The molten CaCl_(2)−CaMoO_(4) system was investigated,and the electrodeposition of protective Mo coatings on Ni plates was demonstrated.The results confirm the high solubility of solid CaMoO_(4) and the electrochemica...The molten CaCl_(2)−CaMoO_(4) system was investigated,and the electrodeposition of protective Mo coatings on Ni plates was demonstrated.The results confirm the high solubility of solid CaMoO_(4) and the electrochemical reactivity of MoO_(4)^(2-)ions in molten CaCl_(2).The eutectic temperature and composition of the system are identified as 1021 K and 4.74 wt.%CaMoO_(4),respectively.Under constant-current electrolysis conditions of−10 mA/cm^(2) at 1123 K,uniform and dense Mo coatings are obtained on Ni plates with up to 90.31%efficiency.Increasing the current density raises the overpotential,leading to refined grains and decreased roughness.The Mo-coated Ni plate exhibits a significant improvement in hardness and corrosion resistance.Microhardness increases from HV 46.00 to HV 215.10 after coating,and the corrosion rate in a 20 wt.%NaCl solution at room temperature decreases to 0.1%that of the bare plate.These findings enhance our understanding of the molten CaCl_(2)–CaMoO_(4) system and emphasize the potential of innovative Mo coating technologies.展开更多
In this study,controllable fabrication of nickel-doped diamond-like carbon(Ni-DLC)films through laser-assisted electrochemical deposition under low-voltage conditions(5 V)is achieved.After substrate polishing,picoseco...In this study,controllable fabrication of nickel-doped diamond-like carbon(Ni-DLC)films through laser-assisted electrochemical deposition under low-voltage conditions(5 V)is achieved.After substrate polishing,picosecond laser irradiation is applied during electrodeposition to precisely control the laser energy and defocus distance during film preparation,with subsequent analysis of surface morphology,composition,and properties in correlation with growth mechanisms.Compared with conventional DLC electrodeposition,the laser-assisted technique significantly improves film quality by maintaining the deposition zone temperature at~52℃,with laser-induced micro-stirring effectively reducing cathode bubble adhesion and suppressing hydrogen evolution.Without laser assistance,the films exhibit poor adhesion,porous structure,and thickness nonuniformity,while increasing the laser energy progressively enhances densification,achieving 3.5μm thickness uniformity.Optimal performance at 8.5μJ laser energy demonstrates an improved deposition rate compared with conventional methods,a minimum corrosion current density(1.116×10^(−6)Amm^(−2)),and a stable friction coefficient(0.143),establishing a novel laser-assisted approach for controllable DLC electrodeposition.展开更多
Preferential magnesium(Mg)electrodeposition on separators is a ubiquitous yet poorly understood phenomenon in rechargeable Mg-metal batteries,posing a fundamental challenge to their development.In this work,the synerg...Preferential magnesium(Mg)electrodeposition on separators is a ubiquitous yet poorly understood phenomenon in rechargeable Mg-metal batteries,posing a fundamental challenge to their development.In this work,the synergy effects of interface-accelerating desolvation and spatial confinement have been demonstrated as the essential causation of this counterintuitive experimental phenomenon.At the molecular level,the imide ring(-CO-NR-CO-,in which R represents the phenyl)groups in an artificially introduced polyimide(PI)interlayer facilitate the strong electrostatic affinity towards Mg^(2+),which accelerates the desolvation process for Mg^(2+)solvation structures at the inner Helmholtz plane.At the nucleation scale,the wedge-like concave geometry formed at the PI/current collector interface provides energetically favorable sites for Mg nucleation.This unique architecture reduces the critical nucleus size,thereby significantly lowering nucleation energy barriers.As a result,the satisfactory Coulombic efficiency for Mg plating/stripping(98.22%)and cycle lifespan(1200 cycles,above 100 days)have been achieved,outperforming most of the previous results.This work pioneers a molecular-level understanding of separator-directed Mg deposition and resolves a long-standing confusion in Mg-metal batteries.展开更多
Zinc(Zn)-based materials show broad application prospects for bone repair due to their biodegradability and good biocompatibility.In particular,Zn metal foam has unique interconnected pore structure that facilitates i...Zinc(Zn)-based materials show broad application prospects for bone repair due to their biodegradability and good biocompatibility.In particular,Zn metal foam has unique interconnected pore structure that facilitates inward growth of new bone tissue,making it ideal candidates for orthopedic implants.However,pure Zn metal foam shows poor mechanical property,high degradation rate,and unsatisfactory osteogenic activity.Herein,Zinc-manganese(Zn-Mn)alloy foams were electrodeposited in Zn and Mn-containing electrolytes to overcome the concerns.The results showed that Mn could be incorporated into the foams in the form of MnZn_(13).Zn-Mn alloy foams showed better mechanical property and osteogenic activity as well as moderate degradation rate when compared with pure Zn metal foam.In addition,these properties could also be regulated by preparation process.The peak stress and osteogenic activity increased with deposition current(0.3‒0.5 A)and electrolyte pH(3‒5),but decreased with electrolyte temperature(20‒40℃),while the degradation rate exhibited opposite tendency,which suggests high deposition current and electrolyte pH and low electrolyte temperature can fabricate Zn-Mn alloy foam with favorable mechanical property,moderate degradation rate,and osteogenic activity.These findings provide a valuable reference for the design and fabrication of novel Zn-based biodegradable materials.展开更多
Electrochemical metallurgy at low temperature(<473 K)shows promise for the extraction and refinement of metals and alloys in a green and sustainable manner.However,the kinetics of the electrodeposition process is g...Electrochemical metallurgy at low temperature(<473 K)shows promise for the extraction and refinement of metals and alloys in a green and sustainable manner.However,the kinetics of the electrodeposition process is generally slow at low temperature,resulting in large overpotential and low current efficiency.Thus,the application of external physical fields has emerged as an effective strategy for improving the mass and charge transfer processes during electrochemical reactions.This review highlights the challenges associated with low-temperature electrochemical processes and briefly discusses recent achievements in optimizing electrodeposition processes through the use of external physical fields.The regulating effects on the optimization of the electrodeposition process and the strategies for select-ing various external physical fields,including magnetic,supergravity,and ultrasonic fields are summarized from the perspectives of equipment and mechanisms.Finally,advanced methods for in-situ characterization of external physical field-assisted electrodeposition processes are reviewed to gain a deeper understanding of metallic electrodeposition.An in-depth exploration of the mechanism by which external physical fields affect the electrode process is essential for enhancing the efficiency of metal extraction at low temperatures.展开更多
