The promoter is very important for effective catalysts,and the relationship among active species,promoter,and support is a hot topic in the field of catalysis.This work aims to investigate the influence of the promote...The promoter is very important for effective catalysts,and the relationship among active species,promoter,and support is a hot topic in the field of catalysis.This work aims to investigate the influence of the promoter on the formation of effective active species.For this purpose,V was leached out from V-loaded TiO2(V/Ti)step by step,and the loaded V was classified into different species based on their performances in the catalytic oxidation of chlorobenzene.As a result,when V/Ti was co-doped with Mo or W,the chlorobenzene conversion rate was increased from 48.1%to 54.0%(Mo)or 61.0%(W)at210℃.The enhancement was attributed to the redistribution of V species.Specifically,7.8%of V was"Inactive"V on V/Ti.This"Inactive"V was transformed into an"Active"species.At the same time,"Highly-active V"amounts were increased from 86.0%(V_(3.3)/Ti)to 88.1%(WV_(3.3)/Ti)and 87.1%(MoV_(3.3)/Ti).According to the mechanism investigation,when W and Mo coexisted with V during the synthesis,V3+was oxidized into V^(5+),which is easily invaded into the TiO_(2),created more strong acidic sites,and activated more active lattice oxygens.These are all in favor of the effective catalytic oxidation of chlorobenzene.The new understanding of the promoter effect will help to produce a more effective catalyst using the same amount of active species.展开更多
Tungsten(W)is considered a critical and strategic material,the recycling of which has proved extremely important due to the substantial amount of W-rich waste and rising demand for W products.This study provides a sou...Tungsten(W)is considered a critical and strategic material,the recycling of which has proved extremely important due to the substantial amount of W-rich waste and rising demand for W products.This study provides a sound technological approach for efficient utilization of bulk W,achieving a high W destruction rate(rw)of 0.3 g·cm^(-2)·h^(-1)via electrochemical oxidation/in situ reduction of W electrodes in oxalic acid under alternating current(AC)with varying symmetries to synthesize WO_(3-x)nanopowders(NPs).Amorphous-crystalline dual-phase reduced WO_(3-x)NPs featuring dense and porous nanoarchitectures were synthesized using asymmetrical and symmetrical AC,respectively.The nano scale interconnecting flaky WO_(3-x)structure arises from the synergy of high anodic voltage etching and the release of H_(2)microbubbles,boosting the exfoliation of WO_(3)flakes.The optimized WO_(3-x)NP exhibits superior electrochemical and electrochromic properties,attributed to the increased surface capacitance alongside an extra contribution from intercalation pseudocapacitance.The number of WO_(3-x)layers deposited by the spin coating technique and the annealing temperature have a significant impact on the electrochemical and electrochromic characteristics of the WO_(3)film.An increase in the transferred charge density(Q),coloring/bleaching time(t_(c)/t_(b))values,and areal capacitance was observed,alongside a decrease in optical modulation(ΔT)and coloration efficiency(CE)with an increasing number of WO_(3)layers.WO_(3)produced at a lower temperature outperforms WO_(3)treated at 400-500℃,particularly in fast switching,enhanced efficiency,and reversibility.TheΔT of 68.7%,CE of 47.9 cm^(2)·C^(-1),areal capacitance of 53.5 mF·cm^(-2),and reversibility close to 100%were achieved in H_(2)SO_(4)for the optimized WO_(3-x)film.The research aligns with the ongoing development strategy of the circular economy and validates the promising features of the efficient recycling of W-containing spent resources through an environmentally sustainable electrochemical approach.展开更多
Lithium-sulfur batteries(LSBs)have emerged as one of the most promising next-generation energy storage systems due to their high theoretical energy density(~2600 Wh·kg^(-1))and cost-effectiveness.However,critical...Lithium-sulfur batteries(LSBs)have emerged as one of the most promising next-generation energy storage systems due to their high theoretical energy density(~2600 Wh·kg^(-1))and cost-effectiveness.However,critical challenges,including polysulfide shuttling,lithium dendrite formation,and interfacial instability,persistently hinder their practical implementation.Conventional material design approaches face intrinsic limitations in reconciling structural stability with catalytic efficacy,underscoring the need for innovative solutions.High-entropy materials(HEMs),a novel class of multi-component systems typically comprising five or more principal elements,have recently demonstrated exceptional potential in addressing these challenges through their unique entropy stabilization effect,lattice distortion engineering,and multi-active site synergy.Since the advent of high-entropy alloys(HEAs),this design concept has been successfully extended to oxides,sulfides,nitrides,and electrolyte systems,where it exhibits unparalleled advantages in LSB applications.This review systematically evaluates recent advancements in the engineering of HEMs for sulfur cathodes,lithium metal anodes,and liquid electrolytes,with a focus on elucidating the mechanistic underpinnings of their enhanced ion transport,catalytic conversion,and interfacial stabilization capabilities.By establishing structure-property relationships and delineating performance optimization pathways,this work constructs a robust framework to accelerate the development of HEMs in energy storage systems while highlighting critical challenges and strategic directions for scalable deployment.展开更多
