Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the eff...Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.展开更多
电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量...电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。展开更多
The oxygen reduction reaction(ORR)is a crucial process in Zn-air systems,and the catalyst plays a significant role in this reaction.However,reported catalysts often suffer from poor durability and stability during the...The oxygen reduction reaction(ORR)is a crucial process in Zn-air systems,and the catalyst plays a significant role in this reaction.However,reported catalysts often suffer from poor durability and stability during the ORR process.Herein,we synthesized La-Fe bimetallic nanoparticles encapsulated in a N-doped porous carbon dodecahedron(La-Fe/NC)originated from ZIF-8 by a simple direct carbonization.The La-Fe/NC catalyst had a numerous mesopores and dendritic outer layer generated by carbon nanotubes(CNTs),forming a high conductivity network that helped to optimize electron transfer and mass transport in the ORR process.The effect of different doping transition metals and metal ratios on the ORR activity of Zn-air batteries was investigated.In alkaline media,the La-Fe/NC showed the highest ORR catalytic activity,with a half-wave potential(E_(1/2))of 0.879 V(vs.RHE,Pt/C 0.845 V).After 5000 cycles,the E_(1/2)of the La-Fe/NC catalyst only decreased by 7 m V,and its performance in stability tests and methanol tolerance tests was superior to Pt/C.When used as the air electrode in a Zn-air battery,the La-Fe/NC catalyst demonstrated an excellent specific capacity of 755 m Ah/g and a peak power density of179.8 m W/cm~2.The results provide important insights for the development of high-performance Zn-air batteries and new directions for the design of ORR catalysts.展开更多
Capacitive deionization(CDI),as an emerging desalination technique,has been intensively explored because of its energy-saving,cost-effectiveness and sustainability.Despite the promise,CDI systems still encounter vario...Capacitive deionization(CDI),as an emerging desalination technique,has been intensively explored because of its energy-saving,cost-effectiveness and sustainability.Despite the promise,CDI systems still encounter various challenges involving active sites,mass transfer and stability that severely limit their further application.So far,there is still much-limited review across material,electrodes and devices to cope with the above challenges.Notably,carbon nanotubes(CNTs),have garnered significant attention owing to their exceptional conductivity,high specific surface area(S_(BET)),unique skeleton role and superior mechanical strength.More importantly,CNTs serve multifunctional roles in CDI systems,including active materials,conductive agents,binders,and even current collectors,while also making for the thick electrode framework construction.Specifically,this review first discusses current challenges in CDI system design.Subsequently,it systemic highlights how CNTs address these issues through material innovation,electrode optimization and device integration.Eventually,a conceptual model for CNT composite self-supporting CDI systems is further proposed,aiming to exploit advanced CDI desalination systems.Overall,this review underscores the pivotal role of CNTs in overcoming technical bottlenecks and driving the practical application of CDI for sustainable water treatment.展开更多
High-performance aqueous zinc(Zn)-ion batteries(AZIBs)have emerged as one of the greatest favorable candidates for next-generation energy storage systems because of their low cost,sustainability,high safety,and eco-fr...High-performance aqueous zinc(Zn)-ion batteries(AZIBs)have emerged as one of the greatest favorable candidates for next-generation energy storage systems because of their low cost,sustainability,high safety,and eco-friendliness.In this report,we prepared magnesium vanadate(MgVO)-based nanostructures by a facile single-step solvothermal method with varying experimental reaction times(1,3,and 6 h)and investigated the effect of the reaction time on