The fabrication of 304L stainless welding wires with a diameter 1.6 mm by using electrochemical cold drawing(ECD)of bars with a diameter of 5.6 mm was investigated,as well as that via traditional cold drawing(TCD)for ...The fabrication of 304L stainless welding wires with a diameter 1.6 mm by using electrochemical cold drawing(ECD)of bars with a diameter of 5.6 mm was investigated,as well as that via traditional cold drawing(TCD)for comparison.The results indicated that the dilute H_(2)SO_(4)aqueous solution was an appropriate electrolyte for ECD,and increasing the H_(2)SO_(4)concentration and current density within a range improved the corrosion rate and uniformity,leading to an easier and more coordinated deformation through uniformly distributing geometrically necessary dislocations and curved large-angle grain boundaries,and decreasing their density,and thus,an enhanced electrochemical plasticization(EP).Under the optimized electrochemical parameters(0.5 mol L^(-1)H_(2)SO_(4)electrolyte and current density of 12.2 mA cm^(-2)),the average cumulative reduction rate required for annealing was up to~34%,obviously higher than~20%of TCD due to the decreased work-hardening from the EP,so that the number of annealing was significantly reduced from 10 of TCD to 5,when the drawing pass was 23.In addition,the surface of the ECD wire was distinctly smoother and brighter than that of the TCD one.These findings confirm the large potential in engineering applications of the ECD technology based on the EP effect.展开更多
Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling perf...Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling performance.The design of a better cathode material is needed to overcome these limitations.A simple method was used to synthesize binder-free electrochemically exfoliated carbon paper(EECP)which modifies the surface of the paper by introducing oxygen functional groups and thus improves its pseudocapacitance.When used in a Zn-ion supercapacitor(ZISC),an EECPbased cathode provides a large surface area and quick charge transfer.As a result,the ZISC had remarkable charge storage properties and had a dominant capacitive-type charge storage mechanism with 78.8%retention of capacity at 10 mV/s of the total storage.Furthermore,at 1 A/g,the EECP electrode had a maximum capacitance of 252.5 F/g.The EECP electrode retained 81.7%of its capacitance after 10000 cycles,indicating its promise for use in the growing renewable energy sector.A ZISC was also constructed using EECP as the positive electrode and Zn as the negative electrode with a 1 mol L^(−1) ZnSO_(4) electrolyte.It had a capacitance of 186.22 F/g at 1 A/g and a 97.01%retention rate after 10000 cycles.It also had an excellent energy density of 46.6 Wh/kg at a power density of 500.4 W/kg.The material is therefore suitable for use in high-rate next-generation ZISCs.展开更多
High-sensitive quantitative determination of alpha-fetoprotein(AFP)is of crucial importance for early clinical diagnosis of cancers.Herein,an AuNPs-free electrochemical immunosensor(Ab1-Fc-COF)was prepared from a carb...High-sensitive quantitative determination of alpha-fetoprotein(AFP)is of crucial importance for early clinical diagnosis of cancers.Herein,an AuNPs-free electrochemical immunosensor(Ab1-Fc-COF)was prepared from a carboxylic group enriched COF by post-functionalization with detecting antibody(Ab1)and ferrocene(Fc),and used for electrochemical detection of AFP.Due to the small,homogeneous pore size of the COF,Ab1 with a big size was immobilized on the surface of the COF,while Fc with a small size was covalently modified both on the surface and in the pores of COF.The covalently immobilized Ab1 was quite stable and beneficial to specifically detect AFP biomarkers.Meanwhile,the enriched Fc molecules not only improved the conductivity of the COF,but also effectively transferred and amplified the electrochemical signal.This proposed immunosensor exhibited high sensitivity in detecting AFP with a detection limit of 0.39 pg/mL(S/N of 3:1)and a wide linear response range spanning from 1 pg/mL to 100 ng/mL when plotted against logarithmic concentrations.Furthermore,this immunosensor showed excellent selectivity,stability and reproducibility in the testing of real samples.This study presents an innovative prototype for construction of a precious metal-free,antibody-directly-immobilized,simple and stable electrochemical immunoprobe.展开更多
Electrochemical nitrate reduction reaction(NO_(3)RR)is a sustainable strategy to treat wastewater and produce ammonia.However,it is still a challenge to prepare electrocatalysts with high activity and selectivity.Here...Electrochemical nitrate reduction reaction(NO_(3)RR)is a sustainable strategy to treat wastewater and produce ammonia.However,it is still a challenge to prepare electrocatalysts with high activity and selectivity.Herein,the CuO_(x) nanowires supported Ru nanoclusters(Ru-CuO_(x))were fabricated via a three-step procedure for efficient nitrate conversion and highly selective ammonia generation.The prepared RuCuO_(x) shows a high ammonia yield rate of 2286.5μg h^(-1) cm^(-2) at-0.7 V vs.RHE and Faradaic efficiency(FE)of 80.1%at-0.4 V vs.RHE.Additionally,the nitrate conversion rate exceeds 90%at the potential range from-0.2 to-0.7 V vs.RHE,and the ammonia selectivity can reach 97.7%at-0.7 V vs.RHE in100 mg L^(-1) NaNO_(3) solution.The systematic characterizations clarify that the introduction of Ru not only regulates the electronic structure of CuO_(x) and accelerates the reconstruction of CuO_(x) to Cu but also promotes H2O dissociation to generate active hydrogen.Moreover.in-situ Raman spectroscopy reveals that the formed Ru-Cu is considered the actual active species during the NO_(3)RR.Density functional theory(DFT)calculations further prove that the obtained Ru-Cu facilitates the adsorption of nitrate and lowers the Gibbs free energy of the rate-determining step,thus improving the NO_(3)RR performance.展开更多
Abuse of chloramphenicol(CAP)could cause serious side effects to human health.Therefore,it is necessary to detect CAP residues in animal sourced food effectively.Here,the superiority(better stability,higher Apt-CAP lo...Abuse of chloramphenicol(CAP)could cause serious side effects to human health.Therefore,it is necessary to detect CAP residues in animal sourced food effectively.Here,the superiority(better stability,higher Apt-CAP loading efficiency,and higher CAP binding associated conformational change,etc.)of tetrahedral structure to double-chained structure for developing aptasensor was evaluated.Then,a self-assembled DNA tetrahedral structure-based electrochemical aptasensor targeting CAP was developed.Under the optimized conditions,the aptasensor exhibited high sensitivity toward CAP with a limit of detection(LOD)of 0.0676 ng/m L(linear range 0.19-387.76 ng/m L),and high selectivity against the structural analogs of CAP.Moreover,the recovery rate of CAP from spiked milk samples ranged from 100.57%to 101.69%,and only USD 1.34 is needed for detecting CAP in 1 sample.These results suggested the application potential of this aptasesor for detecting CAP in animal sourced foods.展开更多
Glucose,ascorbic acid(AA),uric acid(UA),and dopamine(DA)are vital biomarkers whose dynamic concentrations correlate with critical diseases;however,multiplexed detection remains challenging for conventional electrochem...Glucose,ascorbic acid(AA),uric acid(UA),and dopamine(DA)are vital biomarkers whose dynamic concentrations correlate with critical diseases;however,multiplexed detection remains challenging for conventional electrochemical sensors because of their limited sensitivity and selectivity.Here,we present a millimeter-scale all-poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)organic electrochemical transistor(OECT)platform that integrates dual-mode sensing with enzyme/metal-free operation for ultrasensitive biomarker monitoring.By engineering polycrystalline PEDOT:PSS channels via H_2 SO_4 post-treatment,the device achieves record-high conductivity(about(2312.0±29.9)S·cm^(–1)),maximum transconductance(about(2.82±0.12)mS),and on/off ratio(about 210.0±7.8),enabling signal amplification at low gate voltages.The dual-mode strategy combines the selectivity of electrochemistry with the sensitivity of OECTs,realizing simultaneous detection of glucose,AA,UA,and DA with clinical-level sensitivity:detection limits down to 8 nmol·L^(–1)(glucose),0.5 nmol·L^(–1)(AA),5 nmol·L^(–1)(DA),and 0.5 nmol·L^(–1)(UA).Validation using human urine samples yielded recovery rates of 94%–114%.This flexible sensing platform provides a new pathway for the development of wearable biosensors for precision diagnostics.展开更多
