In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride ...In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride molten salt as the reaction medium at 923 K.The study assessed the effects of lithium thermochemical reduction and electrolytic reduction of ZnO.The volatilization behavior of metal oxides in molten salts,the equivalent of a reducing agent,reduction time,amount of molten salt,stirring time,and the method of reduction feed were investigated for their impacts on the reduction yield and product composition.X-ray powder diffraction(XRD)analysis of the products showed that lithium reduction of ZnO not only produced metallic Zn but also formed a LiZn alloy.Electrolytic reduction can be used to obtain the metallic Zn product by controlling the potential below-2.2 V(vs Ag/Ag^(+)).Moreover,sintered oxides and higher electrode potentials could enhance the efficiency of electrolysis.Under the optimal reaction conditions determined experimentally,the lithium reduction experiment achieved a yield of 77.2%after a 12-h test,and the electrolytic reduction reached a yield of 85.4%after a 6-h test.展开更多
To address the inefficient utilization of electrolytic manganese residue(EMR)caused by its high inert content,this study developed a multifunctional solid waste cementitious material by replacing 50-60%of ordinary Por...To address the inefficient utilization of electrolytic manganese residue(EMR)caused by its high inert content,this study developed a multifunctional solid waste cementitious material by replacing 50-60%of ordinary Portland cement(PO 42.5)with wet-ground electrolytic manganese residue(WEMR),wetground granulated blast-furnace slag(WGBFS),and carbide slag(CS).The mechanical properties,hydration characteristics,microstructure,and carbon emissions of the material were systematically investigated with varying WEMR dosages.The experimental results demonstrates that the wet-grinding process significantly refines the particle size and enhances the reactivity of both EMR and GBFS.As the WEMR dosage increases,the 28-day compressive strength initially rise and then declines.Optimal mechanical performance was achieved with 24%WEMR and 6%CS,yielding a 28-day compressive strength of 48.2 MPa.Advanced analytical techniques,including XRD,TG-DTG,SEM,and MIP,were employed to examine the hydration products.The findings reveal that the wet-grinding-alkali-sulfur synergistic activation system in the multi-solid waste cementitious material effectively utilize EMR to generate abundant hydration products such as AFt and C-(A)-S-H.Additionally,the fine particles of WEMR fill the pores in the mortar,further enhancing compressive strength.The cost and carbon emissions of this multifunctional system are only 65.97%and 46.9% of those of PO 42.5,respectively.This study provides a feasible approach for the efficient utilization of EMR,contributing to sustainable construction practices.展开更多
With growing concerns regarding electromagnetic pollution,low-cost,environmentally friendly,and high-performance electromagnetic wave absorption(EWA)materials have attracted significant attention.This paper reports on...With growing concerns regarding electromagnetic pollution,low-cost,environmentally friendly,and high-performance electromagnetic wave absorption(EWA)materials have attracted significant attention.This paper reports on the synthesis of porous Fe_(3)O_(4)/C composites that incorporate dielectric and magnetic loss mechanisms via the carbothermal reduction method and optimization of waste ratio to enhance EWA performance.The Fe_(3)O_(4)/C composites with 10wt%soybean residues(Fe_(3)O_(4)/C-10),demonstrated the best EWA performance,achieving the minimum reflection loss of−56.4 dB and a bandwidth of 2.14 GHz at a thickness of 2.23 mm.This enhanced EWA performance is primarily attributable to improved impedance matching and the synergistic effect between dielectric and magnetic losses.Furthermore,radar cross-sectional simulations confirmed the practical feasibility of the porous Fe_(3)O_(4)/C composites.This study proposes a viable strategy for utilizing soybean residue and electrolytic manganese residue,highlighting their potential applications in EWA.展开更多
Low-cost and high-safety aqueous Zn-I_(2) batteries attract extensive attention for large-scale energy storage systems.However,polyiodide shuttling and sluggish iodine conversion reactions lead to inferior rate capabi...Low-cost and high-safety aqueous Zn-I_(2) batteries attract extensive attention for large-scale energy storage systems.However,polyiodide shuttling and sluggish iodine conversion reactions lead to inferior rate capability and severe capacity decay.Herein,a three-dimensional polyaniline is wrapped by carboxylcarbon nanotubes(denoted as C-PANI)which is designed as a catalytic cathode to effectively boost iodine conversion with suppressed polyiodide shuttling,thereby improving Zn-I_(2) batteries.Specifically,carboxyl-carbon nanotubes serve as a proton reservoir for more protonated-NH+=sites in PANI chains,achieving a direct I0/I−reaction for suppressed polyiodide generation and Zn corrosion.Attributing to this“proton-iodine”regulation,catalytic protonated C-PANI strongly fixes electrolytic iodine species and stores proton ions simultaneously through reversible-N=/-NH^(+)-reaction.Therefore,the electrolytic Zn-I_(2) battery with C-PANI cathode exhibits an impressive capacity of 420 mAh g^(−1) and ultra-long lifespan over 40,000 cycles.Additionally,a 60 mAh pouch cell was assembled with excellent cycling stability after 100 cycles,providing new insights into exploring effective organocatalysts for superb Zn-halogen batteries.展开更多
The accumulation of contaminated soils and solid waste stockpiles has led to significant resource wastage and environmental pollution.This study investigates a novel solidification/stabilization(S/S)curing agent,named...The accumulation of contaminated soils and solid waste stockpiles has led to significant resource wastage and environmental pollution.This study investigates a novel solidification/stabilization(S/S)curing agent,named ECPG,synthesized from electrolytic manganese residue(EMR),coal gangue(CG),and phosphoric acid,for the treatment of Pb-contaminated soils.The influences of ECPG dosages,CG to EMR ratios,Pb2+and phosphoric acid concentrations,curing age,and durability on the strength development and leaching characteristics of the solidified soils were systematically investigated.Durability tests under different freeze-thaw and wet-dry cycles were also conducted to assess long-term performance.The mechanisms of geopolymerization,S/S,and strength enhancement were elucidated through tests and molecular simulations.The results demonstrated that the optimal CG to EMR ratio was 8:2 with 7 mol/L phosphoric acid,resulting in a peak strength of 5.9 MPa and immobilization rates of 99.7%,99.3%,and 81.5%for Pb,Mn,and NH_(4)^(+)-N after curing for 28 d.Freeze-thaw and wet-dry cycles demonstrated excellent durability,with unconfined compressive strength(UCS)above 85%and Pb leaching value of 0.42 mg/L.Molecular simulations revealed that Pb and Mn were primarily immobilized by adsorption,with ion exchange serving as a secondary mechanism,and a minor fraction resulted in the formation of phosphate precipitates.Conversely,NH_(4)^(+)-N was predominantly immobilized via ion exchange,with a portion forming MgNH_(4)PO_(4)·6H_(2)O and MnNH_(4)PO_(4)·H_(2)O.This study can not only contribute to the advancement of safe disposal and resource reuse of contaminated soil and solid waste,but also offers a theoretical foundation for S/S technology from a multi-scale perspective.展开更多
