In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active ...In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.展开更多
While most of the present medical implants are nonbiodegradable,biodegradable materials are thought to replace many nonbiodegradable ones in the future,which is dependent on development of the corresponding core techn...While most of the present medical implants are nonbiodegradable,biodegradable materials are thought to replace many nonbiodegradable ones in the future,which is dependent on development of the corresponding core techniques of biomaterials[1-4].Much progress has been made in the field of biodegradable materials during the last decade[5-7].展开更多
As an ideal solution to energy and environment issues,conversion of sunlight into solar fuels by photocatalytic water splitting and greenhouse gas(CO_2)reduction has attracted keen research interest of multi-field sci...As an ideal solution to energy and environment issues,conversion of sunlight into solar fuels by photocatalytic water splitting and greenhouse gas(CO_2)reduction has attracted keen research interest of multi-field scientists.In the past four decades,a large number of semiconductor photocatalysts have been展开更多
Recently,doped ternary zinc halides with high photoluminescence quantum yields(PLQYs)have demonstrated great potential in light emitting applications.However,the composition-dependent photophysical properties of terna...Recently,doped ternary zinc halides with high photoluminescence quantum yields(PLQYs)have demonstrated great potential in light emitting applications.However,the composition-dependent photophysical properties of ternary zinc halides have not been investigated,and their X-ray scintillation performances remain unexplored.Here,a compositional engineering strategy for highly efficient Cu^(+)-doped zerodimensional A_(2)ZnX_(4)(A=Rb,Cs;X=Cl,Br)blue emitters is presented.It is found that the A-site cations show a negligible influence on the emission spectra of both pure A_(2)ZnX_(4) and Cu^(+)-doped A_(2)ZnX_(4),while the change of the halide anion slightly shifts the emission peak of doped A_(2)ZnX_(4).The detailed photoluminescence(PL)studies indicate that the emission of Cu^(+)-doped A_(2)ZnX_(4) may come from two selftrapped exciton(STE)emission centers,namely Zn-related and Cu-related STEs.An energy transfer process from the Zn-related STE to the Cu-related STE is proposed.Based on the composition dependent photophysical and scintillation property study,Cu^(+)-doped Cs_(2)ZnBr_(4) is found to show the best scintillation performance among these zinc halides.Cu^(+)-doped Cs_(2)ZnBr_(4) shows a relatively high light yield of~10000 photons MeV^(-1),a low detection limit of 57 nGyair s^(-1),and good radiation stability.The X-ray imaging results based on a doped Cs_(2)ZnBr_(4) scintillation screen show a high spatial resolution of up to 9 line pairs per millimeter.These results demonstrate that the doped Cs_(2)ZnBr_(4) scintillator could be a potential candidate for sensitive X-ray detection and imaging.展开更多
A high breakdown strength(E_(b))together with a large maximum polarization(P_(m))is essential for achieving a high recoverable energy density(W_(rec))in energy storage dielectric ceramics.However,meeting the urgent ne...A high breakdown strength(E_(b))together with a large maximum polarization(P_(m))is essential for achieving a high recoverable energy density(W_(rec))in energy storage dielectric ceramics.However,meeting the urgent need for practical applications remains a challenge due to the intrinsic properties of bulk dielectric ceramics.Herein,a composition and structure optimization strategy combined with a two-step sintering(TSS)process is proposed to design and fabricate(1−x)Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9)O_(3−x)Bi(Mg_(1/2)Sn_(1/2))O_(3)(BCZT-BMSx-TSS)lead-free ceramics.Highly dynamic locally polar nano-regions(PNRs)are formed via composition optimization,exhibiting a very high P_(m) and energy storage efficiency(η).Compared to the traditional one-step sintering(OSS)process,the TSS process results in a composition with finer grain size and higher density,dramatically increasing E_(b).As a result,an ultrahigh energy storage performance with W_(rec)∼10.53 J cm^(−3) and η∼85.71%is achieved for the BCZT-BMSx-TSS(x=0.08)ceramic which is attributed to a record high E_(b)∼830 kV cm^(−1) and a large P_(m)∼44.66μC cm^(−2).Complex impedance spectroscopy revealed that the activation energies of the bulk and grain boundary counterparts significantly increased,suggesting an increase in insulation resistance and a decrease in oxygen vacancies,which is the main reason for the high E_(b) value.In addition,excellent thermal/frequency stability is achieved in both energy density and efficiency,along with good charge–discharge performance.These findings suggest that BCZT-based lead-free ceramics have the potential for practical use in the future.展开更多
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)
文摘In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.
