Direct Current Method Research Articles

Calibrated the direct current potential drop method for fatigue crack propagation testing of nickel-based superalloy with film cooling hole

Turbine blades in aviation engines commonly feature a nickel-based superalloy structure integrated with film cooling holes to enhance inlet gas temperature. However, the presence of these film cooling holes often results in frequent occurrences of fracture failures nearby. The direct current potential drop (DCPD) method, renowned for its exceptional crack sensitivity, is frequently utilized for crack length monitoring. This study establishes a FEM model of the film cooling hole plate specimen to determine the optimal probe point location. Subsequently, a mapping relationship is derived to calibrate Johnson’s formula, accounting for the unequal crack lengths at the edges of film cooling holes. It is confirmed that the crack length measured by the DCPD method represents the cumulative crack lengths on both sides of the hole. Fatigue crack propagation experiments are then conducted, with crack length monitored using a microscope. The results affirm the successful application of the calibrated formula to the film cooling hole plate specimen, exhibiting an average error within 0.1 mm.

Effect of Tween 80 on the Electrocatalytic Performance of a Ti/PbO2‐MWCNTs Electrode

AbstractIn this work, Ti/PbO2‐MWCNTs anodes modified with different amount with different amount of Tween 80 (0.0–2.0 g/L) were prepared by the direct current electrodeposition method used as anode materials for Zinc electrowinning. The MWCNTs were dispersed in a lead nitrate solution with Tween 80, and the effects of the amount of added Tween 80 on the morphology, phase composition and electrocatalytical performance of lead dioxide coating were investigated. Physical characterizations show that with the increase of the amount of Tween 80, both grain size of PbO2 and carbon content in PbO2 layer firstly increased and then decreased, the preferential orientation and crystallinity of the PbO2 grain growth in the deposition process changed. Electrochemical tests demonstrate that the optimal modified electrode achieved the minimum Eo value and maximum j0 of 2.038 V and 3.781×10−4 A, respectively, an increase of capacitance to 368.8 μF cm−2, and a decrease of charge transfer resistance to 92.74 Ω cm2, which is mainly attributed to the PbO2 electrode modified with Tween 80, coupled with the synergistic effects of MWCNTs doping.

Magnetic properties of bamboo-like Ni-Zn-in nanowires using 3D-AAO templates

In this paper, using three-dimensional porous alumina (3D-AAO) as a template, Ni-Zn-In nanowires array with periodically changing diameters was successfully prepared by direct current electrodeposition method. The effect of deposition voltage on the morphology, crystal structure and magnetic properties of Ni-Zn-In ternary alloy nanowires was studied. The experimental results show that the diameters of the nanowires are 212 nm and 151 nm, and the periodic length is 800 nm, which matches the pore size of the phosphoric acid-etched 3D-AAO template. XRD results indicate that the crystal structure of Ni-Zn-In nanowires can be adjusted by the deposition voltage. The VSM results reveal that the Ni-Zn-In nanowires possess soft magnetic properties and significant magnetic anisotropy, with the easy magnetization direction parallel to the film. The nanowires deposited at −1.5 V exhibit the highest coercivity of 161 Oe and squareness of 0.045. Micromagnetic simulations show that the magnetization reversal mechanism of the Ni-Zn-In nanowires is localized nucleation mode.

Impedance Spectroscopy Study of Charge Transfer in the Bulk and Across the Interface in Networked SnO2/Ga2O3 Core–Shell Nanobelts in Ambient Air

Metal oxide core–shell fibrous nanostructures are promising gas-sensitive materials for the detection of a wide variety of both reducing and oxidizing gases. In these structures, two dissimilar materials with different work functions are brought into contact to form a coaxial heterojunction. The influence of the shell material on the transportation of the electric charge carriers along these structures is still not very well understood. This is due to homo-, hetero- and metal/semiconductor junctions, which make it difficult to investigate the electric charge transfer using direct current methods. However, in order to improve the gas-sensing properties of these complex structures, it is necessary to first establish a good understanding of the electric charge transfer in ambient air. In this article, we present an impedance spectroscopy study of networked SnO2/Ga2O3 core–shell nanobelts in ambient air. Tin dioxide nanobelts were grown directly on interdigitated gold electrodes, using the thermal sublimation method, via the vapor–liquid–solid (VLS) mechanism. Two forms of a gallium oxide shell of varying thickness were prepared via halide vapor-phase epitaxy (HVPE), and the impedance spectra were measured at 189–768 °C. The bulk resistance of the core–shell nanobelts was found to be reduced due to the formation of an electron accumulation layer in the SnO2 core. At temperatures above 530 °C, the thermal reduction of SnO2 and the associated decrease in its work function caused electrons to flow from the accumulation layer into the Ga2O3 shell, which resulted in an increase in bulk resistance. The junction resistance of said core–shell nanostructures was comparable to that of SnO2 nanobelts, as both structures are likely connected through existing SnO2/SnO2 homojunctions comprising thin amorphous layers.

