For efficient colloidal quantum dot(CQD)solar cells(CQD-SCs),thiol-passivated p-type CQDs are generally used as a hole-transporting material(HTM);however,there are issues with the control of optoelectrical properties,...For efficient colloidal quantum dot(CQD)solar cells(CQD-SCs),thiol-passivated p-type CQDs are generally used as a hole-transporting material(HTM);however,there are issues with the control of optoelectrical properties,low thiol passivation rate,and poor morphology with a power conversion efficiency(PCE)of approximately 11%.Although polymeric HTMs have been introduced to address these issues,maximizing efficiency and achieving green-solvent processability and thermal stability for commercialization is necessary.Here,we synthesize a novel benzodifuran(BDF)-based HTM(asy-ranPBTBDF)showing an electron-deficient state,low steric hindrance,and low planarity compared to those of a typical benzodithiophene(BDT)-based HTM(asy-ranPBTBDT).BDF properties lead to deep high occupied molecular orbital(HOMO)levels,closeπ-πstacking,excellent solubility,and amorphous properties related to efficiency,green-solvent processability,and thermal stability.With these benefits,the asy-ranPBTBDF-based CQD-SC showed enhanced open-circuit voltage(Voc)(0.65 V)and PCE(13.29%)compared to those of the asy-ranPBTBDT-based device(0.63 V and 12.22%)in toxic processes with chlorobenzene.The asy-ranPBTBDF-based CQD-SC showed a PCE of 12.51%in a green-solvent process with 2-methylanisole and improved thermal stability at 80℃(83.8%retaining after 24 h)owing to less lateral crystallization than the asy-ranPBTBDT-based device(60.8%retaining after 24 h).展开更多
The neurovascular unit and stem cell therapy in ischemic stroke:Ischemic stroke,accounts for approximately 85% of all stroke incidents and is a major global health burden.It is the leading cause of disability and deat...The neurovascular unit and stem cell therapy in ischemic stroke:Ischemic stroke,accounts for approximately 85% of all stroke incidents and is a major global health burden.It is the leading cause of disability and death worldwide,posing immense societal and economic challenges due to the long-term care required for stro ke survivors and the significant healthcare costs associated with its treatment and management(Amarenco et al.,2009).展开更多
Exploring highly efficient Pt-free catalysts for hydrogen evolution reaction(HER)is of great importance for hydrogen(H2)production.Herein,a novel HER electrocatalyst having abundant ultra-small(2–3 nm)Ru electronical...Exploring highly efficient Pt-free catalysts for hydrogen evolution reaction(HER)is of great importance for hydrogen(H2)production.Herein,a novel HER electrocatalyst having abundant ultra-small(2–3 nm)Ru electronically confined by a B,N codoped polar carbon surface(Ru/(B-N)-PC)was constructed.The Ru/(B-N)-PC catalyst exhibits a low overpotential of 15 mV at the current density of 10 mA·cm^(−2),a low Tafel slope of 22.6 mV·dec^(−1),superior durability,which outperforms the benchmark Pt/C catalyst.Both experimental characterizations and theory calculations suggest that an electron communication established between B,N co-doped carbon surface and ultra-small Ru nanoparticles with electrons transferred from N atoms to Ru and backtransferred from Ru to B atoms,which exerts a moderate electronic modification of Ru.This,in turn,affords a modest H adsorption energy and a lower H2O dissociation barrier,leading to the high-performance hydrogen evolution reaction.The work provides meaningful insight into the size control and electronic modulation of Ru catalyst for intrinsic HER activity improvement.展开更多
基金supported by National Research Foundation of Korea(NRF)grant funded by Ministry of Science and ICT(MSIT)(2021R1A2C3004420,2021M3H4A1A02055684,and 2020R1C1C1012256)the DGIST R&D Program of the Ministry of Science and ICT(21-CoE-ET-01)Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1A6A3A14038599).
文摘For efficient colloidal quantum dot(CQD)solar cells(CQD-SCs),thiol-passivated p-type CQDs are generally used as a hole-transporting material(HTM);however,there are issues with the control of optoelectrical properties,low thiol passivation rate,and poor morphology with a power conversion efficiency(PCE)of approximately 11%.Although polymeric HTMs have been introduced to address these issues,maximizing efficiency and achieving green-solvent processability and thermal stability for commercialization is necessary.Here,we synthesize a novel benzodifuran(BDF)-based HTM(asy-ranPBTBDF)showing an electron-deficient state,low steric hindrance,and low planarity compared to those of a typical benzodithiophene(BDT)-based HTM(asy-ranPBTBDT).BDF properties lead to deep high occupied molecular orbital(HOMO)levels,closeπ-πstacking,excellent solubility,and amorphous properties related to efficiency,green-solvent processability,and thermal stability.With these benefits,the asy-ranPBTBDF-based CQD-SC showed enhanced open-circuit voltage(Voc)(0.65 V)and PCE(13.29%)compared to those of the asy-ranPBTBDT-based device(0.63 V and 12.22%)in toxic processes with chlorobenzene.The asy-ranPBTBDF-based CQD-SC showed a PCE of 12.51%in a green-solvent process with 2-methylanisole and improved thermal stability at 80℃(83.8%retaining after 24 h)owing to less lateral crystallization than the asy-ranPBTBDT-based device(60.8%retaining after 24 h).
基金supported by the NIH National Cancer Institute career development award(K25CA201545,to WL)。
文摘The neurovascular unit and stem cell therapy in ischemic stroke:Ischemic stroke,accounts for approximately 85% of all stroke incidents and is a major global health burden.It is the leading cause of disability and death worldwide,posing immense societal and economic challenges due to the long-term care required for stro ke survivors and the significant healthcare costs associated with its treatment and management(Amarenco et al.,2009).
基金the National Natural Science Foundation of China(No.22072069)the Research Fund Program of Guangdong Provincial Key Lab of Green Chemical Product Technology(No.GC202101)+3 种基金the Hubei Key Laboratory of Processing and Application of Catalytic materials(No.202121904)the State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter(No.20210012)the JST-ERATO Yamauchi Materials Space-Tectonics Project(No.JPMJER2003)the Researchers Supporting Project(No.RSP-2021/243),King Saud University,Riyadh,Saudi Arabia.
文摘Exploring highly efficient Pt-free catalysts for hydrogen evolution reaction(HER)is of great importance for hydrogen(H2)production.Herein,a novel HER electrocatalyst having abundant ultra-small(2–3 nm)Ru electronically confined by a B,N codoped polar carbon surface(Ru/(B-N)-PC)was constructed.The Ru/(B-N)-PC catalyst exhibits a low overpotential of 15 mV at the current density of 10 mA·cm^(−2),a low Tafel slope of 22.6 mV·dec^(−1),superior durability,which outperforms the benchmark Pt/C catalyst.Both experimental characterizations and theory calculations suggest that an electron communication established between B,N co-doped carbon surface and ultra-small Ru nanoparticles with electrons transferred from N atoms to Ru and backtransferred from Ru to B atoms,which exerts a moderate electronic modification of Ru.This,in turn,affords a modest H adsorption energy and a lower H2O dissociation barrier,leading to the high-performance hydrogen evolution reaction.The work provides meaningful insight into the size control and electronic modulation of Ru catalyst for intrinsic HER activity improvement.