With the rapid development of electric vehicles and grid-scale renewable integration,the demand for lithium-ion batteries(LIBs)has significantly increased with high expectations on enhanced energy density,cycle stabil...With the rapid development of electric vehicles and grid-scale renewable integration,the demand for lithium-ion batteries(LIBs)has significantly increased with high expectations on enhanced energy density,cycle stability,and failure resilience.Electrochemical models(EMs),serving as pivotal mechanismdriven analytical frameworks in battery research and applications,demonstrate unprecedented quantitative fidelity in characterizing intricate multi-physics dynamics for the next-generation battery management systems(BMS).The breakthrough innovations in artificial intelligence(AI)driven methods have revolutionized the dynamic modeling of LIBs.However,the deployment of AI-augmented EMs in BMS faces significant identifiability challenges due to strong parameter coupling.In addition,research on model simplification,parameter determination,and dynamic parameter identification remains largely fragmented.There is a lack of a comprehensive review to pave the way for the cross-domain innovations in BMS.To fill this gap,this paper presents a systematic review of the EMs for LIBs and examines the advancements in parameter determination techniques from both experimental measurement and numerical simulation perspectives.Besides,a comprehensive assessment of the progress in parameter identification from the standpoint of dynamic recognition is presented,encompassing both modelbased approaches and intelligent methods.Additionally,from the BMS standpoint,the strengths and limitations of existing approaches are evaluated.Finally,a coordinated framework for multi-stage identification needs to be established in the future.The potential of digital twins(DT),deep reinforcement learning(DRL),and large language models(LLMs)in enhancing EMs also warrants further exploration.The purpose of this work is to provide insights and guidance for the future development of EMs in LIB applications.展开更多
To improve the solid–solid interface performance of all solid-state lithium batteries(ASSLBs),a novel sandwich-structured solid electrolyte(SSE,total thickness of 0.7 mm)was investigated.It comprises a central layer ...To improve the solid–solid interface performance of all solid-state lithium batteries(ASSLBs),a novel sandwich-structured solid electrolyte(SSE,total thickness of 0.7 mm)was investigated.It comprises a central layer of perovskite-type Li_(0.37)Sr_(0.44)Zr_(0.25)Ta_(0.75)O_(3)(LSZT)electrolyte(thickness of 0.5 mm)sandwiched between two layers of composite solid polymer electrolyte(CSPE,each with a thickness of 0.1 mm).The thin CSPE interlayer not only effectively reduces interfacial resistance between LSZT and electrodes,but also suppresses Li-induced reduction degradation of LSZT while ensuring uniform current density distribution across the interface.The SSE demonstrates an ionic conductivity of 8.76×10^(−5)S·cm^(−1)at 30℃,increasing to 1.13×10^(−3)S·cm^(−1)at 100℃,with an activation energy of 0.36 eV.In addition,SSE is stable for Li metal and achieves electrochemical stability up to 4.58 V vs.Li^(+)/Li.SSE shows outstanding electrode/electrolyte interfacial compatibility and significant suppression of the growth of Li dendrite.Ascribing to these merits,Li|SSE|Li symmetric cell maintained stable operation for 500 h at a current density of 0.3 mA·cm^(−2)without short circuit,confirming robust interfacial compatibility between SSE and Li electrode.The all-solid-state LiFePO_(4)|Li battery with SSE has an initial reversible discharge capacity of 109.8 mAh·g^(−1)and a reversible capacity of 118.1 mAh·g^(−1)after 50 cycles at a charge/discharge rate of 0.1C(30℃),demonstrating good cycling performance.展开更多
In manganese electrolysis,electrochemical oscillations and manganese dendrite growth are typical nonlinear phenomena critical for energy consumption reduction.Nonetheless,existing research lacks a deep understanding o...In manganese electrolysis,electrochemical oscillations and manganese dendrite growth are typical nonlinear phenomena critical for energy consumption reduction.Nonetheless,existing research lacks a deep understanding of their underlying mechanisms.In this study,we systematically explored the evolution of anode electrochemical oscillations during manganese electrolysis and designed a square wave circuit to effectively suppress oscillations and dendrite growth while reducing energy consumption.A novel four-dimensional differential equation was introduced to explore the internal dynamic mechanisms of typical nonlinear behaviors.The experimental results showed that while the evolutionary patterns of current and potential oscillation signals were consistent,their waveform directions were opposite.The square wave current effectively suppressed both electrochemical oscillations and the growth of manganese dendrites.Furthermore,compared to direct current electrolysis,the square wave current improved the current efficiency by 3.6%and reduced the energy consumption by 0.32 kW·h·kg^(−1).展开更多
Organic electrochemical transistors(OECTs)are promising for next-generation bioelectronics due to their high performance and biocompatibility.Nevertheless,they still face tremendous operational stability challenges du...Organic electrochemical transistors(OECTs)are promising for next-generation bioelectronics due to their high performance and biocompatibility.Nevertheless,they still face tremendous operational stability challenges due to the limited robustness of the organic mixed ionic-electronic conductor(OMIEC)channel.Here,by modulating the molecular weight(MW)of OMiEC,enhanced OECT and relevant circuit operation stabilities are demonstrated,showing more than 3,000,0o0 full cycles(~42 h)with less than 15%current variation in an OECT,and 150,000 cycles(~4 h)with less than 5%voltage variation in an OECT-based inverter,which are among the highest of reported OECT-based electronics.Specifically,p(g2T-T),a typical p-type OMIEC,with varying MW(7-43 kDa),is synthesized,where lower-MW p(g2T-T)(~9 kDa)exhibits superior device performance and cycling stability in OECTs,outperforming those in high-MW counterparts(>30 kDa).It is indicated that low-MW p(g2T-T)maintains higher volumetric capacitance,ordered orientation,and reduced swelling.Therefore,irreversible microstructural degradation is effectively avoided,along with better performance yield.Furthermore,MW regulation enables physiological signal sensing with high tolerance to body fluid environments for 7 days.These findings highlight MW modulation as a versatile approach to suppress excessive swelling,advancing the design of durable OECT-based electronics.展开更多
