An electro-responsive silver donor ceramic membrane based on low cathode potential regulation, and a preparation method and application thereof

Abstract

The application relates to an electric response silver donor ceramic membrane based on low cathode potential regulation, a preparation method and application thereof, and belongs to the field of electrochemical water treatment and membrane separation coupling technology. The specific scheme is as follows: an electric response silver donor ceramic membrane based on low cathode potential regulation, which comprises a porous ceramic membrane, an intermediate layer and a silver donor functional layer; the intermediate layer is in-situ constructed on the porous ceramic membrane, and the silver donor functional layer is in-situ constructed on the surface of the intermediate layer and constitutes a continuous electron conduction path. In the electrolyte water body containing chlorine, the electric response silver donor ceramic membrane is used as a working electrode, a low cathode potential is applied in the filtration operation process, two kinds of reactions of ROS auxiliary driving silver oxidation dissolution and AgCl passivation layer electric reduction are generated at the silver / water interface of the electric response silver donor ceramic membrane surface, and the two kinds of reactions are synergistically regulated, so that Ag + Real-time adjustable output and long-period stable release of the dose.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical water treatment and membrane separation coupling technology, specifically relating to an electroresponsive silver donor ceramic membrane based on low cathode potential regulation, its preparation method, and its application in water treatment. Background Technology

[0002] Silver-based disinfectants have long been used in water treatment and public health due to their broad-spectrum and highly effective antibacterial properties. Silver nanoparticles or silver functional layers release Ag through oxidation and dissolution. + This is the main source of its bactericidal effect. Ag + It can interact with key components of bacteria such as proteins and nucleic acids, causing cell membrane damage and metabolic disorders. Therefore, maintaining a suitable and sustainable Ag level is crucial under different water quality and bacterial load conditions. + Release rate is crucial for ensuring both the high efficiency and safety of silver-based materials. Existing technologies aim to regulate Ag release. + Release primarily relies on pre-designed material structures or chemical methods, such as controlling the size of silver nanoparticles, passivating surfaces with ligands like citrates / sulfides / thiol groups, embedding silver nanoparticles into polymer networks, or using pre-oxidation methods like hydrogen peroxide or ozone to accelerate or inhibit dissolution. While these strategies can alter Ag to some extent... + While the release kinetics are understood, it remains essentially a form of "passive regulation": the release rate is predetermined by the material structure and the surrounding water matrix, lacking real-time external controllability during operation, making it difficult to implement on-demand dosage based on water quality fluctuations or changes in bacterial load. More importantly, Cl, which is ubiquitous in real water bodies... - It rapidly induces AgCl generation and forms a passivation layer on the silver surface, significantly inhibiting Ag... + The release of silver-based film, which decays over time, further limits the stability and sustainability of its sterilization process. This creates a dilemma: insufficient release leads to sterilization failure, while excessive release leads to compliance risks and accelerated silver consumption. This has become a core bottleneck in the engineering application of silver-based film materials.

[0003] Electrochemical modulation offers new possibilities for solving the above problems. By driving interfacial redox and double-layer processes with an applied potential, dynamic modulation of the reaction and dissolution behavior of silver surfaces can be achieved without introducing additional chemical agents. Current research on electrochemically enhanced sterilization mainly focuses on pathways such as electroporation, electrostatic interaction, or electrochemical generation of active species, while research targeting the "dominant sterilization mechanism—Ag" in silver-based materials remains a challenge. + The electromodulation mechanism of the "release" itself and its coupling relationship with AgCl passivation inhibition are still significantly insufficient. Therefore, it is necessary to develop a method that can actively modulate Ag using low cathode potential during filtration operation. +The system and method for releasing and simultaneously weakening the passivation decay of AgCl on the surface of silver with electroresponsive properties have significant theoretical value and engineering needs. Summary of the Invention

[0004] The purpose of this invention is to overcome the following technical problems existing in the prior art:

[0005] 1. Ag + Release the problem of passive and non-real-time adjustment

[0006] Among existing silver-based film materials, Ag + The release rate is mainly determined by the material structure and water matrix in advance. During operation, it is difficult to achieve externally controllable and on-demand dosage supply based on changes in bacterial load and water quality, which can easily lead to compliance risks caused by insufficient disinfection or excessive release.

