Vanadium oxide cathode materials with stable crystal structure and fast Zn^(2+) storage capabilities are extremely important to achieving outstanding electrochemical performance in aqueous zinc‐ion batteries.In this ...Vanadium oxide cathode materials with stable crystal structure and fast Zn^(2+) storage capabilities are extremely important to achieving outstanding electrochemical performance in aqueous zinc‐ion batteries.In this work,a one‐step hydrothermal method was used to manipulate the bimetallic ion intercalation into the interlayer of vanadium oxide.The pre‐intercalated Cu ions act as pillars to pin the vanadium oxide(V‐O)layers,establishing stabilized two‐dimensional channels for fast Zn^(2+) diffusion.The occupation of Mn ions between V‐O interlayer further expands the layer spacing and increases the concentration of oxygen defects(Od),which boosts the Zn^(2+) diffusion kinetics.As a result,as‐prepared Cu_(0.17)Mn_(0.03)V_(2)O_(5−□)·2.16H_(2)O cathode shows outstanding Zn‐storage capabilities under room‐and lowtemperature environments(e.g.,440.3 mAh g^(−1) at room temperature and 294.3 mAh g^(−1)at−60°C).Importantly,it shows a long cycling life and high capacity retention of 93.4%over 2500 cycles at 2 A g^(−1) at−60°C.Furthermore,the reversible intercalation chemistry mechanisms during discharging/charging processes were revealed via operando X‐ray powder diffraction and ex situ Raman characterizations.The strategy of a couple of 3d transition metal doping provides a solution for the development of superior room‐/lowtemperature vanadium‐based cathode materials.展开更多
The improper disposal of spent selective catalytic reduction (SCR) catalysts causes environmental pollution and metal resource waste.A novel process to recover anatase titanium dioxide (TiO_(2)) from spent SCR catalys...The improper disposal of spent selective catalytic reduction (SCR) catalysts causes environmental pollution and metal resource waste.A novel process to recover anatase titanium dioxide (TiO_(2)) from spent SCR catalysts was proposed.The process included alkali (NaOH) hydrothermal treatment,sulfuric acid washing,and calcination.Anatase TiO_(2) in spent SCR catalyst was reconstructed by forming Na_(2)Ti_(2)O_(4)(OH)_(2) nanosheet during NaOH hydrothermal treatment and H_(2)Ti_(2)O_(4)(OH)_(2) during sulfuric acid washing.Anatase TiO_(2) was recovered by decomposing H_(2)Ti_(2)O_(4)(OH)_(2) during calcination.The surface pore properties of the recovered anatase TiO_(2) were adequately improved,and its specific surface area (SSA) and pore volume (PV) were 85 m^(2)·g^(-1)and 0.40 cm^(3)·g^(-1),respectively.The elements affecting catalytic abilities(arsenic and sodium) were also removed.The SCR catalyst was resynthesized using the recovered TiO_(2) as raw material,and its catalytic performance in NO selective reduction was comparable with that of commercial SCR catalyst.This study realized the sustainable recycling of anatase TiO_(2) from spent SCR catalyst.展开更多
How to effectively improve Zn^(2+)-storage properties is now becoming an urgent issue in the development of high-energy-density aqueous zinc-ion batteries.Here,a new method is proposed to massively increase the electr...How to effectively improve Zn^(2+)-storage properties is now becoming an urgent issue in the development of high-energy-density aqueous zinc-ion batteries.Here,a new method is proposed to massively increase the electrochemical capacity of aqueous Zn/V_(5)O_(12)·6H_(2)Obatteries.By adding a small amount of platinum(Pt,1.5 wt.%)and keeping other factors constant,the V_(5)O_(12)·6H_(2)O-Pt electrodes deliver a much higher specific capacity(440 m Ah g^(-1)at 500 m A g^(-1))than do V_(5)O_(12)·6H_(2)Oelectrodes(270 m Ah g^(-1)at500 m A g^(-1)).The structural and morphological evolution of V_(5)O_(12)·6H_(2)Oduring cycling results in Zn^(2+)ion insertion/extraction and the formation/disappearance of the zinc hydroxyl complex(Zn_(4)SO_(4)(OH)_(6)·5H_(2)O,ZHS),where the latter is closely related to the surface redox reaction,promoting Zn^(2+)ion stripping/plating on the Zn anode and consequently leading to extra electron transfer.Electrochemical tests in the absence of oxygen reveal that the Pt additive has no contribution and is even counterproductive to electric conductivity but favors remarkable enhancement of the pseudocapacitance.Accordingly,it is apparent that a strong causal relationship exists between Pt and the ZHS.In consideration of the catalytic application for oxygen reduction,Pt is expected to play a vital role in enhancing the electrochemical capacity through the pseudo-Zn-air reaction.This finding introduces a new strategy for achieving high-performance aqueous zinc-ion batteries.展开更多
