High-temperature oxidation behavior of ferrovanadium(FeV_(2)O_(4))and ferrochrome(FeCr_(2)O_(4))spinels is crucial for the application of spinel as an energy material,as well as for the clean usage of high-chromium va...High-temperature oxidation behavior of ferrovanadium(FeV_(2)O_(4))and ferrochrome(FeCr_(2)O_(4))spinels is crucial for the application of spinel as an energy material,as well as for the clean usage of high-chromium vanadium slag.Herein,the nonisothermal oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)prepared by high-temperature solid-state reaction was examined by thermogravimetry and X-ray diffraction(XRD)at heating rates of 5,10,and 15 K/min.The apparent activation energy was determined by the Kissinger-Akahira-Sunose(KAS)method,whereas the mechanism function was elucidated by the Malek method.Moreover,in-situ XRD was conducted to deduce the phase transformation of the oxidation mechanism for FeV_(2)O_(4)and FeCr_(2)O_(4).The results reveal a gradual increase in the overall apparent activation energies for FeV_(2)O_(4)and FeCr_(2)O_(4)during oxidation.Four stages of the oxidation process are observed based on the oxidation conversion rate of each compound.The oxidation mechanisms of FeV_(2)O_(4)and FeCr_(2)O_(4)are complex and have distinct mechanisms.In particular,the chemical reaction controls the entire oxidation process for FeV_(2)O_(4),whereas that for FeCr_(2)O_(4)transitions from a three-dimensional diffusion model to a chemical reaction model.According to the in-situ XRD results,numerous intermediate products are observed during the oxidation process of both compounds,eventually resulting in the final products FeVO_(4)and V2O_(5)for FeV_(2)O_(4)and Fe_(2)O_(3)and Cr_(2)O_(3)for FeCr_(2)O_(4),respectively.展开更多
The interaction of MgO-MgAl_(2)O_(4)-based and MgO-Cr_(2)O_(3)-based refractories with X70 molten steel was studied by immersion experiments at 1560℃.The effects of immersion time(30 and 60 min)on the contents of tot...The interaction of MgO-MgAl_(2)O_(4)-based and MgO-Cr_(2)O_(3)-based refractories with X70 molten steel was studied by immersion experiments at 1560℃.The effects of immersion time(30 and 60 min)on the contents of total oxygen(TO),Al,Nb,Si,Mn,and Cr as well as the composition,number density,and size distribution of inclusions in the molten steel were investigated.The influence of the penetration and erosion degree of the molten steel to the refractory on the steel-refractory interface layer was analyzed.The results show that,at 1560℃,the MgO-MgAl_(2)O_(4)-based refractory can better control the contents of TO and the composition of molten steel compared with the MgO-Cr_(2)O_(3)-based refractory.The TO content is only 16×10^(-4) wt.%in the molten steel after reacted with the Mg0-MgAl_(2)O_(4)-based refractory at the end point of refining,4 accounting for 11.5%of that reacted with the MgO-Cr_(2)O_(3)-based refractory(139×10^(-4) wt.%).The number density of inclusions is only 14 mm^(-2),and the average size ofinclusions is only 1.31μm,with thelargest proportion of inclusions in 1-2μm(70%).The Al_(2)O_(3)-MnS-CaO complex inclusions in the original steel changed to complex inclusions dominated by Cr-Nb-Mn-S-O and MgO.Al_(2)O_(3),corresponding to the MgO-Cr_(2)O_(3)-based and MgO-MgAl_(2)O_(4)-based refractories,respectively.The MgO.Al_(2)O_(3) layer was formed at the reaction interface between MgO-MgAl_(2)O_(4)-based refractory and molten steel,which is helpful to restrict the erosion of refractories and the pollution of molten steel.The damage mechanism of the MgO-Cr_(2)O_(3)-based refractory is mainly permeation and chemical reaction,while the damage of the MgO-MgAl_(2)O_(4)-based refractory is mainlyscouring erosion.展开更多