The application of conventional manganese dioxide(MnO_(2))materials in sodium-ion supercapacitors(Na-SCs)is considerably limited by their low conductivity and structural instability.Biomimetic morphology engineering c...The application of conventional manganese dioxide(MnO_(2))materials in sodium-ion supercapacitors(Na-SCs)is considerably limited by their low conductivity and structural instability.Biomimetic morphology engineering can optimize the electrochemical performance of MnO_(2).Here,based on the metal-organic frameworks(MOFs)-derived method and electrochemical reconstruction,a coral-like MnO_(2)structure integrated with a functional nitrogen-doped carbon(NC)coating is designed for Na-SC application.The bioinspired coral-like structure captures numerous electrolyte ions and increases the Na+concentration on the electrode surface,which is beneficial for optimizing the Na+transport pathway and accelerating the electrode reaction kinetics.Moreover,the coral-like crosslinked structure effectively enhances the mechanical properties,enabling the maintenance of the structure of MnO_(2)-based electrodes during long-term operation.Furthermore,in/ex-situ characterizations are performed to elucidate the mechanism of lattice transformation during electrochemical phase reconstruction.Additionally,the theoretical calculation and simulation results reveal the ion/electron dynamics in the fabricated electrode.The prepared electrode demonstrates excellent capacitance storage ability(340.7 F g^(−1)at 0.5 A g^(−1))and cycling stability(85.1%capacitance retention after 10,000 cycles).The assembled hybrid device exhibits exceptional life-span(82.0%capacitance retention after 10,000 cycles)and exceptional energy density(36.5 Wh kg^(−1)).This study provides a reliable biomimetic morphology design strategy for MnO_(2)cathodes,paving the way for the fabrication of high-performance Na-SCs.展开更多
During electrochemical machining(ECM),the passivation film formed on the surface of titanium alloy can lead to uneven dissolution and pitting.Solid particle erosion can effectively remove this passivation film.In this...During electrochemical machining(ECM),the passivation film formed on the surface of titanium alloy can lead to uneven dissolution and pitting.Solid particle erosion can effectively remove this passivation film.In this paper,the electrochemical dissolution behavior of Ti-6.5Al-2Zr-1Mo-1V(TA15)titanium alloy at without particle impact,low(15°)and high(90°)angle particle impact was investigated,and the influence of Al_(2)O_(3)particles on ECM was systematically expounded.It was found that under the condition of no particle erosion,the surface of electrochemically processed titanium alloy had serious pitting corrosion due to the influence of the passivation film,and the surface roughness(Sa)of the local area reached 10.088μm.Under the condition of a high-impact angle(90°),due to the existence of strain hardening and particle embedding,only the edge of the surface is dissolved,while the central area is almost insoluble,with the surface roughness(S_(a))reaching 16.086μm.On the contrary,under the condition of a low-impact angle(15°),the machining efficiency and surface quality of the material were significantly improved due to the ploughing effect and galvanic corrosion,and the surface roughness(S_(a))reached 2.823μm.Based on these findings,the electrochemical dissolution model of TA15 titanium alloy under different particle erosion conditions was established.展开更多
The pseudo-two-dimensional(P2D)model plays an important role in exploring physicochemical mechanisms,predicting the state of health,and improving the fast charge capability for Li-ion batteries(LIBs).However,the fast ...The pseudo-two-dimensional(P2D)model plays an important role in exploring physicochemical mechanisms,predicting the state of health,and improving the fast charge capability for Li-ion batteries(LIBs).However,the fast charge leads to the lithium concentration gradient in the solid and electrolyte phases and the non-uniform electrochemical reaction at the solid/electrolyte interface.In order to decouple charge transfer reactions in LIBs under dynamic conditions,understanding the spatio-temporal resolution of the P2D model is urgently required.Till now,the study of this aspect is still insufficient.This work studies the spatio-temporal resolution for dynamic/static electrochemical impedance spectroscopy(DEIS/SEIS)on multiple scales.In detail,DEIS and SEIS with spatio-temporal resolutions are used to decouple charge transfer reactions in LIBs based on the numerical solution of the P2D model in the frequency domain.The calculated results indicate that decoupling solid diffusion requires a high spatial resolution along the r-direction in particles,decoupling electrolyte diffusion and interfacial transfer reaction requires a high spatial resolution along the x-direction,and decoupling charge transfer reactions in LIBs at an extremely low state of charge(SOC)requires an extremely high temporal resolution along the t-direction.Finally,the optimal range of spatio-temporal resolutions for DEIS/SEIS is derived,and the method to decouple charge transfer reactions with spatio-temporal resolutions is developed.展开更多
In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mi...In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mild conditions.Various substituted benzylamines containing diverse functional groups and even highly reactive moieties,such as cyano,amide and alkene groups could be successfully transformed to the carboxylated products.Notably,this method proved to be applicable to the late-stage modification of biorelevant compounds,highlighting its potential for synthetic chemistry.Mechanistic studies such as radical trapping experiments,kinetic isotope effect(KIE) tests and cyclic voltammetry(CV) studies provided useful insight into this transformation.展开更多
Supercapacitors represent one specific class of energy storage devices that bridge the gap between traditional capacitors and batteries.In current work,δ-MnO_(2) nanoflakes arrayed on electrochemically exfoliated gra...Supercapacitors represent one specific class of energy storage devices that bridge the gap between traditional capacitors and batteries.In current work,δ-MnO_(2) nanoflakes arrayed on electrochemically exfoliated graphene(EEG)nanosheets were easily made as one composited electrode material for boosting the charge storage performances of supercapacitors.Coupled with the fluent electron and ion transport from two-dimensional EEG nanosheets,the uniformly anchoredδ-MnO_(2) nanoflake arrays present high reversible capacity,superior cycling stability,and unique rate capability.As expected,the MnO_(2)/EEG-10 electrode delivers high specific capacitance of 190 F·g^(−1) at 0.2 A·g^(−1),and holds 97.3%of its initial capacitance after 10000 cycles at 5 A·g^(−1).Furthermore,an asymmetrical supercapacitor using MnO_(2)/EEG-10 as the positive electrode achieves an energy density of 17.7 W·h·kg^(−1) at a power density of 922.7 W·kg^(−1) with 82.9%capacity retention upon 10000 cycles at 5 A·g^(−1).This work highlights the facile fabrication of high-performance MnO_(2)/graphene composites with excellent structure stability using graphene nanosheets as the conductive matrix.展开更多
The rate capability and cycling stability of sodium metal batteries taking FeS_(2) or sulfur as cathode are limited due to their low reaction kinetics and severe shuttle effect.Herein,we rationally design a novel sing...The rate capability and cycling stability of sodium metal batteries taking FeS_(2) or sulfur as cathode are limited due to their low reaction kinetics and severe shuttle effect.Herein,we rationally design a novel single-atom-dispersed S_(2)-FeNC/FeS_(2) nanocluster heterojunction embedded in carbon spheres(SFNC/FeS_(2)) for the electrode material of sodium metal batteries.Interestingly,during the discharging process,the Na^(+) is inserted into FeS_(2) to generate Na_(2)S,as well as the unique electrochemical reaction between S_(2)-FeNC and Na^(+) to form Na_(2)S.Meanwhile,the FeNC can adsorb Na_(2)S and catalyze the conversion from Na_(2)S and Fe to FeS_(2) or from Na_(2)S and FeNC to S_(2)-FeNC for suppressing the shuttle effect and promoting the distinct hybrid reversible electrochemical behavior,which improves performance tremendously.Notably,the SFNC/FeS_(2) electrode delivers a specific capacity of 338.7 mAh g^(-1) after superlong 2000 cycles at a current density of 5.0 A g^(-1) and achieves a high energy density of 430.1 Wh Kg^(-1) at a current density of 0.05 A g^(-1).This work presents a novel approach to studying sodium metal batteries with hybrid behavior for excellent high energy density and cycling stability.展开更多