the morphology and layered structure for MgVO-based compounds.The newly prepared MgVO-1 h,MgVO-3 h and MgVO-6 h samples were used as cathode materials for AZIBs.Compared to the MgVO-1 h and MgVO-6 h cathodes,the MgVO-3 h cathode showed a higher specific capacity of 492.74 mA h g^(-1) at 1 A g^(-1) over 500 cycles and excellent rate behavior(291.58 mA h g^(-1) at 3.75 A g^(-1))with high cycling stability(116%)over 2000 cycles at 5 A g^(-1).Moreover,the MgVO-3 h electrode exhibited good electrochemical performance owing to its fast Zn-ion diffusion kinetics.Additionally,various ex-situ analyses confirmed that the MgVO-3 h cathode displayed excellent insertion/extraction of Zn^(2+)ions during charge and discharge processes.This study offers an efficient method for the synthesis of nanostructured MgVO-based cathode materials for high-performance AZIBs.展开更多
The ability to control the electrode interfaces in an electrochemical energy storage system is essential for achieving the desired electrochemical performance.However,achieving this ability requires an in-depth unders...The ability to control the electrode interfaces in an electrochemical energy storage system is essential for achieving the desired electrochemical performance.However,achieving this ability requires an in-depth understanding of the detailed interfacial nanostructures of the electrode under electrochemical operating conditions.In-situ transmission electron microscopy(TEM)is one of the most powerful techniques for revealing electrochemical energy storage mechanisms with high spatiotemporal resolution and high sensitivity in complex electrochemical environments.These attributes play a unique role in understanding how ion transport inside electrode nanomaterials and across interfaces under the dynamic conditions within working batteries.This review aims to gain an in-depth insight into the latest developments of in-situ TEM imaging techniques for probing the interfacial nanostructures of electrochemical energy storage systems,including atomic-scale structural imaging,strain field imaging,electron holography,and integrated differential phase contrast imaging.Significant examples will be described to highlight the fundamental understanding of atomic-scale and nanoscale mechanisms from employing state-of-the-art imaging techniques to visualize structural evolution,ionic valence state changes,and strain mapping,ion transport dynamics.The review concludes by providing a perspective discussion of future directions of the development and application of in-situ TEM techniques in the field of electrochemical energy storage systems.展开更多
Metallic glass composites hold significant potential as structural materials.However,few methods are available to enhance their mechanical properties postcasting.In this study,simple pre-tensile training was applied t...Metallic glass composites hold significant potential as structural materials.However,few methods are available to enhance their mechanical properties postcasting.In this study,simple pre-tensile training was applied to a TRIP-reinforced metallic glass composite,resulting in a more than one-third increase in plasticity,while the reliability of plasticity was also enhanced.The deformation mechanism was further elucidated,revealing that pre-tension induced the formation of multilayered nanostructures at the dendrite-glass interface.This microstructural evolution facilitates the formation of finer martensite laths within the dendrites and multiple shear bands in the glass matrix during compression,thereby enabling more uniform plastic deformation.These findings suggest that simple preloading treatments may offer a viable approach to regulating the microstructure of as-cast metallic glass composites and optimizing their mechanical properties.展开更多
