The benefits of perovskite oxides include their low cost,customizable composition,ordered atomic structure,and extremely flexible electronic structure.They are the ideal substitute for precious metal catalysts in vari...The benefits of perovskite oxides include their low cost,customizable composition,ordered atomic structure,and extremely flexible electronic structure.They are the ideal substitute for precious metal catalysts in various electrocatalytic reactions.However,the initial activity of perovskite oxides is often quite limited,which is extremely related to their crystal structure and electronic structure.In this regard,component regulation is the simplest and most effective strategy to increase their stability and catalytic activity.In this review,we briefly outline the recent progress in the modulating component of perovskite oxides to enhance their catalytic properties.The outline was categorized according to the sites in the ABO3-type perovskite structure,including A-site,B-site,and O-site regulation.Finally,potential research directions aimed at modulating of perovskite oxide constituents are discussed.展开更多
The Zn/Sn ratio in Cu2ZnSn（S, Se）4 （CZTSSe） films has been regulated to control the composition-related phase, defect, and photoelectric properties for high performance kesterite solar cells. It is found that the ...The Zn/Sn ratio in Cu2ZnSn（S, Se）4 （CZTSSe） films has been regulated to control the composition-related phase, defect, and photoelectric properties for high performance kesterite solar cells. It is found that the increase in the Zn/Sn ratio can slightly narrow the energy band gap to extend the light absorption range and improve the photocurrent. Optimal Zn/Sn ratio of 1.39 in CZTSSe film is obtained with the least secondary phase, the lowest defect density, and the longest charge recombination lifetime. Up to 10.1% photoelectric conversion efficiency has been achieved by this composition regulation.展开更多
Rechargeable metal-air batteries generally require efficient,durable,and safe bifunctional electrocatalysts to simultaneously support oxygen reduction/evolution reactions(ORR/OER).Herein,we employed first-principles c...Rechargeable metal-air batteries generally require efficient,durable,and safe bifunctional electrocatalysts to simultaneously support oxygen reduction/evolution reactions(ORR/OER).Herein,we employed first-principles calculations to explore the structure-activity relationship between the composition control of metal atoms and the catalytic activity of Pt-doped Ti_(2-x) Mn_(x) CO_(2) single-atom catalysts(SACs).The research found a clear linear relationship between the proportion of Mn and bifunctional performance,which can effectively modulate catalytic activity.Additionally,it shows excellent bifunctional catalytic activity at medium concentrations,among which the catalyst of Pt-V_(O)-Ti_(0.89) Mn_(1.11) CO_(2) displays the lowest overpo-tential(η^(ORR/OER)=0.26/0.28 V).Attributed to the modulation of the average magnetism of Mn and the d-band center of Pt by different com ponents,the bonding strength of the active center of Pt to adsorption intermediates is changed,resulting in the enhancement of the catalyst activity.Crucially,the molecular orbital-level bonding between the active site Pt and the adsorbed intermediate OH is clarified,shedding light on the involvement of the partially occupied antibonding state of Pt’s d orbital in the activation process.The research extensively explores the control of catalyst activity through composition,offering strong support for designing and optimizing highly active Janus MXene-supported SACs.展开更多
Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely bee...Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely been produced through the modulation of their structure and composition.In this study,a series of bimetallic nickel-iron phosphide(Ni_(x)Fe_(2-x)P,where 0<x<2)cocatalysts with controllable structures and overpotentials were designed by adjusting the atomic ratio of Ni/Fe onto nonmetallic elemental red phosphorus(RP)for the photocatalytic selective oxidation of benzyl alcohol(BA)coupled with hydrogen production.The catalysts exhibited an outstanding photocatalytic activity for benzaldehyde and a high H_(2)yield.The RP regulated by bimetallic phosphide cocatalysts(Ni_(x)Fe_(2-x)P)demonstrated higher photocatalytic oxidation-reduction activity than that regulated by monometallic phosphide cocatalysts(Ni_(2)P and Fe2P).In particular,the RP regulated by Ni_(1.25)Fe_(0.75)P exhibited the best photocatalytic performance.In addition,experimental and theoretical calculations further illustrated that Ni_(1.25)Fe_(0.75)P,with the optimized electronic structure,possessed good electrical conductivity and provided strong adsorption and abundant active sites,thereby accelerating electron migration and lowering the reaction energy barrier of RP.This finding offers valuable insights into the rational design of highly effective cocatalysts aimed at optimizing the photocatalytic activity of composite photocatalysts.展开更多
