A bimodal microvia modified molybdenum-based BDD electrode and a femtosecond laser preparation method thereof

Abstract

The application relates to the field of laser processing electrode materials, and mainly relates to a double-scale micro-hole modified molybdenum-based BDD electrode and a femtosecond laser preparation method thereof. The femtosecond laser preparation method of the double-scale micro-hole modified molybdenum-based BDD electrode comprises the following steps: performing room-temperature non-contact cold processing on a molybdenum base by using a femtosecond laser to obtain a modified molybdenum base; performing purification treatment on the modified molybdenum base; depositing BDD diamond on the modified molybdenum base subjected to the purification treatment to obtain an activated part; and performing activation treatment on the activated part to obtain the double-scale micro-hole modified molybdenum-based BDD electrode. The BDD electrode obtained by the application has higher electrochemical activity area, faster mass transfer rate, lower interface impedance, stronger structural stability and longer service life, and can better meet the use requirements of efficient, stable and reliable work in the scenes of electrochemical detection, water treatment, organic electro-synthesis and the like.

Description

Technical Field

[0001] This application relates to the field of laser processing electrode materials, and mainly to a dual-scale microporous modified molybdenum-based BDD electrode and its femtosecond laser preparation method. Background Technology

[0002] Boron-doped diamond (BDD) electrodes are ideal electrode materials for electrochemical detection, water treatment, and organic electrosynthesis due to their advantages such as wide potential window, low background current, high chemical stability, and strong corrosion resistance. Molybdenum metal is the most commonly used conductive substrate material for BDD electrodes because of its excellent conductivity, matching coefficient of thermal expansion with diamond, and good high-temperature resistance.

[0003] However, existing molybdenum-based BDD electrodes still have many obvious defects and shortcomings: the molybdenum substrate has a dense plate structure, resulting in low electrolyte mass transfer efficiency and difficulty in rapid desorption of bubbles generated by electrochemical reactions, which easily cover the electrode active sites and lead to a decrease in reaction efficiency; the bonding force between molybdenum and diamond is weak, and long-term use is prone to film peeling and cracking; the molybdenum substrate is easily oxidized during processing and deposition, leading to increased electrode interfacial impedance and poor electrochemical stability; at the same time, traditional molybdenum substrate modification processes are prone to thermal damage and mechanical stress, which destroy the crystal structure of molybdenum materials and cannot simultaneously achieve a synergistic improvement in high mass transfer efficiency, high active area, high interfacial bonding force and low impedance of BDD electrodes, resulting in the overall catalytic efficiency, response speed and service life of the electrode failing to meet the requirements of high-efficiency electrochemical applications.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a dual-scale microporous modified molybdenum-based BDD electrode and its femtosecond laser fabrication method. Addressing the technical defects of molybdenum-based BDD electrodes, such as limited electrolyte mass transfer, difficulty in bubble desorption, insufficient electrochemical active area, weak bonding between molybdenum and diamond, and high resistance due to easy oxidation of the molybdenum substrate, this application employs femtosecond laser micro-nano processing to modify the molybdenum conductive substrate. Through a triple innovative process of dual-scale gradient microporous array, in-situ nanotexturing of the pore walls, and integrated oxidation-free deposition, a BDD diamond layer is then deposited to construct a high-performance composite electrode. All process parameters, structural design, and functional roles are precisely adapted to synergistically achieve a comprehensive improvement in the electrochemical performance of the molybdenum-based BDD electrode.

[0006] The technical solution of this application is as follows: A femtosecond laser fabrication method for a dual-scale microporous modified molybdenum-based BDD electrode includes the following steps: Modified molybdenum substrates were obtained by non-contact cold processing at room temperature using a femtosecond laser. The parameters of the femtosecond laser were: pulse width 80-120 fs, wavelength 750-850 nm, and peak power density 1×10⁻⁶. 12 -1×10 14 W / cm 2 Single pulse energy 1-10μJ, focused spot diameter 10-30μm, laser repetition frequency 1-100kHz, laser scanning speed 1-10mm / s; The modified molybdenum-based material is then purified. BDD diamond is deposited on the purified modified molybdenum substrate to obtain the activated part; The element to be activated is subjected to activation treatment to obtain a dual-scale microporous modified molybdenum-based BDD electrode.