Metal-organic framework(MOF)nanostructures have emerged as a prominent class of materials in the advancement of electrochemical sensors.The rational design of bimetallic MOF-functionalized microelectrode is of importa...Metal-organic framework(MOF)nanostructures have emerged as a prominent class of materials in the advancement of electrochemical sensors.The rational design of bimetallic MOF-functionalized microelectrode is of importance for improv-ing the electrochemical performance but still in great challenge.In this work,the bimetallic FeCo-MOF nanostructures were assembled onto a gold disk ultramicroelectrode(Au UME,5.2μm in diameter)via an in-situ electrodeposition method,which enhanced the sensitive detection of epinephrine(EP).The in-situ electrodeposited FeCo-MOF exhibited a character-istic nanoflower-like morphology and was uniformly dispersed on the Au UME.The FeCo-MOF/Au UME demonstrated excellent electrochemical performance on the detection of EP with a high sensitivity of 36.93μA·μmol^(-1)·L·cm^(-2)and a low detection limit of 1.28μmol·L^(-1).It can be attributed to the nonlinear diffusion of EP onto the ultra-micro working substrate,coupled with synergistical catalytic activity of the bimetallic Fe,Co within MOF structure.Furthermore,the FeCo-MOF/Au UME has been successful applied to the analysis of EP in human serum samples,yielding high recovery rates.These results not only contribute to the expansion of the research area of electrochemical sensors,but also provide novel insights and directions into the development of high-performance MOF-based electrochemical sensors.展开更多
Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is cons...Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is constructed by reversible metal electrodeposition(RME)of Bi/Cu on WO_(3)·xH_(2)O film electrodeposited onto fluorine-doped tin oxide(FTO)transparent conductive glass.The electrolyte consists of CuCl_(2),BiCl_(3),KCl and HCl aqueous solution,supplying necessary components for both electrochemical and electrodeposition processes.The ECD shows ability to rapidly transition between colorless and black states,which achieves a large optical modulation of 77.0%at 570 nm.In the black state,the ECD exhibits a near-zero transmittance in the wavelength range of 400-1100 nm while maintaining 96.6%of its initial optical modulation after coloration/bleaching cycling of 60000 s,exhibiting good cyclic stability.This RMED has relatively high stability under open-circuit voltage and also possesses excellent heat insulation performance.The results offer a solution to overcome the poor cyclic stability of RMEDs and improve the optical modulation of ECDs.展开更多
pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric ex...pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric experiments and buffering properties of the solutions(pH 3-10).Cyclic voltammetry indicated changes in electrochemical behavior of cobalt species caused by different ionic compositions of the electrolytes.Tafel slopes were calculated and discussed in relation to electroreduction of cobalt species.Chronoamperometric studies showed 3D instantaneous nucleation of cobalt followed by diffusion-controlled growth,but it was disturbed at higher pH due to the release of cation from gluconate complexes as a limiting step.Diffusion coefficients of cobalt species were found.Changes in the pH were also reflected by modifications of morphology(SEM),development of preferred orientation planes(XRD,texture coefficients)and current efficiency,but not the thickness of the coatings deposited at constant potential of-1.0 V(vs Ag/AgCl).Anodic stripping analysis showed changes in anodic responses originated from the existence of preferentially oriented planes in cobalt layers.展开更多
Copper materials have emerged as the preferred choice for marine heat exchangers owing to their excep-tional thermal conductivity.The enhancement of surface performance can be significantly achieved by engineering mic...Copper materials have emerged as the preferred choice for marine heat exchangers owing to their excep-tional thermal conductivity.The enhancement of surface performance can be significantly achieved by engineering micro-nano structures on the material’s surface,thereby attaining improved corrosion resis-tance and antibacterial properties in complex marine environments.In this study,we directly fabricated a copper nanopillar array structure on the substrate via template-assisted electrodeposition.Subsequently,passivation of the pillar-structured copper surface was achieved through a formate&dodecanethiol-assisted solvothermal process(Cu/FA-DT).The results indicate that the nanopillar structure effectively eliminates bacteria through physical rupture upon contact,leading to an 85.47%reduction in P.aerug-inosa adhesion compared to untreated samples after 72 h of immersion in seawater.Furthermore,cor-rosion resistance is significantly enhanced,with inhibition rates of approximately 95.27%and 90.50%in natural and P.aeruginosa containing seawater,respectively.Notably,the thermal conductivity of copper is well preserved,ensuring its functional integrity in marine heat exchange environments.After 7 days of immersion in natural and P.aeruginosa containing seawater,the thermal conductivity of Cu/FA-DT de-creased by only 15.41%and 2.78%,respectively,demonstrating superior thermal conductivity retention compared to untreated bare copper.This study provides valuable insights into the potential application of traditional copper in marine heat exchange environments.展开更多
Aqueous zinc-ion batteries(AZIBs)are attractive for large-scale energy storage due to their safety and low cost,but practical use is limited by dendrite growth,hydrogen evolution,and passivation.Traditional solutions ...Aqueous zinc-ion batteries(AZIBs)are attractive for large-scale energy storage due to their safety and low cost,but practical use is limited by dendrite growth,hydrogen evolution,and passivation.Traditional solutions often introduce additional complexity without addressing the root cause:unstable zinc deposition.Recent advancements now focus on controlling zinc crystallographic orientation to fundamentally suppress inhomogeneous nucleation and growth.The(002)basal plane supports smooth,reversible growth and can be promoted via heteroepitaxy or homoepitaxy,enabling long cycle life even at high rates.However,emerging studies show that Zn(100)and Zn(101)orientations may offer comparable benefits through faster kinetics and reduced parasitic reactions.Scalable,non-epitaxial methods,such as electrolyte tuning and pressure control also show promise.Despite these advances,balancing thermodynamic stability with kinetic performance remains a major challenge.Future research should integrate orientation control with strategies against corrosion and calendar aging to enable practical,highperformance AZIBs.展开更多
