Electro-response silver donor ceramic membrane based on low cathode potential regulation and control as well as preparation method and application of electro-response silver donor ceramic membrane

Abstract

The invention discloses an electroresponse silver donor ceramic membrane based on low cathode potential regulation and control as well as a preparation method and application thereof, and belongs to the technical field of electrochemical water treatment and membrane separation coupling. According to the specific scheme, the electrical response silver donor ceramic membrane based on low cathode potential regulation and control comprises a porous ceramic membrane, a middle layer and a silver donor functional layer, the middle layer is constructed on the porous ceramic membrane in situ, and the silver donor functional layer is constructed on the surface of the middle layer in situ and forms a continuous electron conduction path. In a chlorine-containing electrolyte water body, the electroresponsive silver donor ceramic membrane is used as a working electrode, and low cathode potential is applied in a filtering operation process, so that ROS is generated on a silver / water interface on the surface of the electroresponsive silver donor ceramic membrane to assist in driving two reactions of oxidation dissolution of silver and electroreduction of an AgCl passivation layer to realize cooperative regulation and control; therefore, the real-time adjustable output and long-period stable release of the Ag < + > dosage are realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical water treatment and membrane separation coupling, and particularly relates to an electro-responsive silver donor ceramic membrane based on low cathode potential regulation and a preparation method and application thereof in water treatment. BACKGROUND

[0002] Silver-based disinfectants have been used in water treatment and public health fields for a long time due to their broad-spectrum and high-efficiency antibacterial capacity, in which silver nanoparticles or silver functional layers release Ag + through oxidation and dissolution, which is the main source of bactericidal action. Ag + can act on key components such as bacterial proteins and nucleic acids, causing cell membrane damage and metabolic disorders. Therefore, under different water qualities and different bacterial loads, maintaining a suitable and sustainable Ag + release rate is the key to ensuring that silver-based materials are both efficient and safe. In order to regulate Ag + release, existing technologies mainly rely on material structure pre-setting or chemical means, such as adjusting the size of silver nanoparticles, using citrate / sulfide / thiol ligands to passivate the surface, embedding silver nanoparticles in a polymer network, or using hydrogen peroxide, ozone and other pre-oxidation methods to accelerate or inhibit dissolution. Although these strategies can change the Ag + release kinetics to some extent, they are still essentially "passive regulation": the release rate is determined by the material architecture and the pre-existing environmental water matrix, lacking external real-time controllability during operation, and it is difficult to implement on-demand dose supply according to water quality fluctuations or bacterial load changes. More importantly, Cl - , which is ubiquitous in real water bodies, can quickly induce the formation of AgCl and form a passivation layer on the silver surface, significantly inhibiting Ag + release and decaying with operation time, further limiting the stability and sustainability of silver-based membrane disinfection. The dilemma of "insufficient release leading to disinfection failure, excessive release leading to compliance risk and accelerated silver consumption" has become a core bottleneck in the engineering application of silver-based membrane materials.

[0003] Electrochemical regulation provides a new possibility to solve the above problems. By applying an external potential to drive the interface redox and double-layer processes, the dynamic regulation of silver surface reaction and dissolution behavior can be achieved without introducing additional chemical reagents. Current research on electrochemical strengthening of sterilization focuses on electroporation, electrostatic action or electrochemical generation of active species, while the electro-regulation law of silver-based materials "main bactericidal mechanism--Ag + release" itself and its coupling relationship with AgCl passivation inhibition are still obviously insufficient. Therefore, it is necessary to develop a kind of silver donor ceramic membrane which can actively regulate Ag +The application discloses a silver functional system and a method for releasing and synchronously weakening AgCl passivation decay of a membrane surface electric response, which has significant theoretical value and engineering demand. SUMMARY

[0004] The present application aims to overcome the following technical problems existing in the prior art:

[0005] 1、Ag + The passive and non-real-time adjustable problem is released

[0006] In the existing silver-based membrane material, Ag + The release rate is mainly determined by the material structure and the water matrix in advance, and it is difficult to realize external controllable and on-demand dose supply according to the bacterial load and water quality change during operation, and it is easy to appear the compliance risk caused by insufficient disinfection or excessive release.

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

[0008] In the real chlorine-containing water system, the silver surface is easy to form AgCl passivation layer, which leads to the rapid decay of Ag + Release over time, it is difficult to ensure long-period stable sterilization performance.

[0009] 3、The prior art lacks a technical scheme for simultaneously realizing Ag + Dose adjustable, long-period release stable, energy controllable and silver concentration in effluent compliant in chlorine-containing water system by synergistically utilizing silver donor membrane structure and low cathode potential in membrane filtration configuration.