[0007] 2. AgCl passivation leads to Ag + The problem of release decaying over time

[0008] In real chlorinated water systems, an AgCl passivation layer easily forms on the silver surface, leading to Ag... + The release rate decreases rapidly over time, making it difficult to guarantee stable bactericidal performance over a long period.

[0009] 3. Existing technologies lack a method that, within a membrane filtration configuration, synergistically utilizes a silver donor membrane structure and a low cathode potential to simultaneously achieve Ag in chlorinated water systems. + A technical solution that features adjustable dosage, stable long-term release, controllable energy consumption, and compliant mercury concentration.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] An electroresponsive silver donor ceramic membrane based on low cathode potential modulation, its preparation method, and its application are disclosed. Specifically, it is a membrane reaction sterilization platform for electromodulated silver ion release. This platform combines a low cathode potential modulation strategy with a conductive silver donor interface constructed on the membrane surface, enabling the porous ceramic membrane to be actively modulated by a controlled potential as a working electrode during filtration, thereby achieving Ag... + The real-time reversible adjustment and continuous output of the dosage makes it suitable for online disinfection and anti-biocontamination scenarios in flow-through or cross-flow membrane filtration processes.

[0012] The essence of this invention lies in constructing a coupling and control mechanism of "low cathode potential - conductive silver donor interface on membrane surface": by constructing a conductive silver donor functional layer in situ on the surface of a porous ceramic membrane, this functional layer is reliably connected to the external circuit and operates as a working electrode during filtration. When a low cathode potential is applied, the potential modulation and the silver / water interface reaction on the membrane surface are specifically coupled, thereby inducing the interface ROS (such as hydrogen peroxide) to assist in the oxidative dissolution of silver and the weakening of the electroreduction of the AgCl passivation layer (AgCl + e). - → Ag) The two processes occur simultaneously and produce a synergistic effect, making Ag + The release exhibits dynamic and controllable characteristics of "wide adjustable range, long-term stability, and minimal attenuation in real chlorine-containing water".

[0013] To achieve the aforementioned coupling regulation, the preparation method of the electroresponsive silver donor ceramic film based on low cathode potential regulation described in this invention is as follows: Using a porous ceramic film as a substrate, an intermediate layer with strong adhesion, complexing ability, and conductivity is first formed in situ on the surface of the porous ceramic film. Then, continuously distributed silver donors are constructed in situ on the intermediate layer to form a silver donor functional layer. This allows the silver donor functional layer to be stably attached to the surface of the intermediate layer while also forming a continuous electron conduction pathway and exposing a tunable active interface. The intermediate layer is preferably a polydopamine (PDA) layer, which is formed by the self-polymerization and deposition of dopamine in a weakly alkaline buffer system. The silver donor functional layer is formed by the adsorption and enrichment of diammine silver complex (silver precursor) on the PDA layer, followed by in-situ reduction by glucose, ascorbic acid, and a mild reducing agent to generate one or more combinations of silver nanoparticles, silver nanoclusters, silver nanosheets, and silver-metal composite donor units, which are then fixed on the surface of the intermediate layer to form an electrochemically modulated conductive silver donor functional layer.

[0014] The silver donor functional layer is capable of releasing Ag through an electrochemical process in chlorinated water systems. + And it is connected to the external circuit.

[0015] The electroresponsive silver donor ceramic membrane has both retention and filtration functions, and can also serve as a working electrode to achieve electroresponsive release of silver ions under the action of an applied potential.

[0016] The application of the electroresponsive silver donor ceramic membrane based on low cathode potential regulation involves the following steps: In a chlorinated electrolyte-containing water body, the electroresponsive silver donor ceramic membrane is used as the working electrode. During filtration operation, a low cathode potential is applied, causing the ROS-assisted silver dissolution and the electroreduction of the AgCl passivation layer at the silver / water interface on the membrane surface to be synergistically regulated, thereby achieving Ag... + Real-time adjustable dose output and long-term stable release.

