A method for preparing Ti-TiO2 pulsed arc ion plating layer for photogenerated cathodic protection

Abstract

The application provides a preparation method of a Ti-TiO2 pulse arc ion plating layer for photogenerated cathodic protection, and the method comprises the following steps: step one, pretreatment; step two, depositing a Ti transition layer; step three, regulating and depositing a TiO2 plating layer; and step four, cooling and taking out: after deposition, the sample is taken out after being cooled to a required temperature T1 in the furnace, and a Ti-TiO2 composite plating layer is obtained. Through the preparation method of the Ti-TiO2 pulse arc ion plating layer for photogenerated cathodic protection, the plating layer has high hardness, wide spectrum absorption characteristics and excellent photogenerated cathodic protection performance on the basis of simplifying the preparation process, and the preparation method is optimized, so that the plating layer not only has the characteristics of green environmental protection, but also has the advantages of simple operation of the preparation equipment, tight combination of the coating and the substrate and large-area deposition.

Description

Technical Field

[0001] This invention relates to the field of marine environment metal corrosion protection and surface modification technology, specifically to a method for preparing a 304 stainless steel-based Ti-TiO2 pulsed arc ion plating layer for photogenerated cathodic protection. Background Technology

[0002] Photogenerated cathodic protection technology is an environmentally friendly, self-driven metal corrosion protection technology based on the photoelectric conversion characteristics of semiconductor materials. Its core principle is to utilize the photogenerated electrons generated by n-type semiconductor materials under sunlight. These electrons migrate to the surface of the protected metal, shifting the metal's potential negatively below its self-corrosion potential, thus achieving cathodic protection. This technology offers advantages such as energy saving, environmental friendliness, long protection cycle, maintenance-free operation, and zero consumables, and has broad application prospects in fields such as marine corrosion prevention.

[0003] Currently, a series of photogenerated cathodic protection materials, represented by TiO2, have been developed both domestically and internationally. To improve their photoelectric performance, optimization methods such as structural modification, doping modification, and composite modification are employed. While these methods significantly enhance photoelectric conversion efficiency, expand the light absorption range, and extend dark-state protection time, problems such as low film layer bonding strength, insufficient hardness, and poor photoanode stability still exist, failing to meet the needs of practical engineering applications. For example, patent CN110344096 B discloses an AgSbS2-sensitized TiO2 composite film material. After composite with AgSbS2 nanoparticles, TiO2 absorption in the visible light region is significantly improved, and the matched band positions after semiconductor composite can drive rapid separation of photogenerated carriers, reducing secondary recombination. However, AgSbS2 is unstable and easily decomposes after prolonged illumination. Patent CN120718480 A discloses an energy storage type photogenerated cathodic protection coating material. First, nano-MoO3 is prepared by precipitation method, and then nano-MoO3 and BiVO4 binary composite material are prepared in situ by low temperature hydrothermal method. It can achieve cathodic protection of metals in dark environment, but the coating has low bonding strength and hardness, and still cannot meet the mechanical strength requirements of engineering applications.

[0004] Therefore, it is of great significance to study how to solve the problem that the mechanical strength of current photogenerated cathodic protection coatings cannot meet the requirements for engineering applications, while still maintaining high cathodic protection performance.

[0005] Patent CN113529020A discloses a corrosion and rust prevention treatment process and coating for iron-based materials. The process involves: 1) pre-treating the iron-based material by polishing or grinding; 2) ultrasonic dewaxing, degreasing, cleaning, and drying after step 1); 3) hanging the treated iron-based material on a fixture after step 2); 4) placing the iron-based material from step 3) into the vacuum chamber of a vacuum coating machine for ion glow discharge activation, and sequentially depositing a base metal layer, a silicon-chromium alloy layer, a top-color chromium plating layer, and a protective layer on the surface of the iron-based material using physical vapor deposition; and 5) removing the iron-based material from the vacuum chamber of the vacuum coating machine after step 4). This method effectively reduces preparation costs and facilitates corrosion and rust prevention treatment of iron-based materials. However, it does not effectively solve the problem that current photogenerated cathodic protection coatings cannot achieve the mechanical strength required for engineering applications while still maintaining high cathodic protection performance. Summary of the Invention

