacuation, maintaining the pressure at 10...-3 Up to 10 -5 Within the range of Torr. A chloroacetic acid precursor is loaded into the precursor supply system, and the temperature and pressure of the precursor vapor are controlled to ensure a stable flow rate into the reaction chamber. High-purity N2 is used as the carrier gas to transport the precursor vapor to the CVD reaction zone. O2 acts as an oxidant to convert Ir to IrO2, which reacts with the Ir precursor during the CVD process to form an IrO2 film. The substrate within the reaction chamber is heated to 400-500°C; this temperature range is suitable for the CVD deposition of IrO2. Temperature control is crucial; too low a temperature will prevent IrO2 from forming a crystalline phase, while too high a temperature may lead to larger film particles and increased surface roughness.

[0064] After the substrate has been heated and stabilized, the gas flow control system is activated to introduce N2 and O2 into the reaction zone, allowing the Ir precursor and oxygen to react on the substrate surface to form an IrO2 transition layer. (This ensures that N2 stably delivers the precursor vapor to the reaction zone while avoiding excessively rapid gas flow that could lead to uneven deposition; the O2 flow rate must be precisely matched to the precursor vapor flow rate (1:1.5-1:3) to ensure that the Ir precursor can be fully oxidized to form IrO2). The thickness of the IrO2 film is controlled by adjusting the deposition time, typically targeting a thickness of tens to hundreds of nanometers. The deposited IrO2 coating is then annealed under Ar gas at a temperature controlled between 400-600℃ to optimize the crystal structure and uniformity of the IrO2 coating. After deposition, the temperature within the CVD chamber is gradually reduced, allowing the sample to cool naturally to room temperature. Rapid cooling may cause the film to crack or peel off.

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

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

[0067] 3.1. Preparation of Sb-doped SnO2 active coating with quantum dot structure:

[0068] Preparation of precursor solution:

[0069] SnO2 sol preparation: First, SnO2 precursors were synthesized via the sol-gel method. SnCl2·H2O was dissolved in a mixed solution of ethanol and deionized water, and a small amount of acid (such as hydrochloric acid) was added as a catalyst. The mixture was stirred and heated to a certain temperature to form a stable SnO2 sol.

[0070] Sb-doped precursor solution: SbCl3 is dissolved in ethanol to form an Sb-doped precursor. 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 quantum dot structure

[0072] Quantum dot formation: SnO2 sol prepared by the sol-gel method was mixed with an Sb-doped solution and subjected to rapid annealing at low temperature. This treatment not only forms Sb-doped SnO2 structures but also promotes the growth of SnO2 particles into quantum dot structures at the nanoscale by controlling the annealing temperature and time. The quantum dot effect alters the electronic energy level structure of SnO2, thereby significantly improving its electrocatalytic performance.

[0073] Optimization of quantum dot formation conditions: The size and distribution of quantum dots (uniform distribution of 2-10 nm quantum dots) were controlled by using different annealing conditions (such as temperature 300-600℃ and time 1-1.5h) to further optimize the electrocatalytic performance and stability of the material.

[0074] Preferably, an annealing temperature in the range of 350℃-450℃ best promotes the formation of Sb-doped SnO2 quantum dots while ensuring their stability.

[0075] 3.3. Preparation of Multilayer Active Coating Structure

[0076] Preparation of Sb-doped SnO2 active coating with quantum dot structure:

[0077] Sb-doped SnO2 quantum dot solution was uniformly coated onto the surface of the pre-treated IrO2 transition layer using spin coating or dip coating methods. During spin coating, the coating thickness was controlled by adjusting the spin speed and coating concentration to ensure uniform distribution of quantum dots on the coating surface. After the coating was allowed to dry naturally at room temperature, it proceeded to the next step of annealing.

[0078] High-temperature annealing: After coating, the electrodes need 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℃-450℃, the annealing time is 1-2 hours, and the atmosphere is controlled as air or nitrogen.

[0079] Optimization of doping stability: During the annealing process, the stability of Sb ions and the uniformity of doping concentration are further optimized, resulting in better long-term stability of the SnO2 coating during the electrocatalytic reaction.

