Electrode material and preparation method thereof, method for treating organic wastewater and coupling hydrogen production, and organic wastewater treatment device

Abstract

Provided are an electrode material and a preparation method thereof, a method for treating organic wastewater coupled with hydrogen production, and an organic wastewater treatment device, and belong to the technical field of electrocatalysis. The preparation method of the electrode material comprises the following steps: through atomic layer deposition, an intermediate layer is deposited on a pretreated porous carrier to obtain a porous carrier with the intermediate layer deposited on the surface; through atomic layer deposition, a catalytic layer is deposited on the porous carrier with the intermediate layer deposited on the surface to obtain a porous carrier with the catalytic layer and the intermediate layer deposited on the surface from outside to inside; the porous carrier with the catalytic layer and the intermediate layer deposited on the surface from outside to inside is subjected to heat annealing treatment to obtain the electrode material; the band gap of the material of the intermediate layer is greater than 5 eV, and the thermal conductivity of the material of the intermediate layer is greater than 250 W / (m*K). The intermediate layer is formed between the porous carrier and the catalytic layer, which can adjust and optimize the electron injection efficiency and path between the porous carrier and the catalytic layer, and improve the catalytic degradation efficiency of the catalytic layer on the organic wastewater.

Description

Technical Field

[0001] This invention relates to the field of electrocatalysis technology, specifically to an electrode material and its preparation method, a method for treating organic wastewater coupled with hydrogen production, and an organic wastewater treatment device; more specifically, it relates to an electrode material and its preparation method, a method for treating integrated circuit organic wastewater coupled with hydrogen production, and an organic wastewater treatment device. Background Technology

[0002] The production process of integrated circuits requires the use of various chemical reagents, generating a significant amount of industrial wastewater. This wastewater contains complex and highly toxic pollutants, necessitating pollutant removal before discharge. Based on type, integrated circuit wastewater is typically categorized into acidic / alkaline wastewater, organic wastewater, fluoride-containing wastewater, and ammonia nitrogen wastewater, among which organic impurities in the wastewater are particularly difficult to remove.

[0003] Organic wastewater from integrated circuits (hereinafter referred to as organic wastewater) mainly originates from processes such as silicon wafer cleaning, chemical mechanical polishing, and photolithography during the production process. Its main components include solvents (organic impurities) such as isopropanol, propylene glycol monomethyl ether acetate, acetone, and xylene. These solvents are characterized by high chemical oxygen demand (COD) and low biodegradability.

[0004] In related technologies, membrane bioreactors are typically used to initially reduce the COD content in organic wastewater before carrying out the Fenton reaction. However, since the pH value of the Fenton reaction is between 2 and 4, while the pH value of organic wastewater is higher than this range, acid needs to be added to adjust the pH value. Furthermore, the catalyst usually uses ferrous ions, which are inorganic salts. After the organic wastewater is purified, the ferrous ions are difficult to recover and recycle, causing secondary pollution to the environment. Summary of the Invention

[0005] In view of this, in order to at least partially solve the aforementioned technical problems, the present invention provides an electrode material and its preparation method, a method for treating organic wastewater coupled with hydrogen production, and an organic wastewater treatment device.

[0006] According to an embodiment of the first aspect of the present invention, a method for preparing an electrode material is provided, comprising: depositing an intermediate layer on a pretreated porous support by atomic layer deposition to obtain a porous support with an intermediate layer deposited on its surface; depositing a catalytic layer on the porous support with the intermediate layer deposited on its surface by atomic layer deposition to obtain a porous support with a catalytic layer and an intermediate layer deposited sequentially from the outside to the inside; and performing thermal annealing on the porous support with the catalytic layer and the intermediate layer deposited sequentially from the outside to the inside to obtain an electrode material; wherein the band gap of the intermediate layer material is >5 eV and the thermal conductivity of the intermediate layer material is >250 W / (m·K).

[0007] According to an embodiment of a second aspect of the present invention, an electrode material is provided having a catalyst layer, an intermediate layer and a porous support arranged sequentially from the outside to the inside, and the electrode material is prepared by the preparation method described above.

[0008] According to an embodiment of a third aspect of the present invention, a method for treating organic wastewater and coupling hydrogen production using the above-mentioned electrode material is provided, comprising: step a: adding hydrogen peroxide solution to organic wastewater to obtain organic wastewater with added hydrogen peroxide solution; step b: under ultraviolet light irradiation, using carbon material as cathode and electrode material as anode, applying a forward bias voltage, and using photoelectric Fenton reaction to preliminarily degrade organic impurities in organic wastewater; step c: turning off the ultraviolet light, using carbon material as anode and electrode material as cathode, applying a reverse bias voltage, and performing electrolytic hydrogen production, while removing degradation intermediates occupying active sites on the electrode surface; step d: repeating n sets of operation cycles, with one step b and one step c as one operation cycle, to achieve deep removal of organic impurities in organic wastewater; n is an integer greater than 1.

[0009] According to an embodiment of a fourth aspect of the present invention, an organic wastewater treatment device is provided, comprising an organic wastewater treatment tank and a shell; wherein, the organic wastewater treatment tank includes a first partition and a second partition sequentially spaced from the inside out, the first partition and the second partition dividing the organic wastewater treatment tank into a first wastewater tank, a second wastewater tank and a third wastewater tank, the first wastewater tank being located inside the first partition, the second wastewater tank being located between the first partition and the second partition, and the third wastewater tank being located between the second partition and the shell; the first partition has a first through hole, and the outer side of the first partition is covered with an electrode material as described above; the second partition has a second through hole, and the diameter of the second through hole on the third wastewater tank side is smaller than the diameter of the second through hole on the second wastewater tank side; an organic wastewater inlet is provided at the top of the first wastewater tank, the third... The top of the second wastewater tank is equipped with a hydrogen outlet and an ultraviolet lamp placement port; the upper part of the third wastewater tank is equipped with an oxygen outlet, and the bottom of the third wastewater tank is equipped with a wastewater outlet; a carbon material electrode is installed between the third wastewater tank and the shell; under the irradiation of the ultraviolet lamp, the organic wastewater mixed with hydrogen peroxide solution in the first wastewater tank flows into the second wastewater tank through the first through hole to carry out a photoelectric Fenton reaction for preliminary degradation of organic impurities; the partially degraded organic wastewater flows into the third wastewater tank through the second through hole, and the organic wastewater in the second and third wastewater tanks undergoes an electrolytic hydrogen production reaction. The resulting hydrogen is discharged through the hydrogen outlet of the second wastewater tank, the resulting oxygen is discharged through the oxygen outlet of the third wastewater tank, and the purified organic wastewater is discharged through the wastewater outlet of the third wastewater tank.

