Electrochemical oxidation of aniline in aqueous solution was investigated over a novel Ti/TiOxHy/Sb-SnO2 electrode prepared by the electrodeposition method.Scanning electron microscopy,X-ray diffraction,and electroche...Electrochemical oxidation of aniline in aqueous solution was investigated over a novel Ti/TiOxHy/Sb-SnO2 electrode prepared by the electrodeposition method.Scanning electron microscopy,X-ray diffraction,and electrochemical measurements were used to characterize its morphology,crystal structure,and electrochemical properties.Removal of aniline by the Ti/TiOxHy/Sb-SnO2electrode was investigated by ultraviolet-Visible spectroscopy and chemical oxygen demand（COD）analysis under different conditions,including current densities,initial concentrations of aniline,pH values,concentrations of chloride ions,and types of reactor.It was found that a higher current density,a lower initial concentration of aniline,an acidic solution,the presence of chloride ions（0.2wt%NaCl）,and a three-dimensional（3D） reactor promoted the removal efficiency of aniline.Electrochemical degradation of aniline followed pseudo-first-order kinetics.The aniline（200 mL of 100mg·L-（-1）） and COD removal efficiencies reached 100%and 73.5%,respectively,at a current density of 20 mA·cm-（-2）,pH of 7.0,and supporting electrolyte of 0.5 wt%Na2SO4 after 2 h electrolysis in a 3D reactor.These results show that aniline can be significantly removed on the Ti/TiOxHy/Sb-SnO2electrode,which provides an efficient way for elimination of aniline from aqueous solution.展开更多
Ti/Sb-SnO2 anodes were prepared by thermal decomposition to examine the influence of the amount of Sb dopant on the structure and electrocatalytic capability of the electrodes in the oxidation of 4-chlorophenol. The p...Ti/Sb-SnO2 anodes were prepared by thermal decomposition to examine the influence of the amount of Sb dopant on the structure and electrocatalytic capability of the electrodes in the oxidation of 4-chlorophenol. The physicochemical properties of the Sb-SnO2 coating were markedly influenced by different amounts of Sb dopant. The electrodes, which contained 5% Sb dopant in the coating, presented a much more homogenous surface and much smaller mud-cracks, compared with Ti/Sb-SnO2 electrodes containing 10% or 15% Sb dopant, which exibited larger mud cracks and pores on the surface. However, the main microstructure remained unchanged with the addition of the Sb dopant. No new crystal phase was observed by X-ray diffraction （XRD）. The electrochemical oxidation of 4-chlorophenol on the Ti/SnO2 electrode with 5% Sb dopant was inclined to electrochemical combustion; while for those containing more Sb dopant, intermediate species were accumulated. The electrodes with 5% Sb dopant showed the highest efficiency in the bulk electrolysis of 4-chlorophenol at a current density of 20 mA/cm^2 for 180 min; and the removal rates of 4-chlorophenol and COD were 51.0% and 48.9%, respectively.展开更多
Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-sec...Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-section in the flow channel is normally adopted,the configuration optimization of which could potentially enhance the performance of the electrolyzer.This paper describes the numerical simulation study on the impact of the flow-channel cross-section shapes in the MEA electrolyzer for CO_(2)RR.The results show that wide flow channels with low heights are beneficial to the CO_(2)RR by providing a uniform flow field of CO_(2),especially at high current densities.Moreover,the larger the electrolyzer,the more significant the effect is.This study provides a theoretical basis for the design of high-performance MEA electrolyzers for CO_(2)RR.展开更多
Integrating the CO_(2)capture process with the CO_(2)electrochemical reduction process into a single system can eliminate the need for storage and transportation following CO_(2)capture.This integrated process offers ...Integrating the CO_(2)capture process with the CO_(2)electrochemical reduction process into a single system can eliminate the need for storage and transportation following CO_(2)capture.This integrated process offers several advantages over multi-step cascade processes,including reduced costs and enhanced CO_(2)utilization.However,the integrated CO_(2)capture and electrochemical reduction(CCER)process encounters several challenges,including the low CO_(2)adsorption performance of the gas diffusion electrode(GDE)and catalyst,as well as the poor activity and selectivity of the catalyst for the electrochemical reduction of CO_(2).This review aims to systematically summarize the fundamentals of the CCER process.Based on an in-depth understanding of the CO_(2)mass transfer,adsorption,and electrochemical reduction processes,GDE design strategies based on the modulation of wettability and structure are discussed to enhance the CO_(2)capture capability at the GDE level.At the catalyst level,catalyst design strategies based on the introduction of CO_(2)capture sites and the construction of CO_(2)mass transfer channels were analyzed,and catalyst design strategies for enhanced CO_(2)capture were proposed.This review summarizes the most common catalysts for CO_(2)electrochemical reduction,such as Ni-based,Bi-based,and Cubased catalysts,and analyzes their design strategies based on reaction pathways for generating specific products.Finally,the problems and challenges of the CCER process are summarized and proposed,which provide ideas for the further application of this technology in the future.展开更多