A Straightforward Method to Estimate Battery's Condition Based on Its Internal Resistance Value

A battery condition monitor can be realized using several methods. Some of these methods have been proven to be more reliable than others. In this study, we focus on assessing a battery's condition based on its internal resistance value using a direct current method (DCM). We developed a simple, fast, and straightforward method, including the necessary equipment for this purpose. Only measurements of the battery's terminal (open-circuit) voltage and battery voltage under a certain load are required. We measured around 100 non-rechargeable AA batteries (double-A batteries) and estimated their internal resistances. Both alkaline and lithium-based batteries were tested. Our measurements show that measuring the terminal voltage (open-circuit voltage) alone does not provide an accurate enough status of a battery's condition or state-of-health, SoH. Especially when the battery condition is declining, the internal resistance value gives a better estimation of the battery's condition and usability.

Three-dimensional observation system of direct current method based on overlapping electrodes and its application

Three-dimensional observation system of direct current method based on overlapping electrodes and its application

Real-Time Prediction of Oil-Type Gas Emissions in Coal-Oil-Gas Coexistence Mines.

Oil-type gas disasters are a frequently occurring concern in coal-oil-gas coexistence mines. In order to actively predict the volume of oil-type gas emissions from floor rocks, this study presents an investigative methodology to forecast the geological conditions of floor rocks in front of the roadway face by utilizing the Direct Current (DC) method. The assessment of electrical resistance in rock formations, which is widely employed for identifying geological characteristics, serves as the basis for proposing a geological anomaly index derived from rock resistivity. This index effectively characterizes the stability of rock strata, providing an indirect evaluation of fracture development. As a real-time geological detection index for floor rocks that are 100 m ahead of the roadway face, it enhances predictive capabilities. Moreover, when combined with parameters such as floor rock thickness and permeability, the paper presents simulations of oil-type gas emissions under varying geological conditions. Subsequently, an adaptive optimization of the Back Propagation (BP) neural network is achieved through the Genetic Algorithm Back Propagation Neural Network (GA-BP) model to evaluate the quantity of oil-type gas emissions in roadways. This advanced real-time prediction method is applied in Huangling coal mining to predict the oil-type gas emissions from the floor rocks in the excavation roadway area. The results show consistency with field monitoring outcomes, confirming the accuracy of the predictive model. In conclusion, this advanced real-time prediction technique enables continuous monitoring and real-time forecasting of oil-type gas emissions in front of roadways. This capability facilitates the implementation of specific measures for pre-extraction in gas disaster prevention and control, thereby ensuring the safety of coal mine production. Moreover, the versatility of this advanced real-time prediction method extends to early warnings of rock mass instability-related disasters. Through a comprehensive understanding of subsurface conditions, continuous monitoring of changes, and the application of predictive models, timely actions can be taken to reduce risks and uphold safety standards.

2D and 3D Modeling of Resistivity and Chargeability to Identify the Type of Saturated Groundwater for Complex Sedimentary Facies