Reinforcement distribution tailoring has been proven effective in strengthening and toughening titanium matrix composites(TMCs).In this work,the analysis of the Ti64(Ti-6Al-4V)-B phase diagram indicated that B content...Reinforcement distribution tailoring has been proven effective in strengthening and toughening titanium matrix composites(TMCs).In this work,the analysis of the Ti64(Ti-6Al-4V)-B phase diagram indicated that B content dominates the TiB distribution.With this philosophy,B content regulation was applied to tailor homogeneous and network structures in Ti64-B composites fabricated via laser-directed energy deposition additive manufacturing(AM).The unique plate-like TiB attends inhomogeneous composites(Ti64–0.05B).However,in network composite(Ti64–0.25B),the TiB whisker(TiBw)arranges along priorβ-Ti grains with the same orientation.Moreover,the synergistic improvement of strength(988 MPa→1202 MPa),stiffness(106 GPa→116 GPa),hardness(325 HV→362 HV),and uniform elongation(5%→7.8%)were achieved.This work exhibited a balanced strength/ductility trade-off,which provides a good guide on microstructure tailoring.展开更多
Magnesium-based energy materials, which combine promising energy-related functional properties with low cost, environmental compatibility and high availability, have been regarded as fascinating candidates for sustain...Magnesium-based energy materials, which combine promising energy-related functional properties with low cost, environmental compatibility and high availability, have been regarded as fascinating candidates for sustainable energy conversion and storage. In this review,we provide a timely summary on the recent progress in three types of important Mg-based energy materials, based on the fundamental strategies of composition and structure engineering. With regard to Mg-based materials for batteries, we systematically review and analyze different material systems, structure regulation strategies as well as the relevant performance in Mg-ion batteries(MIBs) and Mg-air batteries(MABs), covering cathodes, electrolytes, anodes for MIBs, and anodes for MABs;as to Mg-based hydrogen storage materials, we discuss how catalyst adding, composite, alloying and nanostructuring improve the kinetic and thermodynamic properties of de/hydrogenation reactions, and in particular, the impacts of composition and structure modification on hydrogen absorption/dissociation processes and free energy modification mechanism are focused;regarding Mg-based thermoelectric materials, the relations between composition/structure and electrical/thermal transport properties of Mg_(3)X_(2)(X = Sb, Bi), Mg_(2)X(X = Si, Ge, Sn) and Mg Ag Sb-based materials, together with the representative research progress of each material system, are summarized and discussed. Finally, by pointing out remaining challenges and providing possible solutions, this review aims to shed light on the directions and perspectives for practical applications of magnesium-based energy materials in the future.展开更多
(Gd,Y,Ce)_(3)(Y_(x)Ga_(1−x))_(2)GaAl_(2)O_(12)(GYGAG:Ce)scintillation ceramics with different Y excess,where x=0.005−0.08,were fabricated by the solid-state reaction method.The effects of stoichiometry on the phase co...(Gd,Y,Ce)_(3)(Y_(x)Ga_(1−x))_(2)GaAl_(2)O_(12)(GYGAG:Ce)scintillation ceramics with different Y excess,where x=0.005−0.08,were fabricated by the solid-state reaction method.The effects of stoichiometry on the phase composition,optical quality,and microstructure of GYGAG:Ce ceramics were analyzed.GYGAG:Ce ceramics have a pure garnet phase and obtain good in-line transmittance when x<0.04,while more Y excess leads to the creation of the secondary phase.The change of x value influences the sintering behavior of the GYGAG:Ce ceramics:The excess of Y works as the self-sintering aid and significantly reduces the sintering temperature of ceramics.When x=0.01–0.04,the X-ray excited luminescence(XEL)spectra and light yields of GYGAG:Ce ceramics are similar.The fast scintillation decay time and afterglow intensity of GYGAG:Ce ceramics show a slight decrease with increasing x value.Finally,additional 50–500 ppm MgO and 100–500 ppm CaO were introduced to the GYGAG:Ce ceramic with x=0.04,and both were found to significantly increase the fast scintillation component and reduce the afterglow intensity by two orders of magnitude to 0.01%after X-ray cut-off.展开更多