[0017] ROS stands for Reactive Oxygen Species, referring to oxidizing intermediates generated at the silver donor functional layer / water interface during electrochemical processes. These include hydrogen peroxide (H₂O₂) and superoxide anion radicals (·O₂). - In this invention, these substances mainly play a supporting role in promoting the dissolution of silver oxide and synergistic sterilization.

[0018] The AgCl passivation layer is formed on the surface of the silver donor functional layer in a chlorine-containing water system due to the presence of Ag. + With Cl - The reaction produces a silver chloride deposit. This deposit hinders further dissolution and electron transfer of silver, leading to Ag... + The release rate decreases over time.

[0019] The low cathode potential is a cathode polarization potential in the range of -0.2 V to -1.5 V relative to the Ag / AgCl reference electrode. This potential range can promote the generation of ROS at the interface and the electroreduction of the AgCl passivation layer, while avoiding strong reduction processes such as violent hydrogen evolution, thus providing a mild and controllable electrochemical modulation effect on the silver donor functional layer.

[0020] The low cathode potential can be applied in constant DC, pulsed, segmented, or AC modes.

[0021] The chlorine-containing electrolyte water system refers to a system containing inorganic chloride ions (Cl). - The aqueous solution system includes artificially prepared chlorine-containing electrolyte solutions (such as NaCl solution) and actual water bodies (such as tap water, surface water, groundwater, etc.), in which Cl... - The concentration is usually in the range of 0.1-100 mM.

[0022] The operation mode of the chlorinated electrolyte water body is either flow-through filtration or cross-flow filtration. Flow-through filtration refers to the influent passing through the electroresponsive silver donor ceramic membrane along a single path and permeating through the membrane in one pass. Cross-flow filtration refers to the influent flowing parallel to the surface of the electroresponsive silver donor ceramic membrane, with only a portion of the water permeating through the membrane, and the remaining water carrying away contaminants as concentrate. Both methods can be used in conjunction with the electroresponsive silver donor ceramic membrane and electroregulation strategy of this invention.

[0023] Unlike simply controlling the structure of silver materials or using electrochemical disinfection methods, this invention emphasizes the synergistic combination of "specific silver donor ceramic membrane structure + low cathode potential operating conditions + chlorine-containing water system," altering Ag through interfacial coupling reactions. + The time evolution and dose distribution of release, rather than just instantaneous Ag. +This coupling scheme enables the improvement of Ag concentration or instantaneous sterilization rate while ensuring compliance with mercury concentration regulations. + Externally controllable adjustment of dosage and sterilization effect.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] Compared to existing technologies that merely alter the structure of chemical materials or employ conventional electrochemical disinfection methods, this invention does not involve introducing entirely new material components or electrochemical device forms. Instead, it organically combines an electroresponsive silver donor ceramic membrane structure with low cathode potential operating conditions in a chlorinated water system. Through the synergistic effect of interfacial ROS generation and the electroreduction of the AgCl passivation layer, the temporal evolution pattern and dosage control method of silver ion release are altered, resulting in a significant improvement in overall performance. Typically, this invention can achieve a wide range and long-term stable AgCl at low cathode potentials. + Release output to achieve 0.27-8.17 mg m -2 day -1 Adjustable release and stable operation for 30 days. Due to cathodic polarization simultaneously weakening the AgCl passivation layer and promoting interfacial ROS formation, Ag... + The release no longer decays rapidly over time, thus significantly improving the reliability of long-term disinfection in real chlorinated water bodies. When the system of this invention is used for electromodulated membrane filtration disinfection, it can achieve highly efficient sterilization of representative microorganisms such as E. coli in multiple filtration cycles, reaching an inactivation level of approximately 8-log in five filtration cycles, and maintaining robust removal of more than 6-log in various real water matrices. This process has low energy consumption, with a unit disinfection energy consumption (ECEO) of less than 3.61 Wh / m³. -3 At the same time, Ag was discharged. + The concentration was maintained at approximately 0.006 mg / L. -1 Significantly lower than 0.1 mg L -1 Commonly used drinking water safety limits. Energy consumption per unit of disinfection (ECEO) refers to the electrical energy consumed to achieve the removal of one logarithmic unit (1-log) of microorganisms, usually expressed in Wh·m³. -3 This indicates the energy efficiency level used to evaluate the electrochemical disinfection process.

