Developing efficient photocatalysts for CO_(2)conversion under full-spectrum irradiation remains a key challenge for solar-to-chemical energy conversion.In this study,a novel S-scheme heterojunction composed of reduct...Developing efficient photocatalysts for CO_(2)conversion under full-spectrum irradiation remains a key challenge for solar-to-chemical energy conversion.In this study,a novel S-scheme heterojunction composed of reduction Cs_(0.32)WO_(3)(CWO)nanosheets with hexagonal structure and oxidation WO_(3)·2H_(2)O(WO)nanorods with monoclinic structure photocatalyst was successfully constructed via an ultrasound strategy.Under full-spectrum irradiation for 4 h,the optimized 2D/1D of heterostructure CWO/WO-0.8 exhibited superior photocatalytic performance,achieving CO and CH_(3)OH yields of 29.74 and 63.71μmol·g^(-1),respectively.The enhanced activity is primarily ascribed to the formation of an S-scheme charge transfer pathway,which facilitates efficient separation and directional migration of photogenerated charge carriers through the internal electric field at the CWO/WO interface.This process facilitates the electron enrichment on the CWO surface and significantly enhances its CO_(2)reduction ability.Besides,the results of various characterizations show that CWO/WO-0.8 possesses enhanced optical response capability.The results of density functional theory calculations and CO_(2)-temperature programmed desorption analysis confirmed that the CWO/WO heterojunction exhibits stronger CO_(2)adsorption and activation abilities compared to the pristine CWO and WO.The reaction pathway for CH_(3)OH production was elucidated by in-situ diffused reflectance Fourier transformed infrared tests.This work provides new insights into the rational design of S-scheme photocatalysts for efficient and selective CO_(2)conversion.展开更多
Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ ...Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.展开更多
The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS...The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.展开更多
The integration of selective oxidation of renewable biomass and its derivatives with hydrogen(H_(2))pro-duction holds significant potential for simultaneously yielding value-added chemicals and“green H_(2)”,contribu...The integration of selective oxidation of renewable biomass and its derivatives with hydrogen(H_(2))pro-duction holds significant potential for simultaneously yielding value-added chemicals and“green H_(2)”,contributing to addressing sustainability challenges.The S-scheme charge transfer mechanism enhances charge separation by maintaining strong redox potentials at both ends,facilitating both oxidation and reduction reactions.Herein,we synthesize a visible-light-responsive oxygen vacancy-rich In_(2)O_(3-x)/tubular carbon nitride(IO_(OV)/TCN)S-scheme heterojunction photocatalyst via electrostatic adherence for selec-tive 5-hydroxymethylfurfural(HMF)oxidation to 2,5-diformylfuran(DFF)and 2,5-furandicarboxylic acid(FDCA),alongside H_(2)production.Under anaerobic conditions and visible-light irradiation,the optimal IOOV/TCN-10 catalyst achieves an HMF conversion of 94.8%with a selectivity of 53.6%for DFF and FDCA,and a H_(2)yield of 754.05μmol g^(−1)in 3 h.The significantly improved photocatalytic activity results from enhanced visible-light absorption,reduced carrier recombination,and abundant catalytic active sites due to the synergistic effect of surface oxygen vacancies,the hollow nanotube-based architecture,and the S-scheme charge transfer mechanism.This work highlights the great potentials of S-scheme heterojunctions in biomass conversion for sustainable energy use and chemical production.展开更多
The development of high-performance cathode materials is critical to the practical application of sodiumion batteries(SIBs).O3-type NaCrO_(2)(NCO)is one of the most competitive cathodes,but it suffers from rapid capac...The development of high-performance cathode materials is critical to the practical application of sodiumion batteries(SIBs).O3-type NaCrO_(2)(NCO)is one of the most competitive cathodes,but it suffers from rapid capacity decay caused by severe irreversible structural evolution.An Mg-Ti co-doped Na_(0.99)Cr_(0.95)Mg_(0.02)Ti_(0.03)O_(2)(NCO-MT)cathode material is designed and synthesized via a facile solid-state reaction to enhance the cyclability of NCO.A capacity retention of 71.6%after 2500 cycles with the capacity fade rate of 0.011%per cycle is achieved for NCO-MT at 5 C,which is attributed to the highly reversible crystal structure during cycling.Our findings offer a novel insight into the high-performance O3-type layered cathode materials for SIBs and are beneficial to promote the development of high-rate SIBs.展开更多
