Electrochemical sensing method for efficiently monitoring disinfection by-products in drinking water

Abstract

The invention discloses an electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water. According to the method, in the enrichment stage, a main molecule cavity maintains the reference size, broad-spectrum adsorption is conducted on halide through a high-electron-density inner cavity of the main molecule cavity, and the local concentration of a target object is remarkably improved; then, in the recognition stage, the cavity is regulated by ions to generate specific deformation, molecules with mismatched sizes are repelled, and meanwhile, the binding energy of a target object is strengthened through dynamic covalent bond recombination. Experiments show that the separation factor and the selectivity coefficient of key by-products are greatly improved through the design. Besides, in combination with an online pH switching function of the micro-fluidic chip, automatic switching of enrichment and recognition modes in each detection period can be realized, so that the recovery rate and reuse times of the method in a complex matrix are superior to those of a traditional technology, and the method shows excellent stability and practicability.

Description

Technical Field

[0001] The present invention belongs to the technical field of drinking water monitoring, and specifically relates to an electrochemical sensing method for efficiently monitoring disinfection by-products in drinking water. Background Art

[0002] Disinfection by-products in drinking water refer to harmful substances generated by the reaction of disinfectants with organic matter in water during the drinking water disinfection process, mainly including compounds such as halogenated hydrocarbons, aldehydes, and ketones. These by-products may have carcinogenic, mutagenic, and reproductive toxicity, posing a potential threat to human health. The monitoring of disinfection by-products in drinking water is an important link to ensure water quality safety, and usually high-precision analysis techniques such as gas chromatography, liquid chromatography, and mass spectrometry are used for detection. The monitoring items include specific indicators such as trihalomethanes, haloacetic acids, and bromate. Through the quantitative analysis of these by-products, the effect of the disinfection process and the safety of drinking water quality can be evaluated, thereby providing a scientific basis for improving the disinfection process and ensuring the drinking water safety of the people.

[0003] However, in the existing technology for detecting disinfection by-products, traditional molecular imprinting or immobilized enzyme methods are limited by static recognition sites and are difficult to distinguish halogenated substances with a structural similarity higher than 90%; at the same time, conventional catalytic materials have low activation efficiency for C-Cl bonds and are easily interfered by macromolecules such as humic acid. Summary of the Invention

[0004] The purpose of the present invention is to provide an electrochemical sensing method for efficiently monitoring disinfection by-products in drinking water to solve the above-mentioned problems.

[0005] The technical solution adopted by the present invention is as follows: An electrochemical sensing method for efficiently monitoring disinfection by-products in drinking water, the method comprising the following steps:

[0006] S1: Perform water sample pretreatment, quickly filter and remove suspended particles using a microporous filter membrane, and release bound target substances by vortex oscillation;

[0007] S2: Layer-by-layer deposit a graphene / carbon nanotube heterojunction on the surface of a glassy carbon electrode to form a porous three-dimensional structure;

[0008] S3: Perform biomimetic molecular trap modification, self-assemble cucurbit[8]uril host molecules with dynamic adaptive cavities on the electrode surface, and achieve pre-enrichment and selective recognition of target substances through host-guest interactions - biomimetic molecular trap modification - self-assemble cucurbit[8]uril host molecules with dynamic adaptive cavities on the electrode surface, and achieve pre-enrichment and selective recognition of target substances through host-guest interactions;

[0009] S4: Introduce palladium-ceria nanoflowers as a co-catalyst, activate the cleavage of the C-Cl bond at a bias voltage of -0.2V to generate a characteristic oxidation current signal;

[0010] S5: Alternately implement square wave voltammetry and chronocoulometry, and eliminate background interference through signal difference.

[0011] S6: Train a convolutional neural network to recognize the fingerprint peak shapes of the mixed system and achieve synchronous multi-component quantification.

[0012] S7: Design a combined system of a serpentine channel and a nanofiber membrane to achieve a fully automated cycle of detection - cleaning - regeneration.

[0013] S8: Introduce a reference ion (Cs + ) as an internal standard to correct the error caused by the fluctuation of electrode activity in real time.

[0014] S9: Deploy a 4×4 electrode matrix in combination with a LoRa transmission module to achieve in-situ continuous monitoring of the water at the end of the pipe network.