In the quest for the development of thermally stable,highly active and low-cost catalysts for use in catalyzed diesel particulate filter,nano-composites are new areas of research.Therefore,we reported the easy synthes...In the quest for the development of thermally stable,highly active and low-cost catalysts for use in catalyzed diesel particulate filter,nano-composites are new areas of research.Therefore,we reported the easy synthesis of spinel NiCo_(2)O_(4)/perovskite LaCoO_(3) nano-composite,and its individual oxides NiCo_(2)O_(4)and LaCoO_(3) for comparison.The detailed insights into the physio-chemical characteristics of formed NiCo_(2)O_(4)/LaCoO_(3) nano-composite were done based on various characterization analysis such as X-ray diffraction(XRD),Fourier transform infrared(FT-IR),N_(2) physiosorption,scanning electron microscopy-energy dispersive spectroscopy(SEM-EDX),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).The characterization analysis of NiCo_(2)O_(4)/LaCoO_(3) revealed the successful formation of a chemical interface possessing strong interfacial interaction,resulting in desirable physicochemical characteristics such as small crystallite size,abundant mesoporosity,high specific surface area and activation of surface lattice oxygen.Owing to the desirable characteristics,the activity results over NiCo_(2)O_(4)/LaCoO_(3) nano-composite showed the excellent CO oxidation performance and high soot oxidation activity,recyclability and thermal stability.This work mainly attempts to emphasize the effectiveness of the facile,inexpensive and conventionally used precipitation method for the successful formation of highly efficient nano-composites.展开更多
Electrocatalysts with optimal efficiency and durability for the oxygen evolution reaction(OER)are becoming increasingly important as the demand for alkaline water/seawater electrolysis technology grows.Herein,a novel ...Electrocatalysts with optimal efficiency and durability for the oxygen evolution reaction(OER)are becoming increasingly important as the demand for alkaline water/seawater electrolysis technology grows.Herein,a novel rose-shaped NiFe-layered double hydroxide(LDH)/NiCo_(2)O_(4)composed of amorphous wrinkled NiFe-LDH and highly crystalline NiCo_(2)O_(4)was synthesized with rich heterointerfaces.Many unsaturated metal sites are generated due to significant charge reconstruction at the heterointerface between the crystalline and amorphous phases.These metal sites could trigger and provide more active sites.The density functional theory(DFT)reveals that a new charge transfer channel(Co-Fe)was formed at the heterointerface between NiFe-LDH as electron acceptor and NiCo_(2)O_(4)as electron donor.The new charge transfer channel boosts interfacial charge transfer and enhances catalytic efficiency.The NiFe-LDH/NiCo_(2)O_(4)/nickel foam(NF)drives current densities of 10 and 100 mA·cm−2 with overpotentials of 193 and 236 mV,respectively.The composite electrode demonstrates a fast turnover frequency(0.0143 s−1)at 1.45 V vs.RHE(RHE=reversible hydrogen electrode),which is 5.5 times greater than pure NiCo_(2)O_(4),suggesting its superior intrinsic activity.Additionally,NiFe-LDH/NiCo_(2)O_(4)/NF electrode exhibited negligible degradation after 150 h of uninterrupted running in alkaline seawater oxidation.This study introduces a method for preparing high-efficiency electrocatalysts utilized in alkaline water/seawater electrolysis.展开更多
Previous results revealed that the defect and/or interface had a great impact on the electromagnetic pa-rameters of materials.In order to understand the main physical mechanisms and effectively utilize these strategie...Previous results revealed that the defect and/or interface had a great impact on the electromagnetic pa-rameters of materials.In order to understand the main physical mechanisms and effectively utilize these strategies,in this study,M Fe_(2)O_(4)and flower-like core@shell M Fe_(2)O_(4)@MoS_(2)(M=Mn,Ni,and Zn)sam-ples with different categories were elaborately designed and selectively produced in large scale through a simple two-step hydrothermal reaction.We conducted the systematical investigation on their microstruc-tures,electromagnetic parameters and microwave absorption performances(MAPs).The obtained results revealed that the large radius of M^(2+)cation could effectively boost the concentration of oxygen vacancy in the M Fe_(2)O_(4)and M Fe_(2)O_(4)@MoS_(2)samples,which resulted in the improvement of dielectric loss capabil-ities and MAPs.Furthermore,the introduction of MoS_(2)nanosheets greatly improved the interfacial effect and enhanced the polarization loss capabilities,which also boosted the MAPs.By taking full advantage of the defect and interface,the designed M Fe_(2)O_(4)@MoS_(2)samples displayed tunable and excellent com-prehensive MAPs including strong absorption capability,wide absorption bandwidth and thin matching thicknesses.Therefore,the clear understanding of defect and interface engineering made these strategies well elaborately designed and applicable to improving MAPs.展开更多