The state-of-the-art anion-exchange membrane water electrolyzers(AEMWEs)require highly stable electrodes for prolonged operation.The stability of the electrode is closely linked to the effective evacuation of H_(2) or...The state-of-the-art anion-exchange membrane water electrolyzers(AEMWEs)require highly stable electrodes for prolonged operation.The stability of the electrode is closely linked to the effective evacuation of H_(2) or O_(2) gas generated from electrode surface during the electrolysis.In this study,we prepared a superhydrophilic electrode by depositing porous nickel–iron nanoparticles on annealed TiO_(2) nanotubes(NiFe/ATNT)for rapid outgassing of such nonpolar gases.The super-hydrophilic NiFe/ATNT electrode exhibited an overpotential of 235 mV at 10 mA cm^(−2) for oxygen evolution reaction in 1.0 M KOH solution,and was utilized as the anode in the AEMWE to achieve a current density of 1.67 A cm^(−2) at 1.80 V.In addition,the AEMWE with NiFe/ATNT electrode,which enables effective outgassing,showed record stability for 1500 h at 0.50 A cm^(−2) under harsh temperature conditions of 80±3℃.展开更多
The pore size distribution is often an important parameter for transport processes in porous media.Cryoporometry experiments can provide such data in the meso and macropore size up to 1 mm providing the sample tempera...The pore size distribution is often an important parameter for transport processes in porous media.Cryoporometry experiments can provide such data in the meso and macropore size up to 1 mm providing the sample temperature is finely controlled.We use a Peltier based system inserted directly into the NMR probe to control the temperature within 0.05℃and impose temperature ramps down to 0.002℃/min,necessary to characterize the largest pore sizes.The pore size information in the macropore range cannot be obtained from gas adsorption techniques while mercury injection is questionable for the material considered here.For porous materials made of paramagnetic minerals such as lithium-iron phosphate(LiFePO_(4),LFP)or nickel-manganese-cobalt oxides(NMC)and saturated with octamethylcyclotetrasiloxane(OMCTS),the T_(2)relaxation times are very short such as protons from the liquid and frozen phases cannot be separated.Hence the usual cryoporometry experiment cannot be performed.Instead,we propose to use the T_(1)contrast to separate these phases.The method is studied in detail along with some temperature effects linked with the T_(1)variation of the bulk frozen OMCTS.We show an example on two cathode materials part of industrial battery product.展开更多
This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-...This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-and(222)-oriented ITO BEs deposited under pure argon and argon–oxygen(20%O_(2))sputtering atmospheres,as well as SrRuO_(3)(SRO),show distinct RS behaviors.The Al/ZrO_(2)/(400)-ITO and Al/ZrO_(2)/SRO devices demonstrate stable bipolar RS performance,with(400)-ITO enabling an abrupt reset process,a wider memory window(>10^(4)),and superior stability,while SRO devices exhibit gradual reset transitions with lower power consumption.Furthermore,the crystallographic orientation control applied to ITO BE significantly affects the V_(O) dynamics and RS performance,with(222)-ITO devices exhibiting irreversible RS behavior.It is irrefutable that BE material and its orientation can strongly influence RS performance by modulating the V_(O) dynamics,electric field distribution,and conductive filament behavior.These findings underscore the importance of BE properties in optimizing ReRAM performance and provide valuable guidance for the development of high-efficiency memory devices.展开更多
The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explo...The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explore a candidate with large SCs,which can stably operate in the negative potential region mean-while.For this propose,we design and fabricate solid-solution Ru_(x)Cu_(1-x)O_(2) nanocrystals(NCs),which exhibit competitive SCs and electrochemical stability within the potential range from-0.9 V to 0.0 V in the aqueous KOH electrolyte.The incorporation of Cu enhances the electrochemical utilization of RuO_(2),reaction kinetics,electronic conductivity,and hydrogen evolution overpotentials,which are all highly dependent upon the added contents of Cu species.The optimized Ru_(0.8)Cu_(0.2)O_(2)(RuCu82)electrode of a high mass loading of 5 mg cm^(-2) reveals the best electrochemical capacitances in terms of reversible SCs and capacitance degradation at room temperature and-20℃.Furthermore,the reversible K^(+)-(de)intercalation induced pseudocapacitance is proposed for electrochemical charge storage process of RuCu82.In particu-lar,remarkable specific energy of 59.1 Wh kg-1 at 400 W kg-1 and excellent cycling stability are achieved in the assembled NiCoO_(2)//RuCu82 AHCs.Our contribution here presents a new promising negative elec-trode platform with high SCs and electrochemical stability for next-generation AHCs.展开更多
Even in small concentrations,toxic metals like lead,cadmium,and mercury are dangerous to the environment and human health.Environmental monitoring depends on precisely identifying these heavy metals,particularly cadmi...Even in small concentrations,toxic metals like lead,cadmium,and mercury are dangerous to the environment and human health.Environmental monitoring depends on precisely identifying these heavy metals,particularly cadmium ions(Cd(Ⅱ)).In this study,we present a novel screen-printed carbon electrode(SPCE)modified with single crystallineα-Fe_(2)O_(3)nano-hexagons that functions as a sensor for detecting Cd(Ⅱ).The performance of the fabricated sensor was thoroughly assessed and compared with unmodified SPCE using the voltammetric method.The crystalline structure of the synthesizedα-Fe_(2)O_(3)nano-hexagons was confirmed through XRD,and surface analysis revealed an average diameter and thickness of 86 nm and 9 nm,respectively.Theα-Fe_(2)O_(3)modified SPCE yields a 7-fold enhanced response(at pH 5.0 vs.Ag/AgCl)to Cd(Ⅱ)than bare SPCE.The modified electrode effectively detects Cd(Ⅱ)with a linear response range of up to 333.0μmol/L and a detection limit of 0.65 nmol/L under ideal circumstances.This newly fabricated sensor offers significant potential for environmental monitoring applications by providing outstanding practicality,anti-interference ability,and repeatability for detecting Cd(Ⅱ)in water samples.展开更多
Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide （CeO2） were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electro...Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide （CeO2） were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electrodes and the impact of α-PbO2 as the intermediate layer. The results show that using α-PbO2 as the intermediate layer will benefit the crystallization of β-PbO2 and β-PbO2 is more suitable as the surface layer than α-PbO2. CeO2 dopants change the crystallite size and crystal structure, enhance the catalytic activity, and even change the deposition mechanism of PbO2. The doping of CeO2 in the PbO2 electrodes can enhance the electro-catalytic activity, which is helpful for oxygen evolution, and therefore reduce the cell voltage.展开更多
In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prep...In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The effects of adding Si on the structure and electrochemical hydrogen storage characteristics of the alloys were investigated systematically. The results indicate that the as-cast and annealed alloys hold multiple structures, involving two major phases of （La, Mg）2Ni7 with a Ce2Ni7-type hexagonal structure and LaNi5 with a CaCu5-type hexagonal structure as well as one residual phase LaNi3. The addition of Si results in a decrease in （La, Mg）2Ni7 phase and an increase in LaNi5 phase without changing the phase structure of the alloys. What is more, it brings on an obvious effect on electrochemical hydrogen storage characteristics of the alloys. The discharge capacities of the as-cast and annealed alloys decline with the increase of Si content, but their cycle stabilities clearly grow under the same condition. Furthermore, the measurements of the high rate discharge ability, the limiting current density, hydrogen diffusion coefficient as well as electrochemical impedance spectra all indicate that the electrochemical kinetic properties of the electrode alloys first increase and then decrease with the rising of Si content.展开更多
Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique...Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy（EDXS）, anode polarization curves, quasi-stationary polarization（Tafel） curves, electrochemical impedance spectroscopy（EIS）, scanning electron microscopy（SEM）, and X-ray diffraction（XRD）. Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential（0.610 V at 500 A/m2） for oxygen evolution, the best electrocatalytic activity, the longest service life（360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2）, and the lowest cell voltage（2.75 V at 500 A/m2）. Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.展开更多
CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@M...CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@MnO2 products grown on Ni foams were obtained through a facile hydrothermal method.The as-synthesized samples employed as electrodes deliver a specific capacitance of 2325.01 F g^-1 at 1 A g^-1.An assembled asymmetric supercapacitor using these products as positive electrodes shows a maximum energy density of 59.73 W h kg^-1 at 1000.09 W kg^-1.The prominent electrochemical performance of the as-prepared electrodes could be attributes to hierarchical structures.These findings suggest that hybrid structures might be potential alternatives for future flexible energy storage devices.展开更多
Ti3C2Tx,a novel two-dimensional layer material,is widely used as electrode materials of supercapacitor due to its good metal conductivity,redox reaction active surface,and so on.However,there are many challenges to be...Ti3C2Tx,a novel two-dimensional layer material,is widely used as electrode materials of supercapacitor due to its good metal conductivity,redox reaction active surface,and so on.However,there are many challenges to be addressed which impede Ti3C2Tx obtaining the ideal specific capacitance,such as restacking,re-crushing,and oxidation of titanium.Recently,many advances have been proposed to enhance capacitance performance of Ti3C2Tx.In this review,recent strategies for improving specific capacitance are summarized and compared,for example,film formation,surface modification,and composite method.Furthermore,in order to comprehend the mechanism of those efforts,this review analyzes the energy storage performance in different electrolytes and influencing factors.This review is expected to predict redouble research direction of Ti3C2Tx materials in supercapacitors.展开更多
Praseodymium was selected as a promoter for SnO2/Ti electrode to improve the electrocatalytic performance by electrodeposition in pharmaceutical wastewater treatment; the micrograph and the structure were characterize...Praseodymium was selected as a promoter for SnO2/Ti electrode to improve the electrocatalytic performance by electrodeposition in pharmaceutical wastewater treatment; the micrograph and the structure were characterized by SEM and XRD. Mixture uniform design was used in the optimization of the electrolytic conditions; mathematical model was established according to the rate of wiping COD off, which revealed the relationship between the current intensity, time of electrolysis, the amount of doped Pr, and the ratio of area （SnOJTi：Al）. On the basis of the analysis of the empirical model, the optimized parameters had been obtained; the rate of wiping COD off was up to 94.9%, it decreased from 392 to 20 mg/L. Experimental results showed that the electrocatalytic performance of the electrode doped with Pr was superior for the treatment of pharmaceutical wastewater.展开更多