The methanol oxidation reaction is a critical half-reaction in direct methanol fuel cells(DMFCs),but its efficiency is limited by the low activity and poor stability of traditional electrocatalysts.This study reports ...The methanol oxidation reaction is a critical half-reaction in direct methanol fuel cells(DMFCs),but its efficiency is limited by the low activity and poor stability of traditional electrocatalysts.This study reports the development of a high-performance PtCo/Mo_(2)CT_(x)catalyst for methanol oxidation in DMFCs.Synthesized by depositing PtCo alloy nanoparticles on Mo_(2)CT_(x)sheets prepared via cetyltrimethylammonium bromide-assisted etching of Mo2Ga2C,the PtCo/Mo_(2)CT_(x)catalyst achieved enhanced interlayer spacing and excellent dispersion of active sites.The optimized PtCo/Mo_(2)CT_(x)catalyst exhibited remarkable catalytic activity,reaching a mass activity of 2296 mA·mg_(Pt)^(-1)—6.5 times that of commercial Pt/C.Electrochemical studies confirmed the catalyst's low charge transfer resistance,high electrochemical surface area,and strong CO antipoisoning ability.Stability tests showed that the catalyst retained 62.26%activity after 1000 cycles.These improvements are attributed to the synergistic effects between Pt and Co,the conductive and layered structure of Mo_(2)CT_(x),making PtCo/Mo_(2)CT_(x)a promising,durable anode material for DMFCs in sustainable energy applications.展开更多
Rapid adsorption of radioactive substances is of great significance in emergency situations.A novel approach combining S-defect introduction and in situ phosphorization was employed to synthesize phosphorized WS_(2)(W...Rapid adsorption of radioactive substances is of great significance in emergency situations.A novel approach combining S-defect introduction and in situ phosphorization was employed to synthesize phosphorized WS_(2)(WS_(2)-PO_(4))for ultra-efficient uranium extraction.At an initial U(VI)concentration of 50 mg·L^(-1),the adsorption of U(VI)by WS_(2)-PO_(4) nanosheets exceeds77%within just 1 min,with high selectivity(SU=78.7%)and good adsorption capacity of 268.82 mg·g^(-1).The phosphate groups have grown on the S defects and taken part in U(VI)extraction through surface complexation,leading to fast,reusable,and highly selective uranium adsorption,showing great potential in emergency treatment of radioactive nuclear wastewater.展开更多
Martensitic transformation offers a pathway to overcome the room-temperature brittleness of refractory high-entropy alloys(RHEAs).The resulting extensive formation of the hexagonal close-packed(hcp)α-martensite neces...Martensitic transformation offers a pathway to overcome the room-temperature brittleness of refractory high-entropy alloys(RHEAs).The resulting extensive formation of the hexagonal close-packed(hcp)α-martensite necessitates deformation coordination via twinning to sustain plasticity during mechanical loading.However,the synergistic formation of multiple twin types and their effect on work hardening remain unclear.Employing advanced characterization techniques,this study identifies three primary martensitic twin systems({1011},{1012},and{1341}),two secondary twin configurations({1011}-{1341}and{1341}-{1011}),and three{1341}twin variants in metastable Ti_(27)Zr_(40)Hf_(23)Ta_(10)RHEAs.The presence of multiple martensitic twins generates dense twin interfaces that refine the grain structure while effectively hindering dislocation motion,thereby enhancing strain hardening capacity.The coexistence of multiple martensitic twins increases the number of independent slip systems within grains and induces variations in slip systems across different regions of the grains.This heterogeneity in slip systems accommodates multi-directional plastic deformation,consequently improving the material's sustained hardening capability.These findings underscore the critical role of synergistic twinning mechanisms in governing the work hardening of metastable martensitic RHEAs.展开更多
基金supported by the Natural Science Foundation of Shanghai 2021 Science and Technology Innovation Action Plan(No.21ZR1424000)。
文摘The promoter is very important for effective catalysts,and the relationship among active species,promoter,and support is a hot topic in the field of catalysis.This work aims to investigate the influence of the promoter on the formation of effective active species.For this purpose,V was leached out from V-loaded TiO2(V/Ti)step by step,and the loaded V was classified into different species based on their performances in the catalytic oxidation of chlorobenzene.As a result,when V/Ti was co-doped with Mo or W,the chlorobenzene conversion rate was increased from 48.1%to 54.0%(Mo)or 61.0%(W)at210℃.The enhancement was attributed to the redistribution of V species.Specifically,7.8%of V was"Inactive"V on V/Ti.This"Inactive"V was transformed into an"Active"species.At the same time,"Highly-active V"amounts were increased from 86.0%(V_(3.3)/Ti)to 88.1%(WV_(3.3)/Ti)and 87.1%(MoV_(3.3)/Ti).According to the mechanism investigation,when W and Mo coexisted with V during the synthesis,V3+was oxidized into V^(5+),which is easily invaded into the TiO_(2),created more strong acidic sites,and activated more active lattice oxygens.These are all in favor of the effective catalytic oxidation of chlorobenzene.The new understanding of the promoter effect will help to produce a more effective catalyst using the same amount of active species.