[0007] Furthermore, the parameters of the femtosecond laser are: pulse width 80-120 fs, wavelength 750-850 nm, and peak power density 5 × 10⁻⁶. 12 -5×10 13 W / cm 2 Single pulse energy 3-7μJ, focused spot diameter 15-25μm, laser repetition frequency 10-50kHz, laser scanning speed 3-7mm / s.

[0008] Furthermore, the deposition of BDD diamond on the modified molybdenum substrate is performed using MPCVD low-temperature deposition. The thickness of the deposited BDD diamond layer on the modified molybdenum-based surface is 5–10 μm.

[0009] Furthermore, the deposition of BDD diamond on the modified molybdenum substrate includes the following steps: Disperse nanodiamond powder in an alcohol solvent to obtain a diamond powder suspension; The modified molybdenum-based material was placed in the diamond powder suspension and then dried. The modified molybdenum substrate was deposited using microwave plasma chemical vapor deposition (IPV). The process conditions were as follows: methane / hydrogen flow rate ratio 1-5%, boron-carbon ratio 3500-4500 ppm, chamber pressure 80-90 Torr, substrate temperature 1200-1300 K, microwave power 3500-4500 W, and time 2-4 h.

[0010] Furthermore, the activation treatment involves hydroxylating the surface of the part to be activated using oxygen plasma.

[0011] Furthermore, the activation treatment parameters are as follows: microwave output power of 500-800W, reaction chamber pressure of 10-20 Torr, oxygen flow rate of 40-60 sccm, treatment temperature of 350-450℃, and treatment time of 3-8 min.

[0012] Furthermore, the purification process includes in-situ plasma non-oxidative purification.

[0013] Furthermore, the in-situ plasma non-oxidative purification treatment includes: after obtaining the modified molybdenum base, without exposing it to the atmosphere, directly using argon plasma for in-situ purification treatment of the modified molybdenum base, with a treatment power of 70-90W and a treatment time of 20-60s.

[0014] This application also provides a dual-scale microporous modified molybdenum-based BDD electrode.

[0015] Furthermore, the modified molybdenum-based material includes several micro-through holes and several micro / nano blind holes; The micro-holes have a diameter of 5–20 μm and a spacing of 50–100 μm, and are arranged vertically. The micro-nano blind holes have a diameter of 1–3 μm and a depth of 0.5–2 μm; The wall surface of the micro-hole is also provided with several nano-scale textured surfaces. The transverse feature size of the nano-textured texture is 100-500 nm, and the longitudinal depression depth is 50-200 nm.

[0016] Compared with the prior art, this application has the following beneficial effects: 1. To address the issues of poor mass transfer, difficulty in bubble desorption, and insufficient active area in molybdenum-based BDD electrodes, this application employs a dual-scale synergistic structure of 5–20 μm micro-through holes and 1–3 μm micro-nano blind holes formed in one step by femtosecond laser. Room temperature cold processing results in no thermal damage or stress, achieving efficient electrolyte mass transfer and rapid bubble overflow.

[0017] 2. To address the issues of weak bonding and easy peeling at the molybdenum / BDD interface, this application employs a specific femtosecond laser technique to generate a nano-texture in situ on the wall of the micro-via, thereby strengthening diamond nucleation and interface anchoring without additional processing.

[0018] 3. To address the issues of easy oxidation of molybdenum substrates and high interfacial impedance, this application adopts an integrated process of in-situ argon plasma purification and re-deposition of BDD without exposing the atmosphere after processing, thereby avoiding molybdenum oxidation and reducing interfacial impedance.

[0019] 4. This application uses a modified molybdenum substrate treated with femtosecond laser for the preparation of BDD electrodes, which synergistically improves mass transfer efficiency, bubble desorption, active area and interfacial bonding. Attached Figure Description

[0020] Figure 1 This is a top view of the modified molybdenum-based embodiment of Example 1 of this application.

[0021] Figure 2 This is a side cross-sectional view of the dual-scale microporous modified molybdenum-based BDD electrode of Example 1 of this application.