Electrocatalytic CO_(2)reduction(eCO_(2)R)in acidic electrolytes is propitious to enhance CO_(2)utilization,yet suffering from low current efficiency due to the rapid kinetics of the competing hydrogen evolution react...Electrocatalytic CO_(2)reduction(eCO_(2)R)in acidic electrolytes is propitious to enhance CO_(2)utilization,yet suffering from low current efficiency due to the rapid kinetics of the competing hydrogen evolution reaction(HER),especially under high current densities.This study proposes the implementation of a singleatom NiNC cocatalyst concurrently generating CO and releasing OH^(-)to neutralize H^(+)in the electrolyte,thereby simultaneously suppressing HER and promoting C–C coupling.By homogeneously mixing the NiNC cocatalyst with Cu nanoparticles(NPs),as opposed to a stratified configuration,a high ethylene Faradaic efficiency(FE)of 57%was achieved at 600 mA cm^(-2)in acidic media,along with a remarkable single-pass CO_(2)conversion efficiency of 52.4%.While rotating disk electrode tests and operando Raman spectroscopy attest to the restricted H^(+)diffusion and elevated local pH near the catalyst surface,in situ Infrared and differential electrochemical mass spectrometries corroborate the spillover of CO from the cocatalyst to neighboring Cu NPs for enhanced C–C coupling.This work offers new insights into the design and application principles of compositional eCO_(2)R catalysts for promoting multicarbon synthesis in acidic media at high current density.展开更多
Electrolytic copper foil has gained significant attention as an essential component in lithium-ion batteries(LIBs),printed circuit boards(PCBs),and chip packaging substrates(CPSs)applications.With the advancement of L...Electrolytic copper foil has gained significant attention as an essential component in lithium-ion batteries(LIBs),printed circuit boards(PCBs),and chip packaging substrates(CPSs)applications.With the advancement of LIBs towards higher energy densities and the increasing density of electronic components on circuits,copper foil is required to have demanding properties,such as extremely thin thickness and extremely high tensile strength.This comprehensive review firstly summarizes recent progress on the fabrication of electrolytic copper foil,and the effects of process parameters,cathode substrate,and additives on the electrodeposition behavior,microstructure,and properties of copper foil are discussed in detail.Then the regulation strategies of mechanical properties of electrolytic copper foil are also summarized,including the formation of nanotwins and texture.Furthermore,the recent advances in novel electrolytic copper foils,such as composite foils and extra-thin copper foils,are also overviewed.Lastly,the remaining challenges and perspectives on the further development of electrolytic copper foils are presented.展开更多
Hydrogen production via seawater electrolysis,leveraging sustainable energy sources such as offshore wind or solar energy,has immense application potential.However,the abundance of chloride ions(Cl^(-))in seawater lea...Hydrogen production via seawater electrolysis,leveraging sustainable energy sources such as offshore wind or solar energy,has immense application potential.However,the abundance of chloride ions(Cl^(-))in seawater leads to the generation of chlorine gas and hypochlorite at the anode during electrolysis,pos-ing a severe threat of corrosion of the catalyst and electrolytic equipment.Herein,we synthesize a NiMo-based catalyst adorned with surface-anchored graphene quantum dots(GQDs).This catalyst possesses ex-cellent Cl^(-)exclusion capabilities.The Mo-NiS/Se@GQDs core-shell nanorod catalyst requires only 170 mV of overpotential to attain a current density of 10 mA cm^(-2) and operates stably for 200 h without degra-dation across a broad current density range from 100 to 400 mA cm^(-2).This remarkable electrocatalytic stability arises from the dynamic and efficient repulsion of Cl^(-)at the catalytic interface,as proven by the post-reaction analysis of Cl^(-)distribution within the catalyst.Furthermore,a potentiodynamic polarization test revealed that the Mo-NiS/Se@GQDs catalyst has high corrosion potential(0.66 V)and low corrosion current density(122.93μA cm^(-2)),underscoring its excellent corrosion resistance.This research presents a novel approach to mitigate Cl^(-)corrosion during hydrogen production through seawater electrolysis,laying a solid foundation for advancing sustainable energy conversion technologies.展开更多
This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the poro...This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the porous MgO layer formed via plasma electrolytic oxidation(PEO).The AZ31 Mg alloy,initially coated with a PEO layer,underwent a dipping treatment in an ethanolic solution of 0.05 M 8HQ at 50℃ for 3 h.The results were compared with those from a different procedure where the PEO layer was subjected to a hydration reaction for 2 h at 90℃ before immersion in the 8HQ solution under the same conditions.The hydration treatment played a crucial role by converting MgO to Mg(OH)_(2),significantly enhancing the surface reactivity.This transformation introduced hydroxyl groups(−OH)on the surface,which facilitated donor-acceptor interactions with the electron-accepting sites on 8HQ molecules.The calculated binding energy(Ebinding)from DFT indicated that the interaction energy of 8HQ with Mg(OH)_(2) was lower compared to 8HQ with MgO,suggesting easier adsorption of 8HQ molecules on the hydrated surface.This,combined with the increased number of active sites and enhanced surface area,allowed for extensive surface coverage by 8HQ,leading to the formation of a stable,flake-like protective layer that sealed the majority of pores on the PEO layer.DFT calculations further suggested that the hydration treatment provided multiple active sites,enabling effective contact with 8HQ and rapid electron transfer,creating ideal conditions for charge-transfer-induced physical and chemical bonding.This study shows that hydration and 8HQ treatments significantly enhance the corrosion resistance of Mg alloys,highlighting their potential for advanced anticorrosive coatings.展开更多
Metal-insulator-metal aluminium electrolytic capacitors(MIM-AECs)combine high capacity-density and high breakdown field strength of solid AECs with high-frequency responsibility,wide workingtemperature window and wate...Metal-insulator-metal aluminium electrolytic capacitors(MIM-AECs)combine high capacity-density and high breakdown field strength of solid AECs with high-frequency responsibility,wide workingtemperature window and waterproof properties of MIM nanocapacitors.However,interfacial atomic diffusion poses a major obstacle,preventing the high-voltage MIM-AECs exploitation and thereby hampering their potential and advantages in high-power and high-energy-density applications.Here,an innovative high-voltage MIM-AECs were fabricated.The AlPO_(4)buffer layer is formed on AlO(OH)/AAO/Al surface by using H_(3)PO_(4)treatment,then a stable van der Waals(vdW)SnO_(2)/AlPO_(4)/AAO/Al multilayer was constructed via atomic layer deposition(ALD)technology.Due to higher diffusion barrier and lower carrier migration of SnO_(2)/AlPO_(4)/AAO interfaces,Sn atom diffusion is inhibited and carrier acceleration by electric field is weakened,guaranteeing high breakdown field strength of dielectric AAO and avoiding local breakdown risks.Through partial etching to hydrated AlO(OH)by H_(3)PO_(4)treatment,the tunnel was further opened up to facilitate subsequent ALD-SnO_(2)entry,thus obtaining a high SnO_(2)coverage.The SnO_(2)/AlPO_(4)/AAO/Al capacitors show a comprehensive performance in high-voltage(260 V),hightemperature(335℃),high-humidity(100%RH)and high-frequency response(100 k Hz),outperforming commercial solid-state AECs,and high-energy density(8.6μWh/cm^(2)),markedly exceeding previously reported MIM capacitors.The work lays the foundation for next-generation capacitors with highvoltage,high-frequency,high-temperature and high-humidity resistance.展开更多