Determining the type and properties of saturated groundwater for complex sedimentary facies, as well as the various properties of these sedimentary facies, requires extensive geological, hydrogeological, and geophysical studies. Therefore, identifying the different types of subsurface deposits and their physical properties as well as their geological, hydrogeological, and structural settings are the interesting features in this study which play an important role in achieving its objectives. To achieve these objectives, the Direct Current (DC) resistivity method and the Direct Current Time-Domain Induced Polarization (DC-TDIP) method were used. These two methods were applied because they are complementary methods, one of which is more accurate in sediments saturated with fresh water (the DC resistivity method) and the other in sediments saturated with salt water (DC-TDIP method). Also, the DC-TDIP method was applied to avoid ambiguity in the resistivity results, as well as their results were compared with the available geological and hydrogeological field data. Accordingly, 2D and 3D resistivity values were designed to describe the hydro-lithological environment of the recorded sediments, and their hydrogeoelectric properties and groundwater zones were also identified and divided. Also, 2D and 3D chargeability values were designed to distinguish between sediments, their depositional facies, and their saturated water properties. These values also succeeded in separating clay from non-clay layers, and clay layers from layers containing salt water. Therefore, it was found that the integration between the two methods helped in identifying and visualizing the characteristics of the sediments and determining their facies and their water content, which helped in understanding the complex sedimentary facies recorded in the study area as well as identifying the types and characteristics of groundwater contained in these facies. Therefore, it can be recommended to apply the previous methodology and include the two geophysical methods and their results to study complex facies deposits and determine their water content and type, especially in similar depositional environments that are located next to a source of salt water mixed with other types of water.

Preparation of Nano twin copper foil with high elongation and excellent suppression self-annealing via pulse superposition direct current method

Pulse electroplated copper has recently received a great deal of attention from the copper foil and microelectronics industries, as its remarkable microstructure is closely linked to several key properties, including the availability of metallic materials with reduced porosity, fine deposited grains and low electrical resistance. The effects of pulse superimposed direct current (DC) on the microstructure and properties of copper foils were investigated by taking advantage of the high deposition rate of pulse current and the long-term stability and easy control of DC current. Further, tests such as scanning electron microscopy (SEM) and confocal laser microscopy (CLM) were used to characterize the surface micromorphology of the copper foils, and the influence of the self-annealing effect at ambient temperature was explored using electron backscattering diffraction (EBSD). The results show that pulsed superimposed DC can obtain copper foils with a small profile and high tensile strength with a Sz of only 0.670 μm, σust 538.67 MPa and an elongation of 4.90%. Further, the specific additive MESS effectively suppresses the mechanical property degradation caused by self-annealing of copper foils, with a tensile strength reduction of only 0.39%.

The Influence of Bias Voltage on the Structure and Properties of TiZrNbMo Coating Deposited by Magnetron Sputtering

TiZrNbMo coatings have been deposited using the direct current pulsed magnetron sputtering method in an argon atmosphere. The synthesis processes have been conducted under various process parameters. The structure (chemical and phase composition) and mechanical properties of the obtained multicomponent coatings are investigated as a function of plasma modulation frequency (10 Hz and 1000 Hz) and substrate bias (0 to −150 V). It is the case that an increase in the substrate bias decreases the deposition rate and alters the coating’s chemical composition. The latter leads to a Ti concentration decrease and a simultaneous increase in Mo and Nb concentrations in the final coating material. X-ray diffraction measurements indicate a single-phase BCC structure, with grain size decreasing as substrate bias increases. This ultimately forms an amorphous–nanocrystalline structure at −150 V. The mechanical properties of the multicomponent TiZrNbMo coatings have been determined using the nanoindentation method. The maximum values of hardness (13.45 GPa) and elastic modulus (188.6 GPa) are achieved at a substrate bias of −150 V. We also show that the minimum elastic modulus (41.8 GPa) is achieved at an intermediate substrate bias of −100 V.

Features of electrical transport and H/D isotope effects in the proton-conducting electrolyte BaCe0.7Zr0.1Y0.1Yb0.1O3-δ

The electrical properties of the proton-conducting electrolyte BaCe0.7Zr0.1Y0.1Yb0.1O3-δ were studied using the 4-probe direct current (DC) method depending on temperature and oxygen partial pressure in the atmospheres, humidified with H2O and D2O. Ionic and electron hole contributions to the electrical conductivity were determined, and the transport numbers of charge carriers were calculated. It is shown that in air conditions BaCe0.7Zr0.1Y0.1Yb0.1O3-δ is a mixed ion-electron hole conductor. The contribution of electron hole conductivity decreases with the decrease of temperature and oxygen partial pressure. A significant isotope H/D effect in the electrical conductivity is observed for all investigated conditions expressed in the decrease in conductivity in D2O-containing atmospheres with the increase of activation energy values. Replacing H2O with D2O leads to decrease in the ion transport numbers and ionic conductivity values, while the electron hole conductivity remains almost the same.