[0006] In view of this, the present invention aims to propose a method for preparing a Ti-TiO2 pulsed arc ion plating layer for photocathode protection, in order to solve the problems of complex process, low coating strength, and poor photocathode protection performance of existing physical vapor deposition methods for preparing TiO2 metal coatings. This method simplifies the preparation process while ensuring the coating has high hardness, broad spectral absorption characteristics, and excellent photocathode protection performance. Furthermore, it optimizes the preparation method to not only be environmentally friendly but also have the advantages of simple equipment operation, tight coating-substrate bonding, and the ability to deposit over large areas.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] This invention relates to a method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection, the method comprising the following steps:

[0009] Step 1, Pretreatment: The stainless steel substrate is pretreated by three methods in sequence: physical impurity removal, chemical decontamination, and arc bombardment cleaning using the prepared equipment.

[0010] Step 2, Deposit Ti transition layer: Adjust the pressure of the inert gas inside the preparation equipment to the first set value P2, turn on the titanium target arc source, set the relevant parameters to the predetermined values, and then deposit the Ti transition layer;

[0011] Step 3: Controlling the deposition of TiO2 coating: Introduce oxygen into the preparation equipment, adjust the volume ratio of inert gas to oxygen to the preset value V0, and maintain the target arc current to the required value T. After adjusting the substrate pulse negative bias voltage, continue to deposit TiO2.

[0012] Step 4: Cooling and unloading: After deposition, the sample is cooled to the required temperature T1 in the furnace and then removed to obtain the Ti-TiO2 composite coating.

[0013] Furthermore, the preparation equipment is an arc ion plating equipment, and argon is used as the inert gas.

[0014] Furthermore, step one includes:

[0015] Step S11: Pretreatment: Select a 304 stainless steel sample of the required size and polish it step by step with diamond sandpaper of different mesh sizes until the surface is smooth.

[0016] Step S12: Using the polished 304 stainless steel sample as a substrate, ultrasonically clean it sequentially with acetone, ethanol, and deionized water within a preset cleaning time t to remove surface oil, oxide layer, and contaminants. After drying, it is ready for use.

[0017] Step S13: Fix the 304 stainless steel sample inside the arc ion plating equipment and clean the sample by arc bombardment using the arc ion plating equipment.

[0018] Furthermore, step S13 includes:

[0019] Step S131: Open the vacuum chamber inside the arc ion plating equipment, process the high-purity titanium target material to the required size and install it in the arc ion plating equipment, and fix the chemically decontaminated 304 stainless steel sample on the sample stage in the vacuum chamber.

[0020] Step S132: Close the vacuum chamber, evacuate to the required preset pressure P0, then heat the vacuum chamber to the preset temperature T0, and introduce argon gas. When the real-time gas pressure P1 in the vacuum chamber rises to the preset pressure P0, turn on the arc-enhanced glow discharge ion source to bombard the surface of the 304 stainless steel sample for a preset time t0; where P0, T0, t0, and P1 are all positive numbers.

[0021] Furthermore, the preset pressure P0 ranges from 0 to 1 × 10⁻¹⁰. -2 Pa; the real-time air pressure P1 ranges from 0.5 Pa to 5 Pa.

[0022] Furthermore, the preset temperature T0 ranges from 300℃ to 700℃; the preset time t0 ranges from 10min to 120min.

[0023] Furthermore, step two includes:

[0024] Step S21: Deposit Ti transition layer: Adjust the pressure of the inert gas inside the preparation equipment to the first set value P2, and turn on the titanium target arc source;

[0025] Step S22: Set the preset arc current value I, the preset matrix pulse negative bias voltage value P3 of the 304 stainless steel sample, and the preset duty cycle value W of the equipment respectively.

[0026] Step S23: After setting the relevant parameters to the preset value, deposit the Ti transition layer within the first preset deposition time t1; where I, P2, P3, and W are all positive numbers.

[0027] Furthermore, the preset base pulse negative bias voltage value P3 is set to a range of -100V to -500V.

[0028] Furthermore, the preset duty cycle value W ranges from 30% to 90%.