[0026] In summary, this invention has significant advantages in terms of "adjustable dosage, continuous stability, low energy consumption, compliance and safety, and adaptability to real water bodies", and is especially suitable for off-grid communities, decentralized and low-maintenance disinfection and water purification scenarios. Attached Figure Description

[0027] Figure 1 This is a flowchart of the preparation process of an electroresponsive silver donor ceramic film;

[0028] Figure 2 This is a schematic diagram illustrating the effect of low cathode potential on the release rate and stability of silver ions.

[0029] Figure 3 This is a schematic diagram of an electroresponsive silver donor ceramic membrane filtration system based on low cathode potential regulation. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. The specific embodiments of the present invention are used to further illustrate the electroresponsive silver donor ceramic membrane and its electro-regulated disinfection and filtration method, and do not limit the scope of protection of the present invention. Those skilled in the art can make equivalent substitutions for the key structures of the materials and the key steps of the method without departing from the concept of the present invention, and all such substitutions should fall within the scope of protection of the present invention. Specific Implementation Method 1

[0032] A method for preparing an electroresponsive silver donor ceramic film based on low cathode potential modulation is disclosed, using a commercially available zirconia porous ceramic film as the substrate (the ceramic film thickness is approximately 2 mm, and the average pore size is approximately 500 nm). The ceramic film is cut to a suitable size (e.g., 1 × 1 cm). 2 The exposed area was then subjected to ultrasonic cleaning or soaking in a 1:1 (v / v) deionized water / ethanol mixture for 3 h to remove surface impurities. The cleaned ceramic membranes were then transferred to a 50 mM, pH 8.5 Tris buffer solution for pre-soaking to stabilize the interface pH.

[0033] A ceramic membrane was placed in a PDA self-polymerization deposition system composed of dopamine hydrochloride (0.5-5 g / L), CuSO4 (1-10 mM), and H2O2 (5-50 mM). The components interacted within the buffer system to induce oxidative self-polymerization of dopamine, resulting in in-situ deposition of a PDA interlayer on the ceramic membrane surface. The buffer system was Tris buffer (50 mM, pH range 7.5-9.0). The self-polymerization reaction was carried out at 20-40℃ for 0.5-4 h, allowing PDA to be uniformly deposited on the ceramic membrane surface and forming a well-adhesive interlayer. After deposition, the membrane was rinsed 2-5 times with deionized water and vacuum-dried at 40-80℃ for 6 h to obtain a densely coated PDA interlayer with complexing and conductive properties.

[0034] The silver donor functional layer was constructed using an in-situ adsorption-reduction strategy: a ceramic membrane with a PDA interlayer was immersed in a diammine silver complex [Ag(NH3)2]. +(20-200 mM) and polyvinylpyrrolidone (PVP, 2 g·L) -1 In a complexation solution of [Ag(NH3)2], adsorption was performed at 40°C for 8 h, resulting in the enrichment and stable complexation of the diammine silver complex in the PDA intermediate layer. Glucose was used as the reducing agent, and the glucose concentration was related to [Ag(NH3)2]. + The concentration ratio was 1:1-3:1, the reduction temperature was 30-60℃, and the reduction time was 3-5 h. This reduced the diammine silver complex to generate silver nanoparticles, which were then deposited and fixed on the surface of the PDA interlayer to form a continuously distributed silver donor functional layer. After the reaction, the film was rinsed with deionized water and vacuum dried at 60℃ for 3 h to obtain the final electroresponsive silver donor ceramic film Ag-DM. Its specific structure is a hierarchical composite structure of "ceramic substrate-PDA interlayer-conductive silver donor functional layer," which can be directly connected to an external circuit as a working electrode.