The organic pollutants,such as quaternary ammonium compounds,in high salinity flowback water from shale gas extraction may pose a severe risk to public health.Conventional biological technologies have limited effectiv...The organic pollutants,such as quaternary ammonium compounds,in high salinity flowback water from shale gas extraction may pose a severe risk to public health.Conventional biological technologies have limited effectiveness in the treatment of high-salt wastewaters,whereas electrocatalytic oxidation has shown potential for treating organic pollutants in high-salt flowback water.This study developed a carbon nanotubes(CNTs)doped Ru/Ir oxide coated Ti electrode CNTs-(Ru_(x)Ir_(y)O_(2))/Ti,which exhibited enhanced electrocatalytic performance for the treatment of quaternary ammonium compound in high-salt wastewater compared to the control metal oxide coated Ti anode(Ru_(x)Ir_(y)O_(2))/Ti,with pseudofirst-order reaction rate constant improved from 7.36×10^(-3) to 1.12×10^(-2) min−1.Moreover,the CNTs-(Ru_(x)Ir_(y)O_(2))/Ti anode electrocatalytic oxidation system exhibited excellent cycling stability.Mechanism studies indicated that the CNTs-(Ru_(x)Ir_(y)O_(2))/Ti electrode enhanced singlet oxygen(^(1)O_(2))generation,which played a major role in pollutant degradation.Furthermore,the formation of high concentrations of HClO and H_(2)O_(2) further facilitated the generation of ^(1)O_(2).This study may provide an efficient and green technology for the treatment of organic pollutants in high-salt shale gas flowback water.展开更多
In this study,carbon nanotubes(CNTs)/AlSi10Mg composite parts with CNTs contents ranging from 0.0 to 2.0wt.%were successfully fabricated via laser powder bed fusion(LPBF)with laser scan speeds ranging from 900 to 1,90...In this study,carbon nanotubes(CNTs)/AlSi10Mg composite parts with CNTs contents ranging from 0.0 to 2.0wt.%were successfully fabricated via laser powder bed fusion(LPBF)with laser scan speeds ranging from 900 to 1,900 mm·s^(-1).Uniform dispersion of CNTs in the powders can be achieved when their content is below 2.0wt.%.In the LPBF samples,the morphology of the CNTs is found to be directly related to their content.Especially,the length of CNTs in samples prepared by LPBF increases as the CNT content increases.The length of CNTs is approximately 200-300 nm in the 1.0wt.%CNTs/AlSi10Mg composites and approximately 500-1,000 nm in the 2.0wt.%CNTs/AlSi10Mg composites.The hardness of the composites reaches its highest value of 143.3 HV when the CNTs content is 1.0wt.%and the laser scan speed is 1,300 mm·s^(-1).It is found that the self-lubricating properties of the CNTs improve the tribological properties of the composites.The coefficient of friction(CoF)and wear rate of the samples decrease with increasing CNT content.At a CNTs content of 2.0wt.%,the CoF and wear rate of the composite decrease by approximately 14%and 30%,respectively,compared to the unreinforced matrix.The presence of CNTs leads to a more complete and refined network microstructure within the samples.Both the CNTs and the aluminum carbide contribute to the Orowan mechanism and the Hall-Petch effect within the matrix.展开更多
The development of highly active,low-cost,and durable electrocatalysts is crucial for the efficient glycerol oxidation reaction(GOR).Herein,a Cu-doped,self-supported NiCo_(2)O_(4)nanosheet array catalyst grown on nick...The development of highly active,low-cost,and durable electrocatalysts is crucial for the efficient glycerol oxidation reaction(GOR).Herein,a Cu-doped,self-supported NiCo_(2)O_(4)nanosheet array catalyst grown on nickel foam(Cu-NiCo_(2)O_(4)/NF)was fabricated through a simple electrodeposition method followed by thermal annealing.The resulting nanosheet arrays are uniformly anchored on the conductive NF substrate,forming a three-dimensional nanoflower-like architecture that offers abundant accessible active sites and enhanced electronic conductivity.Moreover,Cu doping effectively tailors the electronic structure of NiCo_(2)O_(4),optimizing the adsorption and transformation of key glycerol oxidation intermediates.This synergistic effect significantly lowers charge transfer resistance and promotes rapid electron transport.Benefiting from these structural and electronic advantages,the Cu-NiCo_(2)O_(4)/NF catalyst achieves a current density of 10 mA·cm^(-2)at a low overpotential of 1.22 V vs.reversible hydrogen electrode(RHE).It delivers a remarkable glycerol conversion rate of 90.4%with a formate Faradaic efficiency of 94.3%at 1.35 V vs.RHE.Furthermore,the catalyst exhibits excellent long-term electrochemical durability with sustained catalytic performance during extended operation.This work offers a promising strategy to boost the electrocatalytic activity of NiCo_(2)O_(4)through Cu doping,providing new insights into the design of efficient GOR electrocatalysts and contributing to the high-value utilization of biomass-derived molecules and the advancement of green electrochemic al energ y technologies.展开更多