The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as ...The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as a high-strength substrate to support fast-ion-conducting polymer-in-salt(PIS)solid-state electrolytes,aiming to suppress lithium dendrite growth and improve full-cell performance.The Al_(2)O_(3)coating layer not only refines the wettability of polyimide porous film to PIS,but also performs as a high modulus protective layer to suppress the growth of lithium dendrites.The resulting PI/AO@PIS exhibits a small thickness of only 35μm with an outstanding tensile strength of 11.3 MPa and Young's modulus of 537.6 MPa.In addition,the PI/AO@PIS delivers a high ionic conductivity of 0.1 m S/cm at 25°C.As a result,the PI/AO@PIS enables symmetric Li cells to achieve exceptional cyclability for over 1000 h at 0.1 m A/cm2without noticeable lithium dendrite formation.Moreover,the PI/AO@PIS-based LiFePO4||Li full cells demonstrate outstanding rate performance(125.7 m Ah/g at 5 C)and impressive cycling stability(96.1%capacity retention at 1 C after 200 cycles).This work highlights the efficacy of enhancing the mechanical properties of polymer matrices and extending cell performance through the incorporation of a dense inorganic interface layer.展开更多
The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO_(2) from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonizatio...The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO_(2) from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonization.However,steelwork off-gases typically contain various impurities,including H_(2)S,which can deactivate commercial methanol synthesis catalysts,Cu/ZnO/Al_(2)O_(3)(CZA).Reverse water-gas shift(RWGS)reaction is the predominant side reaction in CO_(2) hydrogenation to methanol which can occur at ambient pressure,enabling the decouple of RWGS from methanol production at high pressure.Then,a series of activated CZA catalysts has been in-situ pretreated in 400 ppm H_(2)S/Ar at 250℃and tested for both RWGS reaction at ambient pressure and CO_(2) hydrogenation to methanol at high pressure.An innovative decoupling strategy was employed to isolate the RWGS reaction from the methanol synthesis process,enabling the investigation of the evolution of active site structures and the poisoning mechanism through elemental analysis,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Fourier Transform Infrared Spectroscopy,Temperature Programmed Reduction and CO_(2) Temperature Programmed Desorption.The results indicate that there are different dynamic migration behaviors of ZnO_(x) in the two reaction systems,leading to different poisoning mechanisms.These interesting findings are beneficial to develop sulfur resistant and durable highly efficient catalysts for CO_(2) hydrogenation to methanol,promoting the carbon emission reduction in steel industry.展开更多
In this work,the TiO_(2)/Sb_(2)S_(3) nanorod arrays(NRAs)were synthesized through a two-stage hydrothermal route for photoelectrochemical(PEC)water splitting.The effect of annealing treatment in Ar ambience on the PEC...In this work,the TiO_(2)/Sb_(2)S_(3) nanorod arrays(NRAs)were synthesized through a two-stage hydrothermal route for photoelectrochemical(PEC)water splitting.The effect of annealing treatment in Ar ambience on the PEC activity of TiO_(2)/Sb_(2)S_(3) composite sample was investigated by electrochemical impedance analysis,including Nyquist and Mott-Schottky(M-S)plots.It was demonstrated that vacuum annealing could crystallize Sb_(2)S_(3) component and change its color from red to black,leading to an increment of photocurrent density from 1.9 A/m^(2) to 4.25 A/m^(2) at 0 V versus saturated calomel electrode(VSCE).The enhanced PEC performance was mainly attributed to the improved visible light absorption.Moreover,annealing treatment facilitated retarding the electron-hole recombination occurred at the solid/liquid interfaces.Our work might provide a novel strategy for enhancing the PEC performance of a semiconductor electrode.展开更多