[0022] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0023] Figure 4 , Figure 5 This is an electrochemical cycling curve of the dual-scale microporous modified molybdenum-based BDD electrode of Example 1 of this application.

[0024] Labeling explanation: 1. Modified molybdenum-based; 11. Micropore; 12. Micro / nano blind hole; 13. Nano-texture; 2. BDD diamond layer. Detailed Implementation

[0025] This application provides a dual-scale microporous modified molybdenum-based BDD electrode and its femtosecond laser fabrication method. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following provides a more detailed description. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0026] This application provides a femtosecond laser fabrication method for a dual-scale microporous modified molybdenum-based BDD electrode, comprising the following steps: Step 1: Pretreatment of the molybdenum substrate: Select high-purity molybdenum sheets with a thickness of 0.1–0.5 mm, and ultrasonically clean them with acetone and anhydrous ethanol for 5–20 minutes each to remove surface oil, impurities and oxide layer. Dry them with nitrogen before use.

[0027] Step 2: Femtosecond laser dual-scale gradient micro-via array fabrication: A femtosecond laser with a pulse width of 80-120 fs, a wavelength of 750-850 nm, and a controllable peak power density was used to perform room temperature non-contact cold processing on a molybdenum substrate to form a dual-scale synergistic structure of a main through hole and surface micro-nano blind holes 12, resulting in modified molybdenum substrate 1.

[0028] Peak power density: 1×10 12 -1×10 14 W / cm 2 The corresponding single pulse energy is 1-10 μJ; the corresponding focused spot diameter is 10-30 μm; the corresponding laser repetition frequency is 1-100 kHz; and the corresponding laser scanning speed is 1-10 mm / s.

[0029] Preferably, the peak power density is 5 × 10⁻⁶. 12 -5×10 13 W / cm 2 The corresponding single pulse energy is 3-7 μJ; the corresponding focused spot diameter is 15-25 μm; the corresponding laser repetition frequency is 10-50 kHz; and the corresponding laser scanning speed is 3-7 mm / s.

[0030] The main through-hole of the modified molybdenum-based 1 is a vertical micro-through-hole 11 with a diameter of 5–20 μm and a spacing of 50–100 μm, which is used for bidirectional electrolyte penetration and rapid bubble overflow. Micro-nano blind holes 12 with a depth of 0.5–2 μm and a diameter of 1–3 μm are generated simultaneously on the subsequent BDD diamond deposition surface of the molybdenum substrate to increase the diamond nucleation area and interface anchoring strength. The entire processing is heat-affected zone-free, burr-free, and microcrack-free, and the hole wall roughness Ra≤0.2 μm.

[0031] This application utilizes a single femtosecond laser parameter to achieve a dual-scale synergistic structure of "main through-hole + surface micro / nano blind hole 12" in a single molding process, without requiring parameter changes or secondary processing. The core principle is based on the inherent radial energy distribution characteristics of a femtosecond laser Gaussian beam, as detailed below: 1. Core Principle: Energy Gradient Distribution of a Gaussian Beam After being focused by the objective lens, the energy of the femtosecond laser spot exhibits a standard Gaussian radial distribution: the energy density is highest in the central region of the spot and decreases exponentially towards the edge; material removal occurs in areas where the energy density is higher than the ablation threshold, while no damage occurs in areas where the energy density is lower than the threshold.

[0032] 2. Synchronous formation mechanism of dual-scale structures By precisely controlling the laser peak power density, the energy in different regions of the laser spot is precisely matched to the processing requirements of the two structures: Main via formation: In the area of ​​about 1 / 3 of the diameter of the light spot, the energy density reaches 5-50 times the ablation threshold, which can instantly vaporize the molybdenum material and form a vertical main via (pore diameter 5-20μm) that runs through the entire substrate.

[0033] Formation of surface micro-nano blind holes 12: In the edge region of the light spot, the energy density is just 1-2.5 times the ablation threshold, which can only ablate shallow blind holes with a depth of 0.5-2μm on the surface of the molybdenum substrate, and cannot penetrate the molybdenum substrate (the hole diameter is 1-3μm, which is determined by the diameter of the region where the edge just reaches the ablation threshold).