Amorphous materials represent a promising platform for advancing CO_(2)electrochemical reduction due to their inherently diverse coordination environments.In this study,we demonstrate computationally the superior perf...Amorphous materials represent a promising platform for advancing CO_(2)electrochemical reduction due to their inherently diverse coordination environments.In this study,we demonstrate computationally the superior performance of amorphous CuNi alloys for CO_(2)electrochemical reduction.By integrating machine learning forcefields for efficient structure generation and density functional theory for subsequent structural refinement and property calculations,we reveal the potential of these disordered systems to outperform their crystalline counterparts.Machine learning forcefields can generate a bulk structure containing a mixture of Cu and Ni atoms,resulting in enhanced catalytic performance.Effective screening of the amorphous surfaces is used to identify undercoordinated Cu and Ni sites in the amorphous structure to synergistically promote selective CO production and favor ethanol formation over ethylene via the stabilization of the*COCHO intermediate,resulting in significantly lower Gibbs free energy changes compared to the crystalline counterpart.The varying atomic coordination environments on amorphous surfaces promote both C–C bond formation and subsequent proton-electron transfer,leading to ethanol formation.These findings demonstrate the superior catalytic performance of amorphous CuNi,highlighting its potential for efficient and selective electroreduction of CO_(2).展开更多
Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed f...Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed flow-through electrochemical reactors(FERs)primarily based on porous electrodes,where the pore structure significantly impacts the electrochemical reaction.Therefore,this study systematically investigated the impact of different pore sizes on the fluid dynamics,current potential distribution,mass transfer processes,and degradation performance of FERs.Computational Fluid Dynamics(CFD)results indicated that smaller pore sizes(10μm,30μm,and 60μm)significantly enhanced convective effects within the fluid,reduced short fluid paths and dead volume regions within the microchannels,and facilitated mass transfer processes.Additionally,smaller pore sizes were conducive to a uniform distribution of current density.Furthermore,Fe(CN)_(6)^(4−)oxidation experiments revealed that the current density at a pore size of 160μm was notably lower than that at 10μm,indicating slower mass transfer of Fe(CN)_(6)^(4−)within larger channels.Calculations based on experimental results demonstrated that the mass transfer rate at a pore size of 10μm was six times than that at 160μm,further confirming the enhancing effect of smaller pore sizes on the mass transfer process.Lastly,experiments on tetracycline degradation showed that at a residence time of 90 s,the removal efficiencies of tetracycline were 80%and 39.1%for porous electrodes with pore sizes of 10μm and 160μm,respectively,demonstrating the superior removal efficiency of smaller pore sizes for tetracycline degradation.展开更多
Magnesium-based anode materials have attracted significant attention in the energy storage domain because of their high theoretical capacities and low electrochemical potentials.However,in conventional electrolyte sys...Magnesium-based anode materials have attracted significant attention in the energy storage domain because of their high theoretical capacities and low electrochemical potentials.However,in conventional electrolyte systems,magnesium metal electrodes dynamically generate an ion-blocking surface layer,resulting in prominent voltage polarization,which severely limits their practical applications.In this study,ZIF-8/carbon nanotubes(CNTs)coatings were used to modify the anodes of magnesium batteries.Compared with the unaltered magnesium battery,the voltage lag time of the ZIF-8/CNTs coating was shortened from 4 s before modification to 0.26 s,and the battery impedance was lowered by two orders of magnitude.The duration of the discharge platform was increased from 4 h before modification to 6-10 h,the anode utilization rate was more than doubled,and the specific energy density was significantly enhanced compared with the battery before modification.The mechanism indicates that the ZIF-8/CNTs coating can limit the infiltration of corrosive substances,extend their transmission path,and offer more effective protection to the magnesium anode.The incorporation of CNTs improves the conductivity of the battery,and it significantly improves the electrochemical performance of the magnesium battery.展开更多
The electrochemical separation of Mn(Ⅱ)impurity from molten NaCl-KCl-MgCl_(2)was systematically investigated to facilitate the electrolytic production of high-purity magnesium.The reduction of Mn(Ⅱ)to Mn metal on tu...The electrochemical separation of Mn(Ⅱ)impurity from molten NaCl-KCl-MgCl_(2)was systematically investigated to facilitate the electrolytic production of high-purity magnesium.The reduction of Mn(Ⅱ)to Mn metal on tungsten electrode was a quasi-reversible process controlled by diffusion.The apparent standard potential and exchange current density of Mn(Ⅱ)/Mn(0)electrode reaction were determined at temperatures ranging from 973 to 1048 K.Solid Mn metal generated during electrolysis aggregated into irregular clumps and adsorbed some needle-like MgO,imposing a detrimental effect on both the aggregation and the purity of magnesium metal.After electrolysis at-1.5 V in molten NaCl-KCl-MgCl_(2)-0.62wt.%MnCl_(2)for 8 h,the concentration of MnCl_(2)impurity decreased to 0.037 wt.%,achieving a removal efficiency of 94.14%.When direct electrolysis was performed in molten NaCl-KCl-MgCl_(2)-0.62wt.%MnCl_(2),the obtained magnesium metal was small blocks with a caviar-like appearance,and the purity was just 98.59%.In contrast,a large globule of magnesium metal was obtained when electrolysis was performed in the purified electrolyte,and its purity was improved to 99.94%.The controlled-potential electrolysis proposed in this work has been verified to be a green and practically effective method to separate the metal ion impurities from molten electrolyte for high purity magnesium extraction.展开更多
基金supported by Major Science and Technology Project of Gansu Province(Grant No.23ZDGA010)National Natural Science Foundation of China(Grant No.51971105).
文摘The fabrication of 304L stainless welding wires with a diameter 1.6 mm by using electrochemical cold drawing(ECD)of bars with a diameter of 5.6 mm was investigated,as well as that via traditional cold drawing(TCD)for comparison.The results indicated that the dilute H_(2)SO_(4)aqueous solution was an appropriate electrolyte for ECD,and increasing the H_(2)SO_(4)concentration and current density within a range improved the corrosion rate and uniformity,leading to an easier and more coordinated deformation through uniformly distributing geometrically necessary dislocations and curved large-angle grain boundaries,and decreasing their density,and thus,an enhanced electrochemical plasticization(EP).Under the optimized electrochemical parameters(0.5 mol L^(-1)H_(2)SO_(4)electrolyte and current density of 12.2 mA cm^(-2)),the average cumulative reduction rate required for annealing was up to~34%,obviously higher than~20%of TCD due to the decreased work-hardening from the EP,so that the number of annealing was significantly reduced from 10 of TCD to 5,when the drawing pass was 23.In addition,the surface of the ECD wire was distinctly smoother and brighter than that of the TCD one.These findings confirm the large potential in engineering applications of the ECD technology based on the EP effect.