[0010] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0011] A kind of electric response silver donor ceramic membrane based on low cathode potential regulation and control, its preparation method and application, specifically a membrane reaction disinfection platform for electrically modulating silver ion release. The platform combines low cathode potential regulation and control strategy with the conductive silver donor interface constructed on the membrane surface, so that the porous ceramic membrane is actively modulated as a working electrode by the controlled potential during filtration operation, thereby realizing the real-time reversible adjustment and continuous output of Ag + Dose, suitable for online disinfection and antibiofouling scenes in flow-through or cross-flow membrane filtration process.

[0012] The essence of the present application is to construct a "low cathode potential-membrane surface conductive silver donor interface" coupling regulation mechanism: by in-situ constructing a conductive silver donor functional layer on the surface of a porous ceramic membrane, making the functional layer reliably conductive with an external circuit and operating 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 occur in a specific coupling, thereby inducing the simultaneous occurrence of ROS (such as hydrogen peroxide and the like) assisted driving of silver oxidation dissolution and the electro-reduction of AgCl passivation layer (AgCl + e - → Ag) two processes and producing a synergistic effect, making Ag + release present "wide range adjustable, long-term stable, not easy to decay in real water containing chlorine".

[0013] To achieve the above coupling regulation, the preparation method of the electric response silver donor ceramic membrane based on low cathode potential regulation is as follows: taking a porous ceramic membrane as a substrate, first forming an intermediate layer with strong adhesion, complexing ability and conductivity on the surface of the porous ceramic membrane in-situ, then constructing a continuous distribution of silver donor on the intermediate layer to form a silver donor functional layer, so that the silver donor functional layer can not only be stably attached to the surface of the intermediate layer, but also form a continuous electron conduction path and expose a controllable active interface. The intermediate layer is preferably a polydopamine (PDA) layer, which is formed by self-polymerization and deposition of dopamine in a weak alkaline buffer system; the silver donor functional layer is a combination of one or more of silver nanoparticle, silver nanocluster, silver nanosheet and silver-metal composite donor unit formed by in-situ reduction of silver precursor adsorbed and enriched on the PDA layer by a mild reducing agent such as glucose and ascorbic acid, and fixed on the surface of the intermediate layer, forming an electrochemically modulated conductive silver donor functional layer.

[0014] The silver donor functional layer can release Ag + in the chlorine-containing water system through an electrochemical process and conduct with the external circuit.

[0015] The electric response silver donor ceramic membrane not only has interception and filtration functions, but also can be used as a working electrode to realize silver ion release in response to electricity under the action of an applied potential.

[0016] The application of the electric response silver donor ceramic membrane based on low cathode potential regulation is as follows: in a chlorine-containing electrolyte water body, the electric response silver donor ceramic membrane is used as a working electrode, and a low cathode potential is applied during filtration operation to produce ROS assisted driving of silver dissolution and electro-reduction of AgCl passivation layer on the membrane surface, thereby realizing real-time adjustable output and long-period stable release of Ag + dose.

[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. +The concentration or instantaneous sterilization rate is improved. The coupling scheme enables the realization of Ag + dosage and external controllable adjustment of sterilization effect.

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

[0025] Compared with the prior art of only changing the structure of chemical materials or only using conventional electrochemical disinfection methods, the present application does not introduce new material components or electrochemical equipment forms, but combines the electroresponsive silver donor ceramic membrane structure with the low cathode potential operating condition in the chlorine-containing water system, changes the time evolution mode and dosage regulation mode of silver ion release through the synergistic effect of interface ROS generation and AgCl passivation layer reduction, thereby bringing significant improvement in comprehensive performance. Typically, the present application can obtain a wide range and long-term stable Ag + release output under low cathode potential, realizing a tunable release of 0.27-8.17 mg m -2 day -1 and maintaining stability within 30 days of continuous operation. Due to the simultaneous weakening of AgCl passivation layer and the promotion of interface ROS generation by cathode polarization, Ag + release is no longer rapidly attenuated with time, thereby significantly improving the long-period disinfection reliability in real chlorine-containing water bodies. After using the present application system for electro-modulated membrane filtration disinfection, high-efficiency sterilization of representative microorganisms such as Escherichia coli can be achieved in multiple cycles of filtration, reaching a total inactivation level of about 8-log in five filtration cycles, and maintaining a stable removal of more than 6-log in various real water matrices. The process has low energy consumption, and the unit disinfection energy consumption (ECEO) can be lower than 3.61 Wh m -3 , while the Ag + concentration in the effluent is maintained at about 0.006 mg L -1 , which is significantly lower than the commonly used safety limit of 0.1 mg L -1 for drinking water. The unit disinfection energy consumption (ECEO) refers to the electrical energy consumed to achieve 1 logarithmic unit (1-log) of microbial removal, usually expressed in Wh·m -3 , used to evaluate the energy efficiency level of electrochemical disinfection process.