[0029] Furthermore, step three includes:

[0030] Step S31: Adjusting the deposited TiO2 coating: Fill the vacuum chamber in the preparation equipment with oxygen and adjust the volume ratio of inert gas to oxygen to the preset value V0; so as to stabilize the total pressure P4 of the vacuum chamber within the required range.

[0031] Step S32: After maintaining the current target arc current I0 to the required value, adjust the current substrate pulse negative bias voltage P5 and the current duty cycle value W1 of the 304 stainless steel sample respectively, and continue to deposit TiO2 within the second preset deposition time t2; where V0, P4, P5, W1 and t2 are all positive numbers.

[0032] Compared with the prior art, the method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection described in this invention has the following advantages:

[0033] By setting the preparation method described above, it is possible to ensure that the coating has high hardness, broad spectral absorption characteristics and excellent photocathode protection performance while simplifying the preparation process. Furthermore, the preparation method is optimized so that it not only has green and environmentally friendly characteristics, but also has the advantages of simple equipment operation, tight bonding between the coating and the substrate, and the ability to deposit over a large area. Attached Figure Description

[0034] The accompanying drawings, which constitute a part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0035] Figure 1 XRD pattern of Ti-TiO2 coating;

[0036] Figure 2a a. Scanning electron microscope image of the overall planar morphology of the Ti-TiO2 coating;

[0037] Figure 2b b is a scanning electron microscope image of the local planar morphology of the Ti-TiO2 coating;

[0038] Figure 2c The longitudinal cross-sectional morphology and overall structure of the Ti-TiO2 coating are shown in the scanning electron microscope (SEM) image.

[0039] Figure 2d The longitudinal cross-sectional morphology of the Ti-TiO2 coating is shown in the local scanning electron microscope image.

[0040] Figure 3 The UV-Vis absorption spectrum of the Ti-TiO2 coating;

[0041] Figure 4 The graph shows the photoelectrochemical performance test results of Ti-TiO2 coated + 304 coupled sample and bare 304 stainless steel sample in seawater.

[0042] Figure 5 The graph shows the photoelectrochemical performance test results of a Ti-TiO2 coated + 304 coupled sample and a bare 304 stainless steel sample coupled in a 0.5 mol / L KOH solution. Detailed Implementation

[0043] The inventive concepts of this disclosure will be described below using terminology commonly used by those skilled in the art to communicate the essence of their work to others skilled in the art. However, these inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0045] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] To address the problems of complex processes, low coating strength, and poor photocathode protection performance in existing physical vapor deposition methods for preparing TiO2 metal coatings, this embodiment proposes a method for preparing a 304 stainless steel-based Ti-TiO2 pulsed arc ion plating layer for photocathode protection, and its application in photocathode protection of metallic materials in high-temperature, high-humidity, and high-UV marine environments. It is particularly suitable for metal protection in high-temperature, high-humidity, and high-UV marine environments. The method includes the following steps:

[0047] Step 1, Pretreatment: The stainless steel substrate is pretreated by three methods in sequence: physical impurity removal, chemical decontamination, and arc bombardment cleaning using the prepared equipment.

[0048] Step 2, Deposit Ti transition layer: Adjust the pressure of the inert gas inside the preparation equipment to the first set value P2, turn on the titanium target arc source, set the relevant parameters to the predetermined values, and deposit the Ti transition layer for a period of time.

[0049] Step 3: Controlling the deposition of TiO2 coating: Introduce oxygen into the preparation equipment, adjust the volume ratio of inert gas to oxygen to the preset value V0, and maintain the target arc current to the required value T. After adjusting the substrate pulse negative bias voltage, continue to deposit TiO2.

[0050] Step 4: Cooling and unloading: After deposition, the sample is cooled to the required temperature T1 in the furnace and then removed to obtain the Ti-TiO2 composite coating.

[0051] The preparation equipment is an arc ion plating equipment, and the inert gas used is argon.