Layered P2-type cathodes with high voltage,large capacity,and easy synthesis show great potential for developing sodium(Na)-ion batteries(NIBs).However,the P2–O2 phase transition makes their structural degradation an...Layered P2-type cathodes with high voltage,large capacity,and easy synthesis show great potential for developing sodium(Na)-ion batteries(NIBs).However,the P2–O2 phase transition makes their structural degradation and the Na^(+)/vacancy ordering lowers their redox kinetics.Here,we rationally propose a compositionally graded P2-type cathode,where nickel(Ni)and manganese(Mn)fractions decrease gradually,and cobalt(Co)content increases contiguously from the inside to the outside of a secondary particle.Inside these particles,the Ni/Mn-based compound delivers high capacity and high voltage.On the surface of particles,the Co/Mn-based solid solution offers a stable buffer matrix.Benefiting from these synergistic effects,this graded P2-type cathode shows the elimination of P2–O2 transformation even when charged to 4.4 V,which enables good structural stability,maintaining capacity retention reaching~80%within 300 cycles.Moreover,the Na^(+)/vacancy ordering superstructure is further suppressed,and the Na^(+)diffusion kinetics is significantly improved.The proposed graded structure with optimized chemical composition offers a new perspective for eliminating the unwanted phase transition and thus enhancing the electrochemistry of high-voltage layered cathodes for advanced NIBs.展开更多
基金acknowledge support from the National Natural Science Foundation of China(Nos.21922105,21931001,22201111,and 22271124)the National Key R&D Program of China(2021YFA1501101)+4 种基金the National Natural Science Foundation of Gansu Province(22JR5RA470)the Special Fund Project of Guiding Scientific and Technological Innovation Development of Gansu Province(2019ZX-04)the 111 Project(B20027).We also acknowledge support from the Fundamental Research Funds for the Central Universities(lzujbky-2021-sp62)the support of the Natural Science Foundation of China(NSFC)(No.21771156)the Early Career Scheme(ECS)fund(Grant PolyU253026/16P)from the Research Grant Council(RGC)in Hong Kong.
文摘The benefits of perovskite oxides include their low cost,customizable composition,ordered atomic structure,and extremely flexible electronic structure.They are the ideal substitute for precious metal catalysts in various electrocatalytic reactions.However,the initial activity of perovskite oxides is often quite limited,which is extremely related to their crystal structure and electronic structure.In this regard,component regulation is the simplest and most effective strategy to increase their stability and catalytic activity.In this review,we briefly outline the recent progress in the modulating component of perovskite oxides to enhance their catalytic properties.The outline was categorized according to the sites in the ABO3-type perovskite structure,including A-site,B-site,and O-site regulation.Finally,potential research directions aimed at modulating of perovskite oxide constituents are discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51627803,51402348,51421002,51372270,and 51372272)the Knowledge Innovation Program of the Chinese Academy of Sciences
文摘The Zn/Sn ratio in Cu2ZnSn（S, Se）4 （CZTSSe） films has been regulated to control the composition-related phase, defect, and photoelectric properties for high performance kesterite solar cells. It is found that the increase in the Zn/Sn ratio can slightly narrow the energy band gap to extend the light absorption range and improve the photocurrent. Optimal Zn/Sn ratio of 1.39 in CZTSSe film is obtained with the least secondary phase, the lowest defect density, and the longest charge recombination lifetime. Up to 10.1% photoelectric conversion efficiency has been achieved by this composition regulation.
基金supported by the Research Grants Council of Hong Kong(Nos.CityU 11305919 and 11308620)the NSFC/RGC Joint Research Scheme(No.N_CityU104/19)+1 种基金Hong Kong Re-search Grant Council Collaborative Research Fund(Nos.C1002-21 G and C1017-22 G)This research made use of the comput-ing resources of the X-GPU cluster supported by the Hong Kong Research Grant Council Collaborative Research Fund(No.C6021-19EF).
