Comprehensive Summary Conjugated fused-ring structures have attracted extensive attention due to their high molecular rigidity to restrain excited-state relaxation and non-radiative decay,and further to enhance the lu...Comprehensive Summary Conjugated fused-ring structures have attracted extensive attention due to their high molecular rigidity to restrain excited-state relaxation and non-radiative decay,and further to enhance the luminance efficiency for emissive materials.Herein,we develop a series of donor-acceptor type thermally activated delayed fluorescence(TADF)emitters by introducing fused-ring 5H-benzofuro[3,2-c]carbazole(32BFCz)as electron donating unit.Through optimizing the numbers and structure of donor and acceptor moieties,three compounds named 32BFCzA,mCF3BFCzOXD and dCF3BFCzOXD are designed,which are composed by mono-32BFCz/trifluoromethylpicolinonitrile,penta-BFCz/3-(trifluoromethyl)phenyl)-1,3,4-oxadiazol-2-yl)benzene and penta-32BFCz/3,5-bis(trifluoromethyl)phenyl)-1,3,4-oxadiazol-2-yl)benzene as donor/acceptor groups,respectively.展开更多
The highest efficiency thermally activated delayed fluorescence(TADF)emitters in OLEDs are mostly based on twisted donor/acceptor(D/A)type organic molecules.Herein,we report the rational molecular design on twisted al...The highest efficiency thermally activated delayed fluorescence(TADF)emitters in OLEDs are mostly based on twisted donor/acceptor(D/A)type organic molecules.Herein,we report the rational molecular design on twisted all ortho-linked carbazole/oxadiazole(Cz/OXD)hybrids with tunable D-A interactions by adjusting the numbers of donor/acceptor units and electron-donating abilities.Singlet-triplet energy bandgaps(ΔEST)are facilely tuned from^0.4,0.15 to^0 eV in D-A,D-A-D to A-D-A type compounds.This variation correlates well with triplet-excited-state frontier orbital spatial separation efficiency.NonTADF feature with solid state photoluminescence quantum yield(PLQY)<10%is observed in D-A type 2CzOXD and D-A-D type 4CzOXD.Owing to the extremely lowΔEST for efficient reverse intersystem crossing,strong TADF with PLQY of 71%-92%is achieved in A-D-A type 4CzDOXD and 4tCzDOXD.High external quantum efficiency from 19.4%to 22.6%is achieved in A-D-A typed 4CzDOXD and 4tCzDOXD.展开更多
The design and construction of effective and stable hydrogen evolution reaction(HER)catalysts represent the key to obtaining hydrogen energy economically.Transition metal phosphides(TMPs)have attracted considerable at...The design and construction of effective and stable hydrogen evolution reaction(HER)catalysts represent the key to obtaining hydrogen energy economically.Transition metal phosphides(TMPs)have attracted considerable attention due to their unique catalytic mechanism,which is similar to hydrogenase.However,single-phase TMPs remain limited by their low activity and weak stability in alkaline solutions.In this work,CoP@CoMoO4 nanosheets with phosphide and oxide heterostructure were synthesized on carbon cloth(CC)through hydrothermal method and subsequently reacted with red phosphorus in a tube furnace.The outstanding synergy between CoP and CoMoO4 enhanced the HER activity and stability in alkaline solution.The CoP@CoMoO4/CC heterostructure exhibited excellent HER activity with a low overpotential of 89 mV at 10 mA cm^-2 with Tafel slope of 69 mV dec^-1,and outstanding stability when compared with single-phase phosphides.Our present research provides a new approach for the preparation of inexpensive,highly active,and highly durable phosphorus-based catalyst for HER.展开更多
基金the National Natural Science Foundation of China(Nos.91833304 and 61761136013).
文摘Comprehensive Summary Conjugated fused-ring structures have attracted extensive attention due to their high molecular rigidity to restrain excited-state relaxation and non-radiative decay,and further to enhance the luminance efficiency for emissive materials.Herein,we develop a series of donor-acceptor type thermally activated delayed fluorescence(TADF)emitters by introducing fused-ring 5H-benzofuro[3,2-c]carbazole(32BFCz)as electron donating unit.Through optimizing the numbers and structure of donor and acceptor moieties,three compounds named 32BFCzA,mCF3BFCzOXD and dCF3BFCzOXD are designed,which are composed by mono-32BFCz/trifluoromethylpicolinonitrile,penta-BFCz/3-(trifluoromethyl)phenyl)-1,3,4-oxadiazol-2-yl)benzene and penta-32BFCz/3,5-bis(trifluoromethyl)phenyl)-1,3,4-oxadiazol-2-yl)benzene as donor/acceptor groups,respectively.
基金National Natural Science Foundation of China(Nos.91833304,61805211)National Key Research and Development Program of China for the Joint Research Program between China and European Union(No.2016YFE0112000)+1 种基金the Natural Science Foundation of Jiangsu Province(Nos.BK20160042 and XYDXX-026)the Foundation for the Author of National Excellent Doctoral Dissertation of China FANEDD(No.201436)
文摘The highest efficiency thermally activated delayed fluorescence(TADF)emitters in OLEDs are mostly based on twisted donor/acceptor(D/A)type organic molecules.Herein,we report the rational molecular design on twisted all ortho-linked carbazole/oxadiazole(Cz/OXD)hybrids with tunable D-A interactions by adjusting the numbers of donor/acceptor units and electron-donating abilities.Singlet-triplet energy bandgaps(ΔEST)are facilely tuned from^0.4,0.15 to^0 eV in D-A,D-A-D to A-D-A type compounds.This variation correlates well with triplet-excited-state frontier orbital spatial separation efficiency.NonTADF feature with solid state photoluminescence quantum yield(PLQY)<10%is observed in D-A type 2CzOXD and D-A-D type 4CzOXD.Owing to the extremely lowΔEST for efficient reverse intersystem crossing,strong TADF with PLQY of 71%-92%is achieved in A-D-A type 4CzDOXD and 4tCzDOXD.High external quantum efficiency from 19.4%to 22.6%is achieved in A-D-A typed 4CzDOXD and 4tCzDOXD.
基金the Key Research and Development Project of Hainan Province(No.ZDYF2018106)the National Natural Science Foundation of China(No.51901059,No.11563003,No.11203009)。
文摘The design and construction of effective and stable hydrogen evolution reaction(HER)catalysts represent the key to obtaining hydrogen energy economically.Transition metal phosphides(TMPs)have attracted considerable attention due to their unique catalytic mechanism,which is similar to hydrogenase.However,single-phase TMPs remain limited by their low activity and weak stability in alkaline solutions.In this work,CoP@CoMoO4 nanosheets with phosphide and oxide heterostructure were synthesized on carbon cloth(CC)through hydrothermal method and subsequently reacted with red phosphorus in a tube furnace.The outstanding synergy between CoP and CoMoO4 enhanced the HER activity and stability in alkaline solution.The CoP@CoMoO4/CC heterostructure exhibited excellent HER activity with a low overpotential of 89 mV at 10 mA cm^-2 with Tafel slope of 69 mV dec^-1,and outstanding stability when compared with single-phase phosphides.Our present research provides a new approach for the preparation of inexpensive,highly active,and highly durable phosphorus-based catalyst for HER.