[0010] According to the electrode material preparation method of this invention, an intermediate layer and a catalytic layer are sequentially deposited on a porous support using atomic layer deposition. The intermediate layer coordinates the differences between the porous support and the catalytic layer, allowing electrons to flow from the porous support to the catalytic layer through the relatively wide bandgap of the intermediate layer via quantum tunneling, thus optimizing electron coupling at different interfaces and improving the intrinsic catalytic activity of the catalytic layer. The electrode material prepared in this manner, when used for subsequent treatment of organic wastewater, promotes mass transfer and charge separation between reactants and products at the interface, thereby improving catalytic efficiency and enhancing the catalytic degradation effect on organic wastewater. Attached Figure Description

[0011] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings.

[0012] Figure 1 A flowchart illustrating the preparation method of the electrode material according to an embodiment of the present invention is shown;

[0013] Figure 2 A cross-sectional schematic diagram of an organic wastewater treatment device according to an embodiment of the present invention is shown;

[0014] Figure 3 The graphs showing the change of COD content in organic wastewater over time in Examples 1, 1, and 2 of the present invention are shown.

[0015] Figure 4 The graphs showing the change of COD content in organic wastewater over time in Examples 2, 3, and 4 of the present invention are shown.

[0016] Figure 5 The graphs showing the change of Tafel slope over time for Embodiment 1, Embodiment 2, Comparative Example 1, and Comparative Example 3 of the present invention are shown.

[0017] The meanings of the reference numerals in the above figures are as follows:

[0018] 1. Organic wastewater treatment pond;

[0019] 11. First partition; 12. Second partition; 13. First wastewater tank; 14. Second wastewater tank; 15. Third wastewater tank; 16. Electrode material; 17. Carbon material electrode;

[0020] 111. First through hole; 121. Second through hole; 131. Organic wastewater inlet; 141. Hydrogen outlet; 142. Ultraviolet lamp placement port; 151. Oxygen outlet; 152. Wastewater outlet;

[0021] 2. Shell;

[0022] 3. Support frame;

[0023] 31. Wastewater pipe outlet. Detailed Implementation

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the invention.

[0025] In the following detailed description, numerous specific details are set forth for ease of explanation to provide a full understanding of embodiments of the invention. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "comprising" as used herein indicates the presence of features, steps, or operations, but does not exclude the presence or addition of one or more other features.

[0027] Currently, advanced oxidation processes are commonly used to treat recalcitrant and highly toxic organic wastewater, such as the Fenton reaction. However, the Fenton reaction has the following drawbacks: it is difficult to directly treat organic wastewater with high COD levels (e.g., 1000~50000 mg / L), and it is usually used in conjunction with a membrane bioreactor. The membrane bioreactor is used first to preliminarily decompose the COD, which increases costs and complicates the process. Furthermore, the Fenton reaction requires the addition of inorganic salts containing ferrous ions, and the recovery and recycling of these ferrous ions is difficult, potentially introducing new impurities into the organic wastewater.

[0028] In realizing the concept of this invention, it was discovered that by introducing an intermediate layer into the electrode material, the electronic coupling between different interfaces can be optimized using the intermediate layer, thereby optimizing the injection efficiency and path of electrons from the porous carrier to the catalytic layer, and improving the catalytic efficiency of the electrode formed by the electrode material in the degradation of organic impurities in organic wastewater.

[0029] Specifically, according to one embodiment of the present invention, a method for preparing an electrode material is provided. Figure 1 A flowchart illustrating a method for preparing electrode materials according to an embodiment of the present invention is shown. Figure 1 As shown, the preparation method includes steps S101 to S103.

[0030] In step S101, an intermediate layer is deposited on the pretreated porous carrier by atomic layer deposition to obtain a porous carrier with an intermediate layer deposited on its surface.

[0031] In step S102, a catalytic layer is deposited on a porous support with an intermediate layer deposited on its surface by atomic layer deposition, resulting in a porous support with a catalytic layer and an intermediate layer deposited sequentially from the outside to the inside.

[0032] In step S103, the porous support with a catalytic layer and an intermediate layer deposited sequentially from the outside to the inside is subjected to thermal annealing to obtain the electrode material.

[0033] According to embodiments of the present invention, the intermediate layer material has a band gap > 5 eV and a thermal conductivity > 250 W / (m·K). The intermediate layer has a large band gap, allowing it to be made of insulating materials or wide-bandgap semiconductors. The porous support has good electrical conductivity, and the catalyst layer can be a semiconductor material. Direct contact between the porous support and the catalyst layer leads to charge rearrangement and a Schottky barrier due to the difference in their work functions, hindering electron migration to some extent. Inserting an intermediate layer with the aforementioned band gap between the conductive porous support and the catalyst layer optimizes the injection efficiency and path of electrons from the porous support to the catalyst layer, improving the intrinsic catalytic activity of the catalyst layer. The intermediate layer material has high thermal conductivity, allowing it to rapidly and uniformly diffuse the heat generated during electrocatalysis after electrode formation into the porous support, preventing localized overheating, improving the thermal stability and lifespan of the catalyst layer, and thus enhancing the reliability of the electrode formed from the aforementioned electrode materials.