Geoelectric Investigation for Groundwater in Imo State University Campus and Environs using Direct Current Electrical Resistivity Method

Eighteen, vertical electrical soundings (VES), were carried out in Imo State University and Environs to delineate the potential site for groundwater. Data were acquired using ABEM SAS 300 resistivity meter. Schlumberger array and maximum electrode spread of 700m were adopted. Data were interpreted with IP2WIN software. Contour maps were done using Sulfer 20 software. Geoelectric cross-sections constructed along three profile lines delineated subsurface stratification. Sediments consist of sequence of sandstone/gravel, silty sand/sand and clay with geology representing the Benin Formation. Groundwater was delineated within the zone interpreted to be sand with quartz making up more than 95% of all grains. Resistivity of aquifer varies across study area and ranges from 159Ωm, observed around Library and Information Department (VES 11) to 100000Ωm recorded at IMSU Plaza (VES 10). Depth to water table also varied across study area with higher values of 150m and 130m observed at College of Health Science (VES 3) and Behind Old ETF (VES 4). A relatively shallow aquifer is delineated behind Senate Building and Okwu-Uratta with water table at depths of 23.5m and 26.5m. The transmissivity values are moderately high except at some locations. The variation in longitudinal conductance and transverse resistance values show that part of the study area such as Aso Rock, Female Hostel, Law Faculty and IMSU Plaza are underlain by relatively resistive (low longitudinal conductance) aquifer material. Distribution of hydraulic conductivity and electrical conductivity values indicates that in some of the VES points, the values are fairly constant. This could be seen as areas with similar geologic settings and water quality. Storativity of study area ranges from 0.00003 at VES 1 and 12 to 0.00028 at VES 4. Study area shows a good prospect for groundwater development, except at Library and Information Department, where the zone delineated is an aquitard.

In situ coupling of reduction and oxidation processes with alternating current-driven bioelectrodes for efficient mineralization of refractory pollutants

The effective elimination of aromatic compounds from wastewater is imperative for safeguarding the ecological environment. Bioelectrochemical processes that combine cathodic reduction and anodic oxidation represent a promising approach for the biomineralization of aromatic compounds. However, conventional direct current bioelectrochemical methods have intrinsic limitations. In this study, a low-frequency and low-voltage alternating current (LFV-AC)-driven bioelectrode offering periodic in situ coupling of reduction and oxidation processes was developed for the biomineralization of aromatic compounds, as exemplified by the degradation of alizarin yellow R (AYR). LFV-AC stimulated biofilm demonstrated efficient bidirectional electron transfer and oxidation–reduction bifunctionality, considerably boosting AYR reduction (63.07% ± 1.91%) and subsequent mineralization of intermediate products (98.63% ± 0.37%). LFV-AC stimulation facilitated the assembly of a collaborative microbiome dedicated to AYR metabolism, characterized by an increased abundance of functional consortia proficient in azo dye reduction (Stenotrophomonas and Bradyrhizobium), aromatic intermediate oxidation (Sphingopyxis and Sphingomonas), and electron transfer (Geobacter and Pseudomonas). The collaborative microbiome demonstrated a notable enrichment of functional genes encoding azo- and nitro-reductases, catechol oxygenases, and redox mediator proteins. These findings highlight the effectiveness of LFV-AC stimulation in boosting azo dye biomineralization, offering a novel and sustainable approach for the efficient removal of refractory organic pollutants from wastewater.

The impact of renewable energy sources on the overload of high voltage lines – power flow tracking versus direct current method

Studying the impact of renewable energy sources planned to be connected to the grid, requires the preparation of expert opinions. The task of this opinion is to verify that there are possibilities enabling the connection of the considered source to the network. Each opinion is required to take into account other facilities and those sources which were previously connected to the grid or connection agreement were signed with them. The need to take into account such a large number of sources contributes to potential thermal overloads of high-voltage lines. Sometimes these overloads are insignificant, but in certain situations it turns out that their occurrence may be a reason for refusing to sign connection agreements for new sources. According to network operators, their presence may constitute a threat to the operational security of the grid. The article presents the use of the method of tracking active power flows and the DC method of determining power flows to estimate the impact of these sources on thermal overloading of lines. Using of the IEEE-118 test network, selected nodes were analysed where connecting sources might significantly worsen overloads previously observed or would cause new overloads. The proposed approach will enable potential investors to make proper decisions regarding selection of source connection points. Combining the results obtained by both methods at the same time will allow for the indication of appropriate connection nodes for sources from the point of view of minimising the number of overloaded lines and prospective costs of their uprating.