A hierarchically structured MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces was designed by a simple,eco-friendly and time-saving in-situ electro-deposition method.The abundance of active oxygen s...A hierarchically structured MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces was designed by a simple,eco-friendly and time-saving in-situ electro-deposition method.The abundance of active oxygen species due to this rich phase interfaces contributed to the excellent benzene combustion performance of MnO_(x)-NiCo_(2)O_(4)-2:2 sample,oxidizing about 90% of benzene(T_(90)) at 198℃ under 12000 h^(-1) gaseous hourly space velocity.This work shed new light on the design of excellent monolithic catalysts,which might pave the way for the industrialization of benzene combustion.展开更多
Heterojunction photocatalysts have shown considerable activities for organic pollutants degradation.However,the faint connection interface and inferior charge shift efficiency critically block the property of heteroju...Heterojunction photocatalysts have shown considerable activities for organic pollutants degradation.However,the faint connection interface and inferior charge shift efficiency critically block the property of heterojunction photocatalysis.Herein,Bi_(2)O_(2)S/NiFe_(2)O_(4) nanosheets heterojunction with ultrastrong inter-face interaction and high internal electric field are designed by an in-situ growth method.Tentative and theoretical consequences prove that the interfacial interaction and internal electric field not only act as the electron flow bridge but also decrease the electrons shift energy obstacle,thus speeding up electrons transfer and achieving effective spatial electron-hole separation.Therefore,a large amount of·O_(2)^(-)and holes as active species were generated.Remarkably,Bi_(2)O_(2) S/NiFe_(2)O_(4) establishes a considerably boosted photocatalytic performance for tetracycline degradation(0.032 min^(-1)),which is about 14.2-fold and 7.8-fold of the pristine BOS and NFO,respectively.This work provides a promising motivation for modulating charge transfer by interface control and internal electric field to boost photocatalytic performance.展开更多
Ethylene carbonate(EC)is widely used in lithium-ion batteries due to its optimal overall performance with satisfactory conductivity,relatively stable solid electrolyte interphase(SEI),and wide electrochemical window.E...Ethylene carbonate(EC)is widely used in lithium-ion batteries due to its optimal overall performance with satisfactory conductivity,relatively stable solid electrolyte interphase(SEI),and wide electrochemical window.EC is also the most widely used electrolyte solvent in sodium ion batteries.However,compared to lithium metal,sodium metal(Na)shows higher activity and reacts violently with EC-based electrolyte(NaPF_(6)as solute),which leads to the failure of sodium metal batteries(SMBs).Herein,we reveal the electrochemical instability mechanism of EC on sodium metal battery,and find that the com-bination of EC and NaPF_(6) is electrically reduced in sodium metal anode during charging,resulting in the reduction of the first coulombic efficiency,and the continuous consumption of electrolyte leads to the cell failure.To address the above issues,an additive modified linear carbonate-based electrolyte is provided as a substitute for EC based electrolytes.Specifically,ethyl methyl carbonate(EMC)and dimethyl carbon-ate(DMC)as solvents and fluoroethylene carbonate(FEC)as SEI-forming additive have been identified as the optimal solvent for NaFP_(6)based electrolyte and used in Na_(4)Fe_(3)(PO_(4))_(2)(P_(2)O_(7))/Na batteries.The batter-ies exhibit excellent capacity retention rate of about 80%over 1000 cycles at a cut-off voltage of 4.3 V.展开更多
To solve the electromagnetic pollution,herein,a CoFe_(2)O_(4)/C/PANI composite was developed by a green route,which was constructed with spinel of metal oxide,graphitized carbon and conductive polymer composites.Benef...To solve the electromagnetic pollution,herein,a CoFe_(2)O_(4)/C/PANI composite was developed by a green route,which was constructed with spinel of metal oxide,graphitized carbon and conductive polymer composites.Benefiting from the designable interfaces and increased dipoles,the microwave dielectric response capability can be boosted significantly and resulted in the enhanced microwave absorbing performance.As revealed by the reflection loss curve,the minimum reflection loss(RLmin) reached-51.81 dB at 12.4 GHz under a matched thickness of 2.57 mm.At 2.5 mm,the effective absorbing band covered 8.88 GHz,suggesting the desirable wideband feature.In our case,the method of utilization of a novel green way to fabricate multiple-component EM absorber can be a promising candidate for high-performance EM absorber.展开更多