[0080] 3.4. Doping with active materials:

[0081] The introduction of doping elements is key to improving the electrocatalytic performance of SnO2-based coatings. Through theoretical calculations (such as DFT) and literature review, PtNi alloy was identified as the optimal dopant. Innovatively, highly active alloying elements and functional nanomaterials are incorporated into the electrode to optimize electron transport channels and catalytic active sites, thereby improving electrode conductivity and electrochemical reaction efficiency, providing a more efficient solution for the degradation of organic pollutants in wastewater treatment. Doping elements are uniformly introduced into the SnO2 quantum dot structure coating through plasma treatment or ion implantation, significantly improving the electrode's conductivity and catalytic activity. This process is further combined with annealing to optimize the distribution of doping elements and their role in the coating, ensuring the material's structural stability and conductivity.

[0082] The specific experimental procedure is as follows:

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

[0084] 3.4.2. Gas flow control: Set up a gas flow control system to adjust the flow rate of carrier gas hydrogen to 50 sccm-1000 sccm to ensure that the flow rate of the reaction gas is within a suitable range.

[0085] 3.4.3. Gas transport of PtNi alloy precursors:

[0086] A Pt(CO)6 and Ni(CO)4 alloy precursor is introduced into the reactor, with the Pt-Ni atomic ratio set between 1:3 and 1:5. The Pt and Ni ratio is controlled, and the flow rate is adjusted to 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, a PtNi alloy-doped Sb-SnO2 alloy film is obtained through stepwise deposition. To create a concentration gradient, a segmented deposition method can be used, i.e., adjusting the gas flow rate and the ratio of PtNi precursor layer by layer.

[0088] Initial stage: Set a high Pt flow rate (900-1000 sccm) to deposit a large amount of Pt on the Sb-doped SnO2 surface first, and set the settling time to 180-240 s.

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

[0090] Final stage: Gradually increase the Ni flow rate (30-100 sccm) and decrease the Pt flow rate (100-300 sccm) to eventually form a multi-layered gradient active layer. The deposition time is set to 60-120 s.

[0091] 3.4.5. Finally, the deposited sample is removed from the reactor and cleaned and dried; then it is further heat-treated (annealed at 600-900℃ for 1-2 hours in a nitrogen atmosphere) to improve the crystal structure and stability of the PtNi alloy.

[0092] Oxide coating: A protective oxide film of ZrO2 is coated on the surface of the Sb-SnO2 layer doped with PtNi alloy to enhance the corrosion resistance of the material and extend its life in harsh electrochemical environments.

[0093] 4. Material Combination Design

[0094] A protective oxide film, such as ZrO2, is coated onto the surface of the active coating to enhance the material's corrosion resistance and extend its lifespan in harsh electrochemical environments. This synergistic effect improves the electrocatalytic performance of the electrode (corrosion resistance, reduction of electrolyte oxidation potential, and increased catalytic efficiency). The specific experimental procedure is as follows: ZrCl4 is used as the Zr source, and H2O is used as the oxygen source. ZrO2 is deposited layer by layer on the surface through a cyclic deposition process using ALD technology. Each reaction deposits only one atomic layer, resulting in very high precision and uniformity. The ALD cycle consists of two steps: pulses of ZrCl4 and pulses of H2O, performed sequentially. The ALD process generally needs to be carried out in a temperature range of 200℃-350℃ under 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 100 cycles are performed (forming a ZrO2 film of 4-20 nm). Finally, annealing is performed in N2 at 500-600℃ for 1-2 hours.

[0095] 5. Surface modification of active coatings - self-cleaning coating design

[0096] In wastewater treatment, the anode surface is easily adsorbed and contaminated by pollutants or intermediate products, leading to 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 through photocatalysis, thereby maintaining the electrode surface activity and extending its service life.

[0097] The specific steps are as follows:

[0098] 5.1. Material Preparation:

[0099] Photocatalytic materials: Highly efficient photocatalytic materials such as TiO2 nanoparticles are selected.

[0100] Solvents and precursors: Based on the selected TiO2 material, prepare suitable solvents such as ethanol and tetraisopropyl titanate precursors.

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

[0102] TiO2 solution preparation: An appropriate amount of tetraisopropyl titanate precursor was added to the solvent, and the solution was uniformly dispersed to form a stable solution using ultrasonic treatment combined with magnetic stirring. The solution concentration was adjusted to 0.5-1 mol / L to ensure the coating thickness and photocatalytic activity.

[0103] TiO2 solution was uniformly coated onto the surface of the prepared active electrode using a spin-coating method. The spin speed was set to 1800-2000 r / min, and the spin-coating time was set to 0.5-1 min. The electrode was then placed in a drying oven for 3-5 min, and this process was repeated 5-10 times to form a uniform coating. Finally, the coated electrode was placed in an oven for heat treatment, typically annealing at 400-500℃, to promote the crystallization process of TiO2, enhance its photocatalytic performance, and improve the stability of the coating.