Nearly undamaged joints of electron beam welded(EBW)dual-phase Mg-8Li-3Al-2Zn-0.5Y alloy were achieved with joint coefficients exceeding 95%.All specimens were fractured at the base metal(BM),implying a significant de...Nearly undamaged joints of electron beam welded(EBW)dual-phase Mg-8Li-3Al-2Zn-0.5Y alloy were achieved with joint coefficients exceeding 95%.All specimens were fractured at the base metal(BM),implying a significant departure from conventional fracture modes of welded joints.The fusion zone(FZ)consists of ultrafine acicular α-Mg and equiaxed β-Li,with grain sizes reduced by approximately 90% and 80%,respectively,compared to the base metal.This results in a significant increase in microhardness of about 40%.A unique multiphase mixture was observed in the heat-affected zone(HAZ),which mainly consists of lamellar eutectoid structures,fine precipitates zone,and numerous fine Mg_(3)(Al,Zn)particles.This mixture was transformed from typical Li(Al,Zn)(a common softening phase)undergoing atomic diffusion and solid-state phase transformation during welding.It introduces a synergistic strengthening effect,making the heat-affected zone no longer the weakest part of the joint.This study provides valuable insights into the electron beam welding technology for Mg-Li alloys and offers theoretical support for manufacturing high-quality joints.展开更多
The ultra-light Mg–8Li–3Al–2Zn–0.5Y(LAZ832–0.5Y)thin wall parts with excellent performances were successfully fabricated by Gas Tungsten Arc Welding(GTAW)in this study.The microstructure of the top,middle and bot...The ultra-light Mg–8Li–3Al–2Zn–0.5Y(LAZ832–0.5Y)thin wall parts with excellent performances were successfully fabricated by Gas Tungsten Arc Welding(GTAW)in this study.The microstructure of the top,middle and bottom regions of the thin wall fabricated under various conditions was examined and the mechanical properties of these thin walls were tested.The results showed that much finer microstructure was obtained by GTAW than that made by conventional casting method.In the as-deposited samples,the needle-like shapedα-Mg phase emerged at the top of the thin wall whereas the bar-shapedα-Mg phase showed up in the middle and bottom regions of the thin wall due to the complex thermal history.The Al2Y phase was dispersed throughout bothα-Mg andβ-Li while the AlLi phase was mainly located in theβ-Li.The best combination of ultimate tensile strength(UTS),yield strength(YS)and elongation to fracture of the as-deposited thin wall were 218.9 MPa,171.4 MPa and 20.9%,respectively,which was manufactured under the optimal condition of 120 A 1800 mm/min 220 mm/min.After solid solution treatment at 350℃for 4 h,the UTS increased slightly by 13%but the YS increased significantly by 65%compared with the samples before solid solution.The solution of the AlLi phase was believed to be the main strengthening mechanism.It is interesting to note that the UTS and YS of the as-deposited sample was better than those of the as-cast sample while the opposite situation took place after solid solution treatment.展开更多
One prominent cathode material utilized in commercial sodium-ion batteries is the O3-type NaNi_(0.5)Mn_(0.5)O_(2).The application of this material is hindered by multistage phase transitions and insufficient air stabi...One prominent cathode material utilized in commercial sodium-ion batteries is the O3-type NaNi_(0.5)Mn_(0.5)O_(2).The application of this material is hindered by multistage phase transitions and insufficient air stability.In this study,an innovative O3-type NaNi_(0.5)Mn_(0.5)O_(2),derived from Ni-MOFs (referred to as M-NNMO),has been developed as a cathode material for sodium-ion batteries.The M-NNMO cathode exhibits a discharge specific capacity of 124 mAh·g^(-1)at a rate of0.1C within 2.0 to 4.0 V.Furthermore,this material demonstrates an impressive capacity retention of 75%after undergoing 100 cycles.Complex phase transitions can be inhibited and ion diffusion rates can be increased simultaneously by Ni-MOFs through the enhancement of transition metal-oxygen bonding and the rise n Na layer gap,which are in charge of the remarkable performance improvement.Importantly,the enhanced stability of the M-NNMO transition metal layer based on the uniquestructural properties of Ni-MOFs in air stability tests.This work will provide theoretical guidance to design sodiumion battery cathode materials with superior performance.展开更多