[0052] The preparation method described in this application simplifies the preparation process while ensuring the coating possesses high hardness, broad-spectrum absorption characteristics, and excellent photocathode protection performance. Furthermore, the optimized preparation method not only boasts environmentally friendly characteristics but also offers advantages such as easy equipment operation, tight coating-substrate adhesion, and the ability to deposit over large areas. In addition, unlike vacuum ion plating, which requires a harsh vacuum environment, this application employs arc ion plating technology. By controlling the oxygen content in the gas environment, it achieves the preparation of arc ion plating layers with high adhesion strength and high wear resistance. Simultaneously, the coating exhibits excellent photoelectrochemical properties, enabling photocathode protection of stainless steel materials in marine atmospheric environments. The 304 stainless steel-based Ti-TiO2 coating prepared in this application combines the high hardness and high adhesion strength of traditional arc ion plating layers with the excellent photocathode protection performance of photocathode protection electrode materials, effectively enhancing the engineering application value of current photocathode protection technology.

[0053] Specifically, step one includes:

[0054] Step S11: Pretreatment: Select a 304 stainless steel sample of the required size and polish it step by step with diamond sandpaper of different mesh sizes until the surface is smooth.

[0055] Step S12: Using the polished 304 stainless steel sample as a substrate, ultrasonically clean it sequentially with acetone, ethanol, and deionized water within a preset cleaning time t to remove surface oil, oxide layer, and contaminants. After drying, it is ready for use.

[0056] Step S13: Fix the 304 stainless steel sample in the arc ion plating equipment, and perform arc bombardment cleaning on the sample to achieve pretreatment of the stainless steel substrate.

[0057] In this embodiment, in step S11, the dimensions of the 304 stainless steel sample are amm × bmm × cmm. a is the length, b is the width, and c is the thickness. The values ​​of a and b range from 10mm to 200mm. The value of c ranges from 2mm to 50mm. The mesh size of the abrasive paper ranges from 200# to 2000#. In step S12, the preset cleaning time t for ultrasonic cleaning with acetone, ethanol, and deionized water ranges from 5min to 30min.

[0058] By pretreating 304 stainless steel samples and cleaning them in three different ways in the required order, the tightness of the adhesion between the coating and the substrate can be effectively guaranteed, which is beneficial to improving the effect and quality of the coating.

[0059] Step S13 includes:

[0060] Step S131: Open the vacuum chamber inside the arc ion plating equipment, process the high-purity titanium target material to the required size and install it in the arc ion plating equipment, and fix the chemically decontaminated 304 stainless steel sample on the sample stage in the vacuum chamber.

[0061] Step S132: Close the vacuum chamber, evacuate to the required preset pressure P0, then heat the vacuum chamber to the preset temperature T0, and introduce argon gas. When the real-time gas pressure P1 in the vacuum chamber rises to the preset pressure P0, turn on the arc-enhanced glow discharge ion source to bombard and clean the surface of the 304 stainless steel sample for a preset time t0, further removing residual oxide layer and contaminants from the sample surface and improving the bonding strength between the subsequent coating and the substrate.

[0062] Where P0, T0, t0, and P1 are all positive numbers. The specific values ​​of P0, T0, and t0 are set according to requirements. The specific value of P1 is obtained through detection. In step S131, the diameter of the high-purity titanium target material ranges from 50mm to 150mm. The thickness of the high-purity titanium target material ranges from 10mm to 40mm. The preset pressure P0, i.e., the vacuum degree of the vacuum chamber back bottom, ranges from 0 to 1×10⁻⁶. -2 Pa. The preset temperature T0 ranges from 300℃ to 700℃. The real-time gas pressure P1, i.e., the argon atmosphere pressure, ranges from 0.5Pa to 5Pa. The preset time t0, i.e., the arc-enhanced glow discharge bombardment cleaning time, ranges from 10min to 120min.

[0063] By using arc bombardment cleaning, the oxide layer and contaminants that are easily left after physical and chemical cleaning can be thoroughly removed, and the cleaning effect on the substrate can be further enhanced, ensuring the cleanliness of the 304 stainless steel sample substrate. Furthermore, the preparation method has the advantages of being environmentally friendly, easy to operate, producing a tight bond between the coating and the substrate, and allowing for large-area deposition.