[0035] The fabrication process of the electroresponsive silver donor ceramic film is shown in the figure below. Figure 1 As shown, it includes four consecutive steps: forming an intermediate layer on the film surface by PDA self-polymerization deposition; adsorbing Ag(NH3)2 + Silver ions are complexed; PVP acts as a stabilizer to regulate the coordination environment of silver ions; finally, Ag nanoparticles are generated and deposited under glucose reduction, forming a uniform conductive silver donor functional layer. The SEM image at the top of the figure reflects the surface morphology changes at each stage, and the structural schematic diagram at the bottom corresponds to each chemical treatment step. Specific Implementation Method Two

[0037] Based on Specific Implementation Method 1, to further adapt to different water qualities or meet lifespan requirements, this invention allows for equivalent replacements of several key components: First, the PDA intermediate layer can be replaced by other conductive / semi-conductive polymer layers with adhesion and complexation capabilities and the ability to provide electronic conduction, such as dopamine-derived polymer layers containing catechol groups or catechol-functionalized polymers, as long as stable enrichment of the silver precursor and conductive continuity can be achieved; Second, the morphology of the silver donor functional layer can be replaced by discrete silver nanoparticles with silver nanoclusters, silver nanosheets, or silver-metal composite donor units, as long as their firm anchoring on the intermediate layer surface and electrochemically tunable interface exposure are maintained; Third, the silver loading can be varied within a certain range by adjusting the precursor concentration, adsorption time, or reduction rate to form different but equivalent silver donor coverage and conductive connectivity. None of the above replacements change the essential characteristics of the "conductive silver donor electro-response interface on the membrane surface." Specific Implementation Method 3

[0039] An application of an electroresponsive silver donor ceramic film based on low cathode potential modulation includes the following steps: electromodulation of Ag +The release experiment was conducted using a three-electrode system. The Ag-DM membrane (exposed area 1 × 1 cm) prepared according to Specific Embodiment 1 was used. 2 The working electrode was a platinum sheet, the counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode under saturated KCl conditions. All electrodes were controlled by an electrochemical workstation (model CHI660E, Shanghai Chenhua). All applied potentials were calibrated relative to the Ag / AgCl reference electrode.

[0040] A 10 mM NaCl solution was used as the electrolyte. Experiments were conducted at room temperature in a dark environment to avoid photoinduced reactions. The system was stirred with a magnetic stirrer at 100 rpm to ensure mass transfer. Applied potentials included open-circuit potential (no potential control), -0.2, -0.5, -0.8, -1.0, -1.2, and -1.5 V, to investigate the modulation of silver ion release by potential. At different time points (1 / 6, 1 / 2, 1, 2, 3, 6, 9, 12, 24, 36, and 48 h), 3 mL of supernatant was taken as samples. The samples were then subjected to ultrafiltration centrifugation (Amicon Ultra, 3 kDa cutoff; 4000×g, 50 min) to remove any silver nanoparticles that might be present in the solution. To completely convert the silver in AgCl into measurable dissolved silver, an excess of 10 mM Na₂S₂O₃ solution was added to the filtrate to allow the AgCl to fully dissolve. + It reacts with AgCl to form a soluble complex [Ag(S2O3)2] 3- Finally, ICP-OES (e.g., PerkinElmer Optima 8300) was used to quantitatively analyze the Ag content, obtaining the Ag content at different potentials. + Its adjustable and stable release characteristics.

[0041] A schematic diagram illustrating the effect of low cathode potential on the release rate and stability of silver ions is shown below. Figure 2 As shown, including five sub-figures (a)-(e), this diagram illustrates the effect of different applied potentials on Ag in a chloride-containing electrolyte solution, using an electroresponsive silver donor ceramic membrane as the working electrode. + Effects on release rate and long-term stability.

[0042] (a) Ag at different potentials + Cumulative concentration and corresponding release rate.

[0043] The left figure shows the Ag content under different cathode potentials (-0.2, -0.5, -0.8, -1.0, -1.2, and -1.5 V) without external voltage. + The cumulative concentration curve over time shows that as the cathode potential shifts negatively, Ag...+ The cumulative concentration increased significantly, exhibiting a near-linear increase at -1.0 V and below. The bar chart on the right shows the Ag concentration at each potential. + Area release rate (unit: mg·m²) -2 ·day -1 The text indicates that the increase in Ag was approximately 40 times compared to the no-potential condition, demonstrating that the Ag potential can be continuously adjusted over a wide range by regulating the cathode potential. + Release rate; Ag + Release rate / area release rate refers to the flux of silver ions released per unit membrane surface area per unit time, usually expressed in mg·m². -2 ·day -1 This indicates that it is used to characterize the silver ion dose output level of an electroresponsive silver donor ceramic membrane under specific potential and water quality conditions.