Ammonia Selective Catalytic Reduction(NHs-SCR)technology has been employed to eliminate NO_(x) from diesel engine exhaust,with Cu-SSZ-13 serving as the commercial catalyst.The greenhouse gas N_(2)O is produced as a by...Ammonia Selective Catalytic Reduction(NHs-SCR)technology has been employed to eliminate NO_(x) from diesel engine exhaust,with Cu-SSZ-13 serving as the commercial catalyst.The greenhouse gas N_(2)O is produced as a byproduct when using Cu-SSZ-13 as the NH_(3)-SCR catalyst.To achieve synergistic control of pollutants and greenhouse gases in diesel engine exhaust,rational design of Cu-SSZ-13 catalysts is required.In this study,the effect of Brønsted acid sites in Cu-SSZ-13 catalysts on the formation of N_(2)O was investigated.Mild thermal treatmentwas innovatively employed to prepare Cu-SSZ-13 catalysts with different amounts of Brønsted acid sites.EPR,H_(2)-TPR,NH_(3)-TPD,NMR were utilized to determine that the Brønsted acid sites were modified while the Cu species remained unchanged.Thereby an accurate assessment of the influence of Brønsted acid sites on N_(2)O formation could be achieved.Our results showed that Cu-SSZ-13 with more Brønsted acid sites produced less N_(2)O during the NH_(3)-SCR reaction.In the low-temperature region,the presence of framework acid sites facilitates the decomposition of the NH_(4)NO_(3)assisted by NO to form N_(2)and H_(2)O,reducing the formation of N_(2)O.In the high-temperature region,the Brønsted acid sites promote the decomposition of NH_(2)NO into N_(2)and H_(2)O.Meanwhile,the N_(2)O-SCR reaction can also be promoted by Brønsted acid sites,thereby decreasing N_(2)O emissions.This study suggests that in the future design and synthesis of Cu-SSZ-13 zeolites,attention should be paid to creating more Brønsted acid sites in Cu-SSZ-13 to reduce N_(2)O emissions.展开更多
文摘Developing efficient photocatalysts for CO_(2)conversion under full-spectrum irradiation remains a key challenge for solar-to-chemical energy conversion.In this study,a novel S-scheme heterojunction composed of reduction Cs_(0.32)WO_(3)(CWO)nanosheets with hexagonal structure and oxidation WO_(3)·2H_(2)O(WO)nanorods with monoclinic structure photocatalyst was successfully constructed via an ultrasound strategy.Under full-spectrum irradiation for 4 h,the optimized 2D/1D of heterostructure CWO/WO-0.8 exhibited superior photocatalytic performance,achieving CO and CH_(3)OH yields of 29.74 and 63.71μmol·g^(-1),respectively.The enhanced activity is primarily ascribed to the formation of an S-scheme charge transfer pathway,which facilitates efficient separation and directional migration of photogenerated charge carriers through the internal electric field at the CWO/WO interface.This process facilitates the electron enrichment on the CWO surface and significantly enhances its CO_(2)reduction ability.Besides,the results of various characterizations show that CWO/WO-0.8 possesses enhanced optical response capability.The results of density functional theory calculations and CO_(2)-temperature programmed desorption analysis confirmed that the CWO/WO heterojunction exhibits stronger CO_(2)adsorption and activation abilities compared to the pristine CWO and WO.The reaction pathway for CH_(3)OH production was elucidated by in-situ diffused reflectance Fourier transformed infrared tests.This work provides new insights into the rational design of S-scheme photocatalysts for efficient and selective CO_(2)conversion.
文摘Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.
文摘The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.
基金financially supported by the Natural Science Foundation of China(Nos.21972058,22102064,and 22302080)Anhui Key Laboratory of Nanomaterials and Nanotechnology,the Major Science and Technology Projects in Anhui Province(No.202305a12020006).