To improve the practical application of carbon steel,developing a superhydrophobic coating with outstanding mechanical properties is essential for effective corrosion resistance protection.Here,we obtained a robust su...To improve the practical application of carbon steel,developing a superhydrophobic coating with outstanding mechanical properties is essential for effective corrosion resistance protection.Here,we obtained a robust superhydrophobic anti-corrosion coating with a cauliflower structure by co-depositing the lauric acid with Ni ions and Mn ions onto a carbon steel through electrodeposition method.As demonstrated by the results,superhydrophobic Ni/Mn alloy(SNMAmit)displays a multi-hierarchical micro/nano cauliflower structure under the synergy of optimal parameters,exhibiting superb superhydrophobicity with contact angle of 161.9°and sliding angle of 6.2°.Surprisingly,the Tafel polarization curves in 3.5%NaCl showed that the corrosion potential of SNMAmit coating was 476 mV,and the corrosion current density was reduced from 1.39×10^(−5)to 5.89×10^(−7)A/cm^(2).The reduced corrosion current density of superhydrophobic Ni/Mn alloy(SNMA)indicates that SNMA coating can significantly enhance the anti-corrosion properties of carbon steel.In addition,after being subjected to various damages such as blade scraping,tape cyclic peeling,acid and alkalis,sandpaper cyclic abrasion,high temperatures,ultrasound,and graphite contaminant,SNMA showed good mechanical stability,interference resistance,heat resistance,and self-cleaning properties,which made it suitable for hostile conditions.展开更多
The development of low-energy consumption and environmentally friendly electrodeposition of metal/alloy films or coatings is presently one of the primary topics for the research community.For this purpose,deep eutecti...The development of low-energy consumption and environmentally friendly electrodeposition of metal/alloy films or coatings is presently one of the primary topics for the research community.For this purpose,deep eutectic solvents(DESs)are valued as electrolytes for their advantages of low operating temperature and wide electrochemical windows.At present,there is large amount of literature on this emerging field,but there are no specialized reviews of these studies.Here,after a brief introduction of DESs’concept and history,we comprehensively reviewed the lastest progress on the metal/alloy electrodeposition in DESs.Additionally,we discussed the key influence factors of the electrodeposition process and analyzed the corresponding mechanisms.Based on these,we emphasized the importance of the establishment of predictive models for dealing with the challenges in large-scale applications.展开更多
The coercivity of Sm-Fe-N/Zn magnets is strongly influenced by the composition and distribution of grain boundary phases.In this study,a Zn layer was uniformly deposited onto the surface of Sm-Fe-N powders via an inno...The coercivity of Sm-Fe-N/Zn magnets is strongly influenced by the composition and distribution of grain boundary phases.In this study,a Zn layer was uniformly deposited onto the surface of Sm-Fe-N powders via an innovative electrodeposition method,followed by a twostep thermal treatment process(hot-pressing+annealing)to precisely control the formation of theГ-FeZn phase and the grain boundary structure.The results indicate that annealing at 430℃promotes the uniform distribution of theΓ-FeZn phase along the grain boundaries,achieving a coercivity of 14.60 kOe—nearly three times higher than that of the untreated sample.Transmission electron microscopy(TEM)analysis reveals that increasing the annealing temperature enhances Zn mobility and diffusion at the grain boundaries,which facilitates the gradual formation of a continuous T-FeZn phase encapsulating the magnetic particles.This structure effectively suppresses exchange coupling between grains,thereby significantly enhancing coercivity.However,when the temperature exceeds 450℃,excessive Zn diffusion leads to the formation of a Sm-Fe(Zn)-N intermediate phase,which weakens the anisotropy field and causes a reduction in coercivity.Unlike previous studies that primarily focused on the presence of the T-FeZn phase,the present work achieves synergistic optimization via electrodeposition and temperature regulation,providing a deeper understanding of the intrinsic relationship among Zn diffusion,grain boundary evolution,and magnetic properties.These findings present a novel strategy and theoretical basis for the design of high-performance Sm-Fe-N magnets.展开更多
Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)u...Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)using one-step electrodeposition method is shown.The effect of processing parameters on surface structure and wettability was thoroughly explored,resulting in the identification of three typical surface morphologies.The prepared coating with petal-like structure(SSN-3)obtained under the optimum parameters exhibited the best water repellency,achieving a contact angle of 162.7°and a sliding angle of 4.1°.The droplet bouncing behavior on SSN coatings surface was studied,and the delayed icing time was recorded.Meanwhile,the mechanical stability and chemical corrosion resistance of SSN coatings were focused.The superhydrophobic SSN-3 coating with unique surface structure exhibited excellent reliability.The anticorrosion mechanism of SSN-3 coating was discussed,and its corrosion protection efficiency was up to 98.5%.The superior properties of the superhydrophobic SSN-3 coating make it suitable for diverse applications.展开更多
Metal coating is a prevalent strategy for enhancing surface properties.Among the numerous methods for preparing coatings,electrodeposition stands out due to its simplicity,cost-effectiveness,and high efficiency,making...Metal coating is a prevalent strategy for enhancing surface properties.Among the numerous methods for preparing coatings,electrodeposition stands out due to its simplicity,cost-effectiveness,and high efficiency,making it widely utilized in various metal coating applications.By meticulously selecting appropriate electrolytes and electrodeposition parameters,metal coatings with diverse structures and morphologies can be obtained,and tailored to meet specific performance requirements.As the demand for superior metal coating performance continues to rise,it is imperative to summarize and forecast electrodeposition techniques to meet the criteria for high quality and precision.This review delves into the electrodeposition preparation of several typical metal coatings in diverse electrolyte systems,including aqueous solutions,ionic liquids,deep eutectic solvents,and molten salts.We also examine the electrodeposition process on the cathode,elucidate the correlation between parameters and coating quality,and suggest future research directions.This review aims to provide valuable insights and guidance for the electrodeposition preparation of metal coatings.展开更多