Discharge performance of K2FeO4 electrode under different conditions was studied by the constant electric current discharge method. The electrochemical characteristics of K2FeO4 electrode were investigated for the fi...Discharge performance of K2FeO4 electrode under different conditions was studied by the constant electric current discharge method. The electrochemical characteristics of K2FeO4 electrode were investigated for the first time by means of cyclic voltammetry. The results show that the K2FeO4 electrode made at moderate pressure (20 MPa) and discharged at lower current has better discharge performance. It is also found that K2FeO4 electrode is significantly rechargeable.展开更多
A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The ...A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.展开更多
In order to improve the electrochemical cycle stability of the RE–Mg–Ni-based A2B7-type electrode alloys, a small amount of Si has been added into the alloys.The casting and annealing technologies were adopted to fa...In order to improve the electrochemical cycle stability of the RE–Mg–Ni-based A2B7-type electrode alloys, a small amount of Si has been added into the alloys.The casting and annealing technologies were adopted to fabricate the La0.8Mg0.2Ni3.3Co0.2Six(x = 0–0.2) electrode alloys. The impacts of the addition of Si and annealing treatment on the structures and electrochemical performances of the alloys were investigated systematically. The results obtained by XRD and SEM show that all the as-cast and annealed alloys are of a multiphase structure, involving two main phases(La, Mg)2Ni7and La Ni5 as well as a residual phase La Ni3. Both adding Si and the annealing treatment lead to an evident change in the phase abundance and cell parameters of(La, Mg)2Ni7and La Ni5 major phases of the alloy without altering its main phase component. Moreover, the annealing treatment has the composition of the alloy distributed more homogeneously overall and simultaneously causes the grain of the alloy to be coarsened obviously. The electrochemical measurements indicate that adding Si and the annealing treatment give a significant rise to the influence on the electrochemical performances of the alloys. In brief, the cycle stability of the as-cast and annealed alloys evidently increases with the rising of Si content, while their discharge capacities obviously decrease under the same circumstances. Furthermore, the electrochemical kineticproperties of the electrode alloys, including the high rate discharge ability, the limiting current density(IL), hydrogen diffusion coefficient(D), and the charge-transfer resistance, first augment and then decline with the rising of Si content. Similarly, it is found that the above-mentioned electrochemical properties first mount up and then go down with the rising annealing temperature.展开更多
Electrochemicaldegradation of2,4-dichlorophenol （2,4-DCP） in aqueous solutionwas investigated over Ti/SnO2-Sb anode. The factors influencing thedegradation rate, such as applied currentdensity （2-40 mA/cm2 ）, pH ...Electrochemicaldegradation of2,4-dichlorophenol （2,4-DCP） in aqueous solutionwas investigated over Ti/SnO2-Sb anode. The factors influencing thedegradation rate, such as applied currentdensity （2-40 mA/cm2 ）, pH （3-11） and initial concentration （5-200 mg/L）were evaluated. Thedegradation of2,4-DCP followed apparent pseudo first-order kinetics. Thedegradation ratio on Ti/SnO2 -Sb anode attained 〉 99.9% after 20 min of electrolysis at initial 5-200 mg/L concentrations at a constant currentdensity of 30 mA/cm2 with a 10 mmol/L sodium sulphate （Na2SO4 ） supporting electrolyte solution. The results showed that 2,4-DCP （100 mg/L）degradation and total organic carbon （TOC） removal ratio achieved 99.9% and 92.8%, respectively, at the optimal conditions after 30 min electrolysis. Under this condition, thedegradation rate constant （k） and thedegradation half-life （t1/2 ）were 0.21 min1 and （2.8 ± 0.2） min, respectively. Mainly carboxylic acids （propanoic acid, maleic acid, propanedioic acid, acetic acid and oxalic acid） weredetected as intermediates. The energy efficiencies for2,4-DCPdegradation （5-200 mg/L）with Ti/SnO2-Sb anode ranged from 0.672 to 1.602 g/kWh. The Ti/SnO2-Sb anodewith a high activity to rapid organic oxidation could be employed todegrade chlorophenols, particularly2,4-DCP inwastewater.展开更多
基金supported by the National Natural Science Foundation of China(21507104)the Fundamental Research Funds for the Central Universities of China
文摘Electrochemical oxidation of aniline in aqueous solution was investigated over a novel Ti/TiOxHy/Sb-SnO2 electrode prepared by the electrodeposition method.Scanning electron microscopy,X-ray diffraction,and electrochemical measurements were used to characterize its morphology,crystal structure,and electrochemical properties.Removal of aniline by the Ti/TiOxHy/Sb-SnO2electrode was investigated by ultraviolet-Visible spectroscopy and chemical oxygen demand（COD）analysis under different conditions,including current densities,initial concentrations of aniline,pH values,concentrations of chloride ions,and types of reactor.It was found that a higher current density,a lower initial concentration of aniline,an acidic solution,the presence of chloride ions（0.2wt%NaCl）,and a three-dimensional（3D） reactor promoted the removal efficiency of aniline.Electrochemical degradation of aniline followed pseudo-first-order kinetics.The aniline（200 mL of 100mg·L-（-1）） and COD removal efficiencies reached 100%and 73.5%,respectively,at a current density of 20 mA·cm-（-2）,pH of 7.0,and supporting electrolyte of 0.5 wt%Na2SO4 after 2 h electrolysis in a 3D reactor.These results show that aniline can be significantly removed on the Ti/TiOxHy/Sb-SnO2electrode,which provides an efficient way for elimination of aniline from aqueous solution.