文摘The integration of selective oxidation of renewable biomass and its derivatives with hydrogen(H_(2))pro-duction holds significant potential for simultaneously yielding value-added chemicals and“green H_(2)”,contributing to addressing sustainability challenges.The S-scheme charge transfer mechanism enhances charge separation by maintaining strong redox potentials at both ends,facilitating both oxidation and reduction reactions.Herein,we synthesize a visible-light-responsive oxygen vacancy-rich In_(2)O_(3-x)/tubular carbon nitride(IO_(OV)/TCN)S-scheme heterojunction photocatalyst via electrostatic adherence for selec-tive 5-hydroxymethylfurfural(HMF)oxidation to 2,5-diformylfuran(DFF)and 2,5-furandicarboxylic acid(FDCA),alongside H_(2)production.Under anaerobic conditions and visible-light irradiation,the optimal IOOV/TCN-10 catalyst achieves an HMF conversion of 94.8%with a selectivity of 53.6%for DFF and FDCA,and a H_(2)yield of 754.05μmol g^(−1)in 3 h.The significantly improved photocatalytic activity results from enhanced visible-light absorption,reduced carrier recombination,and abundant catalytic active sites due to the synergistic effect of surface oxygen vacancies,the hollow nanotube-based architecture,and the S-scheme charge transfer mechanism.This work highlights the great potentials of S-scheme heterojunctions in biomass conversion for sustainable energy use and chemical production.
基金financially supported by National Key Research and Development Program of China(No.2022YFE0202400)the National Natural Science Foundation of China(No.22379103)+2 种基金Natural Science Foundation of Guangdong Province of China(No.2021A1515010388)the Science and Technology Projects of Suzhou City(No.SYC2022043)the Qing Lan Project of Jiangsu Province(2022)。
文摘The development of high-performance cathode materials is critical to the practical application of sodiumion batteries(SIBs).O3-type NaCrO_(2)(NCO)is one of the most competitive cathodes,but it suffers from rapid capacity decay caused by severe irreversible structural evolution.An Mg-Ti co-doped Na_(0.99)Cr_(0.95)Mg_(0.02)Ti_(0.03)O_(2)(NCO-MT)cathode material is designed and synthesized via a facile solid-state reaction to enhance the cyclability of NCO.A capacity retention of 71.6%after 2500 cycles with the capacity fade rate of 0.011%per cycle is achieved for NCO-MT at 5 C,which is attributed to the highly reversible crystal structure during cycling.Our findings offer a novel insight into the high-performance O3-type layered cathode materials for SIBs and are beneficial to promote the development of high-rate SIBs.
基金the financial support from the 261Project of MIIT and Natural Science Foundation of Jiangsu Province(No.BK20240179)。
文摘The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as a high-strength substrate to support fast-ion-conducting polymer-in-salt(PIS)solid-state electrolytes,aiming to suppress lithium dendrite growth and improve full-cell performance.The Al_(2)O_(3)coating layer not only refines the wettability of polyimide porous film to PIS,but also performs as a high modulus protective layer to suppress the growth of lithium dendrites.The resulting PI/AO@PIS exhibits a small thickness of only 35μm with an outstanding tensile strength of 11.3 MPa and Young's modulus of 537.6 MPa.In addition,the PI/AO@PIS delivers a high ionic conductivity of 0.1 m S/cm at 25°C.As a result,the PI/AO@PIS enables symmetric Li cells to achieve exceptional cyclability for over 1000 h at 0.1 m A/cm2without noticeable lithium dendrite formation.Moreover,the PI/AO@PIS-based LiFePO4||Li full cells demonstrate outstanding rate performance(125.7 m Ah/g at 5 C)and impressive cycling stability(96.1%capacity retention at 1 C after 200 cycles).This work highlights the efficacy of enhancing the mechanical properties of polymer matrices and extending cell performance through the incorporation of a dense inorganic interface layer.
基金supported by the National Natural Science Foundation of China(Nos.22276060 and 21976059)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515012636)China Scholarship Council Scholarship(No.201906155006)。
文摘The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO_(2) from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonization.However,steelwork off-gases typically contain various impurities,including H_(2)S,which can deactivate commercial methanol synthesis catalysts,Cu/ZnO/Al_(2)O_(3)(CZA).Reverse water-gas shift(RWGS)reaction is the predominant side reaction in CO_(2) hydrogenation to methanol which can occur at ambient pressure,enabling the decouple of RWGS from methanol production at high pressure.Then,a series of activated CZA catalysts has been in-situ pretreated in 400 ppm H_(2)S/Ar at 250℃and tested for both RWGS reaction at ambient pressure and CO_(2) hydrogenation to methanol at high pressure.An innovative decoupling strategy was employed to isolate the RWGS reaction from the methanol synthesis process,enabling the investigation of the evolution of active site structures and the poisoning mechanism through elemental analysis,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Fourier Transform Infrared Spectroscopy,Temperature Programmed Reduction and CO_(2) Temperature Programmed Desorption.The results indicate that there are different dynamic migration behaviors of ZnO_(x) in the two reaction systems,leading to different poisoning mechanisms.These interesting findings are beneficial to develop sulfur resistant and durable highly efficient catalysts for CO_(2) hydrogenation to methanol,promoting the carbon emission reduction in steel industry.