[0064] Step two includes:

[0065] Step S21: Deposit Ti transition layer: Adjust the pressure of the inert gas, i.e. argon atmosphere, inside the preparation equipment to the first set value P2, and turn on the titanium target arc source;

[0066] Step S22: Set the preset arc current value I, the preset matrix pulse negative bias voltage value P3 of the 304 stainless steel sample, and the preset duty cycle value W of the equipment respectively.

[0067] Step S23: After setting the relevant parameters to the preset value, deposit the Ti transition layer within the first preset deposition time t1.

[0068] In this context, I, P2, P3, and W are all constant values, and all of them are positive numbers. The specific values ​​of I, P2, P3, and W are set as needed.

[0069] In this embodiment, the first preset value P2 ranges from 0.5 Pa to 5 Pa. The preset arc current value I ranges from 50 A to 300 A. The preset substrate pulse negative bias voltage value P3 ranges from -100 V to -500 V. The preset duty cycle value W ranges from 30% to 90%. The first preset deposition time t1 ranges from 1 min to 20 min.

[0070] By setting a Ti transition layer, it can be coordinated with the controlled deposition of TiO2 coating in step three to ensure coating quality. It also solves the problem in existing technologies where photogenerated cathodic protection coatings cannot achieve the mechanical strength required for engineering applications while still maintaining high cathodic protection performance. This enables the coating to be widely used in marine engineering. Furthermore, it simplifies the preparation method, enabling the industrial production of Ti-TiO2 arc ion plating on 304 stainless steel surfaces.

[0071] Step three includes:

[0072] Step S31: Adjusting the deposited TiO2 coating: Fill the vacuum chamber in the preparation equipment with oxygen and adjust the volume ratio of inert gas, i.e., argon, to oxygen to the preset value V0; so that the total pressure P4 of the vacuum chamber can be stabilized within the required range.

[0073] Step S32: After maintaining the current target arc current I0 to the required value, adjust the current substrate pulse negative bias voltage P5 and the current duty cycle W1 of the 304 stainless steel sample respectively, and continue to deposit TiO2 within the second preset deposition time t2.

[0074] Among them, V0, P4, P5, W1, and t2 are all positive numbers, and the specific values ​​of V0, P4, P5, W1, and t2 are set according to the requirements.

[0075] In this embodiment, the volume ratio of argon to oxygen, up to the preset value V0, ranges from 0.5 to 3. The total pressure P4 of the vacuum chamber ranges from 0.1 Pa to 1 Pa. The current target arc current I0 ranges from 50 A to 300 A. The current substrate pulse negative bias voltage P5 ranges from -200 V to 600 V. The current duty cycle W1 ranges from 10% to 70%. The second preset deposition time t2 ranges from 5 min to 100 min. Additionally, in step four, the required temperature T1 ranges from 50 °C to 200 °C.

[0076] By adjusting the settings of the deposited TiO2 coating, the flexibility and precision of the preparation method in controlling the coating progress can be improved, and the coating settings can be set as needed. This further enhances the efficiency and reliability of the coating. Furthermore, the coordinated setup of stainless steel substrate pretreatment, Ti transition layer deposition, and continuous TiO2 coating deposition process for preparing Ti-TiO2 composite coatings on 304 stainless steel surfaces achieves the following advantages: 1) Simple and environmentally friendly process: Specifically, pulsed arc ion plating technology eliminates the need for complex operating steps, process conditions are easily controlled, equipment operation is safe, and large-area and automated production is feasible. The entire preparation process generates no toxic or harmful substances, meeting green environmental protection requirements and suitable for industrial mass production. 2) High coating bonding strength and excellent hardness: Specifically, by adjusting the deposition voltage and current, oxygen vacancies in the coating can be controlled simultaneously with Ti-TiO2 deposition, effectively improving the bonding strength between the Ti-TiO2 coating and the 304 stainless steel substrate, and enhancing the photoelectrochemical performance of the coating. The resulting coating has significantly higher hardness than the substrate, possessing excellent physical protection capabilities and resisting external wear and corrosive media erosion. 3) It can optimize light absorption performance; specifically, the light absorption threshold of the obtained Ti-TiO2 coating is red-shifted to 389nm, and the absorption range is extended into the visible light region, resulting in higher light utilization. 4) It can achieve excellent photo-generated cathodic protection performance; specifically, the residual Ti in the coating can form a Schottky junction with TiO2, suppressing photogenerated electron-hole recombination, accelerating electron migration rate, and possessing a certain electron storage capacity, providing protection even in the dark. 5) It can ensure a broad application prospect for the coating; specifically, the Ti-TiO2 coating prepared in this application has both physical protection and photo-generated cathodic protection functions, and can be widely used for the protection of 304 stainless steel and other metal materials in corrosive marine environments, solving the shortcomings of existing anti-corrosion technologies.