[0034] In this invention, "atomic layer deposition" can be understood as a process of growing thin films layer by layer at the atomic or molecular level. Furthermore, the atomic layer deposition of this invention is a chemical deposition process.

[0035] In some embodiments, the porous support comprises nickel foam. Nickel foam has a three-dimensional porous structure, which is suitable for providing a core framework for electrode materials, providing a large attachment area for intermediate and catalytic layers of atomic layer deposition, increasing the loading of active sites, and providing mechanical support and structural stability for electrode materials.

[0036] In some embodiments, the intermediate layer is made of either aluminum nitride or beryllium oxide. It is understood that both aluminum nitride and beryllium oxide are insulating materials. Because the insulating material is located between the porous support and the catalyst layer, the intermediate layer facilitates the flow of electrons from the porous support to the active sites of the catalyst layer via quantum tunneling. This regulates and optimizes the injection efficiency and path from the porous support to the active sites of the catalyst layer, placing the Fermi level of the catalyst layer in a position more conducive to hydrogen adsorption and desorption during electrolytic hydrogen production, further enhancing the intrinsic catalytic activity of the catalyst layer.

[0037] In some embodiments, the catalyst layer material comprises a two-dimensional transition metal chalcogenide, such as molybdenum sulfide (MoS2).

[0038] It is understandable that molybdenum sulfide has a layered structure, a sandwich-like structure formed by alternating layers of molybdenum and sulfur atoms, with a layer of molybdenum atoms sandwiched between two layers of sulfur atoms. Its edge sites (such as S atoms) and defect sites constitute the main active sites. In subsequent electrode material composition, these active sites promote the desorption and adsorption of hydrogen during electrocatalysis; during the electro-Fenton process, molybdenum sulfide can promote the generation of sulfate radicals and hydroxyl radicals by regulating the electron transfer process, as well as the formation of singlet oxygen, or synergistically promote the degradation of organic impurities through electron transfer with organic impurities.

[0039] The following section uses aluminum nitride (AlN) as an example to illustrate the deposition process for forming an aluminum nitride interlayer:

[0040] When the substrate temperature reaches 300~400℃ (e.g., 300℃, 350℃ or 400℃), AlN thin film is deposited on the pretreated porous support. Trimethylaluminum can be selected as the Al source, with a 1s introduction time and a 5s purging with nitrogen; ammonia (NH3) can be used as the N source, with a 2s introduction time and a 10s purging with nitrogen (N2); the Al source and N source are used alternately to grow the film 8~12 times (e.g., 8 times, 10 times or 12 times) to complete the deposition of the aluminum nitride intermediate layer.

[0041] The following section uses molybdenum sulfide (MoS2) as an example to illustrate the deposition process of forming a molybdenum sulfide catalyst layer:

[0042] Based on the aforementioned aluminum nitride intermediate layer, molybdenum pentachloride (MoCl5) was selected as the Mo source, with an introduction time of 3 s and nitrogen purging for 15 s; hydrogen sulfide (H2S) was selected as the S source, with nitrogen purging for 20 s; the Mo and S sources were used alternately to grow the layer for 48 to 52 times (e.g., 48, 50, or 52 times) to complete the deposition of the MoS2 catalyst layer.

[0043] In some embodiments, the thermal annealing treatment is performed at a temperature of 300–500°C in a hydrogen atmosphere. This temperature range helps provide energy for atomic rearrangement, promoting the formation of a more complete and ordered crystal structure in the catalyst layer of the electrode material, improving electronic conductivity, and activating and optimizing electrocatalytic performance. Simultaneously, this temperature range helps promote interfacial bonding between the porous support, the intermediate layer, and the catalyst layer, enabling atomic diffusion and chemical bonding at the interfaces, reducing the risk of peeling or delamination between the layers during subsequent recycling, and improving the mechanical stability and lifespan of the electrode thus prepared. If the thermal annealing temperature is too high, for example, above the upper limit, it may reach the melting point of the porous support, limiting its effectiveness due to the thermal stability of the porous support and intermediate layer. If the thermal annealing temperature is too low, for example, below the lower limit, it is difficult to initiate the crystallization and phase transition process of the catalyst layer, resulting in limited improvement in the intrinsic catalytic activity of the catalyst layer.

[0044] Optionally, the temperature of the heat annealing treatment may be, for example, 300°C, 350°C, 400°C, 450°C or 500°C, or a range consisting of any two of the above values.

[0045] In some embodiments, the heat annealing time is 5 to 20 minutes. This setting forms a faster annealing process, which can ensure that the catalyst layer fully crystallizes and undergoes a phase transformation while suppressing excessive diffusion between the materials used in the above layers (e.g., the catalyst layer indirectly diffuses into the porous support).

[0046] Optionally, the heat annealing time can be, for example, 5 min, 10 min, 15 min or 20 min, or a range between any two of the above values.

[0047] In some embodiments, the pretreated porous support is prepared by plasma treatment of the porous support. Plasma treatment helps to thoroughly clean and activate the inner and outer surfaces of the porous support, improves the hydrophilicity of the inner and outer surfaces of the porous support, facilitates the subsequent deposition of the intermediate layer, and enhances the adhesion strength between the intermediate layer and the porous support.

[0048] In some implementations, the plasma used for plasma processing can be hydrogen plasma or ammonia plasma.

[0049] In some embodiments, the plasma treatment power can be 60~120W, for example, 60W, 80W, 100W, or 120W, or a range between any two of the above values. The treatment time can be 5~30s, for example, 5s, 10s, 15s, 20s, 25s, or 30s, or a range between any two of the above values. This setting is more conducive to the more uniform adhesion of the subsequent intermediate layer, improving the bonding strength between the intermediate layer and the porous carrier.