[0034] While processing the micro-via 11 with femtosecond laser, due to specific laser parameter settings, a uniform nano-texture 13 is generated in situ on the wall of the micro-via 11 using the cold processing effect. Strict control of the low peak power density ensures only instantaneous atomic / molecular-level material removal without high-temperature melting. The entire processing environment is conducted at room temperature, normal pressure, and atmospheric conditions, without heating the molybdenum substrate, using no coolant, or applying high-temperature assistance; cold ablation is achieved through ultra-short pulses. Beam movement (ensuring uniform cold processing of the vertical hole wall): The laser beam performs a 360° high-speed rotation scan along the central axis of the vertical circular hole, always irradiating the hole wall perpendicularly and at equal intervals. The single-point action time is extremely short, with no heat diffusion or accumulation. Integrated cold processing forming and hole construction are completed simultaneously in one step, without secondary etching, sandblasting, heat treatment, or any other post-processing that might generate heat / stress. Throughout the process, the molybdenum substrate remains free from thermal damage, burrs, microcracks, and oxidation discoloration. No additional etching, coating or other post-processing is required, which provides uniform nucleation sites and mechanical interlocking structure for subsequent BDD diamond, and strengthens the interfacial bonding force.

[0035] The transverse feature size of the nano-texture 13 is 100-500 nm (equivalent diameter of a single protrusion or depression), and the longitudinal depression depth is 50-200 nm.

[0036] When the lateral feature size of the nano-texture 13 is less than 100 nm, the number of diamond nucleation sites is insufficient, the mechanical anchoring effect is not obvious, and the film-substrate bonding strength is improved by less than 20%. When the size is greater than 500 nm, it will destroy the overall flatness of the pore wall, resulting in uneven thickness and void defects during BDD deposition, which will reduce the interfacial bonding strength.

[0037] Step 3: In-situ plasma non-oxidative purification: After step 2 is completed, without exposure to the atmosphere, argon plasma in-situ purification treatment is directly used (power 70-90W, processing time 20-60s) to quickly remove trace oxide layers, processing impurities and residual contaminants from the wall of the micro-hole 11, maintain the high cleanliness of the modified molybdenum-based 1 interface and avoid the increase in interface impedance caused by oxidation.

[0038] Step 4: MPCVD low-temperature deposition of BDD diamond layer: The purified modified molybdenum substrate 1 was directly fed into an MPCVD deposition apparatus. Using a boron source as a dopant, a BDD diamond layer 2 was uniformly deposited on the surface of the modified molybdenum substrate 1, the inner wall of the micro-vias 11, the micro / nano blind holes 12, and the nano-texture 13. The thickness of the BDD diamond layer 2 on the surface of the modified molybdenum substrate 1 was controlled between 5 and 10 μm. The modified molybdenum substrate 1 with the BDD diamond layer deposited on its surface was defined as the part to be activated.

[0039] The deposition temperature is adapted to the properties of molybdenum material, resulting in no thermal damage. The BDD diamond layer 2 is continuous, dense, and free of voids, breaks, and interface defects.

[0040] Specifically: Use a 2.45GHz / 10kW MPCVD device.

[0041] The purified modified molybdenum-based material 1 was ultrasonically treated in a 45-55 nm diamond powder suspension for 20-60 min to promote diamond nucleation, followed by drying under a nitrogen flow. A uniform boron-doped diamond film was epitaxially grown on the modified molybdenum-based material 1 using a 2.45 GHz / 10 kW microwave plasma chemical vapor deposition (MPCVD) process. The entire deposition process lasted 2-4 h under fixed process parameters: methane / hydrogen flow ratio 1-5%, boron-to-carbon ratio (B / C) 3500-4500 ppm. Gases used: boron source (0.5-2% trimethylboron TMB / H2), hydrogen (H2), methane (CH4). Chamber pressure 80-90 Torr, substrate temperature 1200-1300 K, microwave power 3500-4500 W.

[0042] The diamond powder suspension is prepared by dispersing 40-60 mg of nano-diamond powder in 150-250 mL of alcohol solvent; the preferred alcohol solvent is ethanol.