α-Ni(OH)2 was synthesized from a NiCl2 solution by electrodeposition method.In order to conduct a systematic study on the effects of experimental parameters,a series of electrolyte initial pH values,current densities...α-Ni(OH)2 was synthesized from a NiCl2 solution by electrodeposition method.In order to conduct a systematic study on the effects of experimental parameters,a series of electrolyte initial pH values,current densities,electrodeposition temperatures,and electrodeposition time were used.Cyclic voltammetry results demonstrated a side reaction of Ni^2++2e→Ni.The X-ray diffraction analysis,Fourier-transform infrared spectrum,and the color of the product showed that pureα-Ni(OH)2 could be obtained in the initial pH value range of 2−5.86,current density range of 10−25 mA/cm^2,electrodeposition temperature range of 25−35℃,and electrodeposition time range of 1.0−3.0 h.When electrodeposition temperature increased to 45℃,a mixture ofα-Ni(OH)2 and metallic Ni was obtained.A current density higher than 30 mA/cm^2 resulted in the sample with features ofβ-Ni(OH)2.A small amount of metallic Ni existed in the as-prepared sample when current density decreased to 5 mA/cm^2.A slight increase of electrolyte pH was observed with increasing initial solution pH and current density.Electrodeposition mass revealed a slight decrease with initial pH decreasing and showed an almost linear increase with current density increasing.The slope of the curve for electrodeposition mass versus electrodeposition time remained stable in the first 2.0 h and then decreased.展开更多
Aluminum was electrodeposited with constant current on AZ31 magnesium alloy pretreated under optimized conditions from trimethyl-phenyl-ammonium chloride and anhydrous aluminum chloride （TMPAC-AlCl3） quaternary ammo...Aluminum was electrodeposited with constant current on AZ31 magnesium alloy pretreated under optimized conditions from trimethyl-phenyl-ammonium chloride and anhydrous aluminum chloride （TMPAC-AlCl3） quaternary ammonium room temperature ionic liquids with benzene as a co-solvent. The corrosion resistance of the as-deposited Al layers was evaluated in 3.5% NaCl solution by the electrochemical technologies. The Al depositions were characterized by scanning electron microscopy equipped with energy dispersion X-ray. The results show that the microstructures of the Al depositions have spherical equiaxed grains obtained at a high current density, and bulk grains at a low current density. The Al deposition obtained at 12.3 mA/cm2 has a smooth and compact surface. The electrochemical measurements indicate that the thicker Al deposition can more effectively protect the Mg substrate. The Al deposition with bulk grains hardly protects the AZ31 Mg substrate from corrosion owing to its porosity.展开更多
In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology ...In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology and composition wereexamined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicatethat TiN nanoparticles were doped successfully in the Ni-P matrix after a series of complex pretreatments including activation, zincimmersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion betweenmagnesium alloy and composite coating. The microhardness of the Ni-P coating increases dramatically by adding TiN nanoparticlesand subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni-P-TiN compositecoating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni-P coating in short immersion time.However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.展开更多
The electrodeposition behaviors of nickel on glassy carbon（GC） and carbon steel（CS） electrodes were investigated in the14.3%-85.7%（mole fraction） betaine.HCl ethylene glycol（EG） ionic liquid using cyclic volta...The electrodeposition behaviors of nickel on glassy carbon（GC） and carbon steel（CS） electrodes were investigated in the14.3%-85.7%（mole fraction） betaine.HCl ethylene glycol（EG） ionic liquid using cyclic voltammetry and chronoamperometry.The results indicated that the reduction of Ni（Ⅱ） on CS electrode via a diffusion-controlled quasi-reversible process was much more facile and easier than that occurred on GC electrode,which followed a diffusion-controlled three-dimensional instantaneous nucleation and growth.Scanning electron microscopy was used to observe that the deposit was dense and contained fine crystallites with average size of（80±4） nm.Energy dispersive spectrometer analysis showed that the obtained deposit was metallic nickel.X-ray diffraction spectroscopy indicated that（111） plane was the most preferred crystal orientation.The nickel deposit was luminous and bright,and had good adhesion with the CS substrate.展开更多
The process parameters were optimized for the electrodeposition of cobalt from cobalt chloride solution in the membrane electrolytic reactor. Effects of parameters such as catholyte composition, current density and t...The process parameters were optimized for the electrodeposition of cobalt from cobalt chloride solution in the membrane electrolytic reactor. Effects of parameters such as catholyte composition, current density and temperature on the current efficiency, specific power consumption and quality of deposition were studied. The catholyte was a mixed solution of cobalt chloride, the initial middle electrolyte consisted of diluted hydrochloric acid, and the anolyte was sulfuric acid. An anion exchange membrane separated the catholyte from the middle electrolyte, and a cation exchange membrane separated the anolyte from the middle electrolyte. The results showed that a maximum current efficiency of 97.5% was attained under the optimum experimental condition of an catholyte composition of 80 g/L Co^2＋, 20 g/L H3BO3, 3 g/L NaF and pH of 4, at a cathode current density of 250 A/m2 and a temperature of 50 ℃ HCl could be produced in the middle compartment electrochemically up to 0.45 mol/L.展开更多
基金supported by Research Center for Industries of the Future(No.WU2022C034)at Westlake University,China。
文摘The molten CaCl_(2)−CaMoO_(4) system was investigated,and the electrodeposition of protective Mo coatings on Ni plates was demonstrated.The results confirm the high solubility of solid CaMoO_(4) and the electrochemical reactivity of MoO_(4)^(2-)ions in molten CaCl_(2).The eutectic temperature and composition of the system are identified as 1021 K and 4.74 wt.%CaMoO_(4),respectively.Under constant-current electrolysis conditions of−10 mA/cm^(2) at 1123 K,uniform and dense Mo coatings are obtained on Ni plates with up to 90.31%efficiency.Increasing the current density raises the overpotential,leading to refined grains and decreased roughness.The Mo-coated Ni plate exhibits a significant improvement in hardness and corrosion resistance.Microhardness increases from HV 46.00 to HV 215.10 after coating,and the corrosion rate in a 20 wt.%NaCl solution at room temperature decreases to 0.1%that of the bare plate.These findings enhance our understanding of the molten CaCl_(2)–CaMoO_(4) system and emphasize the potential of innovative Mo coating technologies.