The effects of gradient nanostructures induced by supersonic fine particle bombardment(SFPB)on the surface integrity,microstructural evolution,and mechanical properties of a Ni-W-Co-Ta medium-heavy alloy(MHA)were syst...The effects of gradient nanostructures induced by supersonic fine particle bombardment(SFPB)on the surface integrity,microstructural evolution,and mechanical properties of a Ni-W-Co-Ta medium-heavy alloy(MHA)were systematically investigated.The results show that gradient nanostructures are formed on the surface of Ni-W-Co-Ta MHA after SFPB treatment.At a gas pressure of 1.0 MPa and an impact time of 60 s,the ultimate tensile strength and yield strength of the alloy reached the maximum values of 1236 MPa and 758 MPa,respectively,which are 22.5%and 38.8%higher than those of the solid solution treated alloy,and the elongation(46.3%)is close to that of the solid solution treated alloy,achieving the optimal strength–ductility synergy.However,microcracks appear on the surface with excessive gas pressure and impact time,generating the relaxed residual stress and decreased strength.With the increase of the impact time and gas pressure,the depth of the deformation layer and the surface microhardness gradually increase,reaching the maximum values(29μm and HV 451)at 1.0 MPa and 120 s.The surface grain size is refined to a minimum of 11.67 nm.Notably,SFPB treatment has no obvious effect on elongation,and the fracture mode changes from the ductile fracture before treatment to ductile–brittle mixed fracture after treatment.展开更多
基金National Key Research and Development Program of China(2023YFB4606400)Supported by Longmen Laboratory Frontier Exploration Topics(LMQYTSKT003)。
文摘Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.
文摘电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。
基金supported by the National Natural Science Foundation of China(No.22278291)the Natural Science Foundation of Shanxi Province(Nos.202203021211145 and 202303021221257)+1 种基金the National Key Research and Development(R&D)Program of China(No.2020YFB1505803)the Key Research and Development(R&D)Projects of Shanxi Province(No.202102070301018)。
文摘The oxygen reduction reaction(ORR)is a crucial process in Zn-air systems,and the catalyst plays a significant role in this reaction.However,reported catalysts often suffer from poor durability and stability during the ORR process.Herein,we synthesized La-Fe bimetallic nanoparticles encapsulated in a N-doped porous carbon dodecahedron(La-Fe/NC)originated from ZIF-8 by a simple direct carbonization.The La-Fe/NC catalyst had a numerous mesopores and dendritic outer layer generated by carbon nanotubes(CNTs),forming a high conductivity network that helped to optimize electron transfer and mass transport in the ORR process.The effect of different doping transition metals and metal ratios on the ORR activity of Zn-air batteries was investigated.In alkaline media,the La-Fe/NC showed the highest ORR catalytic activity,with a half-wave potential(E_(1/2))of 0.879 V(vs.RHE,Pt/C 0.845 V).After 5000 cycles,the E_(1/2)of the La-Fe/NC catalyst only decreased by 7 m V,and its performance in stability tests and methanol tolerance tests was superior to Pt/C.When used as the air electrode in a Zn-air battery,the La-Fe/NC catalyst demonstrated an excellent specific capacity of 755 m Ah/g and a peak power density of179.8 m W/cm~2.The results provide important insights for the development of high-performance Zn-air batteries and new directions for the design of ORR catalysts.