Research on Quantitative Diagnosis of Dendrites Based on Titration Gas Chromatography Technology

Lithium plating can cause capacity fade and thermal runaway safety issues in lithium-ion batteries. Therefore, accurately detecting the amount of lithium plating on the surface of the battery’s negative electrode is crucial for battery safety. This is especially crucial in high-energy-density applications such as battery energy storage systems or in electric vehicles (EVs). Early detection of lithium plating is crucial for evaluation of reliability and longevity. It also serves as a method for early diagnostics in practical industrial applications or infrastructure, such as EV transportation. This can enhance its impact on customers. This study validates the effectiveness of titration gas chromatography (TGC) technology in quantitatively detecting lithium plating on graphite negative electrodes in lithium-ion batteries. The results show that it can detect a minimum of 2.4 μmol of metallic lithium. Compared with the heating direct current resistance and reference electrode methods, which can be used to perform only qualitative dendrite detection, TGC has a wider range of detection. Compared with the nuclear magnetic resonance (NMR) method with higher quantitative detection accuracy, the maximum difference between the detection results of the two methods was only 7.2%, but the TGC method had lower cost and higher implementation convenience. In summary, among various dendrite detection methods, the TGC method can not only realize the effective quantitative detection of lithium plating, but also comprehensively consider its detection range, implementation convenience, cost, and detection accuracy, indicating that it is suitable for engineering applications and has the prospect of realizing large-scale quantitative detection of lithium plating in lithium-ion batteries.

Effect of sputtering pressure on the properties of large area IWO thin films deposited by direct current magnetron sputtering

Tungsten doped indium oxide (In2O3: W, IWO) thin films have been attracting increasing attention due to their excellent optoelectronic properties. Here, a series of IWO thin films were prepared using direct current (DC) magnetron sputtering method, by varying the sputtering pressure. Analysis revealed that the IWO films prepared under sputtering pressure of 0.4 Pa exhibited excellent optoelectronic performance, with low square resistance, resistivity, high carrier concentration and mobility. The resulting semi-transparent perovskite solar cells (ST-PSCs), with IWO fabricated under 0.4 Pa, yield a PCE of 15.71 % for the large area modules of 100 cm2 (active area 64.8 cm2).

Forward and inversion approach for direct current resistivity based on an unstructured mesh and its application to tunnel engineering

AbstractThe accurate identification of water‐bearing structures is urgently required for the safe construction of tunnel engineering. Currently, the direct current resistivity method is an effective method for detecting water‐bearing structures in tunnels. In the advanced detection of the direct current resistivity based on the finite element method, the traditional hexahedron mesh performs poorly for the discretization of models of complex tunnel structure sections such as horseshoe‐shaped and round sections. Therefore, this study adopts unstructured grid generation technology combining tetrahedra and hexahedra to achieve more accurate modelling of complex structures, such as round and horseshoe‐shaped sections, and establishes a forward modelling method of the direct current resistivity in tunnels based on an unstructured mesh. The maximum error between the numerical simulation and theoretical results for an infinite tabular body in full space is less than 0.8%. It is more complicated to calculate the sensitivity matrix and model constraint term for the inversion region containing two types of grid than for one. For this purpose, the sensitivity matrix of different types of grid areas is calculated, a model constraint term based on the dual constraints of volume and distance is constructed, and finally, a partitioned domain‐weighted least‐squares inversion method based on an unstructured mesh is proposed. Synthetic examples of typical water‐bearing structures are analysed, and the results show that the proposed forward and inverse methods of the direct current resistivity in tunnels based on an unstructured mesh can effectively capture the position and morphology of the water‐bearing structure. Finally, an on‐site application was conducted in the Yellow River Diversion Project in central Shanxi. The proposed method could effectively identify the water body in front of the tunnel face and guide the on‐site construction of the project. These results can improve the interpretation of the direct current resistivity data in tunnels and play a positive role in promoting the use of the direct current resistivity method to prevent and control water‐inrush disasters in tunnels with complex structures.