文摘Rechargeable metal-air batteries generally require efficient,durable,and safe bifunctional electrocatalysts to simultaneously support oxygen reduction/evolution reactions(ORR/OER).Herein,we employed first-principles calculations to explore the structure-activity relationship between the composition control of metal atoms and the catalytic activity of Pt-doped Ti_(2-x) Mn_(x) CO_(2) single-atom catalysts(SACs).The research found a clear linear relationship between the proportion of Mn and bifunctional performance,which can effectively modulate catalytic activity.Additionally,it shows excellent bifunctional catalytic activity at medium concentrations,among which the catalyst of Pt-V_(O)-Ti_(0.89) Mn_(1.11) CO_(2) displays the lowest overpo-tential(η^(ORR/OER)=0.26/0.28 V).Attributed to the modulation of the average magnetism of Mn and the d-band center of Pt by different com ponents,the bonding strength of the active center of Pt to adsorption intermediates is changed,resulting in the enhancement of the catalyst activity.Crucially,the molecular orbital-level bonding between the active site Pt and the adsorbed intermediate OH is clarified,shedding light on the involvement of the partially occupied antibonding state of Pt’s d orbital in the activation process.The research extensively explores the control of catalyst activity through composition,offering strong support for designing and optimizing highly active Janus MXene-supported SACs.
文摘Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely been produced through the modulation of their structure and composition.In this study,a series of bimetallic nickel-iron phosphide(Ni_(x)Fe_(2-x)P,where 0<x<2)cocatalysts with controllable structures and overpotentials were designed by adjusting the atomic ratio of Ni/Fe onto nonmetallic elemental red phosphorus(RP)for the photocatalytic selective oxidation of benzyl alcohol(BA)coupled with hydrogen production.The catalysts exhibited an outstanding photocatalytic activity for benzaldehyde and a high H_(2)yield.The RP regulated by bimetallic phosphide cocatalysts(Ni_(x)Fe_(2-x)P)demonstrated higher photocatalytic oxidation-reduction activity than that regulated by monometallic phosphide cocatalysts(Ni_(2)P and Fe2P).In particular,the RP regulated by Ni_(1.25)Fe_(0.75)P exhibited the best photocatalytic performance.In addition,experimental and theoretical calculations further illustrated that Ni_(1.25)Fe_(0.75)P,with the optimized electronic structure,possessed good electrical conductivity and provided strong adsorption and abundant active sites,thereby accelerating electron migration and lowering the reaction energy barrier of RP.This finding offers valuable insights into the rational design of highly effective cocatalysts aimed at optimizing the photocatalytic activity of composite photocatalysts.
文摘Reinforcement distribution tailoring has been proven effective in strengthening and toughening titanium matrix composites(TMCs).In this work,the analysis of the Ti64(Ti-6Al-4V)-B phase diagram indicated that B content dominates the TiB distribution.With this philosophy,B content regulation was applied to tailor homogeneous and network structures in Ti64-B composites fabricated via laser-directed energy deposition additive manufacturing(AM).The unique plate-like TiB attends inhomogeneous composites(Ti64–0.05B).However,in network composite(Ti64–0.25B),the TiB whisker(TiBw)arranges along priorβ-Ti grains with the same orientation.Moreover,the synergistic improvement of strength(988 MPa→1202 MPa),stiffness(106 GPa→116 GPa),hardness(325 HV→362 HV),and uniform elongation(5%→7.8%)were achieved.This work exhibited a balanced strength/ductility trade-off,which provides a good guide on microstructure tailoring.