A novel approach to reduce Ni content for the 310S austenitic stainless steel was proposed.The nano-ceramic additive(L)was applied to 310S steel to replace part of Ni element and reduce the cost.By means of thermal si...A novel approach to reduce Ni content for the 310S austenitic stainless steel was proposed.The nano-ceramic additive(L)was applied to 310S steel to replace part of Ni element and reduce the cost.By means of thermal simulation,X-ray diffraction,field emission scanning electron microscopy,and electron backscattered diffraction,the effects of nanoceramic additives on high-temperature mechanical properties and corrosion behavior of the 310S steel were studied.The results indicate that the morphology and density of the(Fe,Cr)_(23)C_(6)carbides are varied,which play an important role in the high-temperature mechanical properties and corrosion behavior.After adding nano-ceramic additives,the high-temperature tensile strength and yield strength are improved simultaneously,in spite of a slight decrease in the total elongation.During high-temperature corrosion process,the mass gain of all the samples is parabolic with time.The mass gain is increased in the 310S steel with nano-ceramic additive,while the substrate thickness is significantly larger than 310S steel.The more stable and adherent FeCr_(2)O_(4)spinel form is the reason why the high-temperature corrosion resistance was increased.The(Fe,Cr)_(23)C_(6)carbides distribution along grain boundaries is detrimental to the high-temperature corrosion resistance.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.52004044)the Natural Science Foundation of Chongqing,China(Nos.cstb2022nscqmsx0801 and cstc2021jcyj-msxmx0882)+2 种基金the Foundation of Chongqing University of Science and Technology(No.ckrc2022030)the Graduate Research Innovation Project of Chongqing University of Science and Technology(No.YKJCX2220216)the National Undergraduate Training Program for Innovation and Entrepreneurship(No.202311551007).
文摘High-temperature oxidation behavior of ferrovanadium(FeV_(2)O_(4))and ferrochrome(FeCr_(2)O_(4))spinels is crucial for the application of spinel as an energy material,as well as for the clean usage of high-chromium vanadium slag.Herein,the nonisothermal oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)prepared by high-temperature solid-state reaction was examined by thermogravimetry and X-ray diffraction(XRD)at heating rates of 5,10,and 15 K/min.The apparent activation energy was determined by the Kissinger-Akahira-Sunose(KAS)method,whereas the mechanism function was elucidated by the Malek method.Moreover,in-situ XRD was conducted to deduce the phase transformation of the oxidation mechanism for FeV_(2)O_(4)and FeCr_(2)O_(4).The results reveal a gradual increase in the overall apparent activation energies for FeV_(2)O_(4)and FeCr_(2)O_(4)during oxidation.Four stages of the oxidation process are observed based on the oxidation conversion rate of each compound.The oxidation mechanisms of FeV_(2)O_(4)and FeCr_(2)O_(4)are complex and have distinct mechanisms.In particular,the chemical reaction controls the entire oxidation process for FeV_(2)O_(4),whereas that for FeCr_(2)O_(4)transitions from a three-dimensional diffusion model to a chemical reaction model.According to the in-situ XRD results,numerous intermediate products are observed during the oxidation process of both compounds,eventually resulting in the final products FeVO_(4)and V2O_(5)for FeV_(2)O_(4)and Fe_(2)O_(3)and Cr_(2)O_(3)for FeCr_(2)O_(4),respectively.
基金support from the National Natural Science Foundation of China(Grant Nos.U1860205 and 52204352)Youth Project of Hubei Natural Science Foundation(Grant No.2022CFB593)+1 种基金Key R&D Project of Hubei Province(Grant No.2022BAA021)Guiding Project of Scientific Research Plan of Hubei Provincial Department of Education(Grant No.B2022019).