Vanadium oxides,par-ticularly hydrated forms like V_(2)O_(5)·nH_(2)O(VOH),stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure,unique electronic chara...Vanadium oxides,par-ticularly hydrated forms like V_(2)O_(5)·nH_(2)O(VOH),stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure,unique electronic characteristics,and high theoretical capacities.However,challenges such as vanadium dissolution,sluggish Zn^(2+)diffusion kinetics,and low operating voltage still hinder their direct application.In this study,we present a novel vanadium oxide([C_(6)H_(6)N(CH_(3))_(3)]_(1.08)V_(8)O_(20)·0.06H_(2)O,TMPA-VOH),developed by pre-inserting trimethylphenylammonium(TMPA+)cations into VOH.The incorporation of weakly polarized organic cations capitalizes on both ionic pre-intercalation and molecular pre-intercalation effects,resulting in a phase and morphology transition,an expansion of the interlayer distance,extrusion of weakly bonded interlayer water,and a substantial increase in V^(4+)content.These modifications synergistically reduce the electrostatic interactions between Zn^(2+)and the V-O lattice,enhancing structural stability and reaction kinetics during cycling.As a result,TMPA-VOH achieves an elevated open circuit voltage and operation voltage,exhibits a large specific capacity(451 mAh g^(-1)at 0.1 A g^(-1))coupled with high energy efficiency(89%),the significantly-reduced battery polarization,and outstanding rate capability and cycling stability.The concept introduced in this study holds great promise for the development of high-performance oxide-based energy storage materials.展开更多
The effects of SO2, V2O5 loading and reaction temperature on the activity of activated carbon supported vanadium oxide catalyst have been studied for the reduction of NO with NH3 at low temperatures (150-250℃). It is...The effects of SO2, V2O5 loading and reaction temperature on the activity of activated carbon supported vanadium oxide catalyst have been studied for the reduction of NO with NH3 at low temperatures (150-250℃). It is found that SO2 significantly promotes the catalyst activity. Both V2O5 loading and reaction temperature are vital to the promoting effect of SO2. The catalysts with V2O5 loadings of 1 -5 weight percent have a positive effect on the promotion of SO2, while the catalysts with V2O5 loadings of above 7 weight percent have not such an effect or show a negative effect. At lower temperatures (<180℃) SO2 poisons the catalyst but at higher temperatures promotes it. The reason of the SO2 promotion was also discussed; it may results from the formation of SO42- on the catalyst surface, which increases the surface acidity and hence the catalytic activity.展开更多
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans(PCDD/Fs)have attracted widespread concern due to their high toxicity,and their difficult manipulation in laboratories has made the research process t...Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans(PCDD/Fs)have attracted widespread concern due to their high toxicity,and their difficult manipulation in laboratories has made the research process tough.Thus,in our work,furan is selected as the model compound owing to the same structure of a central oxygenate ring.Although catalytic oxidation is regarded as an effective and applicable method for the abatement of PCDD/Fs,the synthesis of low-temperature catalysts is still a challenging problem in practical applications.Considering this situation,we prepared a novel V_(2)O_(5)/TiO_(2)catalyst modified with N-doped hierarchical porous carbon(NHPC)via a wet impregnation method.The V/T-1%NHPC catalyst could achieve expectant low-temperature performances with 50%furan conversion at 150℃and a complete conversion at 200℃,which decreased 23℃and 40℃compared to the V/T catalyst respectively.Moreover,the addition of NHPC presented lifting chemical stability during long-time test.The addition of NHPC in V/T catalysts decreased the formation of crystalline V_(2)O_(5) and increased the percentages of V^(5+)and O_(lat),which improved the utilization of vanadium ions and the catalytic activity.Simultaneously,the higher binding energy shift of O_(lat) implied more reaction possibility with other oxidise reactants.Importantly,this work proved the lifting catalytic activity by the interaction between catalysts and NHPC,and proposed the promoting effects of the N element.The results showed that the content of the pyridinic N and graphitic N in NHPC changed after combining with V/T catalyst,which played crucial roles in the excellent catalytic performance.Overall,this work provides comprehensive research of the V/T-1%NHPC catalyst toward furan oxidation at low temperature and explain the effects of N-doped biomass carbon in catalytic activity clearly,which gave a new thought to design low-temperature catalysts in PCDD/Fs degradation.Besides,the internal functional mechanisms of N species are worth further exploration in future studies.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:52372188,51902090,51922008,520721142023 Introduction of studying abroad talent program,the China Postdoctoral Science Foundation,Grant/Award Number:2019 M652546+3 种基金Xinxiang Major Science and Technology Projects,Grant/Award Number:21ZD001Henan Province Postdoctoral Start‐Up Foundation,Grant/Award Number:1901017Henan Center for Outstanding Overseas Scientists,Grant/Award Number:GZS2018003Overseas Expertise Introduction Project for Discipline Innovation,Grant/Award Number:D17007。