[0015] In a preferred embodiment, in the step S1, a nylon microporous filter membrane with a pore size of 0.22 μm is used for primary filtration, and the sample is vortexed at a speed of 3000 rpm for 10 minutes simultaneously to destroy the surface adsorption layer of the colloidal encapsulated by-products. The pretreated water sample needs to be stored in the dark at 4°C and the subsequent detection should be completed within 2 hours to avoid the loss of volatile halogenated compounds. This process can remove 99.7% of the suspended impurities and simultaneously increase the release efficiency of the bound target substances to more than 92%.

[0016] In a preferred embodiment, in the step S2, the first layer is deposited with a thin layer of graphene oxide at a potential of -1.0 V in a constant current mode, and then switched to a pulsed voltage mode to deposit a vertically aligned carbon nanotube array. Finally, annealing is carried out at 800°C for 2 hours in an argon atmosphere to reconstruct the carbon material lattice to form an interconnected porous network. This structure has a hierarchical pore distribution (2 - 50 nm), and its tortuosity factor is controlled below 1.8 to ensure that the electrolyte penetration rate reaches 5 μL / s·cm 2 , providing an ideal carrier for subsequent modification.

[0017] In a preferred embodiment, in step S3, first, the interface self-assembly technology is adopted to directionally modify the cucurbituril host molecule layer on the surface of the three-dimensional gradient electrode. In specific operations, the electrode is immersed in an ethanol-water mixed solution containing a specific concentration of CB[8] and KCl, and a constant potential is applied for a period of time. Utilizing the π-π stacking effect driven by electrochemistry, the host molecules are arranged vertically with their bowl-shaped openings facing the electrode to form a dense monolayer film. The unique cucurbit-shaped cavity of this host molecule constructs a dynamic gating structure through the hydrogen bond network of the peripheral uracil units, and its cavity size can elastically contract or expand with the pH value of the solution. When the halogenated by-products in the water sample diffuse to the electrode interface, their hydrophobic halogenated groups generate strong host-guest interactions with the dipole field on the inner wall of the host molecule, triggering the conformational adjustment of the cavity: smaller molecules induce the cavity to contract and achieve capture through multiple interactions; while slightly larger molecules promote the cavity to expand, forming a more stable cooperative recognition site, thereby realizing the efficient discrimination of molecules with sub-angstrom size differences.

[0018] In a preferred embodiment, in step S4, the lattice matching degree between the palladium core and the cerium oxide shell reaches 98%, and a synergistic catalytic effect mediated by oxygen vacancies is generated during the electrochemical polarization process. When a -0.2V bias voltage is applied, Pd-Ce 3+ active sites are formed at the interface of the nanoflowers, which can selectively break the C-Cl bond and simultaneously inhibit the competitive hydrogen evolution reaction. The catalytic reaction path is confirmed by in-situ Raman spectroscopy, and the characteristic vibration peak at 680 cm -1 corresponds to the Cl- desorption process, and the catalytic turnover frequency reaches 1.2×10 4 times / hour.

[0019] In a preferred embodiment, in step S5, the square wave voltammetry scans with an amplitude of 50 mV and a frequency of 25 Hz to capture the redox characteristic peaks of the target substance; the chronocoulometry maintains a step at the characteristic potential for 30 seconds to record the charge accumulation process. By differentially processing the current-time curves obtained by the two modes, a dynamic compensation model for the background current is established, increasing the signal-to-noise ratio to 48 dB. The algorithm automatically identifies the illegal Faraday current generated by the interferents, achieving a pseudo-signal filtering rate of more than 96%.

[0020] In a preferred embodiment, in step S6, the size of the first-layer convolution kernel is set to 0.1V×5s to extract local peak shape features; the last-layer fully connected network correlates the non-linear relationship between concentration and peak height. After being optimized by transfer learning, the model has an analysis error of less than 0.5% for overlapping peaks, and the predicted recovery rate in unknown samples is stable in the range of 98±2%.

[0021] In a preferred embodiment, in step S7, the nanofiber membrane is composed of a polyacrylonitrile / carbon black composite prepared by electrospinning, which has both sample filtration and electrode protection functions. The fluid control system realizes a three-stage cycle through pneumatic drive: the flow rate in the detection stage is 5 μL / min, a pH 9.0 borate buffer solution is injected in the cleaning stage, and the regeneration stage is backwashed with a 0.5 M NaCl solution. The whole process takes no more than 8 minutes.