[0050] In one specific embodiment, taking a porous carrier of nickel foam, an intermediate layer of aluminum nitride, and a catalyst layer of molybdenum sulfide as an example, the preparation method of the electrode material can be as follows:

[0051] The nickel foam material is placed in a plasma-enhanced atomic layer deposition (PEALD) device, and the surface of the nickel foam is treated with hydrogen plasma or ammonia plasma (taking ammonia plasma treatment as an example, it can be a mixture of ammonia and inert gas, and the inert gas can be nitrogen or argon). The plasma treatment power can be 60~120W and the treatment time can be 5~30s.

[0052] According to another aspect of the present invention, an electrode material is provided having a catalyst layer, an intermediate layer and a porous support arranged sequentially from the outside to the inside, and the electrode material is prepared by the preparation method described above.

[0053] According to embodiments of the present invention, the porous support of the electrode material provides good mechanical support; the intermediate layer can connect the porous support and the catalyst layer, allowing electrons to pass through via quantum tunneling, which helps optimize the injection efficiency and path of electrons from the porous support to the catalyst layer. When subsequently used as an electrode, this makes the Fermi level of the catalyst layer more favorable for hydrogen adsorption and desorption during the electrolytic hydrogen production process.

[0054] Furthermore, the porous support (such as nickel foam), insulating intermediate layer (such as beryllium oxide), and catalytic layer (such as molybdenum sulfide semiconductor) of the present invention form a structure similar to "metal-insulator-semiconductor". This structure generates strong polarization and built-in electric field at the interface, which helps to promote subsequent applications, such as water electrolysis to produce hydrogen, and promotes mass transfer and charge separation of reactants and / or products (such as water, hydrogen ions, hydrogen gas, etc.) at the interface, thereby further improving catalytic efficiency.

[0055] It should be noted that the materials and functions of the porous carrier, intermediate layer, and catalyst layer of the present invention are the same as those described above, and will not be repeated here.

[0056] Furthermore, aluminum nitride or beryllium oxide, as an intermediate layer, optimizes electron transfer through its insulating and tunneling properties. Its high thermal conductivity also helps dissipate heat, further enhancing the catalytic activity and stability of the catalyst layer (molybdenum sulfide).

[0057] In some embodiments, the thickness of the interlayer is 0.5–2 nm. At this thickness, the insulating interlayer allows for controlled electron transport between the porous support and the catalyst layer via quantum tunneling. This avoids complete insulation of the electrode, ensuring the establishment of the electrochemical reaction circuit. Simultaneously, while retaining tunneling performance, it effectively blocks the free migration of charge carriers, preventing short circuits. If the thickness is too large, for example, exceeding the upper limit, the tunneling probability decreases exponentially, resulting in excessively high electrode resistance and hindering operation. If the thickness is too small, for example, below the lower limit, it is difficult to form a continuous interlayer, making it difficult to provide effective physical isolation, leading to undesirable inter-atomic diffusion between the porous support and the catalyst layer during annealing and / or the reaction process.

[0058] Optionally, the thickness of the intermediate layer can be, for example, 0.5 nm, 0.8 nm, 1 nm, 1.5 nm or 2 nm, or a range consisting of any two of the above values, preferably 0.8 to 1 nm.

[0059] According to another embodiment of the present invention, a method for treating organic wastewater and coupling hydrogen production using the electrode material described above is provided, comprising the steps a to d.

[0060] In step a, hydrogen peroxide solution is added to the organic wastewater to obtain organic wastewater with added hydrogen peroxide solution.

[0061] In step b, under the irradiation of an ultraviolet lamp, a carbon material is used as the cathode and the aforementioned electrode material is used as the anode. A forward bias voltage is applied, and the organic impurities in the organic wastewater are initially degraded using a photoelectric Fenton reaction.

[0062] In step c, the ultraviolet lamp is turned off, carbon material is used as the anode, the above-mentioned electrode material is used as the cathode, a reverse bias voltage is applied, and hydrogen is produced by electrolysis, while removing degradation intermediates occupying the active sites on the electrode surface.

[0063] In step d, one operation cycle consists of one step b and one step c, and n sets of operation cycles are repeated to achieve deep removal of organic impurities from organic wastewater; n is an integer greater than 1.

[0064] According to embodiments of the present invention, in the photoelectric Fenton reaction process, under ultraviolet light excitation, hydrogen peroxide (H2O2) reacts with active sites on the electrode surface to generate hydroxyl radicals (·OH), which can efficiently degrade organic impurities and significantly reduce chemical oxygen demand (COD). The applied positive bias voltage causes surface pre-activation of the catalyst layer. Taking molybdenum sulfide as an example, sulfur-rich vacancies and highly active edge sites are formed, providing favorable conditions for subsequent electrolytic hydrogen production. In the electrolytic hydrogen production process of the present invention, under the action of a reverse electric field, the degradation intermediates of organic impurities occupying active sites on the electrode surface detach from the electrode surface, re-exposing the active sites on the electrode surface, restoring the electrode's ability to generate ·OH, and effectively promoting the photoelectric Fenton reaction. The electrode material of the present invention, such as the one described above, can couple the degradation of organic impurities in the photoelectric Fenton reaction with electrolytic hydrogen production, and has the advantages of mutual promotion of the photoelectric Fenton reaction and electrolytic hydrogen production, energy saving, simple and easy processing, and recyclability, which is conducive to further promotion.

[0065] In addition, the present invention overcomes the dependence on membrane bioreactors in related technologies, and the present invention does not require adjustment of the pH value of organic wastewater or addition of ferrous inorganic salts, and can directly treat high-concentration COD organic wastewater, with advantages such as simple process route and fast treatment speed.

[0066] It should be noted that by coupling the photoelectric Fenton reaction with electrolytic hydrogen production, the defects of related technologies in electrolytic hydrogen production, such as passivation of electrode material surface, gradual decline in electrolytic hydrogen production effect and reduction of electrocatalytic activation sites, are overcome.

[0067] In some specific implementations, taking molybdenum sulfide as an example, the process of producing hydrogen by electrolysis is described in detail.

[0068] Electrolysis hydrogen production process:

[0069] The active sites of molybdenum sulfide can adsorb hydrogen ions and promote the formation of adsorbed hydrogen atoms (H*).