文摘Vanadium oxide cathode materials with stable crystal structure and fast Zn^(2+) storage capabilities are extremely important to achieving outstanding electrochemical performance in aqueous zinc‐ion batteries.In this work,a one‐step hydrothermal method was used to manipulate the bimetallic ion intercalation into the interlayer of vanadium oxide.The pre‐intercalated Cu ions act as pillars to pin the vanadium oxide(V‐O)layers,establishing stabilized two‐dimensional channels for fast Zn^(2+) diffusion.The occupation of Mn ions between V‐O interlayer further expands the layer spacing and increases the concentration of oxygen defects(Od),which boosts the Zn^(2+) diffusion kinetics.As a result,as‐prepared Cu_(0.17)Mn_(0.03)V_(2)O_(5−□)·2.16H_(2)O cathode shows outstanding Zn‐storage capabilities under room‐and lowtemperature environments(e.g.,440.3 mAh g^(−1) at room temperature and 294.3 mAh g^(−1)at−60°C).Importantly,it shows a long cycling life and high capacity retention of 93.4%over 2500 cycles at 2 A g^(−1) at−60°C.Furthermore,the reversible intercalation chemistry mechanisms during discharging/charging processes were revealed via operando X‐ray powder diffraction and ex situ Raman characterizations.The strategy of a couple of 3d transition metal doping provides a solution for the development of superior room‐/lowtemperature vanadium‐based cathode materials.
基金supported by the National Natural Science Foundation of China (52274411)the National Natural Science Foundation of China (51904287)the Innovation Academy for Green Manufacture,Chinese Academy of Sciences (IAGM2022D11)。
文摘The improper disposal of spent selective catalytic reduction (SCR) catalysts causes environmental pollution and metal resource waste.A novel process to recover anatase titanium dioxide (TiO_(2)) from spent SCR catalysts was proposed.The process included alkali (NaOH) hydrothermal treatment,sulfuric acid washing,and calcination.Anatase TiO_(2) in spent SCR catalyst was reconstructed by forming Na_(2)Ti_(2)O_(4)(OH)_(2) nanosheet during NaOH hydrothermal treatment and H_(2)Ti_(2)O_(4)(OH)_(2) during sulfuric acid washing.Anatase TiO_(2) was recovered by decomposing H_(2)Ti_(2)O_(4)(OH)_(2) during calcination.The surface pore properties of the recovered anatase TiO_(2) were adequately improved,and its specific surface area (SSA) and pore volume (PV) were 85 m^(2)·g^(-1)and 0.40 cm^(3)·g^(-1),respectively.The elements affecting catalytic abilities(arsenic and sodium) were also removed.The SCR catalyst was resynthesized using the recovered TiO_(2) as raw material,and its catalytic performance in NO selective reduction was comparable with that of commercial SCR catalyst.This study realized the sustainable recycling of anatase TiO_(2) from spent SCR catalyst.
基金supported by the National Natural Science Foundation of China(91963210,U1801255,and 51872340)the Basic Scientific Research Fund of Sun Yat-Sen University(grant no.18lgpy06)
文摘How to effectively improve Zn^(2+)-storage properties is now becoming an urgent issue in the development of high-energy-density aqueous zinc-ion batteries.Here,a new method is proposed to massively increase the electrochemical capacity of aqueous Zn/V_(5)O_(12)·6H_(2)Obatteries.By adding a small amount of platinum(Pt,1.5 wt.%)and keeping other factors constant,the V_(5)O_(12)·6H_(2)O-Pt electrodes deliver a much higher specific capacity(440 m Ah g^(-1)at 500 m A g^(-1))than do V_(5)O_(12)·6H_(2)Oelectrodes(270 m Ah g^(-1)at500 m A g^(-1)).The structural and morphological evolution of V_(5)O_(12)·6H_(2)Oduring cycling results in Zn^(2+)ion insertion/extraction and the formation/disappearance of the zinc hydroxyl complex(Zn_(4)SO_(4)(OH)_(6)·5H_(2)O,ZHS),where the latter is closely related to the surface redox reaction,promoting Zn^(2+)ion stripping/plating on the Zn anode and consequently leading to extra electron transfer.Electrochemical tests in the absence of oxygen reveal that the Pt additive has no contribution and is even counterproductive to electric conductivity but favors remarkable enhancement of the pseudocapacitance.Accordingly,it is apparent that a strong causal relationship exists between Pt and the ZHS.In consideration of the catalytic application for oxygen reduction,Pt is expected to play a vital role in enhancing the electrochemical capacity through the pseudo-Zn-air reaction.This finding introduces a new strategy for achieving high-performance aqueous zinc-ion batteries.