[0043] Step 5: Electrode terminal activation: Oxygen plasma was used to hydroxylate the surface of the part to be activated, resulting in a highly active and stable dual-scale microporous modified molybdenum-based BDD electrode.

[0044] Specifically, oxygen plasma treatment is performed using MPCVD equipment with the following parameters: microwave output power of 500-800W, reaction chamber pressure of 10-20 Torr, oxygen (O2) flow rate of 40-60 sccm, treatment temperature of 350-450℃, and treatment time of 3-8 min.

[0045] This application utilizes an innovative process of femtosecond laser micro / nano-fabrication to modify a molybdenum substrate, followed by integrated oxide-free BDD deposition, significantly improving the overall electrochemical performance and structural stability of molybdenum-based BDD electrodes. Specifically, the femtosecond laser dual-scale gradient microporous array enables efficient bidirectional mass transfer of the electrolyte and rapid desorption of reaction bubbles, greatly enhancing electrochemical reaction efficiency; the in-situ nanotexture of the pore walls increases the diamond nucleation area of ​​the BDD, forming a synergistic effect of mechanical anchoring and covalent bonding, completely solving the problems of weak molybdenum / diamond interface bonding and easy peeling; and in-situ plasma oxide-free purification avoids molybdenum substrate oxidation, effectively reducing electrode interface impedance and improving electron transport efficiency. The synergistic effect of the three innovative processes not only solves the problems of poor mass transfer, bubble retention, small active area, weak interfacial bonding, and high resistance to oxidation of traditional molybdenum-based BDD electrodes, but also achieves precise modification without thermal damage or stress. Ultimately, the electrodes have a higher electrochemical active area, faster mass transfer rate, lower interfacial impedance, stronger structural stability and longer service life, which can better meet the requirements of efficient, stable and reliable operation in electrochemical detection, water treatment, organic electrosynthesis and other scenarios.

[0046] The present application will be further described below through specific embodiments. Example 1

[0047] This embodiment provides a femtosecond laser fabrication method for a dual-scale microporous modified molybdenum-based BDD electrode, including the following steps: Step 1: Pretreatment of the molybdenum substrate: Select a 0.1mm thick high-purity molybdenum sheet, and clean it with acetone and anhydrous ethanol for 10 minutes each to remove surface oil, impurities and oxide layer. Dry it with nitrogen and set it aside.

[0048] Step 2: A femtosecond laser with a pulse width of 100 fs, a wavelength of 800 nm, and a controllable peak power density is used to perform non-contact cold processing on the molybdenum substrate at room temperature to obtain modified molybdenum substrate 1.

[0049] Peak power density: 1.6 × 10 13 W / cm 2 The corresponding single pulse energy is 5 μJ; the corresponding focused spot diameter (800 nm wavelength) is 20 μm; the corresponding laser repetition frequency is 20 kHz; and the corresponding laser scanning speed is 5 mm / s.

[0050] The main through-hole of the modified molybdenum-based 1 is a vertical micro-through-hole 11 with a pore diameter of 10 μm and a pore spacing of 50 μm. Micro-nano blind holes 12 with a depth of 0.5-2 μm and a pore diameter of 1-3 μm are generated on the BDD diamond deposition surface of the modified molybdenum-based 1; the pore wall roughness Ra≤0.2 μm. The wall surface of the micro-through-hole 11 generates a uniform nano-texture 13.

[0051] The transverse feature size of the nano-texture 13 is 100-500 nm, and the longitudinal depression depth is 50-200 nm.

[0052] The size of each nano-texture 13 is not an absolutely identical fixed value, because the nano-texture 13 is a self-organized structure generated by the interaction between the femtosecond laser and the molybdenum material. The size of a single texture has a small statistical distribution, but under the process parameters determined in this embodiment, its size distribution range is highly stable and controllable.

[0053] The size distribution of each nanotexture 13 is entirely determined by the laser parameters. In this embodiment, with the parameters fixed, the batch-to-batch size deviation is <10%, ensuring stable repeatability. This distribution range provides optimal diamond nucleation site density and mechanical anchoring effect. Forcing all structures to have completely identical dimensions would increase process complexity without providing additional functional gain. (See top view of modified molybdenum-based 1.) Figure 1 .