[0070] The hydrogen evolution process can be represented by the following reaction:

[0071] H + +e - →H*, where hydrogen ions (H) + Adsorbed electrons (e - (This forms adsorbed hydrogen atoms.)

[0072] H + +e - +H*→H2, where adsorbed hydrogen atoms combine with hydrogen ions to generate hydrogen gas (H2).

[0073] 2H*→H2, where two adsorbed hydrogen atoms directly combine to form hydrogen gas.

[0074] As shown in the above reaction process, molybdenum sulfide can achieve a highly efficient electrolytic hydrogen production process by adjusting the hydrogen adsorption energy.

[0075] It is understandable that the catalytic mechanism of molybdenum sulfide in the photoelectro-Fenton reaction is similar to that of related technologies, and will not be elaborated here.

[0076] In some embodiments, the operating cycle n can be, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, etc. The present invention can be adaptively adjusted according to the concentration of COD in the organic wastewater to be treated, and there is no particular limitation thereto.

[0077] In some embodiments, the ratio of hydrogen peroxide solution concentration to chemical oxygen demand (COD) concentration in the organic wastewater is 0.05 to 0.4. This configuration enables the deep degradation of organic impurities in the organic wastewater.

[0078] Optionally, the ratio of hydrogen peroxide solution concentration to chemical oxygen demand concentration in organic wastewater can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, or 0.4, or a range consisting of any two of the above ratios.

[0079] In some implementations, the applied forward bias voltage can be 2 to 4V, for example, 2V, 3V, or 4V. The reverse bias current density can be 1100 to 1300 mA / cm². 2 For example, it could be 1100mA / cm 2 1200mA / cm 2 Or 1300mA / cm 2 The present invention can be adjusted according to the COD concentration of the organic wastewater to be treated, and does not impose special limitations on the pressure and current density.

[0080] In some implementations, the time for applying the forward bias and / or reverse bias can be 5 to 15 minutes, for example, 5 minutes, 10 minutes or 15 minutes, or a range consisting of any two of the above values.

[0081] According to another embodiment of the present invention, an organic wastewater treatment apparatus is provided. Figure 2 A cross-sectional schematic diagram of an organic wastewater treatment device according to an embodiment of the present invention is shown, as follows: Figure 2 As shown, the organic wastewater treatment device includes an organic wastewater treatment tank 1 and a shell 2.

[0082] The organic wastewater treatment tank 1 can be a cylindrical closed structure, comprising a first partition 11 and a second partition 12 arranged sequentially from the inside out. The first partition 11 and the second partition 12 are hollow cylinders, and can be made of non-conductive materials, such as plastic. The first partition 11 and the second partition 12 are spaced apart, dividing the organic wastewater treatment tank 1 into a first wastewater tank 13, a second wastewater tank 14, and a third wastewater tank 15 arranged sequentially from the inside out. The first wastewater tank 13 is located inside the first partition 11, the second wastewater tank 14 is located between the first partition 11 and the second partition 12, and the third wastewater tank 15 is located between the second partition 12 and the shell 2. The shell 2 can be made of a non-conductive material, such as plastic.

[0083] The first partition 11 has a plurality of first through holes 111 on its sidewall, and the outer side of the first partition 11 is at least partially covered with the aforementioned electrode material 16. It is understood that the electrode material does not cover the first through holes 111 to allow organic wastewater to pass through smoothly; preferably, the outer sidewall of the first partition 11, except for the first through holes 111, is completely covered with the aforementioned electrode material 16. The second partition 12 has a second through hole 121 on its sidewall, and the diameter of the second through hole 121 located on the side of the third wastewater tank 15 is smaller than the diameter of the second through hole 121 located on the side of the second wastewater tank 14. For example, it can be as follows... Figure 2 As shown, the design incorporates asymmetric or tapered apertures. This design extends the residence time of organic wastewater in the second wastewater tank 14, ensuring sufficient contact between the wastewater and the catalytic layer on the electrode material surface within the tank (the core area for the photoelectric Fenton reaction and electrolytic hydrogen production). This allows for more complete reaction, improving the degradation rate of organic impurities and the yield of hydrogen. Furthermore, this structure reduces the risk of hydrogen and oxygen cross-contamination through the liquid, facilitating separate collection, enhancing gas recovery value, and improving operational safety.

[0084] The top of the first wastewater tank 13 is equipped with an organic wastewater inlet 131, suitable for receiving organic wastewater from the outside. The top of the second wastewater tank 14 is equipped with a hydrogen outlet 141 and an ultraviolet lamp placement port 142. The ultraviolet lamp extends from the ultraviolet lamp placement port 142 to the bottom of the second wastewater tank 14, allowing the organic wastewater at different heights in the second wastewater tank 14 to fully undergo the photoelectric Fenton reaction. The hydrogen outlet 141 can be located inside the ultraviolet lamp placement port 142, or it can be located in other positions as needed. The upper part of the third wastewater tank 13 is equipped with an oxygen outlet 151, and the bottom of the third wastewater tank 13 is equipped with a wastewater outlet 152.

[0085] A carbon material electrode 17 is provided between the third wastewater tank 13 and the shell 2. The carbon material electrode 17 can be, for example, a graphite electrode.

[0086] According to an embodiment of the present invention, under the irradiation of an ultraviolet lamp, organic wastewater mixed with hydrogen peroxide solution located in the first wastewater tank 13 flows into the second wastewater tank 14 through the first through-hole 111 to undergo a photoelectric Fenton reaction to preliminarily degrade organic impurities in the wastewater. A portion of the preliminarily degraded organic wastewater flows into the third wastewater tank 15 through the second through-hole 121. The organic wastewater located in the second and third wastewater tanks 14 undergoes an electrolytic hydrogen production reaction. The resulting hydrogen is discharged through the hydrogen outlet 141 of the second wastewater tank 14, and the resulting oxygen is discharged through the oxygen outlet 151 of the third wastewater tank 15. The purified organic wastewater is discharged through the wastewater outlet 152 of the third wastewater tank 15.