基金supported by National Natural Science Foundation of China(52472194)the Deanship of Research and Graduate Studies at King Khalid University through Large Research Project(RGP-2/687/46).
文摘Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling performance.The design of a better cathode material is needed to overcome these limitations.A simple method was used to synthesize binder-free electrochemically exfoliated carbon paper(EECP)which modifies the surface of the paper by introducing oxygen functional groups and thus improves its pseudocapacitance.When used in a Zn-ion supercapacitor(ZISC),an EECPbased cathode provides a large surface area and quick charge transfer.As a result,the ZISC had remarkable charge storage properties and had a dominant capacitive-type charge storage mechanism with 78.8%retention of capacity at 10 mV/s of the total storage.Furthermore,at 1 A/g,the EECP electrode had a maximum capacitance of 252.5 F/g.The EECP electrode retained 81.7%of its capacitance after 10000 cycles,indicating its promise for use in the growing renewable energy sector.A ZISC was also constructed using EECP as the positive electrode and Zn as the negative electrode with a 1 mol L^(−1) ZnSO_(4) electrolyte.It had a capacitance of 186.22 F/g at 1 A/g and a 97.01%retention rate after 10000 cycles.It also had an excellent energy density of 46.6 Wh/kg at a power density of 500.4 W/kg.The material is therefore suitable for use in high-rate next-generation ZISCs.
基金the Natural Science Foundation of ZhejiangProvince(No.LZ24B020005)the National Natural Science Foundation of China(No.22071040)for financial support.
文摘High-sensitive quantitative determination of alpha-fetoprotein(AFP)is of crucial importance for early clinical diagnosis of cancers.Herein,an AuNPs-free electrochemical immunosensor(Ab1-Fc-COF)was prepared from a carboxylic group enriched COF by post-functionalization with detecting antibody(Ab1)and ferrocene(Fc),and used for electrochemical detection of AFP.Due to the small,homogeneous pore size of the COF,Ab1 with a big size was immobilized on the surface of the COF,while Fc with a small size was covalently modified both on the surface and in the pores of COF.The covalently immobilized Ab1 was quite stable and beneficial to specifically detect AFP biomarkers.Meanwhile,the enriched Fc molecules not only improved the conductivity of the COF,but also effectively transferred and amplified the electrochemical signal.This proposed immunosensor exhibited high sensitivity in detecting AFP with a detection limit of 0.39 pg/mL(S/N of 3:1)and a wide linear response range spanning from 1 pg/mL to 100 ng/mL when plotted against logarithmic concentrations.Furthermore,this immunosensor showed excellent selectivity,stability and reproducibility in the testing of real samples.This study presents an innovative prototype for construction of a precious metal-free,antibody-directly-immobilized,simple and stable electrochemical immunoprobe.
基金the Natural Science Foundation of China(Grant No.NSFC-22072062,22202098)the Science and Technology Project of China Northern Rare Earth(BFXT-2023-D-0048 and BFXT-2022-D-0078)。
文摘Electrochemical nitrate reduction reaction(NO_(3)RR)is a sustainable strategy to treat wastewater and produce ammonia.However,it is still a challenge to prepare electrocatalysts with high activity and selectivity.Herein,the CuO_(x) nanowires supported Ru nanoclusters(Ru-CuO_(x))were fabricated via a three-step procedure for efficient nitrate conversion and highly selective ammonia generation.The prepared RuCuO_(x) shows a high ammonia yield rate of 2286.5μg h^(-1) cm^(-2) at-0.7 V vs.RHE and Faradaic efficiency(FE)of 80.1%at-0.4 V vs.RHE.Additionally,the nitrate conversion rate exceeds 90%at the potential range from-0.2 to-0.7 V vs.RHE,and the ammonia selectivity can reach 97.7%at-0.7 V vs.RHE in100 mg L^(-1) NaNO_(3) solution.The systematic characterizations clarify that the introduction of Ru not only regulates the electronic structure of CuO_(x) and accelerates the reconstruction of CuO_(x) to Cu but also promotes H2O dissociation to generate active hydrogen.Moreover.in-situ Raman spectroscopy reveals that the formed Ru-Cu is considered the actual active species during the NO_(3)RR.Density functional theory(DFT)calculations further prove that the obtained Ru-Cu facilitates the adsorption of nitrate and lowers the Gibbs free energy of the rate-determining step,thus improving the NO_(3)RR performance.
基金supported by the National Nature Science Foundation of China(82174531)the Medicine and Health Science Technology Development Project of Shandong Province,China(202212060626).
文摘Abuse of chloramphenicol(CAP)could cause serious side effects to human health.Therefore,it is necessary to detect CAP residues in animal sourced food effectively.Here,the superiority(better stability,higher Apt-CAP loading efficiency,and higher CAP binding associated conformational change,etc.)of tetrahedral structure to double-chained structure for developing aptasensor was evaluated.Then,a self-assembled DNA tetrahedral structure-based electrochemical aptasensor targeting CAP was developed.Under the optimized conditions,the aptasensor exhibited high sensitivity toward CAP with a limit of detection(LOD)of 0.0676 ng/m L(linear range 0.19-387.76 ng/m L),and high selectivity against the structural analogs of CAP.Moreover,the recovery rate of CAP from spiked milk samples ranged from 100.57%to 101.69%,and only USD 1.34 is needed for detecting CAP in 1 sample.These results suggested the application potential of this aptasesor for detecting CAP in animal sourced foods.
基金financially supported by the National Natural Science Foundation of China(Nos.52272214,52372082,52466013,52373184,and U24A20660)Jiangxi Provincial Natural Science Foundation(Nos.20242BAB26059,20232BAB204032,20252BAC200290,20252BEJ730349,and 20252BAC240326)Doctoral Start-Up Fund of Jiangxi Science&Technology Normal University(No.2024BSQD16)。
文摘Glucose,ascorbic acid(AA),uric acid(UA),and dopamine(DA)are vital biomarkers whose dynamic concentrations correlate with critical diseases;however,multiplexed detection remains challenging for conventional electrochemical sensors because of their limited sensitivity and selectivity.Here,we present a millimeter-scale all-poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)organic electrochemical transistor(OECT)platform that integrates dual-mode sensing with enzyme/metal-free operation for ultrasensitive biomarker monitoring.By engineering polycrystalline PEDOT:PSS channels via H_2 SO_4 post-treatment,the device achieves record-high conductivity(about(2312.0±29.9)S·cm^(–1)),maximum transconductance(about(2.82±0.12)mS),and on/off ratio(about 210.0±7.8),enabling signal amplification at low gate voltages.The dual-mode strategy combines the selectivity of electrochemistry with the sensitivity of OECTs,realizing simultaneous detection of glucose,AA,UA,and DA with clinical-level sensitivity:detection limits down to 8 nmol·L^(–1)(glucose),0.5 nmol·L^(–1)(AA),5 nmol·L^(–1)(DA),and 0.5 nmol·L^(–1)(UA).Validation using human urine samples yielded recovery rates of 94%–114%.This flexible sensing platform provides a new pathway for the development of wearable biosensors for precision diagnostics.