A new perspective was reported to design the self-densified plasma electrolytic oxidation(SDF-PEO)coat-ings on magnesium alloys based on the dissolution-ionization-diffusion-deposition(DIDD)model.The main consideratio...A new perspective was reported to design the self-densified plasma electrolytic oxidation(SDF-PEO)coat-ings on magnesium alloys based on the dissolution-ionization-diffusion-deposition(DIDD)model.The main considerations of the new PEO electrolyte include the establishment of a thermodynamics diagram,the construction of a liquid-solid sintering system and the regulation of plasma sparkling kinetics.The SDF-PEO coating exhibited a homogeneous and dense microstructure,superior corrosion resistance and good technological adaptability.This work offers a novel theory to design surface treatment solutions with superior corrosion resistance and promising application prospects.展开更多
Plasma electrolytic oxidation(PEO)coatings were prepared on Al−Mg laminated macro composites(LMCs)using both unipolar and bipolar waveforms in an appropriate electrolyte for both aluminum and magnesium alloys.The tech...Plasma electrolytic oxidation(PEO)coatings were prepared on Al−Mg laminated macro composites(LMCs)using both unipolar and bipolar waveforms in an appropriate electrolyte for both aluminum and magnesium alloys.The techniques of FESEM/EDS,grazing incident beam X-ray diffraction(GIXRD),and electrochemical methods of potentiodynamic polarization and electrochemical impedance spectroscopy(EIS)were used to characterize the coatings.The results revealed that the coatings produced using the bipolar waveform exhibited lower porosity and higher thickness than those produced using the unipolar one.The corrosion performance of the specimens’cut edge was investigated using EIS after 1,8,and 12 h of immersion in a 3.5 wt.%NaCl solution.It was observed that the coating produced using the bipolar waveform demonstrated the highest corrosion resistance after 12 h of immersion,with an estimated corrosion resistance of 5.64 kΩ·cm^(2),which was approximately 3 times higher than that of the unipolar coating.Notably,no signs of galvanic corrosion were observed in the LMCs,and only minor corrosion attacks were observed on the magnesium layer in some areas.展开更多
The hot deformation behavior of electrolytic copper was investigated using a Gleeble-3500 thermal simulation testing machine at temperatures ranging from 500℃ to 800℃ and strain rates ranging from 0.01 s^(-1) to 10 ...The hot deformation behavior of electrolytic copper was investigated using a Gleeble-3500 thermal simulation testing machine at temperatures ranging from 500℃ to 800℃ and strain rates ranging from 0.01 s^(-1) to 10 s^(-1),under 70% deformation conditions.The true stress-true strain curves were analyzed and a constitutive equation was established at a strain of 0.5.Based on the dynamic material model proposed by Prasad,processing maps were developed under different strain conditions.Microstructure of compressed sample was observed by electron backscatter diffraction.The results reveal that the electrolytic copper demonstrates high sensitivity to deformation temperature and strain rate during high-temperature plastic deformation.The flow stress decreases gradually with raising the temperature and reducing the strain rate.According to the established processing map,the optimal processing conditions are determined as follows:deformation temperatures of 600-650℃ and strain rates of 5-10 s^(-1).Discontinuous dynamic recrystallization of electrolytic copper occurs during high-temperature plastic deformation,and the grains are significantly refined at low temperature and high strain rate conditions.展开更多
The effects of calcination temperature and mechanical ball milling on the physicochemical properties of electrolytic manganese residue(EMR),mineral phase transition,pozzolanic activity,and pore structure were studied....The effects of calcination temperature and mechanical ball milling on the physicochemical properties of electrolytic manganese residue(EMR),mineral phase transition,pozzolanic activity,and pore structure were studied.The experimental results show that the strength activity index(SAI)of 20%EMR mixed mortar at 28 days is 90.54%,95.40%,and 90.73%,respectively,after pretreatment with EMR at 800℃calcined for 3,5,and 8 min.This is mainly attributed to the high temperature decomposition of gypsum dihydrate to form activated calcium oxide.In addition,high temperature and mechanical force destroys the Si-O chemical bond and promotes the formation of calcium silicate gel structure.Due to the existence of a large number of gypsum phases in EMR mixed mortar,a large number of ettringite,C-S-H,aluminosilicate,C-A-S-H,and AFm are formed,which strongly verifies the volcanic activity of EMR.The leaching test shows that high temperature calcination has a significant effect on the stabilization of NH_(3)-N.However,the curing effect of Mn^(2+)is significant only in the calcination at 1000℃,but both Mn^(2+)and NH_(3)-N in the calcined EMR are higher than the emission standard.The encapsulation effect of EMR composite mortar provided by hydration products,and the buffering capacity of the Si-Al system for solidification of heavy metals and strong alkalis are conducive to the stability of Mn^(2+)and NH_(3)-N.After the EMR mixed mortar is aged for 3 days,Mn and NH_(3)-N are completely lower than the emission standard.In general,the EMR mixed mortar can meet the requirements for green building use.展开更多
This study introduced a low-temperature thermochemical method for the treatment of EMR in the presence of carbide slag(CS)to achieve an economical and efficient harmless effect.The experimental results indicate that,u...This study introduced a low-temperature thermochemical method for the treatment of EMR in the presence of carbide slag(CS)to achieve an economical and efficient harmless effect.The experimental results indicate that,under suitable conditions,the NH_(4)^(+)and Mn^(2+)contents in EMR decrease notably with the increasing CS content,accompanied by an increase in pH value.Furthermore,the concentration of NH_(4)^(+)in EMR considerably decreases with the increasing liquid-to-solid ratio,eventually stabilizing.Similarly,the pH value first increases and then decreases,ultimately stabilizing.At a CS content of 12%and a liquid-to-solid ratio of 0.7,the leaching concentrations of NH_(4)^(+)and Mn^(2+)in EMR(127.7 mg/kg and 0.15 mg/L,respectively)fall below the standard detection limit(2 mg/L),with the pH measuring 8.26,meeting the conditions outlined in the GB 8978.NH_(4)^(+)is converted to NH_(3),while Mn^(2+)is transformed into solid precipitates such as Mn(OH)_(2),Mn_(2)O_(3),MnO_(2),Ca_(3)Mn_(2)O_(7),and Ca_(2)MnO_(4).The majority of manganese ions exist in trivalent or tetravalent states and remain stable over time.The cost of using CS as a reagent for treating 1 ton of EMR is merely$1.01.The high OH^(-)concentration provided by CS enables the effective removal of NH_(4)^(+)from EMR and the solidification of Mn^(2+)during thermal reactions.展开更多