[0087] According to embodiments of the present invention, the present invention cleverly couples the photoelectric Fenton reaction and the electrolytic hydrogen production process into the same device through the above-mentioned organic wastewater treatment apparatus. The first wastewater tank 13, located at the center, provides a buffering effect; the second wastewater tank 14, in the core reaction zone, mainly performs photoelectric Fenton degradation and hydrogen evolution reaction; and the third wastewater tank 15 performs the oxygen evolution reaction, thus purifying the organic wastewater. This structure ensures that the organic wastewater flows in a unidirectional and orderly path, avoiding the safety hazards caused by the mixing of hydrogen and oxygen. Furthermore, the present invention spatially separates the electrodes for hydrogen and oxygen production, improving the purity of gas collection and thus increasing the utilization rate of the recovered gas. Organic impurities in the organic wastewater, as "pollutants," are degraded by free radicals, and their degradation products further participate in electrochemical hydrogen production, achieving a significant degree of material conversion and utilization.

[0088] Furthermore, this application utilizes the main structure of a cylindrical organic wastewater treatment device and employs concentric circles formed by the first partition 11 and the second partition 12 for spatial partitioning, successfully integrating photoelectric Fenton and water electrolysis for hydrogen production. This not only efficiently removes organic impurities, achieving deep purification and environmental protection, but also simultaneously produces high-value hydrogen and oxygen during the treatment process, transforming traditional consumable-type environmental treatment into a productive resource recovery process.

[0089] In some embodiments, the organic wastewater treatment apparatus further includes a pretreatment tank (not shown in the figure), which is suitable for mixing hydrogen peroxide solution with organic wastewater. The organic wastewater mixed with hydrogen peroxide solution is then introduced into the first wastewater tank 13 through the organic wastewater inlet 131.

[0090] In some embodiments, the organic wastewater treatment apparatus further includes a circulation pump (not shown in the figure) disposed between the pretreatment tank and the organic wastewater treatment tank 1 to circulate the organic wastewater back and forth between the pretreatment tank and the organic wastewater treatment tank 1.

[0091] In some embodiments, the organic wastewater treatment device also includes a support frame 3 located below the organic wastewater treatment tank 1. The support frame 3 is adapted to support the organic wastewater treatment tank 1. The support frame 3 has a wastewater pipe outlet 31, which is connected to the wastewater outlet 152 via a pipe so that the purified organic wastewater discharged from the third wastewater tank can be discharged through the pipe to the wastewater pipe outlet 31.

[0092] The present application is further illustrated below through embodiments, accompanying drawings, and related test experiments and results. In the following detailed description, numerous specific details are set forth for ease of explanation to provide a comprehensive understanding of the embodiments of the present application. However, it is apparent that one or more embodiments may be implemented without these specific details. Moreover, the details in the following embodiments can be arbitrarily combined to form other feasible embodiments without conflict.

[0093] It should be noted that the specific embodiments described below are merely illustrative examples, and the scope of protection of this application is not limited thereto. The chemicals and raw materials used in the following embodiments are all commercially available or prepared using recognized processing methods.

[0094] Example 1

[0095] This embodiment 1 provides a method for treating organic wastewater from integrated circuits, and the specific steps are as follows.

[0096] The preparation process of electrode materials includes the following steps.

[0097] The cleaned porous nickel foam is placed in a plasma-enhanced atomic layer deposition (PEALD) system. Once the substrate temperature reaches 250°C, the surface of the porous nickel foam is subjected to plasma treatment using ammonia plasma, which consists of high-purity NH3 and argon gas. The plasma treatment power is 75W, and the treatment time is 10s. Then, N2 is introduced for purging for 35s. At this point, the pretreatment is complete.

[0098] Intermediate layer deposition: After the substrate temperature reaches 350℃, AlN thin film deposition is performed. Trimethylaluminum (TMA) is selected as the Al source, with a 1s introduction time and N2 purging for 5s; NH3 is selected as the N source, with a 2s introduction time and N2 purging for 10s; Al source and N source are alternately grown 10 times to complete the intermediate layer deposition, with a thickness of about 0.8nm.

[0099] MoS2 thin film deposition: MoCl5 was selected as the Mo source, and it was introduced for 3 s, followed by purging with N2 for 15 s; H2S was selected as the S source, and it was introduced for 3 s, followed by purging with N2 for 20 s; the Mo source and S source were alternated for 50 cycles to complete the deposition of the MoS2 thin film (catalytic layer).

[0100] The porous nickel foam with the deposited catalyst layer was placed in a hydrogen annealing furnace for hot annealing at a temperature of 300°C for 5 minutes to obtain the electrode material.

[0101] The organic wastewater treatment process is as follows: High-concentration (63 g / L) organic wastewater from integrated circuits is introduced into a pretreatment tank, and hydrogen peroxide solution is added to ensure a hydrogen peroxide content of 16.65 g / L. A circulation pump circulates the pretreated organic wastewater between the pretreatment tank and the dual-function organic wastewater treatment tank. In the dual-function organic wastewater treatment tank, the prepared electrode material is used as the anode material, connected to the positive terminal of the power supply; graphite paper is used as the cathode material, connected to the negative terminal. A forward bias of 3V is applied, and a UV lamp is turned on to remove organic matter from the wastewater using a photoelectric Fenton reaction for 10 minutes. Immediately afterwards, the UV lamp is turned off, and a reverse bias is applied for hydrogen electrolysis. During this process, the prepared electrode material is connected to the negative terminal of the power supply, and the graphite paper is connected to the positive terminal, with a current density of 1200 mA / cm², for a treatment time of 10 minutes. The above-mentioned forward bias and reverse bias processes were repeated 9 times, with a total treatment time of 180 minutes, to remove organic impurities from the organic wastewater.