基金financial support of the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grants No.163105819)Nanjing Forestry University High-level Talent Introduction Research Foundation(Grants No.163105774)。
文摘Capacitive deionization(CDI),as an emerging desalination technique,has been intensively explored because of its energy-saving,cost-effectiveness and sustainability.Despite the promise,CDI systems still encounter various challenges involving active sites,mass transfer and stability that severely limit their further application.So far,there is still much-limited review across material,electrodes and devices to cope with the above challenges.Notably,carbon nanotubes(CNTs),have garnered significant attention owing to their exceptional conductivity,high specific surface area(S_(BET)),unique skeleton role and superior mechanical strength.More importantly,CNTs serve multifunctional roles in CDI systems,including active materials,conductive agents,binders,and even current collectors,while also making for the thick electrode framework construction.Specifically,this review first discusses current challenges in CDI system design.Subsequently,it systemic highlights how CNTs address these issues through material innovation,electrode optimization and device integration.Eventually,a conceptual model for CNT composite self-supporting CDI systems is further proposed,aiming to exploit advanced CDI desalination systems.Overall,this review underscores the pivotal role of CNTs in overcoming technical bottlenecks and driving the practical application of CDI for sustainable water treatment.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.2018R1A6A1A03025708).
文摘High-performance aqueous zinc(Zn)-ion batteries(AZIBs)have emerged as one of the greatest favorable candidates for next-generation energy storage systems because of their low cost,sustainability,high safety,and eco-friendliness.In this report,we prepared magnesium vanadate(MgVO)-based nanostructures by a facile single-step solvothermal method with varying experimental reaction times(1,3,and 6 h)and investigated the effect of the reaction time on the morphology and layered structure for MgVO-based compounds.The newly prepared MgVO-1 h,MgVO-3 h and MgVO-6 h samples were used as cathode materials for AZIBs.Compared to the MgVO-1 h and MgVO-6 h cathodes,the MgVO-3 h cathode showed a higher specific capacity of 492.74 mA h g^(-1) at 1 A g^(-1) over 500 cycles and excellent rate behavior(291.58 mA h g^(-1) at 3.75 A g^(-1))with high cycling stability(116%)over 2000 cycles at 5 A g^(-1).Moreover,the MgVO-3 h electrode exhibited good electrochemical performance owing to its fast Zn-ion diffusion kinetics.Additionally,various ex-situ analyses confirmed that the MgVO-3 h cathode displayed excellent insertion/extraction of Zn^(2+)ions during charge and discharge processes.This study offers an efficient method for the synthesis of nanostructured MgVO-based cathode materials for high-performance AZIBs.
基金supported by the National Key Research Program of China under Grant No.2024YFA1408000the National Natural Science Foundation of China(52231007,12327804,T2321003,22088101)+1 种基金in part by the National Key Research Program of China under Grant 2021YFA1200600the support from the U.S.National Science Foundation(CHE 2102482)。
文摘The ability to control the electrode interfaces in an electrochemical energy storage system is essential for achieving the desired electrochemical performance.However,achieving this ability requires an in-depth understanding of the detailed interfacial nanostructures of the electrode under electrochemical operating conditions.In-situ transmission electron microscopy(TEM)is one of the most powerful techniques for revealing electrochemical energy storage mechanisms with high spatiotemporal resolution and high sensitivity in complex electrochemical environments.These attributes play a unique role in understanding how ion transport inside electrode nanomaterials and across interfaces under the dynamic conditions within working batteries.This review aims to gain an in-depth insight into the latest developments of in-situ TEM imaging techniques for probing the interfacial nanostructures of electrochemical energy storage systems,including atomic-scale structural imaging,strain field imaging,electron holography,and integrated differential phase contrast imaging.Significant examples will be described to highlight the fundamental understanding of atomic-scale and nanoscale mechanisms from employing state-of-the-art imaging techniques to visualize structural evolution,ionic valence state changes,and strain mapping,ion transport dynamics.The review concludes by providing a perspective discussion of future directions of the development and application of in-situ TEM techniques in the field of electrochemical energy storage systems.