To investigate the feasibility of applying electrolytic manganese residue(EMR)in cementitious materials,an approach combining high-temperature activation(200,400,600,800 and 1000℃)and mechanical grinding(5 min)was ad...To investigate the feasibility of applying electrolytic manganese residue(EMR)in cementitious materials,an approach combining high-temperature activation(200,400,600,800 and 1000℃)and mechanical grinding(5 min)was adopted to stimulate the EMR activity.We analyzed the effect of calcination temperature on the performance of EMR with the aid of X-ray diffraction(XRD),specific surface area test(BET)and pozzolanic activity test,explored the effects of EMR activation temperature and content(0%,10%,15% and 20%)on the setting time,soundness,drying shrinkage,compressive strength,hydration products of cement-EMR mixed slurry,and assessed the effect of cement hydration on the solidification of harmful NH_(4)^(+)-N and Mn^(2+) in EMR.The research results show that high-temperature calcination can lead to the dehydration,decomposition or crystalline phase transformation of the inert sulfate and other substances in EMR,mechanical grinding can improve its particle distribution,and the coupling of the two can effectively enhance the pozzolanic activity of EMR.The decomposition and recombination of aluminum-silica phase at 800℃ optimized the EMR activity,and the strength activity index(SAI)of EMR at 28 d reached up to 95%.Appropriate calcination temperature and EMR content can ensure the workability of the mixed slurry,and when the EMR calcination temperature was 400-1000℃,the setting time of the mixed slurry under different EMR contents satisfied the specification requirements.When the calcination temperature was 600-1000℃ and EMR content was less than 20%,the soundness of the mixed slurry satisfied the specification requirements.The compressive strength of the mixed slurry increased and then decreased with the increase of activated EMR content,when the EMR content was 10%,the compressive strength of all specimens was optimal and higher than the baseline group;when the activation temperature was 800℃,the C-S-H gel in the mixed slurry interconnected with the rod-like Aft and blocked Ca(OH)_(2),and the 28 d compressive strength was increased by 14%compared with that of the baseline group.The solidification rate of Mn^(2+) in EMR by cement hydration was higher than 99%,and that of NH_(4)^(+)-N was higher than 97%.The leaching toxicity after solidification can meet the requirements of toxic emission.The results of the study may provide theoretical basis for the feasibility of the application of EMR in cementitious materials.展开更多
In this study,laser-assisted plasma electrolytic oxidation(Laser/PEO)coating was prepared on AZ31B magnesium alloy for corrosion protection,due to insufficient corrosion protection caused by the inherent defects,crack...In this study,laser-assisted plasma electrolytic oxidation(Laser/PEO)coating was prepared on AZ31B magnesium alloy for corrosion protection,due to insufficient corrosion protection caused by the inherent defects,cracks and poor quality of PEO coatings.The plasma discharge evolution,morphological characteristics,elemental composition during coating growth were characterized by high-speed camera,SEM,EDX,XRD and XPS,respectively.Meanwhile,Mott Schottky(M-S)curves,potentiodynamic polarization(PDP)curves and electrochemical impedance spectroscopy(EIS)tests characterized the oxygen vacancy defects and corrosion resistance of the coatings.The results demonstrated that laser-assisted irradiation not only induced plasma discharge on the anode surface,but also limited the plasma discharge size in the post-processing stage,which significantly increased the proportion of corrosion-resistant phase Mg_(2)SiO_(4)(the proportion of Mg_(2)SiO_(4)increased from 23.70%to 39.22%),thickness and density in the coating,and obviously reduced the oxygen vacancy defects and microcracks in the coating.As a result,the corrosion resistance of the Laser/PEO coating(9.29(±0.76)×10^(-7)A·cm^(-2))was further enhanced in comparation with the PEO coating(3.06(±0.19)×10^(-6) A·cm^(-2)).展开更多
The corrosion resistance of magnesium alloys is a significant concern in industries seeking to use these materials for lightweight structures.Plasma electrolytic oxidation(PEO)is a process that forms a ceramic oxide f...The corrosion resistance of magnesium alloys is a significant concern in industries seeking to use these materials for lightweight structures.Plasma electrolytic oxidation(PEO)is a process that forms a ceramic oxide film on Mg alloy surfaces,effectively enhancing their corrosion performance in the short term.In this regard,optimizing PEO process parameters is crucial for creating a stable oxide layer.An improved level of corrosion resistance is ensured by applying superhydrophobic coating(SHC)on top of the PEO layer to prevent moisture infiltration,creating air pockets on the surface.Various methods are employed to fabricate SHC on Mg alloys,including techniques like electrophoretic deposition(EPD),Hydrothermal(HT),dip,and spray coating.The synergistic combination of PEO and SHC coatings has demonstrated encouraging outcomes in enhancing the corrosion performance of Mg alloys.This study offers an extensive overview of recent progress in the preparation,characterization,and corrosion behavior of Mg alloys by employing PEO coatings and SHC treatment processes.展开更多
The effect of the initial(Al+Si)/MnO molar ratio and slag composition on MnO recovery from electroslag by remelting at 1773 K was investigated.High-purity aluminum metal and silicon were employed as the deoxidizers to...The effect of the initial(Al+Si)/MnO molar ratio and slag composition on MnO recovery from electroslag by remelting at 1773 K was investigated.High-purity aluminum metal and silicon were employed as the deoxidizers to effectively promote the recovery of manganese metal(MM).The reduction of MnO in slag,through the interaction between molten MM with a deoxidizer and the Na_(2)O-enriched electroslag melt,was assessed both thermodynamically and kinetically.The sulfur content of high-sulfur rejected electrolytic manganese metal(EMM)scrap decreased to 0.58%with high-temperature pretreatment.The mass ratio between slag and high-sulfur rejected EMM scrap is 2/3.When the Al_(2)O_(3)content in the initial slags decreased and the Na_(2)O content increased,the MnO reduction ratio increased.The residual MnO concentration of the slag reduced with increasing the Al–Si deoxidizer content.When the(Al+Si)/MnO molar ratio reached 0.83,the MnO concentration in the final slag was only 3%.A deoxidizer mainly containing aluminum and a small amount of Si could be added to recover MnO from the slag,resulting in the improvement in the cleanliness of final Mn metal.展开更多
A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic ox...A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic oxidation to enhance its corrosion resistance and self-healing properties.The morphology,chemical composition,structure,and functional properties of the composite coating were investigated by scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),polarization curve,alternating current impedance,and salt immersion test.The experimental results showed that,after immersion in a 3.5 wt%NaCl solution for 12 h,the coating could effectively protect AZ91D from corrosion.When the coating was damaged,the exposed alloy surface would release metal ions in the corrosive environment and react with the corrosion inhibitor 8-hydroxyquinoline to form a Mg(8-HQ)_(2) chelate,exhibiting significant self-healing behavior.The study results demonstrate the broad application prospects of microcapsule technology in the coating field,providing new ideas for the development of efficient anti-corrosion coatings.展开更多
文摘In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride molten salt as the reaction medium at 923 K.The study assessed the effects of lithium thermochemical reduction and electrolytic reduction of ZnO.The volatilization behavior of metal oxides in molten salts,the equivalent of a reducing agent,reduction time,amount of molten salt,stirring time,and the method of reduction feed were investigated for their impacts on the reduction yield and product composition.X-ray powder diffraction(XRD)analysis of the products showed that lithium reduction of ZnO not only produced metallic Zn but also formed a LiZn alloy.Electrolytic reduction can be used to obtain the metallic Zn product by controlling the potential below-2.2 V(vs Ag/Ag^(+)).Moreover,sintered oxides and higher electrode potentials could enhance the efficiency of electrolysis.Under the optimal reaction conditions determined experimentally,the lithium reduction experiment achieved a yield of 77.2%after a 12-h test,and the electrolytic reduction reached a yield of 85.4%after a 6-h test.