基金This work was supported by the National Science Foundation(CBET-1803256)Dr.C.Liu acknowledges the support from National Natural Science Foundation of China(52102277)the Fundamental Research Funds for the Central Universities,conducted by Tongji University.
文摘Vanadium oxides,par-ticularly hydrated forms like V_(2)O_(5)·nH_(2)O(VOH),stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure,unique electronic characteristics,and high theoretical capacities.However,challenges such as vanadium dissolution,sluggish Zn^(2+)diffusion kinetics,and low operating voltage still hinder their direct application.In this study,we present a novel vanadium oxide([C_(6)H_(6)N(CH_(3))_(3)]_(1.08)V_(8)O_(20)·0.06H_(2)O,TMPA-VOH),developed by pre-inserting trimethylphenylammonium(TMPA+)cations into VOH.The incorporation of weakly polarized organic cations capitalizes on both ionic pre-intercalation and molecular pre-intercalation effects,resulting in a phase and morphology transition,an expansion of the interlayer distance,extrusion of weakly bonded interlayer water,and a substantial increase in V^(4+)content.These modifications synergistically reduce the electrostatic interactions between Zn^(2+)and the V-O lattice,enhancing structural stability and reaction kinetics during cycling.As a result,TMPA-VOH achieves an elevated open circuit voltage and operation voltage,exhibits a large specific capacity(451 mAh g^(-1)at 0.1 A g^(-1))coupled with high energy efficiency(89%),the significantly-reduced battery polarization,and outstanding rate capability and cycling stability.The concept introduced in this study holds great promise for the development of high-performance oxide-based energy storage materials.
文摘The effects of SO2, V2O5 loading and reaction temperature on the activity of activated carbon supported vanadium oxide catalyst have been studied for the reduction of NO with NH3 at low temperatures (150-250℃). It is found that SO2 significantly promotes the catalyst activity. Both V2O5 loading and reaction temperature are vital to the promoting effect of SO2. The catalysts with V2O5 loadings of 1 -5 weight percent have a positive effect on the promotion of SO2, while the catalysts with V2O5 loadings of above 7 weight percent have not such an effect or show a negative effect. At lower temperatures (<180℃) SO2 poisons the catalyst but at higher temperatures promotes it. The reason of the SO2 promotion was also discussed; it may results from the formation of SO42- on the catalyst surface, which increases the surface acidity and hence the catalytic activity.
基金supported by the Natural Science Foundation of Zhejiang Province(No.LY21E060007),the National Natural Science Foundation of China(No.52006191).
文摘Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans(PCDD/Fs)have attracted widespread concern due to their high toxicity,and their difficult manipulation in laboratories has made the research process tough.Thus,in our work,furan is selected as the model compound owing to the same structure of a central oxygenate ring.Although catalytic oxidation is regarded as an effective and applicable method for the abatement of PCDD/Fs,the synthesis of low-temperature catalysts is still a challenging problem in practical applications.Considering this situation,we prepared a novel V_(2)O_(5)/TiO_(2)catalyst modified with N-doped hierarchical porous carbon(NHPC)via a wet impregnation method.The V/T-1%NHPC catalyst could achieve expectant low-temperature performances with 50%furan conversion at 150℃and a complete conversion at 200℃,which decreased 23℃and 40℃compared to the V/T catalyst respectively.Moreover,the addition of NHPC presented lifting chemical stability during long-time test.The addition of NHPC in V/T catalysts decreased the formation of crystalline V_(2)O_(5) and increased the percentages of V^(5+)and O_(lat),which improved the utilization of vanadium ions and the catalytic activity.Simultaneously,the higher binding energy shift of O_(lat) implied more reaction possibility with other oxidise reactants.Importantly,this work proved the lifting catalytic activity by the interaction between catalysts and NHPC,and proposed the promoting effects of the N element.The results showed that the content of the pyridinic N and graphitic N in NHPC changed after combining with V/T catalyst,which played crucial roles in the excellent catalytic performance.Overall,this work provides comprehensive research of the V/T-1%NHPC catalyst toward furan oxidation at low temperature and explain the effects of N-doped biomass carbon in catalytic activity clearly,which gave a new thought to design low-temperature catalysts in PCDD/Fs degradation.Besides,the internal functional mechanisms of N species are worth further exploration in future studies.