基金supported by the National Natural Science Foundation of China(Grant Nos.52275431 and 52075227).
文摘In this study,controllable fabrication of nickel-doped diamond-like carbon(Ni-DLC)films through laser-assisted electrochemical deposition under low-voltage conditions(5 V)is achieved.After substrate polishing,picosecond laser irradiation is applied during electrodeposition to precisely control the laser energy and defocus distance during film preparation,with subsequent analysis of surface morphology,composition,and properties in correlation with growth mechanisms.Compared with conventional DLC electrodeposition,the laser-assisted technique significantly improves film quality by maintaining the deposition zone temperature at~52℃,with laser-induced micro-stirring effectively reducing cathode bubble adhesion and suppressing hydrogen evolution.Without laser assistance,the films exhibit poor adhesion,porous structure,and thickness nonuniformity,while increasing the laser energy progressively enhances densification,achieving 3.5μm thickness uniformity.Optimal performance at 8.5μJ laser energy demonstrates an improved deposition rate compared with conventional methods,a minimum corrosion current density(1.116×10^(−6)Amm^(−2)),and a stable friction coefficient(0.143),establishing a novel laser-assisted approach for controllable DLC electrodeposition.
基金supported by the National Natural Science Foundation of China(22279068,52374306)the Taishan Scholars of Shandong Province(tsqn202408202)the Qingdao New Energy Shandong Laboratory Open Project(QNESL OP202312)。
文摘Preferential magnesium(Mg)electrodeposition on separators is a ubiquitous yet poorly understood phenomenon in rechargeable Mg-metal batteries,posing a fundamental challenge to their development.In this work,the synergy effects of interface-accelerating desolvation and spatial confinement have been demonstrated as the essential causation of this counterintuitive experimental phenomenon.At the molecular level,the imide ring(-CO-NR-CO-,in which R represents the phenyl)groups in an artificially introduced polyimide(PI)interlayer facilitate the strong electrostatic affinity towards Mg^(2+),which accelerates the desolvation process for Mg^(2+)solvation structures at the inner Helmholtz plane.At the nucleation scale,the wedge-like concave geometry formed at the PI/current collector interface provides energetically favorable sites for Mg nucleation.This unique architecture reduces the critical nucleus size,thereby significantly lowering nucleation energy barriers.As a result,the satisfactory Coulombic efficiency for Mg plating/stripping(98.22%)and cycle lifespan(1200 cycles,above 100 days)have been achieved,outperforming most of the previous results.This work pioneers a molecular-level understanding of separator-directed Mg deposition and resolves a long-standing confusion in Mg-metal batteries.
基金supported by the Key Research and Development Program of Shanxi Province(202102130501007)the Natural Science Foundation of Shanxi Province(202403021212109,202203021211173)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2024L039).
文摘Zinc(Zn)-based materials show broad application prospects for bone repair due to their biodegradability and good biocompatibility.In particular,Zn metal foam has unique interconnected pore structure that facilitates inward growth of new bone tissue,making it ideal candidates for orthopedic implants.However,pure Zn metal foam shows poor mechanical property,high degradation rate,and unsatisfactory osteogenic activity.Herein,Zinc-manganese(Zn-Mn)alloy foams were electrodeposited in Zn and Mn-containing electrolytes to overcome the concerns.The results showed that Mn could be incorporated into the foams in the form of MnZn_(13).Zn-Mn alloy foams showed better mechanical property and osteogenic activity as well as moderate degradation rate when compared with pure Zn metal foam.In addition,these properties could also be regulated by preparation process.The peak stress and osteogenic activity increased with deposition current(0.3‒0.5 A)and electrolyte pH(3‒5),but decreased with electrolyte temperature(20‒40℃),while the degradation rate exhibited opposite tendency,which suggests high deposition current and electrolyte pH and low electrolyte temperature can fabricate Zn-Mn alloy foam with favorable mechanical property,moderate degradation rate,and osteogenic activity.These findings provide a valuable reference for the design and fabrication of novel Zn-based biodegradable materials.
基金supported by Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.SML2023SP243)the National Key Research and Development Program of China(No.2022YFC2906100)the National Natural Science Foundation of China(No.92475202)are acknowledged.
文摘Electrochemical metallurgy at low temperature(<473 K)shows promise for the extraction and refinement of metals and alloys in a green and sustainable manner.However,the kinetics of the electrodeposition process is generally slow at low temperature,resulting in large overpotential and low current efficiency.Thus,the application of external physical fields has emerged as an effective strategy for improving the mass and charge transfer processes during electrochemical reactions.This review highlights the challenges associated with low-temperature electrochemical processes and briefly discusses recent achievements in optimizing electrodeposition processes through the use of external physical fields.The regulating effects on the optimization of the electrodeposition process and the strategies for select-ing various external physical fields,including magnetic,supergravity,and ultrasonic fields are summarized from the perspectives of equipment and mechanisms.Finally,advanced methods for in-situ characterization of external physical field-assisted electrodeposition processes are reviewed to gain a deeper understanding of metallic electrodeposition.An in-depth exploration of the mechanism by which external physical fields affect the electrode process is essential for enhancing the efficiency of metal extraction at low temperatures.