[0026] In summary, the present application has significant advantages in the comprehensive dimensions of "dose adjustable, continuous and stable, low energy consumption, compliant and safe, and adaptation to real water bodies", and is especially suitable for off-grid community, decentralized and low-maintenance disinfection water purification scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a preparation flowchart of the electroresponsive silver donor ceramic membrane;

[0028] Figure 2 is a schematic diagram of the regulation effect of low cathode potential on silver ion release rate and stability;

[0029] Figure 3 is a schematic diagram of an electrically responsive silver donor ceramic membrane filtration system based on low cathode potential regulation. DETAILED DESCRIPTION

[0030] The technical solutions in the present application will be described clearly and completely below in combination with the drawings and specific embodiments. The specific embodiments of the present application are used to further illustrate the electrically responsive silver donor ceramic membrane and the electrically regulated disinfection filtration method, and do not limit the protection scope of the present application. Those skilled in the art can make equivalent substitutions to the key structures of materials and the key steps of methods without departing from the concept of the present application, and all should fall within the protection scope of the present application. DETAILED DESCRIPTION

[0032] A preparation method of an electrically responsive silver donor ceramic membrane based on low cathode potential regulation, a commercially available zirconium dioxide porous ceramic membrane is selected as a substrate (ceramic membrane thickness of about 2 mm, average pore size of about 500 nm). The ceramic membrane is cut into a suitable size (such as 1x1 cm 2 exposed area) and sequentially cleaned by ultrasonic cleaning or immersion cleaning in a 1:1 (v / v) deionized water / ethanol mixed solution for 3 h to remove surface impurities. The cleaned ceramic membrane sheet is transferred to a 50 mM, pH 8.5 Tris buffer for pre-soaking to stabilize the interface pH.

[0033] The ceramic membrane is 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), and the components in the buffer system act together to induce the oxidation and self-polymerization of dopamine and form a PDA intermediate layer in situ on the surface of the ceramic membrane. The buffer system is a Tris buffer (50 mM, pH range of 7.5-9.0). The self-polymerization reaction is carried out at 20-40°C for 0.5-4 h, so that the PDA is uniformly deposited on the surface of the ceramic membrane and forms a well-adhered intermediate layer. After the deposition is completed, the ceramic membrane is rinsed with deionized water for 2-5 times and vacuum dried at 40-80°C for 6 h, thereby obtaining a PDA intermediate layer that is covered with a dense layer, has complexing ability and electrical conductivity.

[0034] The silver donor functional layer is constructed by an in-situ adsorption-reduction strategy: the ceramic membrane with a PDA intermediate layer is immersed in a silver diamine 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. A low-cathode potential-controlled electroresponsive silver donor ceramic membrane, characterized in that: It includes a porous ceramic membrane, an intermediate layer, and a silver donor functional layer; the intermediate layer is constructed in situ on the porous ceramic membrane and has adhesion, complexation ability, and conductivity; the silver donor functional layer is constructed in situ on the surface of the intermediate layer and forms a continuous electron conduction pathway, so that the electroresponsive silver donor ceramic membrane has the structural and electrochemical functional characteristics of serving as a working electrode and used for regulating the release of silver ions at low cathode potential.

2. 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 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 electroresponsive silver donor ceramic membrane 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. A method for preparing an electroresponsive silver donor ceramic film based on low cathode potential modulation as described in any one of claims 1-4, characterized in that, Includes the following steps: Using a porous ceramic membrane as a substrate, an intermediate layer with adhesion, complexation and conductivity is first formed in situ on the surface of the porous ceramic membrane. Then, a continuously distributed silver donor is 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 and to form a continuous electron conduction pathway while exposing a tunable active interface.

6. The preparation method 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 preparation method according to claim 6, characterized in that: The silver precursor includes a diammonium silver complex; the reducing agent is one or more of glucose and ascorbic acid.

8. An application of the electroresponsive silver donor ceramic film based on low cathode potential modulation as described in claims 1-4, characterized in that: In chlorinated electrolyte-containing water, using the electroresponsive silver donor ceramic membrane as the working electrode, a low cathode potential is applied during filtration operation. This causes ROS-assisted oxidation and dissolution of silver at the silver / water interface on the surface of the electroresponsive silver donor ceramic membrane, along with the electroreduction of the AgCl passivation layer, to be synergistically regulated, thereby achieving Ag... + Real-time adjustable dose output and long-term stable release.

9. The application according to claim 8, characterized in that: 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.

10. The application according to claim 8, characterized in that: The low cathode potential can be applied in constant DC, pulsed, segmented, or AC modes.

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