文摘The interaction of MgO-MgAl_(2)O_(4)-based and MgO-Cr_(2)O_(3)-based refractories with X70 molten steel was studied by immersion experiments at 1560℃.The effects of immersion time(30 and 60 min)on the contents of total oxygen(TO),Al,Nb,Si,Mn,and Cr as well as the composition,number density,and size distribution of inclusions in the molten steel were investigated.The influence of the penetration and erosion degree of the molten steel to the refractory on the steel-refractory interface layer was analyzed.The results show that,at 1560℃,the MgO-MgAl_(2)O_(4)-based refractory can better control the contents of TO and the composition of molten steel compared with the MgO-Cr_(2)O_(3)-based refractory.The TO content is only 16×10^(-4) wt.%in the molten steel after reacted with the Mg0-MgAl_(2)O_(4)-based refractory at the end point of refining,4 accounting for 11.5%of that reacted with the MgO-Cr_(2)O_(3)-based refractory(139×10^(-4) wt.%).The number density of inclusions is only 14 mm^(-2),and the average size ofinclusions is only 1.31μm,with thelargest proportion of inclusions in 1-2μm(70%).The Al_(2)O_(3)-MnS-CaO complex inclusions in the original steel changed to complex inclusions dominated by Cr-Nb-Mn-S-O and MgO.Al_(2)O_(3),corresponding to the MgO-Cr_(2)O_(3)-based and MgO-MgAl_(2)O_(4)-based refractories,respectively.The MgO.Al_(2)O_(3) layer was formed at the reaction interface between MgO-MgAl_(2)O_(4)-based refractory and molten steel,which is helpful to restrict the erosion of refractories and the pollution of molten steel.The damage mechanism of the MgO-Cr_(2)O_(3)-based refractory is mainly permeation and chemical reaction,while the damage of the MgO-MgAl_(2)O_(4)-based refractory is mainlyscouring erosion.
文摘In the quest for the development of thermally stable,highly active and low-cost catalysts for use in catalyzed diesel particulate filter,nano-composites are new areas of research.Therefore,we reported the easy synthesis of spinel NiCo_(2)O_(4)/perovskite LaCoO_(3) nano-composite,and its individual oxides NiCo_(2)O_(4)and LaCoO_(3) for comparison.The detailed insights into the physio-chemical characteristics of formed NiCo_(2)O_(4)/LaCoO_(3) nano-composite were done based on various characterization analysis such as X-ray diffraction(XRD),Fourier transform infrared(FT-IR),N_(2) physiosorption,scanning electron microscopy-energy dispersive spectroscopy(SEM-EDX),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).The characterization analysis of NiCo_(2)O_(4)/LaCoO_(3) revealed the successful formation of a chemical interface possessing strong interfacial interaction,resulting in desirable physicochemical characteristics such as small crystallite size,abundant mesoporosity,high specific surface area and activation of surface lattice oxygen.Owing to the desirable characteristics,the activity results over NiCo_(2)O_(4)/LaCoO_(3) nano-composite showed the excellent CO oxidation performance and high soot oxidation activity,recyclability and thermal stability.This work mainly attempts to emphasize the effectiveness of the facile,inexpensive and conventionally used precipitation method for the successful formation of highly efficient nano-composites.
基金the National Natural Science Foundation of China(Nos.21878242,52206277,and 21828802)the Basic Science Center Program for Ordered Energy Conversion of National Nature Science Foundation(No.51888103)the China Postdoctoral Science Foundation(No.2022MD723821).
文摘Electrocatalysts with optimal efficiency and durability for the oxygen evolution reaction(OER)are becoming increasingly important as the demand for alkaline water/seawater electrolysis technology grows.Herein,a novel rose-shaped NiFe-layered double hydroxide(LDH)/NiCo_(2)O_(4)composed of amorphous wrinkled NiFe-LDH and highly crystalline NiCo_(2)O_(4)was synthesized with rich heterointerfaces.Many unsaturated metal sites are generated due to significant charge reconstruction at the heterointerface between the crystalline and amorphous phases.These metal sites could trigger and provide more active sites.The density functional theory(DFT)reveals that a new charge transfer channel(Co-Fe)was formed at the heterointerface between NiFe-LDH as electron acceptor and NiCo_(2)O_(4)as electron donor.The new charge transfer channel boosts interfacial charge transfer and enhances catalytic efficiency.The NiFe-LDH/NiCo_(2)O_(4)/nickel foam(NF)drives current densities of 10 and 100 mA·cm−2 with overpotentials of 193 and 236 mV,respectively.The composite electrode demonstrates a fast turnover frequency(0.0143 s−1)at 1.45 V vs.RHE(RHE=reversible hydrogen electrode),which is 5.5 times greater than pure NiCo_(2)O_(4),suggesting its superior intrinsic activity.Additionally,NiFe-LDH/NiCo_(2)O_(4)/NF electrode exhibited negligible degradation after 150 h of uninterrupted running in alkaline seawater oxidation.This study introduces a method for preparing high-efficiency electrocatalysts utilized in alkaline water/seawater electrolysis.