Groundwater Protection Assessment using Frequency Domain Electromagnetic Method and Direct Current Electrical Resistivity Method in Papalanto South-West Nigeria

The aim of this work is to assess the extent of protection of the subsurface hydrogeological structures. Fieldworks were performed integrated geophysical techniques namely Frequency Domain Electromagnetic Method (FDEM) using Geonics-EM-34 to determine the vertical and lateral variations of subsurface conductivity probing depths of 20m, 40m and 60m, while subsurface profiles were obtained using Direct Current Resistivity (DCRE) with AGI Super-sting Earth Resistivity meter; current electrode spacing (AB) ranging from 1 to maximum of 100m and the potential electrodes (MN) were consequently changed from 0.25m to 5m respectively. 1141.92 mmho/m was recorded as the highest true conductivity value for the Horizontal Dipole in the second layer (Profile EMPAP5) while the highest true conductivity value for the Vertical Dipole in the first layer was 134.31 mmho/m (Profile EMPAP1). Four principal geoelectric layers inferred from the VES data where the Topsoil is partly lateritic and alluvium, Sandy Clay/Clay/Silt, Sand/Clay/Shale, and Limestone/Sandstone. Resistivity values for these layers vary from 9.78 to 1428, 1.46 to 1057, 1.46 to 451, and 15 to 10,000 Ω m with corresponding thickness of 0.5m to1.43m, 1.29m to 13m, 2.8m to 84.4m and infinity, respectively. The higher resistivity values at the surface and extremes of both edges were indication of little or no presence of leachates or contaminant plume accumulation in other area. Also, there was a noticeable general decrease of resistivity values of formation rock with depth in these investigated areas; this is an indication that the plumes must have infiltrated rapidly into the subsurface through the massive presence of weathered rock materials of average lateral distances of 15m to 167m of considerable depth and thickness of about 24.9m. The degree of leachate contamination range from 0.0007264 mho to 0.668 mho with the highest value in VESPAP2 followed by VESPAP13 and VESPAP19 while VESPAP22 exhibited the lowest conductance.

Parallel multi‐rate simulation scheme for modular multilevel converter‐based high‐voltage direct current with accurate simulation of high‐frequency characteristics and field programmable gate array‐based implementation

AbstractThe real‐time simulation of the modular multilevel converter‐based high‐voltage direct current (MMC‐HVDC) transmission system has become a popular research topic. However, in order to meet the real‐time performance, the real‐time simulation technology will cause additional simulation errors for MMC‐HVDC, especially on its frequency characteristics. Therefore, a parallel multi‐rate simulation scheme for MMC‐HVDC is developed in this work to ensure accurate simulation of high‐frequency characteristics. Firstly, a non‐error method based on converter transformer decoupling is proposed to decouple the converter and alternating current system; direct current transmission line decoupling and arm decoupling methods are used to achieve decoupling among and within converters. A multi‐rate data synchronous mechanism is established by considering the differences among high‐frequency characteristics caused by delayed data interaction. Secondly, the computing architectures of the primary system solver and modular multilevel converter controller are designed based on a field programmable gate array (FPGA). The real‐time simulation platform for a four‐terminal true bipolar MMC‐HVDC is constructed based on the FPGA array. Thirdly, the factors in multi‐rate simulation affecting the simulation accuracy of high‐frequency characteristics are analysed. The simulator is shown to be accurate in steady and dynamic states. The authors also verify its applicability for further research on high‐frequency resonance based on control experiments.

Insights into the Mechanism of Selective Removal of Heavy Metal Ions by the Pulsed/Direct Current Electrochemical Method.

Heavy metal pollution treatment in industrial wastewater is crucial for protecting biological and environmental safety. However, the highly efficient and selective removal of heavy metal ions from multiple cations in wastewater is a significant challenge. This work proposed a pulse electrochemical method with a low-/high-voltage periodic appearance to selectively recover heavy metal ions from complex wastewater. It exhibited a higher recovery efficiency for heavy metal ions (100% for Pb2+ and Cd2+, >98% for Mn2+) than other alkali and alkaline earth metal ions (Na+, Ca2+, and Mg2+ were kept below 3.6, 1.3, and 2.6%, respectively) in the multicomponent solution. The energy consumption was only 34-77% of that of the direct current electrodeposition method. The results of characterization and experiment unveil the mechanism that the low-/high-voltage periodic appearance can significantly suppress the water-splitting reaction and break the mass-transfer limitation between heavy metal ions and electrodes. In addition, the plant study demonstrates the feasibility of treated wastewater for agricultural use, further proving the high sustainability of the method. Therefore, it provides new insights into the selective recovery of heavy metals from industrial wastewater.