文摘While most of the present medical implants are nonbiodegradable,biodegradable materials are thought to replace many nonbiodegradable ones in the future,which is dependent on development of the corresponding core techniques of biomaterials[1-4].Much progress has been made in the field of biodegradable materials during the last decade[5-7].
基金financially supported by the National Natural Science Foundation of China (U1305242 and 21673043)
文摘As an ideal solution to energy and environment issues,conversion of sunlight into solar fuels by photocatalytic water splitting and greenhouse gas(CO_2)reduction has attracted keen research interest of multi-field scientists.In the past four decades,a large number of semiconductor photocatalysts have been
基金financially supported by the Basic Science Center Program for Multiphase Evolution in Hypergravity of the National Natural Science Foundation of China(No.51988101)the National Natural Science Foundation of China(21701009,12174016)the Beijing Outstanding Young Scientists Projects(BJJWZYJH01201910005018).
文摘Recently,doped ternary zinc halides with high photoluminescence quantum yields(PLQYs)have demonstrated great potential in light emitting applications.However,the composition-dependent photophysical properties of ternary zinc halides have not been investigated,and their X-ray scintillation performances remain unexplored.Here,a compositional engineering strategy for highly efficient Cu^(+)-doped zerodimensional A_(2)ZnX_(4)(A=Rb,Cs;X=Cl,Br)blue emitters is presented.It is found that the A-site cations show a negligible influence on the emission spectra of both pure A_(2)ZnX_(4) and Cu^(+)-doped A_(2)ZnX_(4),while the change of the halide anion slightly shifts the emission peak of doped A_(2)ZnX_(4).The detailed photoluminescence(PL)studies indicate that the emission of Cu^(+)-doped A_(2)ZnX_(4) may come from two selftrapped exciton(STE)emission centers,namely Zn-related and Cu-related STEs.An energy transfer process from the Zn-related STE to the Cu-related STE is proposed.Based on the composition dependent photophysical and scintillation property study,Cu^(+)-doped Cs_(2)ZnBr_(4) is found to show the best scintillation performance among these zinc halides.Cu^(+)-doped Cs_(2)ZnBr_(4) shows a relatively high light yield of~10000 photons MeV^(-1),a low detection limit of 57 nGyair s^(-1),and good radiation stability.The X-ray imaging results based on a doped Cs_(2)ZnBr_(4) scintillation screen show a high spatial resolution of up to 9 line pairs per millimeter.These results demonstrate that the doped Cs_(2)ZnBr_(4) scintillator could be a potential candidate for sensitive X-ray detection and imaging.
基金supported by the Projects of the Jilin Provincial Science and Technology Department(Grant No.YDZJ202201ZYTS420)the Projects of the Jilin Provincial Education Department(Grant No.JJKH20230298KJ)the National Science Foundation for Yong Scientists China(Grant No.62004081).
文摘A high breakdown strength(E_(b))together with a large maximum polarization(P_(m))is essential for achieving a high recoverable energy density(W_(rec))in energy storage dielectric ceramics.However,meeting the urgent need for practical applications remains a challenge due to the intrinsic properties of bulk dielectric ceramics.Herein,a composition and structure optimization strategy combined with a two-step sintering(TSS)process is proposed to design and fabricate(1−x)Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9)O_(3−x)Bi(Mg_(1/2)Sn_(1/2))O_(3)(BCZT-BMSx-TSS)lead-free ceramics.Highly dynamic locally polar nano-regions(PNRs)are formed via composition optimization,exhibiting a very high P_(m) and energy storage efficiency(η).Compared to the traditional one-step sintering(OSS)process,the TSS process results in a composition with finer grain size and higher density,dramatically increasing E_(b).As a result,an ultrahigh energy storage performance with W_(rec)∼10.53 J cm^(−3) and η∼85.71%is achieved for the BCZT-BMSx-TSS(x=0.08)ceramic which is attributed to a record high E_(b)∼830 kV cm^(−1) and a large P_(m)∼44.66μC cm^(−2).Complex impedance spectroscopy revealed that the activation energies of the bulk and grain boundary counterparts significantly increased,suggesting an increase in insulation resistance and a decrease in oxygen vacancies,which is the main reason for the high E_(b) value.In addition,excellent thermal/frequency stability is achieved in both energy density and efficiency,along with good charge–discharge performance.These findings suggest that BCZT-based lead-free ceramics have the potential for practical use in the future.