[0054] Step 3: In-situ plasma non-oxidative purification: The modified molybdenum-based 1 was purified in situ using argon plasma with a power of 80W and a treatment time of 30s.

[0055] Step 4: MPCVD low-temperature deposition of BDD diamond layer 2: The purified modified molybdenum substrate 1 was ultrasonically treated in a 50 nm diamond powder suspension for 30 min to promote diamond nucleation, and then dried under a nitrogen flow. A uniform boron-doped diamond film, namely BDD diamond layer 2, was epitaxially grown on the modified molybdenum substrate 1 using a 2.45 GHz / 10 kW microwave plasma chemical vapor deposition (MPCVD) process. The thickness of the BDD diamond layer 2 on the surface of the modified molybdenum substrate 1 was 8 μm. The modified molybdenum substrate 1 with the deposited BDD diamond layer 2 was defined as the element to be activated.

[0056] The entire deposition process lasted for 3 hours under fixed process parameters: methane / hydrogen flow rate ratio 3%, boron-to-carbon ratio (B / C) 4000 ppm. Gases used: boron source (1% trimethylboron TMB / H2), hydrogen (H2), methane (CH4). Chamber pressure 85 Torr, substrate temperature 1252 K, microwave power 4000 W.

[0057] This diamond powder suspension was prepared by dispersing 50 mg of nano-diamond powder in 200 mL of ethanol.

[0058] Step 5: Electrode terminal activation: The surface of the part to be activated was treated with oxygen plasma using an MPCVD device with the following parameters: microwave output power of 600W, reaction chamber pressure of 15 Torr, oxygen (O2) flow rate of 50 sccm, treatment temperature of 400℃, and treatment time of 5 min. A dual-scale microporous modified molybdenum-based BDD electrode was obtained.

[0059] Side cross-sectional view of dual-scale microporous modified molybdenum-based BDD electrode (refer to...) Figure 2 , 3 .

[0060] Electrochemical cycling curve of dual-scale microporous modified molybdenum-based BDD electrode (refer to) Figure 4 , 5 .

[0061] according to Figure 4 As can be seen from the curves, the cyclic voltammetry curves exhibit near-ideal reversible redox characteristics with symmetrical peaks, high responsibility, and stable cycling, fully demonstrating the core advantages of this invention: the integrated oxidation-free process completely solves the problem of increased interfacial impedance caused by molybdenum substrate oxidation, achieving efficient electron transport; the dual-scale gradient microporous array combined with in-situ nanotexture of the pore walls constructs a three-dimensional active interface, significantly increasing the electrochemical active area of ​​the electrode; the mechanical anchoring effect brought by the nanotexture strengthens the film-substrate bonding force, ensuring the performance stability of the electrode during cycling.

[0062] according to Figure 5 As can be seen from the electrochemical window test curves, this electrode possesses an ultra-wide electrochemical stability window approaching 4V in the Ag / AgCl reference system. The background current is extremely low and free of impurity peaks throughout the entire range. The current response is stable and without abrupt changes across a wide range of positive and negative potentials, effectively demonstrating the technical value of this application: a thermally damage-free femtosecond cold processing combined with a high-cleanliness in-situ deposition process achieves high sp... 3 The preparation of phase-purity, continuous and dense BDD diamond layer 2 fully preserves and enhances the core advantages of BDD materials, such as wide potential window and low background current. The efficient mass transfer and bubble desorption capabilities of the dual-scale through-hole structure, combined with the strongly bonded fully encapsulated BDD diamond layer 2, significantly improve the corrosion resistance and long-term service stability of the electrode under extreme potential environments, making it suitable for the demanding electrochemical application requirements of various scenarios.

[0063] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of this application.