[0044] (b) This invention and Ag under different control strategies + Comparison of release rates.

[0045] The x-axis is Ag + Release rate (mg·m -2 ·day -1 (Double logarithmic coordinates), with the ordinate representing different Ag values. + The control or disinfection strategies (AE represent the following strategies of this invention: A. Potential control strategy, B. Ozone pre-oxidation promotion strategy, C. Commercial and unmodified silver materials, D. Citric acid exchange inhibition strategy, E. Sulfation inhibition strategy) are shown in the figure. Different shapes and colors of the markers correspond to the release rates of the system of this invention at no potential and at various low cathode potentials. It can be seen that this invention forms an adjustable window within the "inhibition-promotion" range, achieving a mid-to-high level of Ag release compared to many existing strategies while ensuring controllable energy consumption. + It releases intensity and has the ability to reversibly adjust the potential.

[0046] (c) Current-time response curves at different cathode potentials.

[0047] The chronoamperometric curves at potentials of -0.2, -0.5, -0.8, -1.0, -1.2, and -1.5 V are shown. It can be seen that the current decays slightly in the initial short period, then enters a stable plateau phase, and the current remains basically stable at each potential. This indicates that the electrode polarization state is controllable and there is no significant deactivation during continuous operation, providing a basis for long-term stable control of Ag. + The release provided the foundation.

[0048] (d) Short-time Ag at different potentials + Linear fitting of the release rate.

[0049] Select Ag within a 3-5 hour time window + By performing linear fitting on the cumulative concentration-time data, the slope K (i.e., instantaneous Ag) corresponding to different potentials was obtained. + (Release rate). The arrows in the figure indicate that the K values ​​for representative potentials of -0.2 V, -1.0 V, and -1.5 V gradually increase with a negative potential shift, demonstrating that Ag can be continuously and predictably adjusted by changing the cathode potential. + Release rate enables precise dosage control.

[0050] (e) Ag running continuously for 30 days + Release stability comparison.

[0051] This demonstrates the performance of Ag under two conditions: a low cathode potential of -1 V and no applied voltage. + The surface release rate curves are shown as a function of operating time (30 days), and the corresponding coefficients of variation (CV) are given. It can be seen that under potential-free conditions, Ag... + The release rate decreased significantly over time, with a CV of approximately 40.41%, indicating that the release process was highly volatile and prone to instability; while at a low cathode potential of -1 V, Ag... + The release rate remained essentially constant throughout the 30 days, with a CV of only about 2.8%, indicating that the electromodulation strategy of this invention can significantly suppress the release decay caused by AgCl passivation, thus achieving Ag... + Stable output over a long period.

[0052] Figure 2 It can be intuitively demonstrated that in chlorine-containing water systems, by using an electroresponsive silver donor ceramic membrane and applying a low cathode potential, Ag can be adjusted over a wide range. + The release rate was improved, and the release stability during long-term operation was significantly enhanced, providing experimental evidence for achieving adjustable dosage, long-lasting effect, and energy-controllable electromodulated membrane disinfection.

[0053] In subsequent continuous filtration sterilization experiments, the Ag-DM membrane and the counter electrode were assembled into a flow-through membrane module, and an external programmable potentiometer was connected. During continuous filtration, a low cathode potential in the range of -0.5 to -1.0 V was applied, causing a synergistic regulation process of ROS-assisted dissolution and AgCl electroreduction on the membrane surface, thereby achieving Ag... + Its real-time adjustable output adapts to different influent bacterial loads, achieving stable disinfection. Specific Implementation Method Four

[0055] Based on Specific Implementation Method 3, this invention allows for equivalent substitutions of key steps in the application method: the applied potential mode can be constant DC potential, or it can be replaced with pulsed potential, segmented potential, or AC potential, as long as it remains within the low cathode range that promotes silver interface activation and inhibits passivation; the electrode system can be a three-electrode system for precise potential control, or it can be replaced with a two-electrode system to simplify engineering implementation; the operating water can be an artificially prepared chlorine-containing electrolyte, or it can be replaced with natural water, surface water, or other real water matrix, and Ag can be applied as needed through potential adjustment. + Dosage supply. The above substitution does not affect the "external low cathode potential active modulation Ag" of the present invention. + The essence of the method is to "release and inhibit AgCl passivation".