基金supported by the Fundamental Research Funds for the Central Universities(No.2019ZDPY04).
文摘In this work,the TiO_(2)/Sb_(2)S_(3) nanorod arrays(NRAs)were synthesized through a two-stage hydrothermal route for photoelectrochemical(PEC)water splitting.The effect of annealing treatment in Ar ambience on the PEC activity of TiO_(2)/Sb_(2)S_(3) composite sample was investigated by electrochemical impedance analysis,including Nyquist and Mott-Schottky(M-S)plots.It was demonstrated that vacuum annealing could crystallize Sb_(2)S_(3) component and change its color from red to black,leading to an increment of photocurrent density from 1.9 A/m^(2) to 4.25 A/m^(2) at 0 V versus saturated calomel electrode(VSCE).The enhanced PEC performance was mainly attributed to the improved visible light absorption.Moreover,annealing treatment facilitated retarding the electron-hole recombination occurred at the solid/liquid interfaces.Our work might provide a novel strategy for enhancing the PEC performance of a semiconductor electrode.
基金financially supported by the National Defense Basic Research Program(No.JCKY2023204A005)Project of High Modulus Magnesium Alloy Forgings(JXXT-2023-014hbza)+1 种基金Research Program of Joint Research Center of Advanced Spaceflight Technologies(No.USCAST2023-3)Major Scientific and Technological Innovation Project of Luoyang(No.2201029A).
文摘Nearly undamaged joints of electron beam welded(EBW)dual-phase Mg-8Li-3Al-2Zn-0.5Y alloy were achieved with joint coefficients exceeding 95%.All specimens were fractured at the base metal(BM),implying a significant departure from conventional fracture modes of welded joints.The fusion zone(FZ)consists of ultrafine acicular α-Mg and equiaxed β-Li,with grain sizes reduced by approximately 90% and 80%,respectively,compared to the base metal.This results in a significant increase in microhardness of about 40%.A unique multiphase mixture was observed in the heat-affected zone(HAZ),which mainly consists of lamellar eutectoid structures,fine precipitates zone,and numerous fine Mg_(3)(Al,Zn)particles.This mixture was transformed from typical Li(Al,Zn)(a common softening phase)undergoing atomic diffusion and solid-state phase transformation during welding.It introduces a synergistic strengthening effect,making the heat-affected zone no longer the weakest part of the joint.This study provides valuable insights into the electron beam welding technology for Mg-Li alloys and offers theoretical support for manufacturing high-quality joints.
基金supported by the National Key Research and Development Program of China(No.2021YFB3701303)Foundation Strengthening Plan Technical Field Fund(No.2021-JJ-0112)+1 种基金Major Scientific and Technological Innovation Project of Luoyang(No.2201029A)National Natural Science Foundation of China(No.U2037601).
文摘The ultra-light Mg–8Li–3Al–2Zn–0.5Y(LAZ832–0.5Y)thin wall parts with excellent performances were successfully fabricated by Gas Tungsten Arc Welding(GTAW)in this study.The microstructure of the top,middle and bottom regions of the thin wall fabricated under various conditions was examined and the mechanical properties of these thin walls were tested.The results showed that much finer microstructure was obtained by GTAW than that made by conventional casting method.In the as-deposited samples,the needle-like shapedα-Mg phase emerged at the top of the thin wall whereas the bar-shapedα-Mg phase showed up in the middle and bottom regions of the thin wall due to the complex thermal history.The Al2Y phase was dispersed throughout bothα-Mg andβ-Li while the AlLi phase was mainly located in theβ-Li.The best combination of ultimate tensile strength(UTS),yield strength(YS)and elongation to fracture of the as-deposited thin wall were 218.9 MPa,171.4 MPa and 20.9%,respectively,which was manufactured under the optimal condition of 120 A 1800 mm/min 220 mm/min.After solid solution treatment at 350℃for 4 h,the UTS increased slightly by 13%but the YS increased significantly by 65%compared with the samples before solid solution.The solution of the AlLi phase was believed to be the main strengthening mechanism.It is interesting to note that the UTS and YS of the as-deposited sample was better than those of the as-cast sample while the opposite situation took place after solid solution treatment.