基金Funded by the Guangxi Key Research and Development Program(Nos.GK AB24010020,and GK AB23026071)the Key Project of Guangxi Natural Science Foundation(No.2025GXNSFDA090046)the Guangxi Science and Technology Base and Talent Special Project(No.GK AD24010062)。
文摘To address the inefficient utilization of electrolytic manganese residue(EMR)caused by its high inert content,this study developed a multifunctional solid waste cementitious material by replacing 50-60%of ordinary Portland cement(PO 42.5)with wet-ground electrolytic manganese residue(WEMR),wetground granulated blast-furnace slag(WGBFS),and carbide slag(CS).The mechanical properties,hydration characteristics,microstructure,and carbon emissions of the material were systematically investigated with varying WEMR dosages.The experimental results demonstrates that the wet-grinding process significantly refines the particle size and enhances the reactivity of both EMR and GBFS.As the WEMR dosage increases,the 28-day compressive strength initially rise and then declines.Optimal mechanical performance was achieved with 24%WEMR and 6%CS,yielding a 28-day compressive strength of 48.2 MPa.Advanced analytical techniques,including XRD,TG-DTG,SEM,and MIP,were employed to examine the hydration products.The findings reveal that the wet-grinding-alkali-sulfur synergistic activation system in the multi-solid waste cementitious material effectively utilize EMR to generate abundant hydration products such as AFt and C-(A)-S-H.Additionally,the fine particles of WEMR fill the pores in the mortar,further enhancing compressive strength.The cost and carbon emissions of this multifunctional system are only 65.97%and 46.9% of those of PO 42.5,respectively.This study provides a feasible approach for the efficient utilization of EMR,contributing to sustainable construction practices.
基金supported by the National Natural Science Foundation of China(No.52471221)the Natural Science Foundation of Hunan Province,China(No.2024JJ7145)the National Sustainable Development Agenda Innovation Demonstration Zone Hunan special project,China(No.2022sfq09).
文摘With growing concerns regarding electromagnetic pollution,low-cost,environmentally friendly,and high-performance electromagnetic wave absorption(EWA)materials have attracted significant attention.This paper reports on the synthesis of porous Fe_(3)O_(4)/C composites that incorporate dielectric and magnetic loss mechanisms via the carbothermal reduction method and optimization of waste ratio to enhance EWA performance.The Fe_(3)O_(4)/C composites with 10wt%soybean residues(Fe_(3)O_(4)/C-10),demonstrated the best EWA performance,achieving the minimum reflection loss of−56.4 dB and a bandwidth of 2.14 GHz at a thickness of 2.23 mm.This enhanced EWA performance is primarily attributable to improved impedance matching and the synergistic effect between dielectric and magnetic losses.Furthermore,radar cross-sectional simulations confirmed the practical feasibility of the porous Fe_(3)O_(4)/C composites.This study proposes a viable strategy for utilizing soybean residue and electrolytic manganese residue,highlighting their potential applications in EWA.
基金supported by the National Natural Science Foundation of China(22209006,21935001)the Natural Science Foundation of Shandong Province(ZR2022QE009)+1 种基金Fundamental Research Funds for the Central Universities(buctrc202307)the Beijing Natural Science Foundation(Z210016).
文摘Low-cost and high-safety aqueous Zn-I_(2) batteries attract extensive attention for large-scale energy storage systems.However,polyiodide shuttling and sluggish iodine conversion reactions lead to inferior rate capability and severe capacity decay.Herein,a three-dimensional polyaniline is wrapped by carboxylcarbon nanotubes(denoted as C-PANI)which is designed as a catalytic cathode to effectively boost iodine conversion with suppressed polyiodide shuttling,thereby improving Zn-I_(2) batteries.Specifically,carboxyl-carbon nanotubes serve as a proton reservoir for more protonated-NH+=sites in PANI chains,achieving a direct I0/I−reaction for suppressed polyiodide generation and Zn corrosion.Attributing to this“proton-iodine”regulation,catalytic protonated C-PANI strongly fixes electrolytic iodine species and stores proton ions simultaneously through reversible-N=/-NH^(+)-reaction.Therefore,the electrolytic Zn-I_(2) battery with C-PANI cathode exhibits an impressive capacity of 420 mAh g^(−1) and ultra-long lifespan over 40,000 cycles.Additionally,a 60 mAh pouch cell was assembled with excellent cycling stability after 100 cycles,providing new insights into exploring effective organocatalysts for superb Zn-halogen batteries.
基金supported by the National Key R&D Program of China(Grant No.2022YFC3901204)the National Natural Science Foundation of China(Grant No.42177163)the China Postdoctoral Science Foundation,China(Grant No.2022M723347).
文摘The accumulation of contaminated soils and solid waste stockpiles has led to significant resource wastage and environmental pollution.This study investigates a novel solidification/stabilization(S/S)curing agent,named ECPG,synthesized from electrolytic manganese residue(EMR),coal gangue(CG),and phosphoric acid,for the treatment of Pb-contaminated soils.The influences of ECPG dosages,CG to EMR ratios,Pb2+and phosphoric acid concentrations,curing age,and durability on the strength development and leaching characteristics of the solidified soils were systematically investigated.Durability tests under different freeze-thaw and wet-dry cycles were also conducted to assess long-term performance.The mechanisms of geopolymerization,S/S,and strength enhancement were elucidated through tests and molecular simulations.The results demonstrated that the optimal CG to EMR ratio was 8:2 with 7 mol/L phosphoric acid,resulting in a peak strength of 5.9 MPa and immobilization rates of 99.7%,99.3%,and 81.5%for Pb,Mn,and NH_(4)^(+)-N after curing for 28 d.Freeze-thaw and wet-dry cycles demonstrated excellent durability,with unconfined compressive strength(UCS)above 85%and Pb leaching value of 0.42 mg/L.Molecular simulations revealed that Pb and Mn were primarily immobilized by adsorption,with ion exchange serving as a secondary mechanism,and a minor fraction resulted in the formation of phosphate precipitates.Conversely,NH_(4)^(+)-N was predominantly immobilized via ion exchange,with a portion forming MgNH_(4)PO_(4)·6H_(2)O and MnNH_(4)PO_(4)·H_(2)O.This study can not only contribute to the advancement of safe disposal and resource reuse of contaminated soil and solid waste,but also offers a theoretical foundation for S/S technology from a multi-scale perspective.
