The energy storage behaviors of MnO_(2) for aqueous Zn-MnO_(2) batteries mainly depend on the Zn^(2+)/H^(+)intercalation but are limited by poor ion/electron migration dynamics and stability.Herein,a strategy is propo...The energy storage behaviors of MnO_(2) for aqueous Zn-MnO_(2) batteries mainly depend on the Zn^(2+)/H^(+)intercalation but are limited by poor ion/electron migration dynamics and stability.Herein,a strategy is proposed that promoting proton migration kinetics ameliorates H^(+)storage activity by introducing Ni^(2+)intoγ-MnO_(2)(Ni-MnO_(2)).Ni^(2+)can lower the diffusion barrier of H^(+)and selectively induce the ion intercalation,thereby alleviating the electrostatic interaction with the lattice.Moreover,Ni^(2+)enables the adjacent[MnO6]octahedrons to have better electron conductivity.The Ni-MnO_(2) exhibits superior rate performance(nearly four times specific capacity compared with MnO_(2))and ultra-long-cycle stability(100%of capacity retention after 11000 cycles at 3.0 A g^(-1)).The calculation indicates that the Ni-MnO_(2) allows H^(+)migrate rapidly along the one-dimensional tunnel due to reduction of the activation energy caused by Ni^(2+)regulating,thus achieving excellent reaction kinetics.This work brings great potential for the development of high-performance aqueous Zn-MnO_(2) batteries.展开更多
Accelerated charge migration and proton transfer to the reaction site are critical factors for improving photocatalytic efficiency.However,realizing both simultaneously is challenging because of the sluggish water(pro...Accelerated charge migration and proton transfer to the reaction site are critical factors for improving photocatalytic efficiency.However,realizing both simultaneously is challenging because of the sluggish water(proton source)oxidation kinetics and interdependent redox reactions.Herein,we design an imide and hydrogen bond to connect carbon nitride ports of the D-π-A system with the dual-engineered linkages.The system uses an acetylene functional group and an imidazole ring as spatially separated water oxidation and oxygen reduction reaction(ORR)catalytic centers for photogenerated charge separation,respectively.The imine bond is a bridge grafted to the oxidation site to act as a hydrogen proton trap,and the hydrogen bond formed between reduction site and carbon nitride is used as the channel for instantaneous proton delivery to the reduction center.In situ characterization confirms that the linking sites protonation optimizes the pathway of ORR to H_(2)O_(2) and facilitates the*OOH intermediates generated.It is concluded that proton transport plays a critical role in optimizing photocatalytic H_(2)O_(2) production.Our work provides a strategy to improve dynamic proton transfer mechanisms.展开更多
In hydrogen-fueled gas turbines,protons are more likely to penetrate the ceramic layer of thermal barrier coating(TBC)system and eventually reach the metallic bond coat.The knowledge about the atomic mechanism of prot...In hydrogen-fueled gas turbines,protons are more likely to penetrate the ceramic layer of thermal barrier coating(TBC)system and eventually reach the metallic bond coat.The knowledge about the atomic mechanism of proton migration in the ceramic layer of TBCs is important to evaluate the feasibility of using current TBCs in hydrogen-fueled gas turbines.In this work,tetragonal zirconia(T-ZrO_(2))and yttria-stabilized tetragonal zirconia(T-YSZ)are focused on,and the configurations,formation energies,and migration of hydrogen defects are studied.The orientation of O-H bond is related to the length of Zr-O bond.This characteristic orientation leads to the differentiation of proton migration paths from the cubic phase and further results in the anisotropy of proton migration.Moreover,the isolated Y atom and Y-oxygen vacancy(VO)-Y triple are introduced into the T-ZrO_(2)supercell to investigate their impacts on proton migration.The former has a limited impact,while the oxygen vacancy has a significant trapping effect on protons.This trapping effect is attributed to changes in the local characteristics(especially the electronic properties)of O atoms near VO due to lattice distortion.These findings provide critical insights into the proton migration mechanisms in TBCs,which are essential for optimizing TBCs for hydrogen-fueled gas turbine applications.展开更多
基金supported by the National Natural Science Foundation of China(No.52002122)the Science and Technology Department of Hubei Province(No.2019AAA038)+1 种基金the Project funded by China Postdoctoral Science Foundation(No.2021M690947)the Wuhan Yellow Crane Talent Program(No.2017-02).