[0104] 5.3. Innovation in Coating Material Preparation Methods - Layer-by-Layer Deposition Technology

[0105] A layer-by-layer (LbL) deposition process was used to fabricate multilayer structures, allowing for precise adjustment of the electrode material's structural properties by controlling the thickness and composition of each layer. This method enables precise control of interlayer transitions, ensuring the uniformity and density of the multilayer coating, thereby improving the material's electrocatalytic performance and durability.

[0106] 6. Novel Laboratory Electrolytic Cell Degradation Device

[0107] This invention presents a novel, highly efficient electrocatalytic degradation device: a modular system with a multi-layered Ti / SnO2-Sb anode structure, further enhancing wastewater degradation efficiency. The device integrates doping elements to improve conductivity and oxidation reaction performance. The transparent, layered design showcases the gradient concentration structure of the electrodes, resulting in a modern, industrial-application-oriented design. The water flow channel is integrated with multiple electrode arrays, optimizing contact efficiency with pollutants in the water. The device design considers factors such as fluid flowability, temperature control, and electrode stability, enabling stable operation under various conditions. An intelligent control system monitors parameters such as current, voltage, and temperature in real time during the reaction process and optimizes reaction conditions based on real-time data, thereby improving degradation efficiency.

[0108] The specific structure is as follows:

[0109] 6.1 Electrolytic Cell Design:

[0110] The electrolytic cell can be designed in a rectangular or cylindrical shape, and its interior can hold the wastewater to be treated, ensuring fluid flow. Fluid inlets and outlets are located on the sides for wastewater entry and exit, ensuring uniform water flow within the electrolytic cell and avoiding dead zones.

[0111] 6.2. Electrode Configuration:

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

[0113] Cathode: A Pt electrode, typically placed opposite the anode to create an electric field distribution. The distance between the two electrodes should ensure a uniform electric field.

[0114] 6.3. Fluid Flowability:

[0115] A water flow guiding device (turbine flow device) can be designed inside the tank to enhance fluid flow, so that the water flow can fully contact the electrode surface and improve reaction efficiency.

[0116] 6.4. Temperature control system:

[0117] Temperature control devices, such as heaters or cooling systems, are installed around the electrolytic cell to maintain the temperature within the range required for the experiment.

[0118] 6.5. Intelligent Control System:

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

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

[0121] Optimized design of doped tin oxide coating: Multiple element doping is used to enhance the electrocatalytic performance of tin oxide electrodes and improve their application effect in wastewater treatment.

[0122] Multilayer structure design: Optimize the thickness of the SnO2 coating (by layer-by-layer deposition, the thickness is controlled at 300-500nm) and surface structure to improve the specific surface area and conductivity, thereby improving the electrocatalytic efficiency.

[0123] Novel Electrolytic Degradation Device: A highly efficient and stable electrolytic cell system was designed, and the electrode configuration and reaction conditions were optimized to enhance 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 reinforcement layer

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

[0128] Vacuum up to 5×10 -7 Torr, introduce argon gas (flow rate 20 sccm), and preheat the substrate to 300°C.

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

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

[0131] 2. Preparation of IrO2 transition layer

[0132] The substrate after TiC deposition was placed in a chemical vapor deposition (CVD) apparatus and evacuated to a vacuum of 5 × 10⁻⁶. -4 Torr.

[0133] Using chloroiridic acid (H2IrCl6) as a precursor, it was mixed with oxygen at a molar ratio of 1:2, and the substrate was heated to 450°C. The reaction pressure was 5 × 10⁻⁶. -4 Torr, with an IrO2 layer thickness of 80 nm.

[0134] Annealing at 550°C for 1 hour in Ar gas, followed by natural cooling.

[0135] 3. Preparation of Sb-PtNi-SnO2 active layer

[0136] Sol-gel synthesis of Sb-SnO2 quantum dots: 3.3848 g SnCl2·H2O and 0.1711 g SbCl3 were weighed and dissolved in ethanol solution, and stirred for 24 hours to form a sol.

[0137] Sol was spin-coated onto the surface of the IrO2 layer (2000 r / min) and rapidly annealed at 350°C for 1 hour (in air) to form Sb-SnO2 quantum dots (3-5 nm in size) with an active layer thickness of 300 nm.