基金supported by the National Natural Science Foundation of China(No.22571222 and 22309125,)the Natural Science Foundation of Jiangsu Province(No.BK20220483,BK20211306,BK20220027,and BK20221239)+2 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB150010)the Six Talent Peaks Project in Jiangsu Province(No.TD-XCL-006)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘Electrocatalytic CO_(2)reduction(eCO_(2)R)in acidic electrolytes is propitious to enhance CO_(2)utilization,yet suffering from low current efficiency due to the rapid kinetics of the competing hydrogen evolution reaction(HER),especially under high current densities.This study proposes the implementation of a singleatom NiNC cocatalyst concurrently generating CO and releasing OH^(-)to neutralize H^(+)in the electrolyte,thereby simultaneously suppressing HER and promoting C–C coupling.By homogeneously mixing the NiNC cocatalyst with Cu nanoparticles(NPs),as opposed to a stratified configuration,a high ethylene Faradaic efficiency(FE)of 57%was achieved at 600 mA cm^(-2)in acidic media,along with a remarkable single-pass CO_(2)conversion efficiency of 52.4%.While rotating disk electrode tests and operando Raman spectroscopy attest to the restricted H^(+)diffusion and elevated local pH near the catalyst surface,in situ Infrared and differential electrochemical mass spectrometries corroborate the spillover of CO from the cocatalyst to neighboring Cu NPs for enhanced C–C coupling.This work offers new insights into the design and application principles of compositional eCO_(2)R catalysts for promoting multicarbon synthesis in acidic media at high current density.
基金supported by the National Key R&D Plan Program of China(No.2021YFB3400800)Henan Key Research and Development Program(No.231111241000)+1 种基金the Joint Fund of Henan Province Science and Technology R&D Program(No.225200810026)Zhongyuan Scholar Workstation Funded Program(No.224400510025).
文摘Electrolytic copper foil has gained significant attention as an essential component in lithium-ion batteries(LIBs),printed circuit boards(PCBs),and chip packaging substrates(CPSs)applications.With the advancement of LIBs towards higher energy densities and the increasing density of electronic components on circuits,copper foil is required to have demanding properties,such as extremely thin thickness and extremely high tensile strength.This comprehensive review firstly summarizes recent progress on the fabrication of electrolytic copper foil,and the effects of process parameters,cathode substrate,and additives on the electrodeposition behavior,microstructure,and properties of copper foil are discussed in detail.Then the regulation strategies of mechanical properties of electrolytic copper foil are also summarized,including the formation of nanotwins and texture.Furthermore,the recent advances in novel electrolytic copper foils,such as composite foils and extra-thin copper foils,are also overviewed.Lastly,the remaining challenges and perspectives on the further development of electrolytic copper foils are presented.
基金financially supported by the National Natural Science Foundation of China(Nos.22103045 and 52273077)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZDKT202108,RZ2000003334,and G2RC202022).
文摘Hydrogen production via seawater electrolysis,leveraging sustainable energy sources such as offshore wind or solar energy,has immense application potential.However,the abundance of chloride ions(Cl^(-))in seawater leads to the generation of chlorine gas and hypochlorite at the anode during electrolysis,pos-ing a severe threat of corrosion of the catalyst and electrolytic equipment.Herein,we synthesize a NiMo-based catalyst adorned with surface-anchored graphene quantum dots(GQDs).This catalyst possesses ex-cellent Cl^(-)exclusion capabilities.The Mo-NiS/Se@GQDs core-shell nanorod catalyst requires only 170 mV of overpotential to attain a current density of 10 mA cm^(-2) and operates stably for 200 h without degra-dation across a broad current density range from 100 to 400 mA cm^(-2).This remarkable electrocatalytic stability arises from the dynamic and efficient repulsion of Cl^(-)at the catalytic interface,as proven by the post-reaction analysis of Cl^(-)distribution within the catalyst.Furthermore,a potentiodynamic polarization test revealed that the Mo-NiS/Se@GQDs catalyst has high corrosion potential(0.66 V)and low corrosion current density(122.93μA cm^(-2)),underscoring its excellent corrosion resistance.This research presents a novel approach to mitigate Cl^(-)corrosion during hydrogen production through seawater electrolysis,laying a solid foundation for advancing sustainable energy conversion technologies.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean government(MSIT)(No.2022R1A2C1006743).
文摘This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the porous MgO layer formed via plasma electrolytic oxidation(PEO).The AZ31 Mg alloy,initially coated with a PEO layer,underwent a dipping treatment in an ethanolic solution of 0.05 M 8HQ at 50℃ for 3 h.The results were compared with those from a different procedure where the PEO layer was subjected to a hydration reaction for 2 h at 90℃ before immersion in the 8HQ solution under the same conditions.The hydration treatment played a crucial role by converting MgO to Mg(OH)_(2),significantly enhancing the surface reactivity.This transformation introduced hydroxyl groups(−OH)on the surface,which facilitated donor-acceptor interactions with the electron-accepting sites on 8HQ molecules.The calculated binding energy(Ebinding)from DFT indicated that the interaction energy of 8HQ with Mg(OH)_(2) was lower compared to 8HQ with MgO,suggesting easier adsorption of 8HQ molecules on the hydrated surface.This,combined with the increased number of active sites and enhanced surface area,allowed for extensive surface coverage by 8HQ,leading to the formation of a stable,flake-like protective layer that sealed the majority of pores on the PEO layer.DFT calculations further suggested that the hydration treatment provided multiple active sites,enabling effective contact with 8HQ and rapid electron transfer,creating ideal conditions for charge-transfer-induced physical and chemical bonding.This study shows that hydration and 8HQ treatments significantly enhance the corrosion resistance of Mg alloys,highlighting their potential for advanced anticorrosive coatings.
基金supported by the National Natural Science Foundation of China(52477221,52202296)the Natural Science Foundation of Shaanxi Province(2023KXJ-246,2022JQ-048)。
文摘Metal-insulator-metal aluminium electrolytic capacitors(MIM-AECs)combine high capacity-density and high breakdown field strength of solid AECs with high-frequency responsibility,wide workingtemperature window and waterproof properties of MIM nanocapacitors.However,interfacial atomic diffusion poses a major obstacle,preventing the high-voltage MIM-AECs exploitation and thereby hampering their potential and advantages in high-power and high-energy-density applications.Here,an innovative high-voltage MIM-AECs were fabricated.The AlPO_(4)buffer layer is formed on AlO(OH)/AAO/Al surface by using H_(3)PO_(4)treatment,then a stable van der Waals(vdW)SnO_(2)/AlPO_(4)/AAO/Al multilayer was constructed via atomic layer deposition(ALD)technology.Due to higher diffusion barrier and lower carrier migration of SnO_(2)/AlPO_(4)/AAO interfaces,Sn atom diffusion is inhibited and carrier acceleration by electric field is weakened,guaranteeing high breakdown field strength of dielectric AAO and avoiding local breakdown risks.Through partial etching to hydrated AlO(OH)by H_(3)PO_(4)treatment,the tunnel was further opened up to facilitate subsequent ALD-SnO_(2)entry,thus obtaining a high SnO_(2)coverage.The SnO_(2)/AlPO_(4)/AAO/Al capacitors show a comprehensive performance in high-voltage(260 V),hightemperature(335℃),high-humidity(100%RH)and high-frequency response(100 k Hz),outperforming commercial solid-state AECs,and high-energy density(8.6μWh/cm^(2)),markedly exceeding previously reported MIM capacitors.The work lays the foundation for next-generation capacitors with highvoltage,high-frequency,high-temperature and high-humidity resistance.