基金Project supported by the Institute of Environmental Engineering,Peking University and China Postdoctoral Science Foundation(No.2005037032)
文摘Ti/Sb-SnO2 anodes were prepared by thermal decomposition to examine the influence of the amount of Sb dopant on the structure and electrocatalytic capability of the electrodes in the oxidation of 4-chlorophenol. The physicochemical properties of the Sb-SnO2 coating were markedly influenced by different amounts of Sb dopant. The electrodes, which contained 5% Sb dopant in the coating, presented a much more homogenous surface and much smaller mud-cracks, compared with Ti/Sb-SnO2 electrodes containing 10% or 15% Sb dopant, which exibited larger mud cracks and pores on the surface. However, the main microstructure remained unchanged with the addition of the Sb dopant. No new crystal phase was observed by X-ray diffraction （XRD）. The electrochemical oxidation of 4-chlorophenol on the Ti/SnO2 electrode with 5% Sb dopant was inclined to electrochemical combustion; while for those containing more Sb dopant, intermediate species were accumulated. The electrodes with 5% Sb dopant showed the highest efficiency in the bulk electrolysis of 4-chlorophenol at a current density of 20 mA/cm^2 for 180 min; and the removal rates of 4-chlorophenol and COD were 51.0% and 48.9%, respectively.
基金the National Key R&D Program of China(No.2021YFA1501503)the National Natural Science Foundation of China(Nos.22250008,22121004,22108197)+3 种基金the Haihe Laboratory of Sustainable Chemical Transformations(No.CYZC202107)the Natural Science Foundation of Tianjin City(No.21JCZXJC00060)the Program of Introducing Talents of Discipline to Universities(No.BP0618007)the Xplorer Prize for financial support。
文摘Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-section in the flow channel is normally adopted,the configuration optimization of which could potentially enhance the performance of the electrolyzer.This paper describes the numerical simulation study on the impact of the flow-channel cross-section shapes in the MEA electrolyzer for CO_(2)RR.The results show that wide flow channels with low heights are beneficial to the CO_(2)RR by providing a uniform flow field of CO_(2),especially at high current densities.Moreover,the larger the electrolyzer,the more significant the effect is.This study provides a theoretical basis for the design of high-performance MEA electrolyzers for CO_(2)RR.
基金supported by the National Natural Science Foundation of China(U23A20573,U23A20140)the Hebei Natural Science Foundation(B202420809,B2024208088)+2 种基金S&T Program of Hebei(242Q4301Z,22373709D)Project of Basic Research at Universities in Shijiazhuang(241790977A)Huang jin tai plan project of Hebei provincial department of education(HJZD202512)。
文摘Integrating the CO_(2)capture process with the CO_(2)electrochemical reduction process into a single system can eliminate the need for storage and transportation following CO_(2)capture.This integrated process offers several advantages over multi-step cascade processes,including reduced costs and enhanced CO_(2)utilization.However,the integrated CO_(2)capture and electrochemical reduction(CCER)process encounters several challenges,including the low CO_(2)adsorption performance of the gas diffusion electrode(GDE)and catalyst,as well as the poor activity and selectivity of the catalyst for the electrochemical reduction of CO_(2).This review aims to systematically summarize the fundamentals of the CCER process.Based on an in-depth understanding of the CO_(2)mass transfer,adsorption,and electrochemical reduction processes,GDE design strategies based on the modulation of wettability and structure are discussed to enhance the CO_(2)capture capability at the GDE level.At the catalyst level,catalyst design strategies based on the introduction of CO_(2)capture sites and the construction of CO_(2)mass transfer channels were analyzed,and catalyst design strategies for enhanced CO_(2)capture were proposed.This review summarizes the most common catalysts for CO_(2)electrochemical reduction,such as Ni-based,Bi-based,and Cubased catalysts,and analyzes their design strategies based on reaction pathways for generating specific products.Finally,the problems and challenges of the CCER process are summarized and proposed,which provide ideas for the further application of this technology in the future.
基金supported by the National Research Foundation of Korea(RS-2023-00207831,RS-2024-00346153).