基金financially supported by the National Natural Science Foundation of China(Nos.52164029,52074099 and 52464033)Natural Science Foundation of Hainan Province(Nos.221RC585,821MS0782,221MS048 and 221RC 1072)+1 种基金Hainan Province Science and Technology Special Fund(Nos.ZDYF2022GXJS004 and ZDYF2021GXJS028)Scientific Research Foundation of Hainan Tropical Ocean University(No.RHDRC202112)
文摘One prominent cathode material utilized in commercial sodium-ion batteries is the O3-type NaNi_(0.5)Mn_(0.5)O_(2).The application of this material is hindered by multistage phase transitions and insufficient air stability.In this study,an innovative O3-type NaNi_(0.5)Mn_(0.5)O_(2),derived from Ni-MOFs (referred to as M-NNMO),has been developed as a cathode material for sodium-ion batteries.The M-NNMO cathode exhibits a discharge specific capacity of 124 mAh·g^(-1)at a rate of0.1C within 2.0 to 4.0 V.Furthermore,this material demonstrates an impressive capacity retention of 75%after undergoing 100 cycles.Complex phase transitions can be inhibited and ion diffusion rates can be increased simultaneously by Ni-MOFs through the enhancement of transition metal-oxygen bonding and the rise n Na layer gap,which are in charge of the remarkable performance improvement.Importantly,the enhanced stability of the M-NNMO transition metal layer based on the uniquestructural properties of Ni-MOFs in air stability tests.This work will provide theoretical guidance to design sodiumion battery cathode materials with superior performance.
基金supported by the National Key R&D Program of China(Nos.2023YFC3707200 and 2022YFC3704400)the National Natural Science Foundation of China(Nos.52200136,22402220,and 52225004)Hangzhou Qianjiang Distinguished Experts Project.
文摘Ammonia Selective Catalytic Reduction(NHs-SCR)technology has been employed to eliminate NO_(x) from diesel engine exhaust,with Cu-SSZ-13 serving as the commercial catalyst.The greenhouse gas N_(2)O is produced as a byproduct when using Cu-SSZ-13 as the NH_(3)-SCR catalyst.To achieve synergistic control of pollutants and greenhouse gases in diesel engine exhaust,rational design of Cu-SSZ-13 catalysts is required.In this study,the effect of Brønsted acid sites in Cu-SSZ-13 catalysts on the formation of N_(2)O was investigated.Mild thermal treatmentwas innovatively employed to prepare Cu-SSZ-13 catalysts with different amounts of Brønsted acid sites.EPR,H_(2)-TPR,NH_(3)-TPD,NMR were utilized to determine that the Brønsted acid sites were modified while the Cu species remained unchanged.Thereby an accurate assessment of the influence of Brønsted acid sites on N_(2)O formation could be achieved.Our results showed that Cu-SSZ-13 with more Brønsted acid sites produced less N_(2)O during the NH_(3)-SCR reaction.In the low-temperature region,the presence of framework acid sites facilitates the decomposition of the NH_(4)NO_(3)assisted by NO to form N_(2)and H_(2)O,reducing the formation of N_(2)O.In the high-temperature region,the Brønsted acid sites promote the decomposition of NH_(2)NO into N_(2)and H_(2)O.Meanwhile,the N_(2)O-SCR reaction can also be promoted by Brønsted acid sites,thereby decreasing N_(2)O emissions.This study suggests that in the future design and synthesis of Cu-SSZ-13 zeolites,attention should be paid to creating more Brønsted acid sites in Cu-SSZ-13 to reduce N_(2)O emissions.