基金supported by the National Natural Sci-ence Foundation of China(Nos.U21A2045 and 52201066)the Liaoning Revitalization Talents Program(No.XLYC2002071).
文摘A new perspective was reported to design the self-densified plasma electrolytic oxidation(SDF-PEO)coat-ings on magnesium alloys based on the dissolution-ionization-diffusion-deposition(DIDD)model.The main considerations of the new PEO electrolyte include the establishment of a thermodynamics diagram,the construction of a liquid-solid sintering system and the regulation of plasma sparkling kinetics.The SDF-PEO coating exhibited a homogeneous and dense microstructure,superior corrosion resistance and good technological adaptability.This work offers a novel theory to design surface treatment solutions with superior corrosion resistance and promising application prospects.
文摘Plasma electrolytic oxidation(PEO)coatings were prepared on Al−Mg laminated macro composites(LMCs)using both unipolar and bipolar waveforms in an appropriate electrolyte for both aluminum and magnesium alloys.The techniques of FESEM/EDS,grazing incident beam X-ray diffraction(GIXRD),and electrochemical methods of potentiodynamic polarization and electrochemical impedance spectroscopy(EIS)were used to characterize the coatings.The results revealed that the coatings produced using the bipolar waveform exhibited lower porosity and higher thickness than those produced using the unipolar one.The corrosion performance of the specimens’cut edge was investigated using EIS after 1,8,and 12 h of immersion in a 3.5 wt.%NaCl solution.It was observed that the coating produced using the bipolar waveform demonstrated the highest corrosion resistance after 12 h of immersion,with an estimated corrosion resistance of 5.64 kΩ·cm^(2),which was approximately 3 times higher than that of the unipolar coating.Notably,no signs of galvanic corrosion were observed in the LMCs,and only minor corrosion attacks were observed on the magnesium layer in some areas.
基金Gansu Province Higher Education Institutions Industrial Support Program Project(2022CYZC-19)Gansu Provincial Science and Technology Major Project(22ZD6GA008)。
文摘The hot deformation behavior of electrolytic copper was investigated using a Gleeble-3500 thermal simulation testing machine at temperatures ranging from 500℃ to 800℃ and strain rates ranging from 0.01 s^(-1) to 10 s^(-1),under 70% deformation conditions.The true stress-true strain curves were analyzed and a constitutive equation was established at a strain of 0.5.Based on the dynamic material model proposed by Prasad,processing maps were developed under different strain conditions.Microstructure of compressed sample was observed by electron backscatter diffraction.The results reveal that the electrolytic copper demonstrates high sensitivity to deformation temperature and strain rate during high-temperature plastic deformation.The flow stress decreases gradually with raising the temperature and reducing the strain rate.According to the established processing map,the optimal processing conditions are determined as follows:deformation temperatures of 600-650℃ and strain rates of 5-10 s^(-1).Discontinuous dynamic recrystallization of electrolytic copper occurs during high-temperature plastic deformation,and the grains are significantly refined at low temperature and high strain rate conditions.
基金Funded by the National Natural Science Foundation of China(No.52178216)the Gansu Provincial Science and Technology Programme(No.23JRRA813)。
文摘The effects of calcination temperature and mechanical ball milling on the physicochemical properties of electrolytic manganese residue(EMR),mineral phase transition,pozzolanic activity,and pore structure were studied.The experimental results show that the strength activity index(SAI)of 20%EMR mixed mortar at 28 days is 90.54%,95.40%,and 90.73%,respectively,after pretreatment with EMR at 800℃calcined for 3,5,and 8 min.This is mainly attributed to the high temperature decomposition of gypsum dihydrate to form activated calcium oxide.In addition,high temperature and mechanical force destroys the Si-O chemical bond and promotes the formation of calcium silicate gel structure.Due to the existence of a large number of gypsum phases in EMR mixed mortar,a large number of ettringite,C-S-H,aluminosilicate,C-A-S-H,and AFm are formed,which strongly verifies the volcanic activity of EMR.The leaching test shows that high temperature calcination has a significant effect on the stabilization of NH_(3)-N.However,the curing effect of Mn^(2+)is significant only in the calcination at 1000℃,but both Mn^(2+)and NH_(3)-N in the calcined EMR are higher than the emission standard.The encapsulation effect of EMR composite mortar provided by hydration products,and the buffering capacity of the Si-Al system for solidification of heavy metals and strong alkalis are conducive to the stability of Mn^(2+)and NH_(3)-N.After the EMR mixed mortar is aged for 3 days,Mn and NH_(3)-N are completely lower than the emission standard.In general,the EMR mixed mortar can meet the requirements for green building use.
基金Funded by the Guangxi Key Research and Development Program(Guike AB23026071 and Guike AB24010020)the Guangxi Science and Technology Base and Talent Project(Guike AD24010062)the Guangxi Beibu Gulf Engineering Research Center for Green Marine Materials。
文摘This study introduced a low-temperature thermochemical method for the treatment of EMR in the presence of carbide slag(CS)to achieve an economical and efficient harmless effect.The experimental results indicate that,under suitable conditions,the NH_(4)^(+)and Mn^(2+)contents in EMR decrease notably with the increasing CS content,accompanied by an increase in pH value.Furthermore,the concentration of NH_(4)^(+)in EMR considerably decreases with the increasing liquid-to-solid ratio,eventually stabilizing.Similarly,the pH value first increases and then decreases,ultimately stabilizing.At a CS content of 12%and a liquid-to-solid ratio of 0.7,the leaching concentrations of NH_(4)^(+)and Mn^(2+)in EMR(127.7 mg/kg and 0.15 mg/L,respectively)fall below the standard detection limit(2 mg/L),with the pH measuring 8.26,meeting the conditions outlined in the GB 8978.NH_(4)^(+)is converted to NH_(3),while Mn^(2+)is transformed into solid precipitates such as Mn(OH)_(2),Mn_(2)O_(3),MnO_(2),Ca_(3)Mn_(2)O_(7),and Ca_(2)MnO_(4).The majority of manganese ions exist in trivalent or tetravalent states and remain stable over time.The cost of using CS as a reagent for treating 1 ton of EMR is merely$1.01.The high OH^(-)concentration provided by CS enables the effective removal of NH_(4)^(+)from EMR and the solidification of Mn^(2+)during thermal reactions.