[0102] Comparative Example 1

[0103] The preparation process of the electrode material in Comparative Example 1 is largely the same as that in Example 1, except that no intermediate layer is formed in Comparative Example 1, and a molybdenum sulfide film is directly deposited on porous nickel foam.

[0104] The treatment process of the organic wastewater in Comparative Example 1 is largely the same as that in Example 1, except that the electrode material prepared in Comparative Example 1 was replaced.

[0105] Comparative Example 2

[0106] The preparation process of the electrode material in Comparative Example 2 is the same as that in Example 1.

[0107] The organic wastewater treatment process is as follows: High-concentration (63 g / L) organic wastewater from integrated circuit manufacturing is introduced into a pretreatment tank, and hydrogen peroxide solution is added to ensure a hydrogen peroxide content of 16.65 g / L. A circulation pump circulates the pretreated organic wastewater between the pretreatment tank and the dual-function organic wastewater treatment tank. In the organic wastewater treatment tank, the electrode material prepared in Example 1 is used as the anode material to connect to the positive terminal of the power supply; graphite paper is used as the cathode material to connect to the negative terminal of the power supply. A forward bias of 3V is applied, and an ultraviolet lamp is turned on to utilize the photoelectric Fenton reaction to remove organic matter from the wastewater. The treatment time is 90 minutes.

[0108] Figure 3This is a graph showing the change in COD content of wastewater over time in Examples 1, 1, and 2 of the present invention. Figure 3 As can be seen, using porous nickel foam lacking an intermediate layer as an electrode, as in Comparative Example 1, resulted in poor wastewater treatment. After 180 minutes, the COD content far exceeded the municipal wastewater discharge standard. The comparison between Comparative Example 2 and Example 1 verified the role of electrode alternation in this invention. In Comparative Example 2, after 90 minutes of treatment, the COD content decreased to 240 mg / L, failing to meet the municipal wastewater discharge standard. However, in Example 1, using the method of this invention, during the 180-minute treatment, 90 minutes were dedicated to electro-Fenton degradation of COD, and the remaining 90 minutes to electrolytic hydrogen production. It can be seen that, after the same 90 minutes of electro-Fenton degradation, the COD content in Example 1 decreased to 30 mg / L, meeting the municipal wastewater discharge standard.

[0109] Example 2

[0110] The preparation process of electrode materials includes the following steps.

[0111] The cleaned porous nickel foam was placed in a plasma-enhanced atomic layer deposition (PEALD) device. When the substrate temperature reached 250°C, the surface of the porous nickel foam was subjected to plasma treatment using ammonia plasma, which is composed of high-purity NH3 and argon. The plasma treatment power was 120W and the treatment time was 5s. Then, N2 was introduced for 15s purging.

[0112] Intermediate layer deposition: After the substrate temperature reaches 350℃, AlN thin film deposition is performed. TMA is selected as the Al source, and the injection time is 1s, followed by N2 purging for 5s. NH3 is selected as the N source, and the injection time is 2s, followed by N2 purging for 10s. Al source and N source are alternately grown 12 times to complete the intermediate layer deposition, with a thickness of about 1nm.

[0113] MoS2 thin film deposition: MoCl5 was selected as the Mo source, and it was introduced for 3 s, followed by purging with N2 for 15 s; H2S was selected as the S source, and it was introduced for 3 s, followed by purging with N2 for 20 s. The Mo source and S source were alternated for 50 cycles to complete the deposition of the MoS2 thin film (catalytic layer).

[0114] The porous nickel foam with the deposited catalyst layer was placed in a hydrogen annealing furnace for hot annealing at a temperature of 500°C for 20 minutes to obtain the electrode material.

[0115] The organic wastewater treatment process is as follows: Low-concentration (220 mg / L) organic wastewater from integrated circuit manufacturing is introduced into a pretreatment tank, and hydrogen peroxide solution is added to ensure a hydrogen peroxide concentration of 25 mg / L. A circulation pump circulates the pretreated organic wastewater between the pretreatment tank and the dual-function organic wastewater treatment tank. In the dual-function organic wastewater treatment tank, the prepared electrode material is used as the anode, connected to the positive terminal of the power supply; graphite paper is used as the cathode, connected to the negative terminal, and a forward bias of 1.5V is applied. Simultaneously, an ultraviolet lamp is turned on to utilize the photoelectric Fenton reaction to remove organic matter from the wastewater for 5 minutes. Immediately afterwards, the ultraviolet lamp is turned off, and a reverse bias is applied for hydrogen electrolysis. During this process, the prepared electrode material is connected to the negative terminal of the power supply, and the graphite paper is connected to the positive terminal, with a current density of 1000 mA / cm², for a treatment time of 5 minutes. Finally, the above-mentioned forward bias and reverse bias processes were repeated 6 times, with a total treatment time of 60 minutes, to remove organic impurities from the organic wastewater.

[0116] Comparative Example 3

[0117] The preparation process of the electrode material in Comparative Example 3 is largely the same as that in Example 2, except that no intermediate layer is formed in Comparative Example 3, and a molybdenum sulfide film is directly deposited on porous nickel foam.

[0118] The treatment process of the organic wastewater in Comparative Example 3 is largely the same as that in Example 2, except that the electrode material prepared in Comparative Example 3 was replaced.

[0119] Comparative Example 4

[0120] The preparation process of the electrode material in Comparative Example 4 is the same as that in Example 2.

[0121] The organic wastewater treatment process is as follows: Low-concentration (220 mg / L) organic wastewater from integrated circuits is introduced into a pretreatment tank, and hydrogen peroxide solution is added to ensure a hydrogen peroxide content of 25 mg / L. A circulation pump circulates the pretreated organic wastewater between the pretreatment tank and the dual-function organic wastewater treatment tank. In the organic wastewater treatment tank, the electrode material prepared in Example 2 is used as the anode material to connect to the positive terminal of the power supply, and graphite paper is used as the cathode material to connect to the negative terminal of the power supply. A forward bias of 1.5V is applied to the graphite paper, and an ultraviolet lamp is turned on to remove organic matter from the wastewater using a photoelectric Fenton reaction. The treatment time is 30 minutes.