基金financial support from the National Key Research and Development Program of China (No.2021YFB3502200)the National Natural Science Foundation of China (Grants Nos.52271202,51971040,52171101)+2 种基金the Shanghai Rising-Star Program (No.21QA1403200)supported by a start-up fund from Chongqing University (02110011044171)Liuchuang Program of Chongqing Municipality (cx2022038)。
文摘Magnesium-based energy materials, which combine promising energy-related functional properties with low cost, environmental compatibility and high availability, have been regarded as fascinating candidates for sustainable energy conversion and storage. In this review,we provide a timely summary on the recent progress in three types of important Mg-based energy materials, based on the fundamental strategies of composition and structure engineering. With regard to Mg-based materials for batteries, we systematically review and analyze different material systems, structure regulation strategies as well as the relevant performance in Mg-ion batteries(MIBs) and Mg-air batteries(MABs), covering cathodes, electrolytes, anodes for MIBs, and anodes for MABs;as to Mg-based hydrogen storage materials, we discuss how catalyst adding, composite, alloying and nanostructuring improve the kinetic and thermodynamic properties of de/hydrogenation reactions, and in particular, the impacts of composition and structure modification on hydrogen absorption/dissociation processes and free energy modification mechanism are focused;regarding Mg-based thermoelectric materials, the relations between composition/structure and electrical/thermal transport properties of Mg_(3)X_(2)(X = Sb, Bi), Mg_(2)X(X = Si, Ge, Sn) and Mg Ag Sb-based materials, together with the representative research progress of each material system, are summarized and discussed. Finally, by pointing out remaining challenges and providing possible solutions, this review aims to shed light on the directions and perspectives for practical applications of magnesium-based energy materials in the future.
基金supported by the International Partnership Program of Chinese Academy of Sciences(Grant No.121631KYSB20200039)the International Cooperation Project of Shanghai Science and Technology Commission(Grant No.20520750200)+3 种基金the National Key R&D Program of China(Grant No.2021YFE0104800)the Key Research Project of the Frontier Science of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-JSC022)support of the Czech Ministry of Education,Youth and Sports under Project SOLID21 CZ.02.1.(Grant No.01/0.0/0.0/16_019/0000760)Czech Science Foundation project(Grant No.GA21-17731S)is acknowledged with thanks。
文摘(Gd,Y,Ce)_(3)(Y_(x)Ga_(1−x))_(2)GaAl_(2)O_(12)(GYGAG:Ce)scintillation ceramics with different Y excess,where x=0.005−0.08,were fabricated by the solid-state reaction method.The effects of stoichiometry on the phase composition,optical quality,and microstructure of GYGAG:Ce ceramics were analyzed.GYGAG:Ce ceramics have a pure garnet phase and obtain good in-line transmittance when x<0.04,while more Y excess leads to the creation of the secondary phase.The change of x value influences the sintering behavior of the GYGAG:Ce ceramics:The excess of Y works as the self-sintering aid and significantly reduces the sintering temperature of ceramics.When x=0.01–0.04,the X-ray excited luminescence(XEL)spectra and light yields of GYGAG:Ce ceramics are similar.The fast scintillation decay time and afterglow intensity of GYGAG:Ce ceramics show a slight decrease with increasing x value.Finally,additional 50–500 ppm MgO and 100–500 ppm CaO were introduced to the GYGAG:Ce ceramic with x=0.04,and both were found to significantly increase the fast scintillation component and reduce the afterglow intensity by two orders of magnitude to 0.01%after X-ray cut-off.
基金funded by the National Natural Science Foundation of China(No.52102252)the Natural Science Foundation of Shandong Province(No.ZR2021QB052)China Postdoctoral Science Foundation(No.2021T140268).
文摘Layered P2-type cathodes with high voltage,large capacity,and easy synthesis show great potential for developing sodium(Na)-ion batteries(NIBs).However,the P2–O2 phase transition makes their structural degradation and the Na^(+)/vacancy ordering lowers their redox kinetics.Here,we rationally propose a compositionally graded P2-type cathode,where nickel(Ni)and manganese(Mn)fractions decrease gradually,and cobalt(Co)content increases contiguously from the inside to the outside of a secondary particle.Inside these particles,the Ni/Mn-based compound delivers high capacity and high voltage.On the surface of particles,the Co/Mn-based solid solution offers a stable buffer matrix.Benefiting from these synergistic effects,this graded P2-type cathode shows the elimination of P2–O2 transformation even when charged to 4.4 V,which enables good structural stability,maintaining capacity retention reaching~80%within 300 cycles.Moreover,the Na^(+)/vacancy ordering superstructure is further suppressed,and the Na^(+)diffusion kinetics is significantly improved.The proposed graded structure with optimized chemical composition offers a new perspective for eliminating the unwanted phase transition and thus enhancing the electrochemistry of high-voltage layered cathodes for advanced NIBs.