[0022] In a preferred embodiment, in step S8, the compensation algorithm is based on the Kalman filter principle, and the sensitivity correction coefficient is updated every 10 seconds, suppressing the long-term drift error within ±1.5%. This mechanism enables the sensor to still maintain 98% of the initial sensitivity after continuous operation for 72 hours, far exceeding the stability performance of the traditional potentiostatic method.

[0023] In a preferred embodiment, in step S9, the LoRa module uses the 470 MHz frequency band to transmit data, and is equipped with an adaptive power adjustment algorithm to ensure that the communication success rate within a range of 200 meters is greater than 99.9%. The system integrates an edge computing unit, which can complete 80% of the data preprocessing locally, and only uploads the eigenvalues to the cloud, reducing the overall power consumption to 12 mW / node and supporting continuous power supply by solar cells.

[0024] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0025] 1. In the present invention, during the enrichment stage, the cavity of the host molecule maintains the reference size, and the halogenated substances are adsorbed in a broad spectrum by its high electron density inner cavity, significantly increasing the local concentration of the target substance; subsequently, in the recognition stage, the cavity undergoes specific deformation under ion regulation, repelling molecules with mismatched sizes, and at the same time strengthening the binding energy of the target substance through dynamic covalent bond recombination. Experiments show that this design significantly improves the separation factor and selectivity coefficient of key by-products. In addition, combined with the online pH switching function of the microfluidic chip, the automatic switching of the enrichment and recognition modes can be realized within each detection cycle, making the method have better recovery rate and reuse times than traditional technologies in complex matrices, showing excellent stability and practicability.

[0026] 2. In the present invention, the introduced palladium-ceria nanoflower cocatalyst significantly improves the detection sensitivity and specificity through the interfacial synergy effect. The lattice-matched interface between the palladium core and the ceria shell forms a high density of oxygen vacancies, which activates the directional cleavage of the C-Cl bond under an electrochemical bias voltage, converting the inert molecules of the halogenated by-products into electroactive Cl- and organic radicals. This process not only amplifies the oxidation current signal of the target by 8.3 times, but also selectively inhibits the interference reaction of non-target substances (such as natural organic matter) by regulating the catalytic path. Experiments have confirmed that this design reduces the detection limit of chloroform from 0.5 μg / L of the traditional method to 0.08 μg / L, and improves the anti-interference ability against humic acid to a concentration ratio of 10^4, solving the sensitivity-selectivity trade-off problem in the detection of trace halogenated substances in complex water matrices. The catalytic enhancement effect and the molecular pre-concentration of S3 form a cascade amplification, ultimately increasing the response speed of the whole method to 3 minutes / sample, meeting the real-time requirements of drinking water safety monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the process principle of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Refer to Figure 1 ,

[0030] An electrochemical sensing method for efficiently monitoring disinfection by-products in drinking water, S1: Pretreat the water sample, quickly filter and remove suspended particles using a microporous filter membrane, and release the bound target by vortex oscillation;

[0031] S2: Deposit a graphene / carbon nanotube heterojunction layer by layer on the surface of the glassy carbon electrode to form a porous three-dimensional structure;

[0032] S3: Perform biomimetic molecular trap modification, self-assemble cucurbit[8]uril host molecules with dynamic adaptive cavities on the electrode surface, and achieve pre-concentration and selective recognition of the target through host-guest interactions. Biomimetic molecular trap modification - self-assemble cucurbit[8]uril host molecules with dynamic adaptive cavities on the electrode surface, and achieve pre-concentration and selective recognition of the target through host-guest interactions;

[0033] S4: Introduce palladium-ceria nanoflowers as a cocatalyst, activate the cleavage of the C-Cl bond at a bias voltage of -0.2 V to generate a characteristic oxidation current signal;

[0034] S5: Alternately implement square wave voltammetry and chronocoulometry, and eliminate background interference through signal difference.

[0035] S6: Train a convolutional neural network to recognize the fingerprint peak shapes of the mixed system and achieve synchronous quantification of multiple components.

[0036] S7: Design a combined system of a serpentine channel and a nanofiber membrane to achieve a fully automated cycle of detection - cleaning - regeneration.

[0037] S8: Introduce a reference ion (Cs + ) as an internal standard to correct the error caused by the fluctuation of electrode activity in real time.

[0038] S9: Deploy a 4×4 electrode matrix in cooperation with a LoRa transmission module to achieve in-situ continuous monitoring of the water at the end of the pipe network.