[0122] Figure 4 The graphs showing the COD content of organic wastewater from Examples 2, 3, and 4 of the present invention as a function of time are presented. Figure 4As can be seen, for wastewater with initially low COD concentrations, Examples 2, 3, and 4 all achieved good results, meeting municipal wastewater discharge standards. Overall, the solution adopted in Example 2 of this invention is the most effective.

[0123] Figure 5 The diagram shows the Tafel slope versus time for Examples 1, 2, Comparative Example 1, and Comparative Example 3 of the present invention. The Tafel slope describes the linear relationship between the electrode overpotential and the logarithm of the reaction current density, and is suitable for quantifying the kinetic difficulty of the electrode reaction. A large slope value indicates that the electrode reaction is more difficult, requiring a larger overpotential to drive the reaction; a small slope value indicates that the electrode reaction is more easy, and a smaller overpotential can significantly accelerate the reaction. Figure 5 The results show that the Tafel slope of the porous foam nickel electrode without intermediate layer modification is higher than that of the porous foam nickel electrode with intermediate layer modification, indicating that the porous foam nickel electrode with intermediate layer addition has a relatively stronger hydrogen production capacity.

[0124] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are 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 producing an electrode material, characterized by, The method comprises the following steps: an intermediate layer is deposited on the pretreated porous carrier by atomic layer deposition to obtain a porous carrier with the intermediate layer deposited on the surface; a catalytic layer is deposited on the porous carrier with the intermediate layer deposited on the surface by atomic layer deposition to obtain a porous carrier with the catalytic layer and the intermediate layer deposited from outside to inside; the porous carrier with the catalytic layer and the intermediate layer deposited from outside to inside is subjected to heat annealing treatment to obtain the electrode material; wherein the material of the intermediate layer has a band gap > 5eV and a thermal conductivity > 250W / (m·K); the material of the intermediate layer comprises any one of aluminum nitride or beryllium oxide; the material of the catalytic layer comprises a two-dimensional transition metal chalcogenide compound; the pretreated porous carrier is prepared by the following method: the porous carrier is subjected to plasma treatment to obtain the pretreated porous carrier; wherein the plasma used in the plasma treatment is hydrogen plasma or ammonia plasma, the power of the plasma treatment is 60-120W, and the treatment time is 5-30s; the porous carrier comprises a nickel foam; wherein the temperature of the heat annealing treatment is 300-500℃, and the thickness of the intermediate layer is 0.5-2nm.

2. The production method according to claim 1, characterized by, The time of the heat annealing treatment is 5-20min.

3. An electrode material, characterized by The electrode material is prepared by the preparation method of claim 1 or 2.

4. A method for treating organic wastewater coupled with hydrogen production using the electrode material according to claim 3, characterized in that, The method comprises the following steps a-d: step a: adding a hydrogen peroxide solution to the organic wastewater to obtain the organic wastewater added with the hydrogen peroxide solution; step b: under the irradiation of an ultraviolet lamp, using a carbon material as a cathode and the electrode material as an anode, applying a forward bias, and using a photoelectro-Fenton reaction to preliminarily degrade organic impurities in the organic wastewater; step c: turning off the ultraviolet lamp, using a carbon material as an anode and the electrode material as a cathode, applying a reverse bias, and performing electrolysis to produce hydrogen while removing degradation intermediates occupying active sites on the electrode surface; step d: taking one step b and one step c as one operation cycle, repeating n groups of operation cycles to achieve deep removal of organic impurities in the organic wastewater; n is an integer greater than 1.

5. The method of claim 4, wherein, The concentration ratio of the hydrogen peroxide solution to the chemical oxygen demand concentration in the organic wastewater is 0.05-0.

4.

6. An organic wastewater treatment device, characterized by comprising: The organic wastewater treatment tank and the shell are included. The first baffle and the second baffle are sequentially and separately arranged in the organic wastewater treatment tank, and the first baffle and the second baffle divide the organic wastewater treatment tank into a first wastewater tank, a second wastewater tank and a third wastewater tank; the first wastewater tank is located in the first baffle, the second wastewater tank is located between the first baffle and the second baffle, and the third wastewater tank is located between the second baffle and the shell; the first baffle has a first through hole, and the outer side of the first baffle is coated with the electrode material of claim 3; the second baffle has a second through hole, and the pore size of the second through hole on the side of the third wastewater tank is smaller than that of the second through hole on the side of the second wastewater tank; The top of the first wastewater pool is provided with an organic wastewater inlet, and the top of the second wastewater pool is provided with a hydrogen gas outlet and an ultraviolet lamp placing opening; the upper part of the third wastewater pool is provided with an oxygen gas outlet, and the bottom of the third wastewater pool is provided with a wastewater outlet; A carbon material electrode is arranged between the third wastewater pool and the shell; Under the irradiation of the ultraviolet lamp, the organic wastewater mixed with the hydrogen peroxide solution in the first wastewater pool flows into the second wastewater pool through the first through hole to perform a photoelectric Fenton reaction, so as to preliminarily degrade the organic impurities; part of the organic wastewater after the preliminary degradation flows into the third wastewater pool through the second through hole, the organic wastewater in the second wastewater pool and the third wastewater pool performs an electrolytic hydrogen production reaction, the obtained hydrogen gas is discharged through the hydrogen gas outlet of the second wastewater pool, the obtained oxygen gas is discharged through the oxygen gas outlet of the third wastewater pool, and the purified organic wastewater is discharged through the wastewater outlet of the third wastewater pool.

7. The organic wastewater treatment device according to claim 6, wherein The organic wastewater treatment device further comprises a support frame arranged below the organic wastewater treatment pool, the support frame being suitable for supporting the organic wastewater treatment pool, and the support frame being provided with a wastewater pipe outlet connected with the wastewater outlet through a pipeline.

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