基金This work was supported by the Fund of Fok Ying Tung Edu-cation Foundation,the Major Research Project of Innovative Group of Guizhou province(No.2018-013)Open Fund from Henan Uni-versity of Science and Technology,the National Science Foundation of China(Nos.11964006 and 11774156)the Foundation of the National Key Project for Basic Research(No.2012CB932304)for fi-nancial support。
文摘Previous results revealed that the defect and/or interface had a great impact on the electromagnetic pa-rameters of materials.In order to understand the main physical mechanisms and effectively utilize these strategies,in this study,M Fe_(2)O_(4)and flower-like core@shell M Fe_(2)O_(4)@MoS_(2)(M=Mn,Ni,and Zn)sam-ples with different categories were elaborately designed and selectively produced in large scale through a simple two-step hydrothermal reaction.We conducted the systematical investigation on their microstruc-tures,electromagnetic parameters and microwave absorption performances(MAPs).The obtained results revealed that the large radius of M^(2+)cation could effectively boost the concentration of oxygen vacancy in the M Fe_(2)O_(4)and M Fe_(2)O_(4)@MoS_(2)samples,which resulted in the improvement of dielectric loss capabil-ities and MAPs.Furthermore,the introduction of MoS_(2)nanosheets greatly improved the interfacial effect and enhanced the polarization loss capabilities,which also boosted the MAPs.By taking full advantage of the defect and interface,the designed M Fe_(2)O_(4)@MoS_(2)samples displayed tunable and excellent com-prehensive MAPs including strong absorption capability,wide absorption bandwidth and thin matching thicknesses.Therefore,the clear understanding of defect and interface engineering made these strategies well elaborately designed and applicable to improving MAPs.
基金financially supported by National Key R&D Program of China(Nos.2017YFC0211503,2016YFC0207100)the National Natural Science Foundation of China(Nos.21401200,51672273)the Open Research Fund of State Key Laboratory of Multi-phase Complex Systems(No.MPCS-2017-D-06)。
文摘A hierarchically structured MnO_(x)-NiCo_(2)O_(4) monolithic catalyst with rich phase interfaces was designed by a simple,eco-friendly and time-saving in-situ electro-deposition method.The abundance of active oxygen species due to this rich phase interfaces contributed to the excellent benzene combustion performance of MnO_(x)-NiCo_(2)O_(4)-2:2 sample,oxidizing about 90% of benzene(T_(90)) at 198℃ under 12000 h^(-1) gaseous hourly space velocity.This work shed new light on the design of excellent monolithic catalysts,which might pave the way for the industrialization of benzene combustion.
基金the financial support by the National Natural Science Foundation of China as general projects(Grant Nos.51779068,52070066,52211530084,42277059,and 22006029)Tianjin Commission of Science and Technology as key technologies R&D projects(No.21YFSNSN00250)+1 种基金Doctoral Inno-vation Project of Hebei Province(CXZZBS2023031)the Royal Society/International Exchanges 2021 Cost Share/NSFC(Grant No.IEC\NSFC\211142).
文摘Heterojunction photocatalysts have shown considerable activities for organic pollutants degradation.However,the faint connection interface and inferior charge shift efficiency critically block the property of heterojunction photocatalysis.Herein,Bi_(2)O_(2)S/NiFe_(2)O_(4) nanosheets heterojunction with ultrastrong inter-face interaction and high internal electric field are designed by an in-situ growth method.Tentative and theoretical consequences prove that the interfacial interaction and internal electric field not only act as the electron flow bridge but also decrease the electrons shift energy obstacle,thus speeding up electrons transfer and achieving effective spatial electron-hole separation.Therefore,a large amount of·O_(2)^(-)and holes as active species were generated.Remarkably,Bi_(2)O_(2) S/NiFe_(2)O_(4) establishes a considerably boosted photocatalytic performance for tetracycline degradation(0.032 min^(-1)),which is about 14.2-fold and 7.8-fold of the pristine BOS and NFO,respectively.This work provides a promising motivation for modulating charge transfer by interface control and internal electric field to boost photocatalytic performance.