文摘The state-of-the-art anion-exchange membrane water electrolyzers(AEMWEs)require highly stable electrodes for prolonged operation.The stability of the electrode is closely linked to the effective evacuation of H_(2) or O_(2) gas generated from electrode surface during the electrolysis.In this study,we prepared a superhydrophilic electrode by depositing porous nickel–iron nanoparticles on annealed TiO_(2) nanotubes(NiFe/ATNT)for rapid outgassing of such nonpolar gases.The super-hydrophilic NiFe/ATNT electrode exhibited an overpotential of 235 mV at 10 mA cm^(−2) for oxygen evolution reaction in 1.0 M KOH solution,and was utilized as the anode in the AEMWE to achieve a current density of 1.67 A cm^(−2) at 1.80 V.In addition,the AEMWE with NiFe/ATNT electrode,which enables effective outgassing,showed record stability for 1500 h at 0.50 A cm^(−2) under harsh temperature conditions of 80±3℃.
文摘The pore size distribution is often an important parameter for transport processes in porous media.Cryoporometry experiments can provide such data in the meso and macropore size up to 1 mm providing the sample temperature is finely controlled.We use a Peltier based system inserted directly into the NMR probe to control the temperature within 0.05℃and impose temperature ramps down to 0.002℃/min,necessary to characterize the largest pore sizes.The pore size information in the macropore range cannot be obtained from gas adsorption techniques while mercury injection is questionable for the material considered here.For porous materials made of paramagnetic minerals such as lithium-iron phosphate(LiFePO_(4),LFP)or nickel-manganese-cobalt oxides(NMC)and saturated with octamethylcyclotetrasiloxane(OMCTS),the T_(2)relaxation times are very short such as protons from the liquid and frozen phases cannot be separated.Hence the usual cryoporometry experiment cannot be performed.Instead,we propose to use the T_(1)contrast to separate these phases.The method is studied in detail along with some temperature effects linked with the T_(1)variation of the bulk frozen OMCTS.We show an example on two cathode materials part of industrial battery product.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.51602160 and 61605086)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20150842)the Talent Project of Nanjing University of Posts and Telecommunications(NUPTSF)(Grant No.NY222127)。
文摘This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-and(222)-oriented ITO BEs deposited under pure argon and argon–oxygen(20%O_(2))sputtering atmospheres,as well as SrRuO_(3)(SRO),show distinct RS behaviors.The Al/ZrO_(2)/(400)-ITO and Al/ZrO_(2)/SRO devices demonstrate stable bipolar RS performance,with(400)-ITO enabling an abrupt reset process,a wider memory window(>10^(4)),and superior stability,while SRO devices exhibit gradual reset transitions with lower power consumption.Furthermore,the crystallographic orientation control applied to ITO BE significantly affects the V_(O) dynamics and RS performance,with(222)-ITO devices exhibiting irreversible RS behavior.It is irrefutable that BE material and its orientation can strongly influence RS performance by modulating the V_(O) dynamics,electric field distribution,and conductive filament behavior.These findings underscore the importance of BE properties in optimizing ReRAM performance and provide valuable guidance for the development of high-efficiency memory devices.
基金supported by the National Natural Science Foundation of China(Nos.U22A20145,51904115,52072151,52171211,and 52271218)Jinan Independent Innovative Team(No.2020GXRC015)the Major Program of Shandong Province Natural Science Foundation(Nos.ZR2023ZD43 and ZR2021ZD05).
文摘The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explore a candidate with large SCs,which can stably operate in the negative potential region mean-while.For this propose,we design and fabricate solid-solution Ru_(x)Cu_(1-x)O_(2) nanocrystals(NCs),which exhibit competitive SCs and electrochemical stability within the potential range from-0.9 V to 0.0 V in the aqueous KOH electrolyte.The incorporation of Cu enhances the electrochemical utilization of RuO_(2),reaction kinetics,electronic conductivity,and hydrogen evolution overpotentials,which are all highly dependent upon the added contents of Cu species.The optimized Ru_(0.8)Cu_(0.2)O_(2)(RuCu82)electrode of a high mass loading of 5 mg cm^(-2) reveals the best electrochemical capacitances in terms of reversible SCs and capacitance degradation at room temperature and-20℃.Furthermore,the reversible K^(+)-(de)intercalation induced pseudocapacitance is proposed for electrochemical charge storage process of RuCu82.In particu-lar,remarkable specific energy of 59.1 Wh kg-1 at 400 W kg-1 and excellent cycling stability are achieved in the assembled NiCoO_(2)//RuCu82 AHCs.Our contribution here presents a new promising negative elec-trode platform with high SCs and electrochemical stability for next-generation AHCs.