基金support from the National Key Research and Development Program of China(2021YFB3201400,2021YFB3201401,2020YFC1908602)the National Natural Science Foundation of China(21904001 and 61774159)+1 种基金the Anhui Provincial Natural Science Foundation(2008085QF288)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Anhui Province(2020LCX032).
文摘Metal-organic framework(MOF)nanostructures have emerged as a prominent class of materials in the advancement of electrochemical sensors.The rational design of bimetallic MOF-functionalized microelectrode is of importance for improv-ing the electrochemical performance but still in great challenge.In this work,the bimetallic FeCo-MOF nanostructures were assembled onto a gold disk ultramicroelectrode(Au UME,5.2μm in diameter)via an in-situ electrodeposition method,which enhanced the sensitive detection of epinephrine(EP).The in-situ electrodeposited FeCo-MOF exhibited a character-istic nanoflower-like morphology and was uniformly dispersed on the Au UME.The FeCo-MOF/Au UME demonstrated excellent electrochemical performance on the detection of EP with a high sensitivity of 36.93μA·μmol^(-1)·L·cm^(-2)and a low detection limit of 1.28μmol·L^(-1).It can be attributed to the nonlinear diffusion of EP onto the ultra-micro working substrate,coupled with synergistical catalytic activity of the bimetallic Fe,Co within MOF structure.Furthermore,the FeCo-MOF/Au UME has been successful applied to the analysis of EP in human serum samples,yielding high recovery rates.These results not only contribute to the expansion of the research area of electrochemical sensors,but also provide novel insights and directions into the development of high-performance MOF-based electrochemical sensors.
文摘Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is constructed by reversible metal electrodeposition(RME)of Bi/Cu on WO_(3)·xH_(2)O film electrodeposited onto fluorine-doped tin oxide(FTO)transparent conductive glass.The electrolyte consists of CuCl_(2),BiCl_(3),KCl and HCl aqueous solution,supplying necessary components for both electrochemical and electrodeposition processes.The ECD shows ability to rapidly transition between colorless and black states,which achieves a large optical modulation of 77.0%at 570 nm.In the black state,the ECD exhibits a near-zero transmittance in the wavelength range of 400-1100 nm while maintaining 96.6%of its initial optical modulation after coloration/bleaching cycling of 60000 s,exhibiting good cyclic stability.This RMED has relatively high stability under open-circuit voltage and also possesses excellent heat insulation performance.The results offer a solution to overcome the poor cyclic stability of RMEDs and improve the optical modulation of ECDs.
文摘pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric experiments and buffering properties of the solutions(pH 3-10).Cyclic voltammetry indicated changes in electrochemical behavior of cobalt species caused by different ionic compositions of the electrolytes.Tafel slopes were calculated and discussed in relation to electroreduction of cobalt species.Chronoamperometric studies showed 3D instantaneous nucleation of cobalt followed by diffusion-controlled growth,but it was disturbed at higher pH due to the release of cation from gluconate complexes as a limiting step.Diffusion coefficients of cobalt species were found.Changes in the pH were also reflected by modifications of morphology(SEM),development of preferred orientation planes(XRD,texture coefficients)and current efficiency,but not the thickness of the coatings deposited at constant potential of-1.0 V(vs Ag/AgCl).Anodic stripping analysis showed changes in anodic responses originated from the existence of preferentially oriented planes in cobalt layers.
基金financially supported by the National Natural Science Foundation of China(Nos.42276212,42176043,and U2106206)the Shandong University Future Plan for Young Scholars.We thank Sen Wang,Haiyan Yu,and Xiaomin Zhao from the State Key Laboratory of Microbial Technology,Shandong University for the assistance in the microimaging of SEM analysis.
文摘Copper materials have emerged as the preferred choice for marine heat exchangers owing to their excep-tional thermal conductivity.The enhancement of surface performance can be significantly achieved by engineering micro-nano structures on the material’s surface,thereby attaining improved corrosion resis-tance and antibacterial properties in complex marine environments.In this study,we directly fabricated a copper nanopillar array structure on the substrate via template-assisted electrodeposition.Subsequently,passivation of the pillar-structured copper surface was achieved through a formate&dodecanethiol-assisted solvothermal process(Cu/FA-DT).The results indicate that the nanopillar structure effectively eliminates bacteria through physical rupture upon contact,leading to an 85.47%reduction in P.aerug-inosa adhesion compared to untreated samples after 72 h of immersion in seawater.Furthermore,cor-rosion resistance is significantly enhanced,with inhibition rates of approximately 95.27%and 90.50%in natural and P.aeruginosa containing seawater,respectively.Notably,the thermal conductivity of copper is well preserved,ensuring its functional integrity in marine heat exchange environments.After 7 days of immersion in natural and P.aeruginosa containing seawater,the thermal conductivity of Cu/FA-DT de-creased by only 15.41%and 2.78%,respectively,demonstrating superior thermal conductivity retention compared to untreated bare copper.This study provides valuable insights into the potential application of traditional copper in marine heat exchange environments.
基金supported by the National Natural Science Foundation of China(No.22179085).
文摘Aqueous zinc-ion batteries(AZIBs)are attractive for large-scale energy storage due to their safety and low cost,but practical use is limited by dendrite growth,hydrogen evolution,and passivation.Traditional solutions often introduce additional complexity without addressing the root cause:unstable zinc deposition.Recent advancements now focus on controlling zinc crystallographic orientation to fundamentally suppress inhomogeneous nucleation and growth.The(002)basal plane supports smooth,reversible growth and can be promoted via heteroepitaxy or homoepitaxy,enabling long cycle life even at high rates.However,emerging studies show that Zn(100)and Zn(101)orientations may offer comparable benefits through faster kinetics and reduced parasitic reactions.Scalable,non-epitaxial methods,such as electrolyte tuning and pressure control also show promise.Despite these advances,balancing thermodynamic stability with kinetic performance remains a major challenge.Future research should integrate orientation control with strategies against corrosion and calendar aging to enable practical,highperformance AZIBs.