[0039] In step S1, a nylon microporous filter membrane with a pore size of 0.22 μm is used for primary filtration. At the same time, the sample is vortexed at a speed of 3000 rpm for 10 minutes to destroy the surface adsorption layer of the colloidal encapsulated by-products by shear force. The pretreated water sample needs to be stored in the dark at 4°C and the subsequent detection should be completed within 2 hours to avoid the loss of volatile halogenated compounds. This process can remove 99.7% of the suspended impurities and at the same time increase the release efficiency of the bound target substances to more than 92%.

[0040] In step S2, the first layer is deposited with a thin layer of graphene oxide at a potential of -1.0 V in the constant current mode, and then switched to the pulsed voltage mode to deposit a vertically aligned carbon nanotube array. Finally, annealing is carried out at 800°C for 2 hours in an argon atmosphere to reconstruct the carbon material lattice to form an interconnected porous network. This structure has a hierarchical pore distribution (2 - 50 nm), and its tortuosity factor is controlled below 1.8 to ensure that the electrolyte penetration rate reaches 5 μL / s·cm 2 , providing an ideal carrier for subsequent modification.

[0041] In step S3, first, the interface self-assembly technique is adopted to directionally modify the cucurbituril host molecule layer on the surface of the three-dimensional gradient electrode. In the specific operation, the electrode is immersed in an ethanol-water mixed solution containing a specific concentration of CB[8] and KCl, and a constant potential is applied for a period of time. By using the π-π stacking effect driven by electrochemistry, the host molecules are arranged vertically on the electrode with their bowl-shaped openings, forming a dense monolayer film. The unique cucurbit-shaped cavity of the host molecule constructs a dynamic gating structure through the hydrogen bond network of the peripheral uracil units, and its cavity size can elastically contract or expand with the pH value of the solution. When the halogenated by-products in the water sample diffuse to the electrode interface, their hydrophobic halogenated groups generate strong host-guest interactions with the dipole field on the inner wall of the host molecule, triggering the conformational adjustment of the cavity: smaller molecules induce the cavity to contract and achieve capture through multiple interactions; while slightly larger molecules promote the cavity to expand, forming a more stable cooperative recognition site, thus realizing the efficient discrimination of molecules with sub-angstrom size differences.

[0042] In step S4, the lattice matching degree between the palladium core and the cerium oxide shell reaches 98%, and a synergistic catalytic effect mediated by oxygen vacancies is generated during the electrochemical polarization process. When a -0.2V bias voltage is applied, Pd-Ce formed at the interface of the nanoflowers 3+ active sites can selectively break the C-Cl bond while suppressing the competitive hydrogen evolution reaction. The catalytic reaction path is confirmed by in-situ Raman spectroscopy, and the characteristic vibration peak is located at 680 cm -1 corresponding to the Cl - desorption process, and the catalytic turnover frequency reaches 1.2×10 4 times per hour.

[0043] In step S5, square wave voltammetry scans at an amplitude of 50 mV and a frequency of 25 Hz to capture the redox characteristic peaks of the target substances; chronocoulometry maintains a step at the characteristic potential for 30 seconds to record the charge accumulation process. By differentially processing the current-time curves obtained from the two modes, a dynamic compensation model for the background current is established, increasing the signal-to-noise ratio to 48 dB. The algorithm automatically identifies the illegal Faraday current generated by the interferents, achieving a false signal filtering rate of over 96%.

[0044] In step S6, the size of the first-layer convolution kernel is set to 0.1V×5s to extract local peak shape features; the last-layer fully connected network correlates the non-linear relationship between concentration and peak height. After being optimized by transfer learning, the model has an analysis error for overlapping peaks of less than 0.5%, and the predicted recovery rate in unknown samples is stable in the range of 98±2%.

[0045] In step S7, the nanofiber membrane is composed of a polyacrylonitrile / carbon black composite material prepared by electrospinning, which has both sample filtration and electrode protection functions. The fluidic system is driven by air pressure to achieve a three-stage cycle: a flow rate of 5 μL / min in the detection stage, a pH 9.0 borate buffer is injected in the cleaning stage, and a 0.5M NaCl solution is used for reverse flushing in the regeneration stage. The whole process takes no more than 8 minutes.

[0046] In step S8, the compensation algorithm is based on the Kalman filter principle and updates the sensitivity correction coefficient every 10 seconds to suppress the long-term drift error within ±1.5%. This mechanism allows the sensor to maintain 98% of its initial sensitivity after 72 hours of continuous operation, far exceeding the stability performance of the traditional constant potential method.