基金financially supported by the National Key Research and Development Plan(No.2021YFA1600600)the National Natural Science Foundation of China(Nos.52271093 and 52074257)+3 种基金the Rare Earth Advanced Materials Technology Innovation Center(No.CXZX-B-2023110011)the Space Application System of China Manned Space Program(No.YYMT1201-EXP08)the special fund for Science and Technology Innovation Teams of Shanxi Province(No.202304051001036)the Fundamental Research Funds for the Central Universities(No.N2325008)
文摘Metallic glass composites hold significant potential as structural materials.However,few methods are available to enhance their mechanical properties postcasting.In this study,simple pre-tensile training was applied to a TRIP-reinforced metallic glass composite,resulting in a more than one-third increase in plasticity,while the reliability of plasticity was also enhanced.The deformation mechanism was further elucidated,revealing that pre-tension induced the formation of multilayered nanostructures at the dendrite-glass interface.This microstructural evolution facilitates the formation of finer martensite laths within the dendrites and multiple shear bands in the glass matrix during compression,thereby enabling more uniform plastic deformation.These findings suggest that simple preloading treatments may offer a viable approach to regulating the microstructure of as-cast metallic glass composites and optimizing their mechanical properties.
基金supported by the National Natural Science Foundation of China(Nos.52200186 and 52070025)Chongqing Natural Science Foundation(No.CSTB2024NSCQ-MSX0407)+1 种基金the National Key Research and Development Program of China(No.2019YFC1805502)Chongqing Municipal Human Resources and Social Security Bureau(No.2309013519935095).
文摘The organic pollutants,such as quaternary ammonium compounds,in high salinity flowback water from shale gas extraction may pose a severe risk to public health.Conventional biological technologies have limited effectiveness in the treatment of high-salt wastewaters,whereas electrocatalytic oxidation has shown potential for treating organic pollutants in high-salt flowback water.This study developed a carbon nanotubes(CNTs)doped Ru/Ir oxide coated Ti electrode CNTs-(Ru_(x)Ir_(y)O_(2))/Ti,which exhibited enhanced electrocatalytic performance for the treatment of quaternary ammonium compound in high-salt wastewater compared to the control metal oxide coated Ti anode(Ru_(x)Ir_(y)O_(2))/Ti,with pseudofirst-order reaction rate constant improved from 7.36×10^(-3) to 1.12×10^(-2) min−1.Moreover,the CNTs-(Ru_(x)Ir_(y)O_(2))/Ti anode electrocatalytic oxidation system exhibited excellent cycling stability.Mechanism studies indicated that the CNTs-(Ru_(x)Ir_(y)O_(2))/Ti electrode enhanced singlet oxygen(^(1)O_(2))generation,which played a major role in pollutant degradation.Furthermore,the formation of high concentrations of HClO and H_(2)O_(2) further facilitated the generation of ^(1)O_(2).This study may provide an efficient and green technology for the treatment of organic pollutants in high-salt shale gas flowback water.
基金supported by the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Grant No.23KJD460003)the Scientific Research Foundation for High-level Talents of Nanjing Institute of Technology(Grant No.YKJ202103)the National Natural Science Foundation of China(Grant Nos.92463301,92163215,52205471,52305470).
文摘In this study,carbon nanotubes(CNTs)/AlSi10Mg composite parts with CNTs contents ranging from 0.0 to 2.0wt.%were successfully fabricated via laser powder bed fusion(LPBF)with laser scan speeds ranging from 900 to 1,900 mm·s^(-1).Uniform dispersion of CNTs in the powders can be achieved when their content is below 2.0wt.%.In the LPBF samples,the morphology of the CNTs is found to be directly related to their content.Especially,the length of CNTs in samples prepared by LPBF increases as the CNT content increases.The length of CNTs is approximately 200-300 nm in the 1.0wt.%CNTs/AlSi10Mg composites and approximately 500-1,000 nm in the 2.0wt.%CNTs/AlSi10Mg composites.The hardness of the composites reaches its highest value of 143.3 HV when the CNTs content is 1.0wt.%and the laser scan speed is 1,300 mm·s^(-1).It is found that the self-lubricating properties of the CNTs improve the tribological properties of the composites.The coefficient of friction(CoF)and wear rate of the samples decrease with increasing CNT content.At a CNTs content of 2.0wt.%,the CoF and wear rate of the composite decrease by approximately 14%and 30%,respectively,compared to the unreinforced matrix.The presence of CNTs leads to a more complete and refined network microstructure within the samples.Both the CNTs and the aluminum carbide contribute to the Orowan mechanism and the Hall-Petch effect within the matrix.