基金the National Natural Science Foundation of China(U21A2057)the Natural Science Foundation of Chongqing(No.cstc2021jcyj-msxmX1139)the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJZD-M202301201 and KJZD-K202304502).
文摘To improve the practical application of carbon steel,developing a superhydrophobic coating with outstanding mechanical properties is essential for effective corrosion resistance protection.Here,we obtained a robust superhydrophobic anti-corrosion coating with a cauliflower structure by co-depositing the lauric acid with Ni ions and Mn ions onto a carbon steel through electrodeposition method.As demonstrated by the results,superhydrophobic Ni/Mn alloy(SNMAmit)displays a multi-hierarchical micro/nano cauliflower structure under the synergy of optimal parameters,exhibiting superb superhydrophobicity with contact angle of 161.9°and sliding angle of 6.2°.Surprisingly,the Tafel polarization curves in 3.5%NaCl showed that the corrosion potential of SNMAmit coating was 476 mV,and the corrosion current density was reduced from 1.39×10^(−5)to 5.89×10^(−7)A/cm^(2).The reduced corrosion current density of superhydrophobic Ni/Mn alloy(SNMA)indicates that SNMA coating can significantly enhance the anti-corrosion properties of carbon steel.In addition,after being subjected to various damages such as blade scraping,tape cyclic peeling,acid and alkalis,sandpaper cyclic abrasion,high temperatures,ultrasound,and graphite contaminant,SNMA showed good mechanical stability,interference resistance,heat resistance,and self-cleaning properties,which made it suitable for hostile conditions.
基金financially supported from the National Natural Science Foundation of China(Nos.52274291,52204305)Beijing Institute of Technology Research Fund Program for Young Scholars,China(No.1740011182102).
文摘The development of low-energy consumption and environmentally friendly electrodeposition of metal/alloy films or coatings is presently one of the primary topics for the research community.For this purpose,deep eutectic solvents(DESs)are valued as electrolytes for their advantages of low operating temperature and wide electrochemical windows.At present,there is large amount of literature on this emerging field,but there are no specialized reviews of these studies.Here,after a brief introduction of DESs’concept and history,we comprehensively reviewed the lastest progress on the metal/alloy electrodeposition in DESs.Additionally,we discussed the key influence factors of the electrodeposition process and analyzed the corresponding mechanisms.Based on these,we emphasized the importance of the establishment of predictive models for dealing with the challenges in large-scale applications.
基金financially supported by the National Natural Science Foundation of China(No.52101235)the Basic public welfare research program of Zhejiang Province(No.LGG22E010010)+2 种基金the Key R&D Project of Zhejiang Provincial Department Science and Technology(No.2024C01146)the Intergovernmental International Science,Technology and Innovation Cooperation Key Project of the National Key R&D Programme(No.2022YFE0109800)the National Key Research and Development Program of China(No.2021YFB3500203)
文摘The coercivity of Sm-Fe-N/Zn magnets is strongly influenced by the composition and distribution of grain boundary phases.In this study,a Zn layer was uniformly deposited onto the surface of Sm-Fe-N powders via an innovative electrodeposition method,followed by a twostep thermal treatment process(hot-pressing+annealing)to precisely control the formation of theГ-FeZn phase and the grain boundary structure.The results indicate that annealing at 430℃promotes the uniform distribution of theΓ-FeZn phase along the grain boundaries,achieving a coercivity of 14.60 kOe—nearly three times higher than that of the untreated sample.Transmission electron microscopy(TEM)analysis reveals that increasing the annealing temperature enhances Zn mobility and diffusion at the grain boundaries,which facilitates the gradual formation of a continuous T-FeZn phase encapsulating the magnetic particles.This structure effectively suppresses exchange coupling between grains,thereby significantly enhancing coercivity.However,when the temperature exceeds 450℃,excessive Zn diffusion leads to the formation of a Sm-Fe(Zn)-N intermediate phase,which weakens the anisotropy field and causes a reduction in coercivity.Unlike previous studies that primarily focused on the presence of the T-FeZn phase,the present work achieves synergistic optimization via electrodeposition and temperature regulation,providing a deeper understanding of the intrinsic relationship among Zn diffusion,grain boundary evolution,and magnetic properties.These findings present a novel strategy and theoretical basis for the design of high-performance Sm-Fe-N magnets.
基金the Natural Science Foundation of Chongqing of China(Nos.CSTB2024NSCQ-MSX1013 and cstc2021jcyj-msxmX1139)the Science and Technology Research Program of Chongqing Education Commission(Nos.KJZD-K202304502,KJQN202201214,KJQN202001243 and KJZD-M202301201)the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan province(No.2024CL05).
文摘Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)using one-step electrodeposition method is shown.The effect of processing parameters on surface structure and wettability was thoroughly explored,resulting in the identification of three typical surface morphologies.The prepared coating with petal-like structure(SSN-3)obtained under the optimum parameters exhibited the best water repellency,achieving a contact angle of 162.7°and a sliding angle of 4.1°.The droplet bouncing behavior on SSN coatings surface was studied,and the delayed icing time was recorded.Meanwhile,the mechanical stability and chemical corrosion resistance of SSN coatings were focused.The superhydrophobic SSN-3 coating with unique surface structure exhibited excellent reliability.The anticorrosion mechanism of SSN-3 coating was discussed,and its corrosion protection efficiency was up to 98.5%.The superior properties of the superhydrophobic SSN-3 coating make it suitable for diverse applications.
基金financial support from the Project supported by the Southern Marine Science and Engineering Guangdong Lab-oratory(Zhuhai)(No.SML2023SP242)the National Natural Sci-ence Foundation of China(Nos.52274291 and 52204305)the Beijing Institute of Technology Research Fund Program for Young Scholars(No.1740011182102).