[0077] Example 1:

[0078] A 10 mm × 10 mm × 10 mm 304 stainless steel sample was progressively polished with sandpaper, using a grit range of 400#-1000#. It was then ultrasonically treated sequentially in acetone, ethanol, and deionized water for 15 min each, and dried before use. The prepared 304 stainless steel sample was placed on the sample stage of the vacuum chamber. A high-purity titanium target with a diameter of 93 mm and a thickness of 28 mm was used. Preferably, the purity of the high-purity titanium target was 99.8% (mass fraction). The background vacuum was 6.0 × 10⁻⁶ mm. -3 After heating the vacuum chamber to 400°C, argon gas was introduced at a pressure of 1.0 Pa. An arc-enhanced glow discharge ion source was then activated to bombard the sample surface for 50 min to remove the surface oxide layer and contaminants, thereby improving the bonding strength between the film and the substrate. Then, maintaining the argon gas pressure at 1.0 Pa, the titanium target arc source was activated with an arc current of 100 A, a substrate pulse negative bias of -200 V, and a duty cycle of 60%, for depositing a Ti transition layer for 5 min. Subsequently, oxygen was introduced, and the argon-to-oxygen ratio was adjusted to 1.5. The vacuum chamber pressure was adjusted to 0.35 Pa, the titanium target arc current remained at 100 A, the substrate pulse negative bias was -400 V, and the duty cycle was 40%, for deposition for 30 min. After deposition, the furnace was further cooled to below 150°C, and the sample was removed.

[0079] The crystal composition and microstructure of the obtained 304-based Ti-TiO2 composite coating are as follows: Figure 1 As shown in Figure 2.

[0080] Example 2:

[0081] A 304 stainless steel sample measuring 50 mm × 100 mm × 5 mm was progressively polished with sandpaper, using a grit range of 200#-2000#. It was then ultrasonically treated sequentially in acetone, ethanol, and deionized water for 30 min each, and dried before use. The prepared 304 stainless steel sample was placed on the sample stage of the vacuum chamber. A high-purity titanium target with a diameter of 150 mm and a thickness of 10 mm was used. Preferably, the purity of the high-purity titanium target was 99.8% (mass fraction). The background vacuum was 1.0 × 10⁻⁶. -3After heating the vacuum chamber to 500°C, argon gas was introduced at a pressure of 2.0 Pa. An arc-enhanced glow discharge ion source was activated to bombard the sample surface for 100 min to remove the surface oxide layer and contaminants, improving the bonding strength between the film and the substrate. Then, maintaining the argon gas pressure at 2.0 Pa, the titanium target arc source was activated with an arc current of 200 A, a substrate pulse negative bias of -150 V, and a duty cycle of 70%, depositing a Ti transition layer for 20 min. Subsequently, oxygen was introduced, adjusting the argon-to-oxygen ratio to 2, adjusting the vacuum chamber pressure to 0.8 Pa, maintaining the titanium target arc current at 150 A, the substrate pulse negative bias at -500 V, and the duty cycle at 30%, depositing for another 20 min. After deposition, the furnace was further cooled to below 50°C, and the sample was removed.

[0082] The obtained 304-based Ti-TiO2 composite coating exhibits the following UV-Vis spectra and photoelectrochemical properties: Figure 3 and Figure 4 As shown in Table 1, the hardness test results of the composite coating and stainless steel are presented. Table 1 shows that the formation of the Ti-TiO2 composite coating on the stainless steel surface significantly improves the hardness and wear resistance of the stainless steel.