基金supported by the National Natural Science Foundation of China(52477222)the Key Research and Development Program of Shaanxi Province(2024GX-YBXM-442)the Xinjiang Uygur Autonomous Region Key R&D Program under Grant(2022B01019-2)。
文摘With the rapid development of electric vehicles and grid-scale renewable integration,the demand for lithium-ion batteries(LIBs)has significantly increased with high expectations on enhanced energy density,cycle stability,and failure resilience.Electrochemical models(EMs),serving as pivotal mechanismdriven analytical frameworks in battery research and applications,demonstrate unprecedented quantitative fidelity in characterizing intricate multi-physics dynamics for the next-generation battery management systems(BMS).The breakthrough innovations in artificial intelligence(AI)driven methods have revolutionized the dynamic modeling of LIBs.However,the deployment of AI-augmented EMs in BMS faces significant identifiability challenges due to strong parameter coupling.In addition,research on model simplification,parameter determination,and dynamic parameter identification remains largely fragmented.There is a lack of a comprehensive review to pave the way for the cross-domain innovations in BMS.To fill this gap,this paper presents a systematic review of the EMs for LIBs and examines the advancements in parameter determination techniques from both experimental measurement and numerical simulation perspectives.Besides,a comprehensive assessment of the progress in parameter identification from the standpoint of dynamic recognition is presented,encompassing both modelbased approaches and intelligent methods.Additionally,from the BMS standpoint,the strengths and limitations of existing approaches are evaluated.Finally,a coordinated framework for multi-stage identification needs to be established in the future.The potential of digital twins(DT),deep reinforcement learning(DRL),and large language models(LLMs)in enhancing EMs also warrants further exploration.The purpose of this work is to provide insights and guidance for the future development of EMs in LIB applications.
基金financial support providedby the National Natural Science Foundation of China (Nos.92475203 and 52474374)the Joint Fund of Henan Province Science and Technology R&D Program,China (No.225200810035)the Research Initiation Grant for High-Level Talents by the Henan Academy of Sciences,China(No.232007016).
文摘To improve the solid–solid interface performance of all solid-state lithium batteries(ASSLBs),a novel sandwich-structured solid electrolyte(SSE,total thickness of 0.7 mm)was investigated.It comprises a central layer of perovskite-type Li_(0.37)Sr_(0.44)Zr_(0.25)Ta_(0.75)O_(3)(LSZT)electrolyte(thickness of 0.5 mm)sandwiched between two layers of composite solid polymer electrolyte(CSPE,each with a thickness of 0.1 mm).The thin CSPE interlayer not only effectively reduces interfacial resistance between LSZT and electrodes,but also suppresses Li-induced reduction degradation of LSZT while ensuring uniform current density distribution across the interface.The SSE demonstrates an ionic conductivity of 8.76×10^(−5)S·cm^(−1)at 30℃,increasing to 1.13×10^(−3)S·cm^(−1)at 100℃,with an activation energy of 0.36 eV.In addition,SSE is stable for Li metal and achieves electrochemical stability up to 4.58 V vs.Li^(+)/Li.SSE shows outstanding electrode/electrolyte interfacial compatibility and significant suppression of the growth of Li dendrite.Ascribing to these merits,Li|SSE|Li symmetric cell maintained stable operation for 500 h at a current density of 0.3 mA·cm^(−2)without short circuit,confirming robust interfacial compatibility between SSE and Li electrode.The all-solid-state LiFePO_(4)|Li battery with SSE has an initial reversible discharge capacity of 109.8 mAh·g^(−1)and a reversible capacity of 118.1 mAh·g^(−1)after 50 cycles at a charge/discharge rate of 0.1C(30℃),demonstrating good cycling performance.
基金support from the Fundamental Research Funds for the Central Universities(2022CDJQY-005,2024CDJXY010)the Guangxi Science and Technology Program(AB24010229)is greatly acknowledged.
文摘In manganese electrolysis,electrochemical oscillations and manganese dendrite growth are typical nonlinear phenomena critical for energy consumption reduction.Nonetheless,existing research lacks a deep understanding of their underlying mechanisms.In this study,we systematically explored the evolution of anode electrochemical oscillations during manganese electrolysis and designed a square wave circuit to effectively suppress oscillations and dendrite growth while reducing energy consumption.A novel four-dimensional differential equation was introduced to explore the internal dynamic mechanisms of typical nonlinear behaviors.The experimental results showed that while the evolutionary patterns of current and potential oscillation signals were consistent,their waveform directions were opposite.The square wave current effectively suppressed both electrochemical oscillations and the growth of manganese dendrites.Furthermore,compared to direct current electrolysis,the square wave current improved the current efficiency by 3.6%and reduced the energy consumption by 0.32 kW·h·kg^(−1).
基金supported by the National Key R&D Program of China(2024YFB3211600)the National Natural Science Foundation of China(Nos.62273073,52273316)+4 种基金the National Key R&D Program of China(2023YFC2411800,2022YFE0134800)the Natural Science Foundation of Sichuan(2025ZNSFSC0515)Chengdu Science Technology Bureau(2023-YF06-00028-HZ)and the Fundamental Research Funds for the Central Universities(ZYGX2025TS009,ZYGX2024XJ029,ZYGX2024XJ031)Sci-entific Research Innovation Capability Support Project for Young Faculty(ZYGXQNJSKYCXNLZCXM-M1P).
文摘Organic electrochemical transistors(OECTs)are promising for next-generation bioelectronics due to their high performance and biocompatibility.Nevertheless,they still face tremendous operational stability challenges due to the limited robustness of the organic mixed ionic-electronic conductor(OMIEC)channel.Here,by modulating the molecular weight(MW)of OMiEC,enhanced OECT and relevant circuit operation stabilities are demonstrated,showing more than 3,000,0o0 full cycles(~42 h)with less than 15%current variation in an OECT,and 150,000 cycles(~4 h)with less than 5%voltage variation in an OECT-based inverter,which are among the highest of reported OECT-based electronics.Specifically,p(g2T-T),a typical p-type OMIEC,with varying MW(7-43 kDa),is synthesized,where lower-MW p(g2T-T)(~9 kDa)exhibits superior device performance and cycling stability in OECTs,outperforming those in high-MW counterparts(>30 kDa).It is indicated that low-MW p(g2T-T)maintains higher volumetric capacitance,ordered orientation,and reduced swelling.Therefore,irreversible microstructural degradation is effectively avoided,along with better performance yield.Furthermore,MW regulation enables physiological signal sensing with high tolerance to body fluid environments for 7 days.These findings highlight MW modulation as a versatile approach to suppress excessive swelling,advancing the design of durable OECT-based electronics.