文摘Metal coating is a prevalent strategy for enhancing surface properties.Among the numerous methods for preparing coatings,electrodeposition stands out due to its simplicity,cost-effectiveness,and high efficiency,making it widely utilized in various metal coating applications.By meticulously selecting appropriate electrolytes and electrodeposition parameters,metal coatings with diverse structures and morphologies can be obtained,and tailored to meet specific performance requirements.As the demand for superior metal coating performance continues to rise,it is imperative to summarize and forecast electrodeposition techniques to meet the criteria for high quality and precision.This review delves into the electrodeposition preparation of several typical metal coatings in diverse electrolyte systems,including aqueous solutions,ionic liquids,deep eutectic solvents,and molten salts.We also examine the electrodeposition process on the cathode,elucidate the correlation between parameters and coating quality,and suggest future research directions.This review aims to provide valuable insights and guidance for the electrodeposition preparation of metal coatings.
基金Project(U1710257)supported by the National Natural Science Foundation of China。
文摘α-Ni(OH)2 was synthesized from a NiCl2 solution by electrodeposition method.In order to conduct a systematic study on the effects of experimental parameters,a series of electrolyte initial pH values,current densities,electrodeposition temperatures,and electrodeposition time were used.Cyclic voltammetry results demonstrated a side reaction of Ni^2++2e→Ni.The X-ray diffraction analysis,Fourier-transform infrared spectrum,and the color of the product showed that pureα-Ni(OH)2 could be obtained in the initial pH value range of 2−5.86,current density range of 10−25 mA/cm^2,electrodeposition temperature range of 25−35℃,and electrodeposition time range of 1.0−3.0 h.When electrodeposition temperature increased to 45℃,a mixture ofα-Ni(OH)2 and metallic Ni was obtained.A current density higher than 30 mA/cm^2 resulted in the sample with features ofβ-Ni(OH)2.A small amount of metallic Ni existed in the as-prepared sample when current density decreased to 5 mA/cm^2.A slight increase of electrolyte pH was observed with increasing initial solution pH and current density.Electrodeposition mass revealed a slight decrease with initial pH decreasing and showed an almost linear increase with current density increasing.The slope of the curve for electrodeposition mass versus electrodeposition time remained stable in the first 2.0 h and then decreased.
文摘Aluminum was electrodeposited with constant current on AZ31 magnesium alloy pretreated under optimized conditions from trimethyl-phenyl-ammonium chloride and anhydrous aluminum chloride （TMPAC-AlCl3） quaternary ammonium room temperature ionic liquids with benzene as a co-solvent. The corrosion resistance of the as-deposited Al layers was evaluated in 3.5% NaCl solution by the electrochemical technologies. The Al depositions were characterized by scanning electron microscopy equipped with energy dispersion X-ray. The results show that the microstructures of the Al depositions have spherical equiaxed grains obtained at a high current density, and bulk grains at a low current density. The Al deposition obtained at 12.3 mA/cm2 has a smooth and compact surface. The electrochemical measurements indicate that the thicker Al deposition can more effectively protect the Mg substrate. The Al deposition with bulk grains hardly protects the AZ31 Mg substrate from corrosion owing to its porosity.
基金Projects(51171172,51131005)supported by the National Natural Science Foundation of ChinaProject(R16E010001)supported by Zhejiang Provincial Natural Science Foundation of China+1 种基金Project(2015QNA3011)supported by Fundamental Research Funds for the Central Universities,ChinaProject(14DZ2261000)supported by Science and Technology Commission of Shanghai Municipality,China
文摘In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology and composition wereexamined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicatethat TiN nanoparticles were doped successfully in the Ni-P matrix after a series of complex pretreatments including activation, zincimmersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion betweenmagnesium alloy and composite coating. The microhardness of the Ni-P coating increases dramatically by adding TiN nanoparticlesand subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni-P-TiN compositecoating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni-P coating in short immersion time.However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.
基金Projects(51274108,21263007,51204080)supported by the National Natural Science Foundation of ChinaProject(2011FA009)supported by the Applied Research Foundation of Yunnan Province,ChinaProject(14118441)supported by the Talents Cultivation Foundation of Kunming University of Science and Technology,China
文摘The electrodeposition behaviors of nickel on glassy carbon（GC） and carbon steel（CS） electrodes were investigated in the14.3%-85.7%（mole fraction） betaine.HCl ethylene glycol（EG） ionic liquid using cyclic voltammetry and chronoamperometry.The results indicated that the reduction of Ni（Ⅱ） on CS electrode via a diffusion-controlled quasi-reversible process was much more facile and easier than that occurred on GC electrode,which followed a diffusion-controlled three-dimensional instantaneous nucleation and growth.Scanning electron microscopy was used to observe that the deposit was dense and contained fine crystallites with average size of（80±4） nm.Energy dispersive spectrometer analysis showed that the obtained deposit was metallic nickel.X-ray diffraction spectroscopy indicated that（111） plane was the most preferred crystal orientation.The nickel deposit was luminous and bright,and had good adhesion with the CS substrate.
基金Project(2015016)supported by the Young Scholars Science Foundation of Lanzhou Jiaotong University,ChinaProject(2015BAE04B01)supported by the National Science-technology Support Program of ChinaProject(21466019)supported by the National Natural Science Foundation of China
文摘The process parameters were optimized for the electrodeposition of cobalt from cobalt chloride solution in the membrane electrolytic reactor. Effects of parameters such as catholyte composition, current density and temperature on the current efficiency, specific power consumption and quality of deposition were studied. The catholyte was a mixed solution of cobalt chloride, the initial middle electrolyte consisted of diluted hydrochloric acid, and the anolyte was sulfuric acid. An anion exchange membrane separated the catholyte from the middle electrolyte, and a cation exchange membrane separated the anolyte from the middle electrolyte. The results showed that a maximum current efficiency of 97.5% was attained under the optimum experimental condition of an catholyte composition of 80 g/L Co^2＋, 20 g/L H3BO3, 3 g/L NaF and pH of 4, at a cathode current density of 250 A/m2 and a temperature of 50 ℃ HCl could be produced in the middle compartment electrochemically up to 0.45 mol/L.