[0083] Table 1 Hardness test results of Ti-TiO2 composite coating and stainless steel

[0084]

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathodic protection, characterized in that, The method includes the following steps: Step 1, Pretreatment: The stainless steel substrate is pretreated by three methods in sequence: physical impurity removal, chemical decontamination, and arc bombardment cleaning using the prepared equipment. Step 2, Deposit Ti transition layer: Adjust the pressure of the inert gas inside the preparation equipment to the first set value P2, turn on the titanium target arc source, set the relevant parameters to the predetermined values, and then deposit the Ti transition layer; Step 3: Controlling the deposition of TiO2 coating: Introduce oxygen into the preparation equipment, adjust the volume ratio of inert gas to oxygen to the preset value V0, and maintain the target arc current to the required value T. After adjusting the substrate pulse negative bias voltage, continue to deposit TiO2. Step 4: Cooling and unloading: After deposition, the sample is cooled to the required temperature T1 in the furnace and then removed to obtain the Ti-TiO2 composite coating.

2. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 1, characterized in that, The preparation equipment is an arc ion plating equipment, and argon is used as the inert gas.

3. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 2, characterized in that, Step one includes: Step S11: Pretreatment: Select a 304 stainless steel sample of the required size and polish it step by step with diamond sandpaper of different mesh sizes until the surface is smooth. Step S12: Using the polished 304 stainless steel sample as a substrate, ultrasonically clean it sequentially with acetone, ethanol, and deionized water within a preset cleaning time t to remove surface oil, oxide layer, and contaminants. After drying, it is ready for use. Step S13: Fix the 304 stainless steel sample inside the arc ion plating equipment and clean the sample by arc bombardment using the arc ion plating equipment.

4. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 3, characterized in that, Step S13 includes: Step S131: Open the vacuum chamber inside the arc ion plating equipment, process the high-purity titanium target material to the required size and install it in the arc ion plating equipment, and fix the chemically decontaminated 304 stainless steel sample on the sample stage in the vacuum chamber. Step S132: Close the vacuum chamber, evacuate to the required preset pressure P0, then heat the vacuum chamber to the preset temperature T0, and introduce argon gas. When the real-time gas pressure P1 in the vacuum chamber rises to the preset pressure P0, turn on the arc-enhanced glow discharge ion source to bombard the surface of the 304 stainless steel sample for a preset time t0; where P0, T0, t0, and P1 are all positive numbers.

5. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 4, characterized in that, The preset pressure P0 ranges from 0 to 1 × 10⁻⁶. -2 Pa; The real-time air pressure P1 ranges from 0.5 Pa to 5 Pa.

6. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 4, characterized in that, The preset temperature T0 ranges from 300℃ to 700℃; the preset time t0 ranges from 10min to 120min.

7. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 2, characterized in that, Step two includes: Step S21: Deposit Ti transition layer: Adjust the pressure of the inert gas inside the preparation equipment to the first set value P2, and turn on the titanium target arc source; Step S22: Set the preset arc current value I, the preset matrix pulse negative bias voltage value P3 of the 304 stainless steel sample, and the preset duty cycle value W of the equipment respectively. Step S23: After setting the relevant parameters to the preset value, deposit the Ti transition layer within the first preset deposition time t1; where I, P2, P3, and W are all positive numbers.

8. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 7, characterized in that, The preset substrate pulse negative bias voltage value P3 ranges from -100V to -500V.

9. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 7, characterized in that, The preset duty cycle value W ranges from 30% to 90%.

10. The method for preparing a Ti-TiO2 pulsed arc ion plating layer for photogenerated cathode protection according to claim 7, characterized in that, Step three includes: Step S31: Adjusting the deposited TiO2 coating: Fill the vacuum chamber in the preparation equipment with oxygen and adjust the volume ratio of inert gas to oxygen to the preset value V0; so as to stabilize the total pressure P4 of the vacuum chamber within the required range. Step S32: After maintaining the current target arc current I0 to the required value, adjust the current substrate pulse negative bias voltage P5 and the current duty cycle value W1 of the 304 stainless steel sample respectively, and continue to deposit TiO2 within the second preset deposition time t2; where V0, P4, P5, W1 and t2 are all positive numbers.

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