[0138] PtNi alloy doping: Pt(CO)6 and Ni(CO)4 were used as precursors by CVD, with Pt∶Ni=1∶3 and deposition temperature of 400℃ to form a gradient doped layer, followed by annealing in N2 at 600℃ for 1.5 hours.

[0139] 4. Preparation of ZrO2 nanocoating layer

[0140] Atomic layer deposition (ALD) was used with ZrCl4 and H2O as precursors, substrate temperature 250℃, 100 cycles, and deposition thickness 8nm.

[0141] Anneal at 500°C for 1 hour in N2.

[0142] 5. Preparation of TiO2 self-cleaning coating

[0143] Tetraisopropyl titanate was dissolved in ethanol (concentration 0.8 mol / L), spin-coated (1900 r / min, repeated 8 times), and annealed at 500℃ for 1.5 hours (air atmosphere) to form a 30 nm crystalline TiO2 layer.

Claims

1. A titanium-based tin oxide electrode, characterized in that: It includes a Ti substrate, a TiC conductive enhancement layer, an IrO2 transition layer and a SnO2 doped active layer, a ZrO2 nanocoating layer and a TiO2 self-cleaning coating, arranged sequentially. ； The TiC conductive reinforcement layer has a thickness of 50-200 nm and is prepared by physical vapor deposition. The ZrO2 nanocoating layer has a thickness of 4-20 nm and is prepared by atomic layer deposition; the TiO2 self-cleaning coating is composed of TiO2 nanoparticles and is used to decompose organic pollutants adsorbed on the electrode surface under light conditions, thereby maintaining the electrocatalytic activity of the electrode.

2. A method for preparing a titanium-based tin oxide electrode, characterized in that, Includes the following steps: a) Deposit a TiC conductive reinforcement layer with a thickness of 50-200 nm on a Ti substrate using physical vapor deposition at a vacuum level below 1×10⁻⁶. -6 The substrate was prepared under Torr conditions using argon as the sputtering gas at a flow rate of 10-50 sccm and preheated to 200-400℃. b) Deposit an 80-300 nm thick IrO2 transition layer on the TiC conductive reinforcement layer via chemical vapor deposition at 400-500 °C and 10 °C. -3 -10 -5 Torr formed by the reaction of chloroiridic acid as a precursor with oxygen in a molar ratio of 1:1.5-1:3; c) Prepare a SnO2 doped active layer on an IrO2 transition layer, comprising an Sb-doped SnO2 quantum dot structure, wherein the Sb doping concentration is 1-5 at%, the quantum dot size is 2-10 nm, and the active layer thickness is 300-500 nm. The quantum dots are synthesized by sol-gel method and annealed at 350-450℃ for 1-3 hours, and then PtNi alloy doping is performed to obtain a PtNi alloy doped Sb-SnO2 layer. d) A ZrO2 nano-coating layer with a thickness of 4-20 nm was prepared on the SnO2 doped active layer by atomic layer deposition at 200-350 °C for 100 cycles. e) A TiO2 self-cleaning coating with a thickness of 10-50 nm is applied to the surface of the ZrO2 nano-coating layer. It is formed by spin-coating a tetraisopropyl titanate solution and then annealing at 400-500℃.

3. The method according to claim 2, characterized in that, The TiC conductive reinforcement layer is annealed at 500-700℃ after deposition and then cooled in an argon atmosphere.

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

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

6. The method according to claim 2, characterized in that, In step c, annealing is used to improve the crystal structure and stability of the PtNi alloy.

7. The method according to claim 2, characterized in that, The self-cleaning TiO2 coating is composed of photocatalytically active TiO2 nanoparticles, which are uniformly coated onto the surface of the ZrO2 nano-coating layer by spin coating and then annealed at 400-500℃ to form a crystallized structure. This coating 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 methods of TiO2 self-cleaning coatings include: a) Disperse the tetraisopropyl titanate precursor in ethanol to form a uniform dispersion with a concentration of 0.5-1 mol / L; b) The dispersion was coated onto the surface of the ZrO2 nano-coating layer by spin coating at a speed of 1800-2000 r / min, and the coating was repeated 5-10 times. c) After coating, anneal at 400-500℃ 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, Including the titanium-based tin oxide electrode of claim 1 as the anode, and: The electrolytic cell is configured as a rectangular or cylindrical structure and is equipped with a fluid inlet and an outlet; A Pt cathode is positioned opposite the anode to form a uniform electric field; The intelligent control system integrates current, voltage, and temperature sensors to adjust electrocatalytic reaction parameters in real time.

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