基金supported by the National Natural Science Foundation of China(22409065)the Guangdong Basic and Applied Basic Research Foundation(2022A1515011906)+2 种基金the China Postdoctoral Science Foundation(2023M731153)the Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technologythe Postdoctoral Fellowship Program of CPSF(GZC20230868).
文摘The application of conventional manganese dioxide(MnO_(2))materials in sodium-ion supercapacitors(Na-SCs)is considerably limited by their low conductivity and structural instability.Biomimetic morphology engineering can optimize the electrochemical performance of MnO_(2).Here,based on the metal-organic frameworks(MOFs)-derived method and electrochemical reconstruction,a coral-like MnO_(2)structure integrated with a functional nitrogen-doped carbon(NC)coating is designed for Na-SC application.The bioinspired coral-like structure captures numerous electrolyte ions and increases the Na+concentration on the electrode surface,which is beneficial for optimizing the Na+transport pathway and accelerating the electrode reaction kinetics.Moreover,the coral-like crosslinked structure effectively enhances the mechanical properties,enabling the maintenance of the structure of MnO_(2)-based electrodes during long-term operation.Furthermore,in/ex-situ characterizations are performed to elucidate the mechanism of lattice transformation during electrochemical phase reconstruction.Additionally,the theoretical calculation and simulation results reveal the ion/electron dynamics in the fabricated electrode.The prepared electrode demonstrates excellent capacitance storage ability(340.7 F g^(−1)at 0.5 A g^(−1))and cycling stability(85.1%capacitance retention after 10,000 cycles).The assembled hybrid device exhibits exceptional life-span(82.0%capacitance retention after 10,000 cycles)and exceptional energy density(36.5 Wh kg^(−1)).This study provides a reliable biomimetic morphology design strategy for MnO_(2)cathodes,paving the way for the fabrication of high-performance Na-SCs.
基金supported by the National Natural Science Foundation of China(No.52175414)the Natural Science Foundation of Jiangsu Province of China(No.BK20220134)+1 种基金the Fundamental Research Funds for the Central Universities,China(No.NE2023002)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(No.KYCX24_0559)。
文摘During electrochemical machining(ECM),the passivation film formed on the surface of titanium alloy can lead to uneven dissolution and pitting.Solid particle erosion can effectively remove this passivation film.In this paper,the electrochemical dissolution behavior of Ti-6.5Al-2Zr-1Mo-1V(TA15)titanium alloy at without particle impact,low(15°)and high(90°)angle particle impact was investigated,and the influence of Al_(2)O_(3)particles on ECM was systematically expounded.It was found that under the condition of no particle erosion,the surface of electrochemically processed titanium alloy had serious pitting corrosion due to the influence of the passivation film,and the surface roughness(Sa)of the local area reached 10.088μm.Under the condition of a high-impact angle(90°),due to the existence of strain hardening and particle embedding,only the edge of the surface is dissolved,while the central area is almost insoluble,with the surface roughness(S_(a))reaching 16.086μm.On the contrary,under the condition of a low-impact angle(15°),the machining efficiency and surface quality of the material were significantly improved due to the ploughing effect and galvanic corrosion,and the surface roughness(S_(a))reached 2.823μm.Based on these findings,the electrochemical dissolution model of TA15 titanium alloy under different particle erosion conditions was established.
基金supported by the National Natural Science Foundation of China(Nos.22479092 and 22078190)。
文摘The pseudo-two-dimensional(P2D)model plays an important role in exploring physicochemical mechanisms,predicting the state of health,and improving the fast charge capability for Li-ion batteries(LIBs).However,the fast charge leads to the lithium concentration gradient in the solid and electrolyte phases and the non-uniform electrochemical reaction at the solid/electrolyte interface.In order to decouple charge transfer reactions in LIBs under dynamic conditions,understanding the spatio-temporal resolution of the P2D model is urgently required.Till now,the study of this aspect is still insufficient.This work studies the spatio-temporal resolution for dynamic/static electrochemical impedance spectroscopy(DEIS/SEIS)on multiple scales.In detail,DEIS and SEIS with spatio-temporal resolutions are used to decouple charge transfer reactions in LIBs based on the numerical solution of the P2D model in the frequency domain.The calculated results indicate that decoupling solid diffusion requires a high spatial resolution along the r-direction in particles,decoupling electrolyte diffusion and interfacial transfer reaction requires a high spatial resolution along the x-direction,and decoupling charge transfer reactions in LIBs at an extremely low state of charge(SOC)requires an extremely high temporal resolution along the t-direction.Finally,the optimal range of spatio-temporal resolutions for DEIS/SEIS is derived,and the method to decouple charge transfer reactions with spatio-temporal resolutions is developed.
基金Financial support from National Key R&D Program of China (No.2023YFA1507203)National Natural Science Foundation of China (Nos.22371149 and 22188101)+3 种基金the Fundamental Research Funds for the Central Universities (No.63224098)Frontiers Science Center for New Organic Matter,Nankai University (No.63181206)Nankai University are gratefully acknowledgedthe Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mild conditions.Various substituted benzylamines containing diverse functional groups and even highly reactive moieties,such as cyano,amide and alkene groups could be successfully transformed to the carboxylated products.Notably,this method proved to be applicable to the late-stage modification of biorelevant compounds,highlighting its potential for synthetic chemistry.Mechanistic studies such as radical trapping experiments,kinetic isotope effect(KIE) tests and cyclic voltammetry(CV) studies provided useful insight into this transformation.
基金supported by Natural Science Foundation of Shandong Province(ZR2023ME155 and ZR2023ME085)the project of“20 Items of University”of Jinan(202228046)the Taishan Scholar Project of Shandong Province(tsqn202306226 and tsqn202211171).
文摘Supercapacitors represent one specific class of energy storage devices that bridge the gap between traditional capacitors and batteries.In current work,δ-MnO_(2) nanoflakes arrayed on electrochemically exfoliated graphene(EEG)nanosheets were easily made as one composited electrode material for boosting the charge storage performances of supercapacitors.Coupled with the fluent electron and ion transport from two-dimensional EEG nanosheets,the uniformly anchoredδ-MnO_(2) nanoflake arrays present high reversible capacity,superior cycling stability,and unique rate capability.As expected,the MnO_(2)/EEG-10 electrode delivers high specific capacitance of 190 F·g^(−1) at 0.2 A·g^(−1),and holds 97.3%of its initial capacitance after 10000 cycles at 5 A·g^(−1).Furthermore,an asymmetrical supercapacitor using MnO_(2)/EEG-10 as the positive electrode achieves an energy density of 17.7 W·h·kg^(−1) at a power density of 922.7 W·kg^(−1) with 82.9%capacity retention upon 10000 cycles at 5 A·g^(−1).This work highlights the facile fabrication of high-performance MnO_(2)/graphene composites with excellent structure stability using graphene nanosheets as the conductive matrix.