基金Funded by the Science and Technology Program of Gansu Province(No.25CXGA070)。
文摘To investigate the feasibility of applying electrolytic manganese residue(EMR)in cementitious materials,an approach combining high-temperature activation(200,400,600,800 and 1000℃)and mechanical grinding(5 min)was adopted to stimulate the EMR activity.We analyzed the effect of calcination temperature on the performance of EMR with the aid of X-ray diffraction(XRD),specific surface area test(BET)and pozzolanic activity test,explored the effects of EMR activation temperature and content(0%,10%,15% and 20%)on the setting time,soundness,drying shrinkage,compressive strength,hydration products of cement-EMR mixed slurry,and assessed the effect of cement hydration on the solidification of harmful NH_(4)^(+)-N and Mn^(2+) in EMR.The research results show that high-temperature calcination can lead to the dehydration,decomposition or crystalline phase transformation of the inert sulfate and other substances in EMR,mechanical grinding can improve its particle distribution,and the coupling of the two can effectively enhance the pozzolanic activity of EMR.The decomposition and recombination of aluminum-silica phase at 800℃ optimized the EMR activity,and the strength activity index(SAI)of EMR at 28 d reached up to 95%.Appropriate calcination temperature and EMR content can ensure the workability of the mixed slurry,and when the EMR calcination temperature was 400-1000℃,the setting time of the mixed slurry under different EMR contents satisfied the specification requirements.When the calcination temperature was 600-1000℃ and EMR content was less than 20%,the soundness of the mixed slurry satisfied the specification requirements.The compressive strength of the mixed slurry increased and then decreased with the increase of activated EMR content,when the EMR content was 10%,the compressive strength of all specimens was optimal and higher than the baseline group;when the activation temperature was 800℃,the C-S-H gel in the mixed slurry interconnected with the rod-like Aft and blocked Ca(OH)_(2),and the 28 d compressive strength was increased by 14%compared with that of the baseline group.The solidification rate of Mn^(2+) in EMR by cement hydration was higher than 99%,and that of NH_(4)^(+)-N was higher than 97%.The leaching toxicity after solidification can meet the requirements of toxic emission.The results of the study may provide theoretical basis for the feasibility of the application of EMR in cementitious materials.
基金The National Natural Science Foundation of China(U2130122,U22A20199,and 51975533)Natural Science Foundation of Zhejiang Province(LGJ22E050002)+1 种基金Equipment pre-research joint fund project of the Ministry of Education(8091B022215)China Postdoctoral Science Foundation(2023M733147)funded this research.
文摘In this study,laser-assisted plasma electrolytic oxidation(Laser/PEO)coating was prepared on AZ31B magnesium alloy for corrosion protection,due to insufficient corrosion protection caused by the inherent defects,cracks and poor quality of PEO coatings.The plasma discharge evolution,morphological characteristics,elemental composition during coating growth were characterized by high-speed camera,SEM,EDX,XRD and XPS,respectively.Meanwhile,Mott Schottky(M-S)curves,potentiodynamic polarization(PDP)curves and electrochemical impedance spectroscopy(EIS)tests characterized the oxygen vacancy defects and corrosion resistance of the coatings.The results demonstrated that laser-assisted irradiation not only induced plasma discharge on the anode surface,but also limited the plasma discharge size in the post-processing stage,which significantly increased the proportion of corrosion-resistant phase Mg_(2)SiO_(4)(the proportion of Mg_(2)SiO_(4)increased from 23.70%to 39.22%),thickness and density in the coating,and obviously reduced the oxygen vacancy defects and microcracks in the coating.As a result,the corrosion resistance of the Laser/PEO coating(9.29(±0.76)×10^(-7)A·cm^(-2))was further enhanced in comparation with the PEO coating(3.06(±0.19)×10^(-6) A·cm^(-2)).
文摘The corrosion resistance of magnesium alloys is a significant concern in industries seeking to use these materials for lightweight structures.Plasma electrolytic oxidation(PEO)is a process that forms a ceramic oxide film on Mg alloy surfaces,effectively enhancing their corrosion performance in the short term.In this regard,optimizing PEO process parameters is crucial for creating a stable oxide layer.An improved level of corrosion resistance is ensured by applying superhydrophobic coating(SHC)on top of the PEO layer to prevent moisture infiltration,creating air pockets on the surface.Various methods are employed to fabricate SHC on Mg alloys,including techniques like electrophoretic deposition(EPD),Hydrothermal(HT),dip,and spray coating.The synergistic combination of PEO and SHC coatings has demonstrated encouraging outcomes in enhancing the corrosion performance of Mg alloys.This study offers an extensive overview of recent progress in the preparation,characterization,and corrosion behavior of Mg alloys by employing PEO coatings and SHC treatment processes.
基金the financial support from the Anhui Key Laboratory of Low Carbon Metallurgy and Solid Waste Resource Utilization(Anhui University of Technology)(No.SKF23-01)Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology(No.FMRUlab23-1010)+1 种基金Open Project of State Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS 2022-07)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200).
文摘The effect of the initial(Al+Si)/MnO molar ratio and slag composition on MnO recovery from electroslag by remelting at 1773 K was investigated.High-purity aluminum metal and silicon were employed as the deoxidizers to effectively promote the recovery of manganese metal(MM).The reduction of MnO in slag,through the interaction between molten MM with a deoxidizer and the Na_(2)O-enriched electroslag melt,was assessed both thermodynamically and kinetically.The sulfur content of high-sulfur rejected electrolytic manganese metal(EMM)scrap decreased to 0.58%with high-temperature pretreatment.The mass ratio between slag and high-sulfur rejected EMM scrap is 2/3.When the Al_(2)O_(3)content in the initial slags decreased and the Na_(2)O content increased,the MnO reduction ratio increased.The residual MnO concentration of the slag reduced with increasing the Al–Si deoxidizer content.When the(Al+Si)/MnO molar ratio reached 0.83,the MnO concentration in the final slag was only 3%.A deoxidizer mainly containing aluminum and a small amount of Si could be added to recover MnO from the slag,resulting in the improvement in the cleanliness of final Mn metal.
基金Funded by the National Natural Science Foundation of China(No.52271066)Basic Research and Innovation Project for Vehicle Power+1 种基金Key Project of"Two-Chain Integration"in Shaanxi Province(No.2023-LL-QY-33-3)Xi'an Key Laboratory of Corrosion Protection and Functional Coating Technology for Military and Civil Light Alloy and Key Project of Shaanxi Natural Science Foundation Research Program(No.2021JZ-54)。
文摘A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic oxidation to enhance its corrosion resistance and self-healing properties.The morphology,chemical composition,structure,and functional properties of the composite coating were investigated by scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),polarization curve,alternating current impedance,and salt immersion test.The experimental results showed that,after immersion in a 3.5 wt%NaCl solution for 12 h,the coating could effectively protect AZ91D from corrosion.When the coating was damaged,the exposed alloy surface would release metal ions in the corrosive environment and react with the corrosion inhibitor 8-hydroxyquinoline to form a Mg(8-HQ)_(2) chelate,exhibiting significant self-healing behavior.The study results demonstrate the broad application prospects of microcapsule technology in the coating field,providing new ideas for the development of efficient anti-corrosion coatings.