[0056] Figure 3 This diagram illustrates an electroresponsive silver donor ceramic membrane filtration system based on low cathode potential regulation, including the electrochemically regulated membrane module structure (Ag-DM as the working electrode, with the counter electrode positioned relative to it, and permeate flowing out through the membrane) and the overall flow path for the filtration experiment: feed water is supplied from a raw material tank, regulated by a peristaltic pump and pressure gauge, and then enters the membrane module, where filtration and Ag are completed under applied potential conditions. + The flow rate is regulated, and the permeate is monitored in real time by an electronic balance and a computer. The flow meter is used to regulate the crossflow velocity, that is, the liquid flow velocity on the membrane surface, which can alleviate membrane fouling to some extent.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An application of an electroresponsive silver donor ceramic film based on low cathode potential modulation, characterized in that: The electroresponsive silver donor ceramic membrane comprises a porous ceramic membrane, an intermediate layer, and a silver donor functional layer. The intermediate layer is in-situ constructed on the porous ceramic membrane and possesses adhesion, complexation ability, and conductivity. The silver donor functional layer is in-situ constructed on the surface of the intermediate layer and forms a continuous electron conduction pathway, enabling the electroresponsive silver donor ceramic membrane to function as a working electrode and to regulate silver ion release at a low cathode potential. In chlorinated electrolyte water, using the electroresponsive silver donor ceramic membrane as the working electrode, a low cathode potential is applied during filtration, causing ROS-assisted oxidation and dissolution of silver and electroreduction of the AgCl passivation layer at the silver / water interface on the surface of the electroresponsive silver donor ceramic membrane to be synergistically regulated, thereby achieving Ag... + The dose is adjustable in real time and released stably over a long period; the low cathode potential is the cathode polarization potential in the range of -0.2 V to -1.5 V relative to the Ag / AgCl reference electrode.

2. The application of the electroresponsive silver donor ceramic film based on low cathode potential modulation according to claim 1, characterized in that: The intermediate layer is a polydopamine layer, a dopamine-derived polymer layer containing catechol groups, or a catechol-functionalized polymer layer.

3. The application of the electroresponsive silver donor ceramic film based on low cathode potential modulation according to claim 2, characterized in that: The polydopamine layer is prepared by self-polymerization and deposition of dopamine in a weakly alkaline buffer system to form a polydopamine layer.

4. The application of the electroresponsive silver donor ceramic film based on low cathode potential modulation according to claim 1, characterized in that: The silver donor functional layer is composed of one or more combinations of silver nanoparticles, silver nanoclusters, silver nanosheets, and silver-metal composite donor units.

5. The application of the electroresponsive silver donor ceramic film based on low cathode potential modulation according to claim 1, characterized in that, The method for preparing the electroresponsive silver donor ceramic film includes the following steps: using a porous ceramic film as a substrate, an intermediate layer with adhesion, complexation and conductivity is first formed in situ on the surface of the porous ceramic film, and then a continuously distributed silver donor is constructed in situ on the intermediate layer to form a silver donor functional layer, so that the silver donor functional layer can be stably attached to the surface of the intermediate layer and can form a continuous electron conduction pathway and expose a tunable active interface.

6. The application of the electroresponsive silver donor ceramic film based on low cathode potential modulation according to claim 5, characterized in that, The in-situ construction method of the silver donor functional layer is as follows: the silver precursor is adsorbed and enriched on the surface of the intermediate layer, and then reduced in situ by a reducing agent to generate a silver donor. The silver donor is fixed on the surface of the intermediate layer to form an electrochemically modulated conductive silver donor functional layer.

7. The application of the electroresponsive silver donor ceramic film based on low cathode potential modulation according to claim 6, characterized in that: The silver precursor includes a diammine silver complex; the reducing agent is one or more of glucose and ascorbic acid.

8. The application of the electroresponsive silver donor ceramic film based on low cathode potential modulation according to claim 1, characterized in that: The low cathode potential can be applied in constant DC, pulsed, segmented, or AC modes.

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