In past decades,Ni-based catalytic materials and electrodes have been intensively explored as low-cost hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts for water splitting.With increasing de...In past decades,Ni-based catalytic materials and electrodes have been intensively explored as low-cost hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts for water splitting.With increasing demands for Ni worldwide,simplifying the fabrication process,increasing Ni recycling,and reducing waste are tangible sustainability goals.Here,binder-free,heteroatom-free,and recyclable Ni-based bifunctional catalytic electrodes were fabricated via a one-step quick electrodeposition method.Typically,active Ni nanodot(NiND)clusters are electrodeposited on Ni foam(NF)in Ni(NO3)2 acetonitrile solution.After drying in air,NiO/NiND composites are obtained,leading to a binder-free and heteroatom-free NiO/NiNDs@NF catalytic electrode.The electrode shows high efficiency and long-term stability for catalyzing hydrogen and oxygen evolution reactions at low overpotentials(10ηHER= 119 mV and 50ηOER=360 mV)and can promote water catalysis at 1.70 V@ 10mA cm-2.More importantly,the recovery of raw materials(NF and Ni(NO3)2)is quite easy because of the solubility of NiO/NiNDs composites in acid solution for recycling the electrodes.Additionally,a large-sized(S^70 cm2)NiO/NiNDs@NF catalytic electrode with high durability has also been constructed.This method provides a simple and fast technology to construct high-performance,low-cost,and environmentally friendly Ni-based bifunctional electrocatalytic electrodes for water splitting.展开更多
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
By introducing various low concentrations of Iridium complexes to the famous donor polymer of PTB7-Th backbone,new heavy metal containing terpolymers have been demonstrated.When blended with PC71BM,an obvious increase...By introducing various low concentrations of Iridium complexes to the famous donor polymer of PTB7-Th backbone,new heavy metal containing terpolymers have been demonstrated.When blended with PC71BM,an obvious increase of power conversion efficiency(PCE)is obtained in 1 mol%Ir containing polymer for different photovoltaic devices either using Ca or PDIN as cathode interface layers.The impact of molecular weight on the photovoltaic performance has been particularly considered by using three batches of control polymer PTB7-Th to ensure a fair and more convincing comparison.At similar molecular weight conditions(Mn:~60 kg mol−1,M_(w):100-110 kg mol^(−1)),the 1 mol%Ir containing PTB7-ThIr1/PC71BM blends exhibits enhanced PCE to 9.19%compared with 7.92%of the control PTB7-Th.Through a combination of physical measurement,such as optoelectrical characterization,GIWAXS and pico-second time-resolved photoluminescence,the enhancement are contributed from comprehensive factors of higher hole mobility,less bimolecular recombination and more efficient slow process of charge separation.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
基金the China and Germany Postdoctoral Exchange Program for this research in Helmholtz-Zentrum Berlin für Materialien und Energiethe Postdoctoral Science Foundation of China (2017M610324)NSFC (21704040)
文摘In past decades,Ni-based catalytic materials and electrodes have been intensively explored as low-cost hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts for water splitting.With increasing demands for Ni worldwide,simplifying the fabrication process,increasing Ni recycling,and reducing waste are tangible sustainability goals.Here,binder-free,heteroatom-free,and recyclable Ni-based bifunctional catalytic electrodes were fabricated via a one-step quick electrodeposition method.Typically,active Ni nanodot(NiND)clusters are electrodeposited on Ni foam(NF)in Ni(NO3)2 acetonitrile solution.After drying in air,NiO/NiND composites are obtained,leading to a binder-free and heteroatom-free NiO/NiNDs@NF catalytic electrode.The electrode shows high efficiency and long-term stability for catalyzing hydrogen and oxygen evolution reactions at low overpotentials(10ηHER= 119 mV and 50ηOER=360 mV)and can promote water catalysis at 1.70 V@ 10mA cm-2.More importantly,the recovery of raw materials(NF and Ni(NO3)2)is quite easy because of the solubility of NiO/NiNDs composites in acid solution for recycling the electrodes.Additionally,a large-sized(S^70 cm2)NiO/NiNDs@NF catalytic electrode with high durability has also been constructed.This method provides a simple and fast technology to construct high-performance,low-cost,and environmentally friendly Ni-based bifunctional electrocatalytic electrodes for water splitting.
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Research Program between China and European Union(2016YFE0112000)the Natural Science Foundation of Jiangsu Province(BK20160042)for financial support.
文摘By introducing various low concentrations of Iridium complexes to the famous donor polymer of PTB7-Th backbone,new heavy metal containing terpolymers have been demonstrated.When blended with PC71BM,an obvious increase of power conversion efficiency(PCE)is obtained in 1 mol%Ir containing polymer for different photovoltaic devices either using Ca or PDIN as cathode interface layers.The impact of molecular weight on the photovoltaic performance has been particularly considered by using three batches of control polymer PTB7-Th to ensure a fair and more convincing comparison.At similar molecular weight conditions(Mn:~60 kg mol−1,M_(w):100-110 kg mol^(−1)),the 1 mol%Ir containing PTB7-ThIr1/PC71BM blends exhibits enhanced PCE to 9.19%compared with 7.92%of the control PTB7-Th.Through a combination of physical measurement,such as optoelectrical characterization,GIWAXS and pico-second time-resolved photoluminescence,the enhancement are contributed from comprehensive factors of higher hole mobility,less bimolecular recombination and more efficient slow process of charge separation.
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.