文摘The energy storage behaviors of MnO_(2) for aqueous Zn-MnO_(2) batteries mainly depend on the Zn^(2+)/H^(+)intercalation but are limited by poor ion/electron migration dynamics and stability.Herein,a strategy is proposed that promoting proton migration kinetics ameliorates H^(+)storage activity by introducing Ni^(2+)intoγ-MnO_(2)(Ni-MnO_(2)).Ni^(2+)can lower the diffusion barrier of H^(+)and selectively induce the ion intercalation,thereby alleviating the electrostatic interaction with the lattice.Moreover,Ni^(2+)enables the adjacent[MnO6]octahedrons to have better electron conductivity.The Ni-MnO_(2) exhibits superior rate performance(nearly four times specific capacity compared with MnO_(2))and ultra-long-cycle stability(100%of capacity retention after 11000 cycles at 3.0 A g^(-1)).The calculation indicates that the Ni-MnO_(2) allows H^(+)migrate rapidly along the one-dimensional tunnel due to reduction of the activation energy caused by Ni^(2+)regulating,thus achieving excellent reaction kinetics.This work brings great potential for the development of high-performance aqueous Zn-MnO_(2) batteries.
文摘Accelerated charge migration and proton transfer to the reaction site are critical factors for improving photocatalytic efficiency.However,realizing both simultaneously is challenging because of the sluggish water(proton source)oxidation kinetics and interdependent redox reactions.Herein,we design an imide and hydrogen bond to connect carbon nitride ports of the D-π-A system with the dual-engineered linkages.The system uses an acetylene functional group and an imidazole ring as spatially separated water oxidation and oxygen reduction reaction(ORR)catalytic centers for photogenerated charge separation,respectively.The imine bond is a bridge grafted to the oxidation site to act as a hydrogen proton trap,and the hydrogen bond formed between reduction site and carbon nitride is used as the channel for instantaneous proton delivery to the reduction center.In situ characterization confirms that the linking sites protonation optimizes the pathway of ORR to H_(2)O_(2) and facilitates the*OOH intermediates generated.It is concluded that proton transport plays a critical role in optimizing photocatalytic H_(2)O_(2) production.Our work provides a strategy to improve dynamic proton transfer mechanisms.
基金supported by the National Natural Science Foundation of China(Nos.U21A2063 and 52102070)Yiran Li acknowledges research support from the Young Elite Scientists Sponsorship Program by CAST(No.2024QNRC001)+1 种基金Juanli Zhao acknowledges research support from the Jiangxi Provincial Program for the Development of Early Career Young Scientific and Technological Talents(No.20244BCE52254)Bin Liu acknowledges research support from the Shanghai Technical Service Center for Advanced Ceramics Structure Design and Precision Manufacturing(No.20DZ2294000).
文摘In hydrogen-fueled gas turbines,protons are more likely to penetrate the ceramic layer of thermal barrier coating(TBC)system and eventually reach the metallic bond coat.The knowledge about the atomic mechanism of proton migration in the ceramic layer of TBCs is important to evaluate the feasibility of using current TBCs in hydrogen-fueled gas turbines.In this work,tetragonal zirconia(T-ZrO_(2))and yttria-stabilized tetragonal zirconia(T-YSZ)are focused on,and the configurations,formation energies,and migration of hydrogen defects are studied.The orientation of O-H bond is related to the length of Zr-O bond.This characteristic orientation leads to the differentiation of proton migration paths from the cubic phase and further results in the anisotropy of proton migration.Moreover,the isolated Y atom and Y-oxygen vacancy(VO)-Y triple are introduced into the T-ZrO_(2)supercell to investigate their impacts on proton migration.The former has a limited impact,while the oxygen vacancy has a significant trapping effect on protons.This trapping effect is attributed to changes in the local characteristics(especially the electronic properties)of O atoms near VO due to lattice distortion.These findings provide critical insights into the proton migration mechanisms in TBCs,which are essential for optimizing TBCs for hydrogen-fueled gas turbine applications.