基金supported by the National Natural Science Foundation of China(52172201,51732005,51902118,and 52102249)the China Postdoctoral Science Foundation(2019M662609and 2020T130217)for financial support。
文摘Ethylene carbonate(EC)is widely used in lithium-ion batteries due to its optimal overall performance with satisfactory conductivity,relatively stable solid electrolyte interphase(SEI),and wide electrochemical window.EC is also the most widely used electrolyte solvent in sodium ion batteries.However,compared to lithium metal,sodium metal(Na)shows higher activity and reacts violently with EC-based electrolyte(NaPF_(6)as solute),which leads to the failure of sodium metal batteries(SMBs).Herein,we reveal the electrochemical instability mechanism of EC on sodium metal battery,and find that the com-bination of EC and NaPF_(6) is electrically reduced in sodium metal anode during charging,resulting in the reduction of the first coulombic efficiency,and the continuous consumption of electrolyte leads to the cell failure.To address the above issues,an additive modified linear carbonate-based electrolyte is provided as a substitute for EC based electrolytes.Specifically,ethyl methyl carbonate(EMC)and dimethyl carbon-ate(DMC)as solvents and fluoroethylene carbonate(FEC)as SEI-forming additive have been identified as the optimal solvent for NaFP_(6)based electrolyte and used in Na_(4)Fe_(3)(PO_(4))_(2)(P_(2)O_(7))/Na batteries.The batter-ies exhibit excellent capacity retention rate of about 80%over 1000 cycles at a cut-off voltage of 4.3 V.
基金financially supported by the National Natural Science Foundation of China (Nos.51407134 and 51801001)the Natural Science Foundation of Shandong Province (No.ZR2019YQ24)+6 种基金the China Postdoctoral Science Foundation (Nos.2016M590619 and 2016M601878)the Provincial Key Research and Development Program of Shaanxi (No.2019GY-197)the Qingchuang Talents Induction Program of Shandong Higher Education Institution (Research and Innovation Team of Structural Functional Polymer Composites)support from The Thousand Talents PlanThe World-Class University and DisciplineThe Taishan Scholar’s Advantageous and Distinctive Discipline Program of Shandong ProvinceThe World-Class Discipline Program of Shandong Province。
文摘To solve the electromagnetic pollution,herein,a CoFe_(2)O_(4)/C/PANI composite was developed by a green route,which was constructed with spinel of metal oxide,graphitized carbon and conductive polymer composites.Benefiting from the designable interfaces and increased dipoles,the microwave dielectric response capability can be boosted significantly and resulted in the enhanced microwave absorbing performance.As revealed by the reflection loss curve,the minimum reflection loss(RLmin) reached-51.81 dB at 12.4 GHz under a matched thickness of 2.57 mm.At 2.5 mm,the effective absorbing band covered 8.88 GHz,suggesting the desirable wideband feature.In our case,the method of utilization of a novel green way to fabricate multiple-component EM absorber can be a promising candidate for high-performance EM absorber.
基金This work was financially supported by the Key Technology Research and Development Program of Shandong(2019TSLH0103)the Fundamental Research Funds for the Central Universities(FRF-TP-19-009A1).
文摘A novel approach to reduce Ni content for the 310S austenitic stainless steel was proposed.The nano-ceramic additive(L)was applied to 310S steel to replace part of Ni element and reduce the cost.By means of thermal simulation,X-ray diffraction,field emission scanning electron microscopy,and electron backscattered diffraction,the effects of nanoceramic additives on high-temperature mechanical properties and corrosion behavior of the 310S steel were studied.The results indicate that the morphology and density of the(Fe,Cr)_(23)C_(6)carbides are varied,which play an important role in the high-temperature mechanical properties and corrosion behavior.After adding nano-ceramic additives,the high-temperature tensile strength and yield strength are improved simultaneously,in spite of a slight decrease in the total elongation.During high-temperature corrosion process,the mass gain of all the samples is parabolic with time.The mass gain is increased in the 310S steel with nano-ceramic additive,while the substrate thickness is significantly larger than 310S steel.The more stable and adherent FeCr_(2)O_(4)spinel form is the reason why the high-temperature corrosion resistance was increased.The(Fe,Cr)_(23)C_(6)carbides distribution along grain boundaries is detrimental to the high-temperature corrosion resistance.
