In-depth understandings of charge carrier transfer dynamics in any artificial catalytic system are of critical importance for the future design of highly efficient photocatalysts.Herein,we synthesized sub-monolayer Zn...In-depth understandings of charge carrier transfer dynamics in any artificial catalytic system are of critical importance for the future design of highly efficient photocatalysts.Herein,we synthesized sub-monolayer ZnSe partial-shell coated CdSe/CdS core/shell quantum dots in a controlled fashion.The ZnSe decorated quantum dots were employed as a model catalyst for photogeneration of H_(2)under light illumination.Both theoretical calculations and experimental results unravel that the growth of ZnSe partial-shell would retard the photogenerated electron transfer,and meanwhile,accelerate the corresponding hole migration process during the H_(2)photogeneration reaction in the artificial photocatalytic system.As such,the performance of the relevant photocatalytic system can be modulated and optimized,and accordingly,a plausible underlying mechanism is rationalized.展开更多
The unique structure of zero-dimensional(0D)perovskite-analogues has attracted a great amount of research interest in recent years.To date,the current compositional library of 0D perovskites is largely limited to the ...The unique structure of zero-dimensional(0D)perovskite-analogues has attracted a great amount of research interest in recent years.To date,the current compositional library of 0D perovskites is largely limited to the lead-based Cs4PbX6(X=Cl,Br,and I)systems.In this work,we report a new synthesis of lead-free 0D Cs3BiX6(X=Cl,Br)perovskite-analogue nanocrystals(NCs)with a uniform cubic shape.We observe a broad photoluminescence peak centered at 390 nm for the 0D Cs3BiCl6 NCs at low temperatures.This feature originates from a self-trapped exciton mechanism.In situ thermal stability studies show that Cs3BiX6 NCs remain stable upon heating up to 200°C without crystal structural degradation.Moreover,we demonstrate that the Cs3BiX6 NCs can transform into other bismuth-based perovskite-analogues via facile anion exchange or metal ion insertion reactions.Our study presented here offers the opportunity for further understanding of the structure-property relationship of 0D perovskite-analogue materials,leading toward their future optoelectronic applications.展开更多
文摘In-depth understandings of charge carrier transfer dynamics in any artificial catalytic system are of critical importance for the future design of highly efficient photocatalysts.Herein,we synthesized sub-monolayer ZnSe partial-shell coated CdSe/CdS core/shell quantum dots in a controlled fashion.The ZnSe decorated quantum dots were employed as a model catalyst for photogeneration of H_(2)under light illumination.Both theoretical calculations and experimental results unravel that the growth of ZnSe partial-shell would retard the photogenerated electron transfer,and meanwhile,accelerate the corresponding hole migration process during the H_(2)photogeneration reaction in the artificial photocatalytic system.As such,the performance of the relevant photocatalytic system can be modulated and optimized,and accordingly,a plausible underlying mechanism is rationalized.
基金support from Brown University startup funds and the National Science Foundation(OIA-1538893)K.H.-K.is supported by the U.S.Department of Education GAANN research fellowship(P200A150037)。
文摘The unique structure of zero-dimensional(0D)perovskite-analogues has attracted a great amount of research interest in recent years.To date,the current compositional library of 0D perovskites is largely limited to the lead-based Cs4PbX6(X=Cl,Br,and I)systems.In this work,we report a new synthesis of lead-free 0D Cs3BiX6(X=Cl,Br)perovskite-analogue nanocrystals(NCs)with a uniform cubic shape.We observe a broad photoluminescence peak centered at 390 nm for the 0D Cs3BiCl6 NCs at low temperatures.This feature originates from a self-trapped exciton mechanism.In situ thermal stability studies show that Cs3BiX6 NCs remain stable upon heating up to 200°C without crystal structural degradation.Moreover,we demonstrate that the Cs3BiX6 NCs can transform into other bismuth-based perovskite-analogues via facile anion exchange or metal ion insertion reactions.Our study presented here offers the opportunity for further understanding of the structure-property relationship of 0D perovskite-analogue materials,leading toward their future optoelectronic applications.