基金supported by the National Natural Science Foundation of China(No.22302051)Hainan Provincial Natural Science Foundation of China(No.223QN186)+1 种基金Scientific Research Starting Foundation of Hainan University(No.KYQD(ZR)-22018)the specific research fund of the Innovation Platform for Academicians of Hainan Province(No.YSPTZX202123)。
文摘The development of highly active,low-cost,and durable electrocatalysts is crucial for the efficient glycerol oxidation reaction(GOR).Herein,a Cu-doped,self-supported NiCo_(2)O_(4)nanosheet array catalyst grown on nickel foam(Cu-NiCo_(2)O_(4)/NF)was fabricated through a simple electrodeposition method followed by thermal annealing.The resulting nanosheet arrays are uniformly anchored on the conductive NF substrate,forming a three-dimensional nanoflower-like architecture that offers abundant accessible active sites and enhanced electronic conductivity.Moreover,Cu doping effectively tailors the electronic structure of NiCo_(2)O_(4),optimizing the adsorption and transformation of key glycerol oxidation intermediates.This synergistic effect significantly lowers charge transfer resistance and promotes rapid electron transport.Benefiting from these structural and electronic advantages,the Cu-NiCo_(2)O_(4)/NF catalyst achieves a current density of 10 mA·cm^(-2)at a low overpotential of 1.22 V vs.reversible hydrogen electrode(RHE).It delivers a remarkable glycerol conversion rate of 90.4%with a formate Faradaic efficiency of 94.3%at 1.35 V vs.RHE.Furthermore,the catalyst exhibits excellent long-term electrochemical durability with sustained catalytic performance during extended operation.This work offers a promising strategy to boost the electrocatalytic activity of NiCo_(2)O_(4)through Cu doping,providing new insights into the design of efficient GOR electrocatalysts and contributing to the high-value utilization of biomass-derived molecules and the advancement of green electrochemic al energ y technologies.
基金supported by the National key Research and Development Program of China(No.2022YFB3705200)the National Natural Science Foundation of China(Nos.U1804146,51905153,52111530068)+1 种基金the Science and Technology Innovation Team Project of Henan University of Science and Technology,China(No.2015XTD006)the Major Science and Technology Project of Henan Province,China(No.221100230200)。
文摘The effects of gradient nanostructures induced by supersonic fine particle bombardment(SFPB)on the surface integrity,microstructural evolution,and mechanical properties of a Ni-W-Co-Ta medium-heavy alloy(MHA)were systematically investigated.The results show that gradient nanostructures are formed on the surface of Ni-W-Co-Ta MHA after SFPB treatment.At a gas pressure of 1.0 MPa and an impact time of 60 s,the ultimate tensile strength and yield strength of the alloy reached the maximum values of 1236 MPa and 758 MPa,respectively,which are 22.5%and 38.8%higher than those of the solid solution treated alloy,and the elongation(46.3%)is close to that of the solid solution treated alloy,achieving the optimal strength–ductility synergy.However,microcracks appear on the surface with excessive gas pressure and impact time,generating the relaxed residual stress and decreased strength.With the increase of the impact time and gas pressure,the depth of the deformation layer and the surface microhardness gradually increase,reaching the maximum values(29μm and HV 451)at 1.0 MPa and 120 s.The surface grain size is refined to a minimum of 11.67 nm.Notably,SFPB treatment has no obvious effect on elongation,and the fracture mode changes from the ductile fracture before treatment to ductile–brittle mixed fracture after treatment.