基金financially supported by the National Natural Science Foundation of China (No. 22579095)the Beijing-Tianjin-Hebei Basic Research Cooperation Special Project (B2024204027)+2 种基金the Youth Top-notch Talent Foundation of Hebei Provincial Universities (BJK2022023)the Natural Science Foundation of Hebei Province (B2023204006)the talent training project of Hebei province (No. B20231004)。
文摘The rate capability and cycling stability of sodium metal batteries taking FeS_(2) or sulfur as cathode are limited due to their low reaction kinetics and severe shuttle effect.Herein,we rationally design a novel single-atom-dispersed S_(2)-FeNC/FeS_(2) nanocluster heterojunction embedded in carbon spheres(SFNC/FeS_(2)) for the electrode material of sodium metal batteries.Interestingly,during the discharging process,the Na^(+) is inserted into FeS_(2) to generate Na_(2)S,as well as the unique electrochemical reaction between S_(2)-FeNC and Na^(+) to form Na_(2)S.Meanwhile,the FeNC can adsorb Na_(2)S and catalyze the conversion from Na_(2)S and Fe to FeS_(2) or from Na_(2)S and FeNC to S_(2)-FeNC for suppressing the shuttle effect and promoting the distinct hybrid reversible electrochemical behavior,which improves performance tremendously.Notably,the SFNC/FeS_(2) electrode delivers a specific capacity of 338.7 mAh g^(-1) after superlong 2000 cycles at a current density of 5.0 A g^(-1) and achieves a high energy density of 430.1 Wh Kg^(-1) at a current density of 0.05 A g^(-1).This work presents a novel approach to studying sodium metal batteries with hybrid behavior for excellent high energy density and cycling stability.
基金partially funded by EPSRC (EP/T022213/1, EP/W032260/1 and EP/P020194/1) via our membership of the UK’s HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202)part of the “Advancing Solid Interface and Lubricants by First Principles Material Design (SLIDE)” project that has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant agreement No. 865633)
文摘Amorphous materials represent a promising platform for advancing CO_(2)electrochemical reduction due to their inherently diverse coordination environments.In this study,we demonstrate computationally the superior performance of amorphous CuNi alloys for CO_(2)electrochemical reduction.By integrating machine learning forcefields for efficient structure generation and density functional theory for subsequent structural refinement and property calculations,we reveal the potential of these disordered systems to outperform their crystalline counterparts.Machine learning forcefields can generate a bulk structure containing a mixture of Cu and Ni atoms,resulting in enhanced catalytic performance.Effective screening of the amorphous surfaces is used to identify undercoordinated Cu and Ni sites in the amorphous structure to synergistically promote selective CO production and favor ethanol formation over ethylene via the stabilization of the*COCHO intermediate,resulting in significantly lower Gibbs free energy changes compared to the crystalline counterpart.The varying atomic coordination environments on amorphous surfaces promote both C–C bond formation and subsequent proton-electron transfer,leading to ethanol formation.These findings demonstrate the superior catalytic performance of amorphous CuNi,highlighting its potential for efficient and selective electroreduction of CO_(2).
基金supported by the National Natural Science Foundation of China(Nos.U22A20241 and 21876105)Shaanxi“Scientist&Engineer”Team(No.2023KXJ-131)Xianyang Key S&T Special Projects(No.L2023-ZDKJ-QCY-SXGG-GY-007).
文摘Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed flow-through electrochemical reactors(FERs)primarily based on porous electrodes,where the pore structure significantly impacts the electrochemical reaction.Therefore,this study systematically investigated the impact of different pore sizes on the fluid dynamics,current potential distribution,mass transfer processes,and degradation performance of FERs.Computational Fluid Dynamics(CFD)results indicated that smaller pore sizes(10μm,30μm,and 60μm)significantly enhanced convective effects within the fluid,reduced short fluid paths and dead volume regions within the microchannels,and facilitated mass transfer processes.Additionally,smaller pore sizes were conducive to a uniform distribution of current density.Furthermore,Fe(CN)_(6)^(4−)oxidation experiments revealed that the current density at a pore size of 160μm was notably lower than that at 10μm,indicating slower mass transfer of Fe(CN)_(6)^(4−)within larger channels.Calculations based on experimental results demonstrated that the mass transfer rate at a pore size of 10μm was six times than that at 160μm,further confirming the enhancing effect of smaller pore sizes on the mass transfer process.Lastly,experiments on tetracycline degradation showed that at a residence time of 90 s,the removal efficiencies of tetracycline were 80%and 39.1%for porous electrodes with pore sizes of 10μm and 160μm,respectively,demonstrating the superior removal efficiency of smaller pore sizes for tetracycline degradation.
基金supported by the Guangxi Natural Science Foundation,China(No.2020GXNSFAA 159011)the National Natural Science Foundation of China(No.51664011).
文摘Magnesium-based anode materials have attracted significant attention in the energy storage domain because of their high theoretical capacities and low electrochemical potentials.However,in conventional electrolyte systems,magnesium metal electrodes dynamically generate an ion-blocking surface layer,resulting in prominent voltage polarization,which severely limits their practical applications.In this study,ZIF-8/carbon nanotubes(CNTs)coatings were used to modify the anodes of magnesium batteries.Compared with the unaltered magnesium battery,the voltage lag time of the ZIF-8/CNTs coating was shortened from 4 s before modification to 0.26 s,and the battery impedance was lowered by two orders of magnitude.The duration of the discharge platform was increased from 4 h before modification to 6-10 h,the anode utilization rate was more than doubled,and the specific energy density was significantly enhanced compared with the battery before modification.The mechanism indicates that the ZIF-8/CNTs coating can limit the infiltration of corrosive substances,extend their transmission path,and offer more effective protection to the magnesium anode.The incorporation of CNTs improves the conductivity of the battery,and it significantly improves the electrochemical performance of the magnesium battery.
基金the financial supports from the National Key Research and Development Program of China(No.2021YFC2901400)he Distinguished Young Research Project of Anhui Higher Education,China(No.2023AH020017)the Xinjiang Tianchi Talent Introduction Plan,China。
文摘The electrochemical separation of Mn(Ⅱ)impurity from molten NaCl-KCl-MgCl_(2)was systematically investigated to facilitate the electrolytic production of high-purity magnesium.The reduction of Mn(Ⅱ)to Mn metal on tungsten electrode was a quasi-reversible process controlled by diffusion.The apparent standard potential and exchange current density of Mn(Ⅱ)/Mn(0)electrode reaction were determined at temperatures ranging from 973 to 1048 K.Solid Mn metal generated during electrolysis aggregated into irregular clumps and adsorbed some needle-like MgO,imposing a detrimental effect on both the aggregation and the purity of magnesium metal.After electrolysis at-1.5 V in molten NaCl-KCl-MgCl_(2)-0.62wt.%MnCl_(2)for 8 h,the concentration of MnCl_(2)impurity decreased to 0.037 wt.%,achieving a removal efficiency of 94.14%.When direct electrolysis was performed in molten NaCl-KCl-MgCl_(2)-0.62wt.%MnCl_(2),the obtained magnesium metal was small blocks with a caviar-like appearance,and the purity was just 98.59%.In contrast,a large globule of magnesium metal was obtained when electrolysis was performed in the purified electrolyte,and its purity was improved to 99.94%.The controlled-potential electrolysis proposed in this work has been verified to be a green and practically effective method to separate the metal ion impurities from molten electrolyte for high purity magnesium extraction.