文摘Even in small concentrations,toxic metals like lead,cadmium,and mercury are dangerous to the environment and human health.Environmental monitoring depends on precisely identifying these heavy metals,particularly cadmium ions(Cd(Ⅱ)).In this study,we present a novel screen-printed carbon electrode(SPCE)modified with single crystallineα-Fe_(2)O_(3)nano-hexagons that functions as a sensor for detecting Cd(Ⅱ).The performance of the fabricated sensor was thoroughly assessed and compared with unmodified SPCE using the voltammetric method.The crystalline structure of the synthesizedα-Fe_(2)O_(3)nano-hexagons was confirmed through XRD,and surface analysis revealed an average diameter and thickness of 86 nm and 9 nm,respectively.Theα-Fe_(2)O_(3)modified SPCE yields a 7-fold enhanced response(at pH 5.0 vs.Ag/AgCl)to Cd(Ⅱ)than bare SPCE.The modified electrode effectively detects Cd(Ⅱ)with a linear response range of up to 333.0μmol/L and a detection limit of 0.65 nmol/L under ideal circumstances.This newly fabricated sensor offers significant potential for environmental monitoring applications by providing outstanding practicality,anti-interference ability,and repeatability for detecting Cd(Ⅱ)in water samples.
基金Project(50964008)supported by the National Natural Science Foundation of ChinaProject(2010287)supported by Analysis and Testing Foundation of Kunming University of Science and Technology,China
文摘Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide （CeO2） were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electrodes and the impact of α-PbO2 as the intermediate layer. The results show that using α-PbO2 as the intermediate layer will benefit the crystallization of β-PbO2 and β-PbO2 is more suitable as the surface layer than α-PbO2. CeO2 dopants change the crystallite size and crystal structure, enhance the catalytic activity, and even change the deposition mechanism of PbO2. The doping of CeO2 in the PbO2 electrodes can enhance the electro-catalytic activity, which is helpful for oxygen evolution, and therefore reduce the cell voltage.
基金Projects(50961009,51161015)supported by the National Natural Science Foundation of ChinaProject(2011AA03A408)supported by the High-tech Research and Development Program of ChinaProjects(2011ZD10,2010ZD05)supported by the Natural Science Foundation of Inner Mongolia,China
文摘In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The effects of adding Si on the structure and electrochemical hydrogen storage characteristics of the alloys were investigated systematically. The results indicate that the as-cast and annealed alloys hold multiple structures, involving two major phases of （La, Mg）2Ni7 with a Ce2Ni7-type hexagonal structure and LaNi5 with a CaCu5-type hexagonal structure as well as one residual phase LaNi3. The addition of Si results in a decrease in （La, Mg）2Ni7 phase and an increase in LaNi5 phase without changing the phase structure of the alloys. What is more, it brings on an obvious effect on electrochemical hydrogen storage characteristics of the alloys. The discharge capacities of the as-cast and annealed alloys decline with the increase of Si content, but their cycle stabilities clearly grow under the same condition. Furthermore, the measurements of the high rate discharge ability, the limiting current density, hydrogen diffusion coefficient as well as electrochemical impedance spectra all indicate that the electrochemical kinetic properties of the electrode alloys first increase and then decrease with the rising of Si content.
基金Projects(51004056,51004057)supported by the National Natural Science Foundation of ChinaProject(KKZ6201152009)supported by the Opening Foundation of Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences+2 种基金Project(2010ZC052)supported by the Applied Basic Research Foundation of Yunnan Province,ChinaProject(20125314110011)supported by the Specialized Research Fund for the Doctoral Program of Higher Education,ChinaProject(2010247)supported by Analysis&Testing Foundation of Kunming University of Science and Technology,China
文摘Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy（EDXS）, anode polarization curves, quasi-stationary polarization（Tafel） curves, electrochemical impedance spectroscopy（EIS）, scanning electron microscopy（SEM）, and X-ray diffraction（XRD）. Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential（0.610 V at 500 A/m2） for oxygen evolution, the best electrocatalytic activity, the longest service life（360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2）, and the lowest cell voltage（2.75 V at 500 A/m2）. Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.
基金supported by the Fundamental Research Funds for the Central Universities (No 30919011410)。
文摘CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@MnO2 products grown on Ni foams were obtained through a facile hydrothermal method.The as-synthesized samples employed as electrodes deliver a specific capacitance of 2325.01 F g^-1 at 1 A g^-1.An assembled asymmetric supercapacitor using these products as positive electrodes shows a maximum energy density of 59.73 W h kg^-1 at 1000.09 W kg^-1.The prominent electrochemical performance of the as-prepared electrodes could be attributes to hierarchical structures.These findings suggest that hybrid structures might be potential alternatives for future flexible energy storage devices.
基金National Natural Science Foundation of China with Grant No.21905304Natural Science Foundation of Shandong Province(No.ZR2019BEM031)the Fundamental Research Funds for the Central Universities(Nos.18CX02158A and 19CX05001A).
文摘Ti3C2Tx,a novel two-dimensional layer material,is widely used as electrode materials of supercapacitor due to its good metal conductivity,redox reaction active surface,and so on.However,there are many challenges to be addressed which impede Ti3C2Tx obtaining the ideal specific capacitance,such as restacking,re-crushing,and oxidation of titanium.Recently,many advances have been proposed to enhance capacitance performance of Ti3C2Tx.In this review,recent strategies for improving specific capacitance are summarized and compared,for example,film formation,surface modification,and composite method.Furthermore,in order to comprehend the mechanism of those efforts,this review analyzes the energy storage performance in different electrolytes and influencing factors.This review is expected to predict redouble research direction of Ti3C2Tx materials in supercapacitors.