Claims

1. A femtosecond laser fabrication method for a dual-scale microporous modified molybdenum-based BDD electrode, characterized in that, Includes the following steps: Modified molybdenum substrate was obtained by non-contact cold processing at room temperature using a femtosecond laser (1); the parameters of the femtosecond laser were: pulse width 80-120 fs, wavelength 750-850 nm, peak power density 1×10 12 -1×10 14 W / cm 2 Single pulse energy 1-10μJ, focused spot diameter 10-30μm, laser repetition frequency 1-100kHz, laser scanning speed 1-10mm / s; The modified molybdenum-based (1) was purified. BDD diamond is deposited on the purified modified molybdenum substrate (1) to obtain the activated part; The element to be activated is subjected to activation treatment to obtain a dual-scale microporous modified molybdenum-based BDD electrode.

2. The femtosecond laser fabrication method for the dual-scale microporous modified molybdenum-based BDD electrode according to claim 1, characterized in that, The parameters of the femtosecond laser are: pulse width 80-120 fs, wavelength 750-850 nm, and peak power density 5 × 10⁻⁶. 12 -5×10 13 W / cm 2 Single pulse energy 3-7μJ, focused spot diameter 15-25μm, laser repetition frequency 10-50kHz, laser scanning speed 3-7mm / s.

3. The femtosecond laser fabrication method for the dual-scale microporous modified molybdenum-based BDD electrode according to claim 1, characterized in that, The deposition of BDD diamond on the modified molybdenum substrate (1) is performed by MPCVD low-temperature deposition. The thickness of the deposited BDD diamond layer (2) on the surface of the modified molybdenum substrate (1) is 5–10 μm.

4. The femtosecond laser fabrication method for the dual-scale microporous modified molybdenum-based BDD electrode according to claim 1, characterized in that, The deposition of BDD diamond on the modified molybdenum substrate (1) includes the following steps: Disperse nanodiamond powder in an alcohol solvent to obtain a diamond powder suspension; The modified molybdenum-based (1) was placed in the diamond powder suspension for treatment and then dried; The modified molybdenum substrate (1) was deposited using microwave plasma chemical vapor deposition (IPD) under the following conditions: methane / hydrogen flow rate ratio 1-5%, boron-carbon ratio 3500-4500ppm, chamber pressure 80-90Torr, substrate temperature 1200-1300K, microwave power 3500-4500W, and time 2-4h.

5. The femtosecond laser fabrication method for the dual-scale microporous modified molybdenum-based BDD electrode according to claim 1, characterized in that, The activation process involves hydroxylating the surface of the workpiece to be activated using oxygen plasma.

6. The femtosecond laser fabrication method for the dual-scale microporous modified molybdenum-based BDD electrode according to claim 5, characterized in that, The activation parameters are as follows: microwave output power of 500-800W, reaction chamber pressure of 10-20 Torr, oxygen flow rate of 40-60 sccm, treatment temperature of 350-450℃, and treatment time of 3-8 min.

7. The femtosecond laser fabrication method for the dual-scale microporous modified molybdenum-based BDD electrode according to claim 1, characterized in that, The purification process includes in-situ plasma non-oxidative purification.

8. The femtosecond laser fabrication method for the dual-scale microporous modified molybdenum-based BDD electrode according to claim 7, characterized in that, The in-situ plasma non-oxidative purification treatment includes: after obtaining the modified molybdenum base (1), without exposing it to the atmosphere, directly using argon plasma in-situ purification treatment of the modified molybdenum base (1), with a treatment power of 70-90W and a treatment time of 20-60s.

9. A dual-scale micro-perforated molybdenum-based BDD electrode prepared by a femtosecond laser fabrication method based on the dual-scale micro-perforated modified molybdenum-based BDD electrode according to any one of claims 1-8.

10. The dual-scale microporous modified molybdenum-based BDD electrode according to claim 9, characterized in that, The modified molybdenum-based (1) comprises several micro-through holes (11) and several micro / nano blind holes (12); The micro-hole (11) has a diameter of 5–20 μm and a spacing of 50–100 μm, and the micro-hole (11) is vertically arranged; The micro-nano blind pores (12) have a diameter of 1–3 μm and a depth of 0.5–2 μm; The wall surface of the micro-hole (11) is also provided with several nano-textures (13); The nano-texture (13) has a lateral feature size of 100-500nm and a longitudinal depression depth of 50-200nm.

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