[0047] In step S9, the LoRa module uses the 470MHz frequency band to transmit data, and uses an adaptive power adjustment algorithm to ensure that the communication success rate within a range of 200 meters is greater than 99.9%. The system integrates an edge computing unit, which can complete 80% of data preprocessing locally and only upload feature values ​​to the cloud, reducing the overall power consumption to 12mW / node and supporting continuous power supply from solar cells.

[0048] In the present invention, first, in the enrichment stage, the main molecular cavity maintains the reference size, and uses its high electron density inner cavity to perform broad-spectrum adsorption of halogenated substances, significantly increasing the local concentration of the target; then in the recognition stage, the cavity undergoes specific deformation under ion regulation, excludes size-mismatched molecules, and strengthens the binding energy of the target through dynamic covalent bond reorganization. Experiments have shown that this design greatly improves the separation factor and selectivity coefficient of key by-products. In addition, combined with the online pH switching function of the microfluidic chip, automatic switching between enrichment and recognition modes can be achieved within each detection cycle, making the method better than traditional technologies in terms of recovery rate and number of reuses in complex matrices, showing excellent stability and practicality.

[0049] In the present invention, the palladium-cerium oxide nanoflower co-catalyst introduced significantly improves the detection sensitivity and specificity through the interfacial synergistic effect. The lattice matching interface between the palladium core and the cerium oxide shell forms a high-density oxygen vacancy, which activates the directional breakage of the C-Cl bond under electrochemical bias, converting the inert molecules of the halogenated byproducts into Cl with electroactive characteristics. -and organic free radicals. This process not only amplifies the oxidation current signal of the target by 8.3 times, but also selectively inhibits the interference reactions of non-target substances (such as natural organic matter) by regulating the catalytic pathway. Experiments have confirmed that this design reduces the detection limit of chloroform from 0.5 μg / L of the traditional method to 0.08 μg / L, and improves the anti-interference ability against humic acid to a concentration ratio of 10^4, solving the sensitivity-selectivity trade-off problem for the detection of trace halogenated compounds in complex water matrices. The catalytic enhancement effect and the molecular pre-concentration of S3 form a cascade amplification, ultimately increasing the response speed of the whole method to 3 minutes / sample, meeting the real-time requirements of drinking water safety monitoring.

[0050] It should be noted that in this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water, characterized in that: The method comprises the following steps: S1: Pre-treat the water sample by using a microporous filter membrane to quickly filter out suspended particles and release the bound target in combination with vortex oscillation; S2: Depositing graphene / carbon nanotube heterojunction layer by layer on the surface of the glassy carbon electrode to form a porous three-dimensional structure; S3: Perform biomimetic molecular trap modification, self-assemble cucurbit [8] uracil main molecules with dynamic adaptive cavities on the electrode surface, and achieve pre-enrichment and selective recognition of the target through host-guest interaction. Biomimetic molecular trap modification - self-assemble cucurbit [8] uracil main molecules with dynamic adaptive cavities on the electrode surface, and achieve pre-enrichment and selective recognition of the target through host-guest interaction; S4: Pd-Cerium oxide nanoflowers were introduced as co-catalysts to activate the C-Cl bond breakage under a bias voltage of -0.2 V, generating a characteristic oxidation current signal; S5: alternately implement square wave voltammetry and chronocoulometry to eliminate background interference by signal differentiation; S6: Train convolutional neural networks to identify fingerprint peaks of mixed systems and achieve multi-component simultaneous quantification; S7: Design a system combining serpentine channels and nanofiber membranes to achieve a fully automated cycle of detection-cleaning-regeneration; S8: Introduce reference ions as internal standards to correct errors caused by fluctuations in electrode activity in real time; S9: Deploy a 4×4 electrode matrix with a LoRa transmission module to achieve in-situ continuous monitoring of water at the end of the pipe network.

2. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S1, a nylon microporous filter membrane with a pore size of 0.22 μm is used for preliminary filtration, and the sample is vortexed at 3000 rpm for 10 minutes to destroy the surface adsorption layer of the colloid-encapsulated by-products through shear force; the pretreated water sample needs to be stored at 4°C in the dark, and subsequent testing must be completed within 2 hours to avoid the loss of volatile halogenated substances; this process can remove 99.7% of suspended impurities and increase the release efficiency of bound targets to more than 92%.

3. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S2, a graphene oxide thin layer is first deposited at a potential of -1.0 V in a constant current mode, and then a pulse voltage mode is switched to deposit a vertically arranged carbon nanotube array; finally, annealing is performed at 800° C. for 2 hours in an argon atmosphere to reconstruct the carbon material lattice to form an interconnected porous network; the structure has a graded pore distribution, and its tortuosity factor is controlled below 1.8, ensuring that the electrolyte penetration rate reaches 5 μL / s·cm 2 , providing an ideal carrier for subsequent modification.

4. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S3, the interface self-assembly technology is first used to directionally modify the cucurbitacin uracil main molecule layer on the surface of the three-dimensional gradient electrode; in the specific operation, the electrode is immersed in a mixed solution of ethanol and water containing a specific concentration of CB[8] and KCl, a constant potential is applied for a period of time, and the π-π stacking effect driven by electrochemistry is used to make the main molecules arrange their bowl-shaped openings perpendicular to the electrodes to form a dense monolayer film; The unique gourd-shaped cavity of the main molecule constructs a dynamic gating structure through the hydrogen bond network of the peripheral uracil units, and its cavity size can elastically shrink or expand with the pH value of the solution; when the halogenated by-products in the water sample diffuse to the electrode interface, their hydrophobic halogenated groups produce strong host-guest interactions with the dipole field of the inner wall of the main molecule, triggering the adjustment of the cavity conformation: smaller molecules induce cavity contraction and achieve capture through multiple actions; while slightly larger molecules cause the cavity to expand, forming a more stable cooperative recognition site.

5. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S4, the lattice matching degree between the palladium core and the cerium oxide shell reaches 98%, and a synergistic catalytic effect mediated by oxygen vacancies is generated during the electrochemical polarization process; when a bias voltage of -0.2 V is applied, the Pd-Ce 3+ The active site can selectively break the C-Cl bond and inhibit the competitive hydrogen evolution reaction. The catalytic reaction path was confirmed by in situ Raman spectroscopy, and the characteristic vibration peak was located at 680cm -1 The corresponding Cl - During the desorption process, the catalytic turnover frequency reached 1.2×10 4 times / hour.

6. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S5, the square wave voltammetry method is scanned with an amplitude of 50mV and a frequency of 25Hz to capture the redox characteristic peak of the target object; the chrono-Coulomb rule is maintained at the characteristic potential step for 30 seconds to record the charge accumulation process; the current-time curves obtained by the two modes are differentially processed to establish a dynamic compensation model for the background current, so that the signal-to-noise ratio is improved to 48dB; the algorithm automatically identifies the non-Faraday current generated by the interferer, achieving a false signal filtering rate of more than 96%.

7. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S6, the size of the first-layer convolution kernel is set to 0.1V×5s to extract local peak shape features; the last-layer fully connected network associates the nonlinear relationship between concentration and peak height; after the model is optimized by transfer learning, the analytical error of overlapping peaks is less than 0.5%, and the predicted recovery rate in unknown samples is stable in the range of 98±2%.

8. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S7, the nanofiber membrane is composed of a polyacrylonitrile / carbon black composite material prepared by electrospinning, and has both sample filtration and electrode protection functions; the fluidic control system is driven by air pressure to achieve a three-stage cycle: a flow rate of 5 μL / min in the detection stage, a pH 9.0 borate buffer is injected in the cleaning stage, and a 0.5 M NaCl solution is used for reverse flushing in the regeneration stage. The whole process takes no more than 8 minutes.

9. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S8, the compensation algorithm is based on the Kalman filter principle, and the sensitivity correction coefficient is updated every 10 seconds to suppress the long-term drift error within ±1.5%. This mechanism enables the sensor to maintain 98% of the initial sensitivity after 72 hours of continuous operation, far exceeding the stability performance of the traditional constant potential method.

10. The electrochemical sensing method for efficiently monitoring disinfection byproducts in drinking water according to claim 1, characterized in that: In step S9, the LoRa module uses the 470MHz frequency band to transmit data, and is combined with an adaptive power regulation algorithm to ensure that the communication success rate within a range of 200 meters is greater than 99.9%; the system integrates an edge computing unit, which can complete 80% of the data preprocessing locally and only upload characteristic values ​​to the cloud, reducing the overall power consumption to 12mW / node and supporting continuous power supply from solar cells.

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