基金the Fund of the Natural Science of Guangxi (0731015)
文摘Praseodymium was selected as a promoter for SnO2/Ti electrode to improve the electrocatalytic performance by electrodeposition in pharmaceutical wastewater treatment; the micrograph and the structure were characterized by SEM and XRD. Mixture uniform design was used in the optimization of the electrolytic conditions; mathematical model was established according to the rate of wiping COD off, which revealed the relationship between the current intensity, time of electrolysis, the amount of doped Pr, and the ratio of area （SnOJTi：Al）. On the basis of the analysis of the empirical model, the optimized parameters had been obtained; the rate of wiping COD off was up to 94.9%, it decreased from 392 to 20 mg/L. Experimental results showed that the electrocatalytic performance of the electrode doped with Pr was superior for the treatment of pharmaceutical wastewater.
基金This work was supported by the National Natural Science Foundation of China (No. 50172041).
文摘Discharge performance of K2FeO4 electrode under different conditions was studied by the constant electric current discharge method. The electrochemical characteristics of K2FeO4 electrode were investigated for the first time by means of cyclic voltammetry. The results show that the K2FeO4 electrode made at moderate pressure (20 MPa) and discharged at lower current has better discharge performance. It is also found that K2FeO4 electrode is significantly rechargeable.
文摘A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.
基金financially supported by the National Natural Science Foundation of China (Nos. 50961009 and 51161015)the National High Technology Research and Development Program of China (No. 2011AA03A408)the National High Technology Research and Development Program of China (Nos. 2011ZD10 and 2010ZD05)
文摘In order to improve the electrochemical cycle stability of the RE–Mg–Ni-based A2B7-type electrode alloys, a small amount of Si has been added into the alloys.The casting and annealing technologies were adopted to fabricate the La0.8Mg0.2Ni3.3Co0.2Six(x = 0–0.2) electrode alloys. The impacts of the addition of Si and annealing treatment on the structures and electrochemical performances of the alloys were investigated systematically. The results obtained by XRD and SEM show that all the as-cast and annealed alloys are of a multiphase structure, involving two main phases(La, Mg)2Ni7and La Ni5 as well as a residual phase La Ni3. Both adding Si and the annealing treatment lead to an evident change in the phase abundance and cell parameters of(La, Mg)2Ni7and La Ni5 major phases of the alloy without altering its main phase component. Moreover, the annealing treatment has the composition of the alloy distributed more homogeneously overall and simultaneously causes the grain of the alloy to be coarsened obviously. The electrochemical measurements indicate that adding Si and the annealing treatment give a significant rise to the influence on the electrochemical performances of the alloys. In brief, the cycle stability of the as-cast and annealed alloys evidently increases with the rising of Si content, while their discharge capacities obviously decrease under the same circumstances. Furthermore, the electrochemical kineticproperties of the electrode alloys, including the high rate discharge ability, the limiting current density(IL), hydrogen diffusion coefficient(D), and the charge-transfer resistance, first augment and then decline with the rising of Si content. Similarly, it is found that the above-mentioned electrochemical properties first mount up and then go down with the rising annealing temperature.
基金supported by the National Science Foundation for Innovative Research Group of China(No.51121003)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20110003110023)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control of China
文摘Electrochemicaldegradation of2,4-dichlorophenol （2,4-DCP） in aqueous solutionwas investigated over Ti/SnO2-Sb anode. The factors influencing thedegradation rate, such as applied currentdensity （2-40 mA/cm2 ）, pH （3-11） and initial concentration （5-200 mg/L）were evaluated. Thedegradation of2,4-DCP followed apparent pseudo first-order kinetics. Thedegradation ratio on Ti/SnO2 -Sb anode attained 〉 99.9% after 20 min of electrolysis at initial 5-200 mg/L concentrations at a constant currentdensity of 30 mA/cm2 with a 10 mmol/L sodium sulphate （Na2SO4 ） supporting electrolyte solution. The results showed that 2,4-DCP （100 mg/L）degradation and total organic carbon （TOC） removal ratio achieved 99.9% and 92.8%, respectively, at the optimal conditions after 30 min electrolysis. Under this condition, thedegradation rate constant （k） and thedegradation half-life （t1/2 ）were 0.21 min1 and （2.8 ± 0.2） min, respectively. Mainly carboxylic acids （propanoic acid, maleic acid, propanedioic acid, acetic acid and oxalic acid） weredetected as intermediates. The energy efficiencies for2,4-DCPdegradation （5-200 mg/L）with Ti/SnO2-Sb anode ranged from 0.672 to 1.602 g/kWh. The Ti/SnO2-Sb anodewith a high activity to rapid organic oxidation could be employed todegrade chlorophenols, particularly2,4-DCP inwastewater.