基金supported by the Russian Science Foundation(No.23-79-10219),https://rscf.ru/en/project/23-79-10219/)。
文摘Tungsten(W)is considered a critical and strategic material,the recycling of which has proved extremely important due to the substantial amount of W-rich waste and rising demand for W products.This study provides a sound technological approach for efficient utilization of bulk W,achieving a high W destruction rate(rw)of 0.3 g·cm^(-2)·h^(-1)via electrochemical oxidation/in situ reduction of W electrodes in oxalic acid under alternating current(AC)with varying symmetries to synthesize WO_(3-x)nanopowders(NPs).Amorphous-crystalline dual-phase reduced WO_(3-x)NPs featuring dense and porous nanoarchitectures were synthesized using asymmetrical and symmetrical AC,respectively.The nano scale interconnecting flaky WO_(3-x)structure arises from the synergy of high anodic voltage etching and the release of H_(2)microbubbles,boosting the exfoliation of WO_(3)flakes.The optimized WO_(3-x)NP exhibits superior electrochemical and electrochromic properties,attributed to the increased surface capacitance alongside an extra contribution from intercalation pseudocapacitance.The number of WO_(3-x)layers deposited by the spin coating technique and the annealing temperature have a significant impact on the electrochemical and electrochromic characteristics of the WO_(3)film.An increase in the transferred charge density(Q),coloring/bleaching time(t_(c)/t_(b))values,and areal capacitance was observed,alongside a decrease in optical modulation(ΔT)and coloration efficiency(CE)with an increasing number of WO_(3)layers.WO_(3)produced at a lower temperature outperforms WO_(3)treated at 400-500℃,particularly in fast switching,enhanced efficiency,and reversibility.TheΔT of 68.7%,CE of 47.9 cm^(2)·C^(-1),areal capacitance of 53.5 mF·cm^(-2),and reversibility close to 100%were achieved in H_(2)SO_(4)for the optimized WO_(3-x)film.The research aligns with the ongoing development strategy of the circular economy and validates the promising features of the efficient recycling of W-containing spent resources through an environmentally sustainable electrochemical approach.
基金supported by the National Natural Science Foundation of China(No.52402305)the High-level Innovation and Entrepreneurship Talent Project of Qinchuangyuan(No.QCYRCXM-2023-084)+1 种基金the Postdoctoral Fellowship Program of CPSF(Nos.GZB20230570 and 2024M752552)the Natural Science Basic Research Program of Shaanxi(No.2024JC-YBQN-0494)。
文摘Lithium-sulfur batteries(LSBs)have emerged as one of the most promising next-generation energy storage systems due to their high theoretical energy density(~2600 Wh·kg^(-1))and cost-effectiveness.However,critical challenges,including polysulfide shuttling,lithium dendrite formation,and interfacial instability,persistently hinder their practical implementation.Conventional material design approaches face intrinsic limitations in reconciling structural stability with catalytic efficacy,underscoring the need for innovative solutions.High-entropy materials(HEMs),a novel class of multi-component systems typically comprising five or more principal elements,have recently demonstrated exceptional potential in addressing these challenges through their unique entropy stabilization effect,lattice distortion engineering,and multi-active site synergy.Since the advent of high-entropy alloys(HEAs),this design concept has been successfully extended to oxides,sulfides,nitrides,and electrolyte systems,where it exhibits unparalleled advantages in LSB applications.This review systematically evaluates recent advancements in the engineering of HEMs for sulfur cathodes,lithium metal anodes,and liquid electrolytes,with a focus on elucidating the mechanistic underpinnings of their enhanced ion transport,catalytic conversion,and interfacial stabilization capabilities.By establishing structure-property relationships and delineating performance optimization pathways,this work constructs a robust framework to accelerate the development of HEMs in energy storage systems while highlighting critical challenges and strategic directions for scalable deployment.
基金supported by the National Natural Science Foundation of China(Nos.52372284,52275187)the Natural Science Foundation of Henan Province(Nos.242300420326,NSFRF240701,232300421135)+1 种基金Fundamental Research Funds for the Universities of Henan Province(No.NSFRF230433)National College Students'Innovation and Entrepreneurship Training Program(No.202310460063)。
文摘The methanol oxidation reaction is a critical half-reaction in direct methanol fuel cells(DMFCs),but its efficiency is limited by the low activity and poor stability of traditional electrocatalysts.This study reports the development of a high-performance PtCo/Mo_(2)CT_(x)catalyst for methanol oxidation in DMFCs.Synthesized by depositing PtCo alloy nanoparticles on Mo_(2)CT_(x)sheets prepared via cetyltrimethylammonium bromide-assisted etching of Mo2Ga2C,the PtCo/Mo_(2)CT_(x)catalyst achieved enhanced interlayer spacing and excellent dispersion of active sites.The optimized PtCo/Mo_(2)CT_(x)catalyst exhibited remarkable catalytic activity,reaching a mass activity of 2296 mA·mg_(Pt)^(-1)—6.5 times that of commercial Pt/C.Electrochemical studies confirmed the catalyst's low charge transfer resistance,high electrochemical surface area,and strong CO antipoisoning ability.Stability tests showed that the catalyst retained 62.26%activity after 1000 cycles.These improvements are attributed to the synergistic effects between Pt and Co,the conductive and layered structure of Mo_(2)CT_(x),making PtCo/Mo_(2)CT_(x)a promising,durable anode material for DMFCs in sustainable energy applications.
基金supported by the National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing(No.2024QZ-KF-05)the National Natural Science Foundation of China(Nos.U24A20194,22366006)+2 种基金Key R&D Program of Jiangxi Province(No.20243BBG71020)Natural Science Foundation of Jiangxi province(Nos.20224BAB213027,20242BAB20109)the Academic and Technical Leaders Training Program of Jiangxi Province(Nos.20212BCJL23046,20212BCJL23047)。
文摘Rapid adsorption of radioactive substances is of great significance in emergency situations.A novel approach combining S-defect introduction and in situ phosphorization was employed to synthesize phosphorized WS_(2)(WS_(2)-PO_(4))for ultra-efficient uranium extraction.At an initial U(VI)concentration of 50 mg·L^(-1),the adsorption of U(VI)by WS_(2)-PO_(4) nanosheets exceeds77%within just 1 min,with high selectivity(SU=78.7%)and good adsorption capacity of 268.82 mg·g^(-1).The phosphate groups have grown on the S defects and taken part in U(VI)extraction through surface complexation,leading to fast,reusable,and highly selective uranium adsorption,showing great potential in emergency treatment of radioactive nuclear wastewater.
基金supported by the National Natural Science Foundation of China(No.52471153)Natural Science Foundation of Hunan Province(No.2024JJ10011)+1 种基金the Science and Technology Innovation Program of Hunan Province(No.2025RC9002)the State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China。
文摘Martensitic transformation offers a pathway to overcome the room-temperature brittleness of refractory high-entropy alloys(RHEAs).The resulting extensive formation of the hexagonal close-packed(hcp)α-martensite necessitates deformation coordination via twinning to sustain plasticity during mechanical loading.However,the synergistic formation of multiple twin types and their effect on work hardening remain unclear.Employing advanced characterization techniques,this study identifies three primary martensitic twin systems({1011},{1012},and{1341}),two secondary twin configurations({1011}-{1341}and{1341}-{1011}),and three{1341}twin variants in metastable Ti_(27)Zr_(40)Hf_(23)Ta_(10)RHEAs.The presence of multiple martensitic twins generates dense twin interfaces that refine the grain structure while effectively hindering dislocation motion,thereby enhancing strain hardening capacity.The coexistence of multiple martensitic twins increases the number of independent slip systems within grains and induces variations in slip systems across different regions of the grains.This heterogeneity in slip systems accommodates multi-directional plastic deformation,consequently improving the material's sustained hardening capability.These findings underscore the critical role of synergistic twinning mechanisms in governing the work hardening of metastable martensitic RHEAs.
