Indoles and their derivatives are an important class of N-heterocycles.In this article,iridium-catalyzed annulation reactions of N-aryl-2-aminopyridines to synthesize indole derivatives are designed and developed,whic...Indoles and their derivatives are an important class of N-heterocycles.In this article,iridium-catalyzed annulation reactions of N-aryl-2-aminopyridines to synthesize indole derivatives are designed and developed,which utilize vinylene carbonate as a new C2 synthon.This protocol is expected to provide a facile and useful access to various indole derivatives.展开更多
Proton exchange membrane water electrolysis(PEMWE)technology is widely recognized as a cornerstone for green hydrogen production,offering high operational current densities exceeding 1.0 A cm^(-2),rapid dynamic respon...Proton exchange membrane water electrolysis(PEMWE)technology is widely recognized as a cornerstone for green hydrogen production,offering high operational current densities exceeding 1.0 A cm^(-2),rapid dynamic response capabilities,and zero-carbon emission characteristics[1].However,the sluggish kinetics of oxygen evolution reaction(OER)at the anode presents a critical bottleneck for large-scale commercial deployment(Fig.1(a)).Despite significant advancements through electronic structure modulation[2]and coordination environment optimization[3],the deprotonation energy barrier of oxygen-containing intermediates and the stability of active sites under acidic conditions remain unresolved challenges.展开更多
Effects of film-forming additive on stability of electrode and cycling performance of LiFePO4/graphite cell at elevated temperature were studied. Two 18650 cells with and without VC additive were investigated by galva...Effects of film-forming additive on stability of electrode and cycling performance of LiFePO4/graphite cell at elevated temperature were studied. Two 18650 cells with and without VC additive were investigated by galvanostatic cycling, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis and Raman spectroscopy. The results show that in the presence of VC additive, dissolution of Fe from LiFePO4 material is greatly depressed and stability of graphite structure is improved; the additive can not only reduce reaction of electrolyte on surface of LiFePO4 electrode but also suppress reduction of solvent and thickening of the solid electrolyte interface （SEI） layer on graphite surface. Electrolyte with VC is considered to be a good candidate for improving cycling performance of the LiFePOa/graphite cell at elevated temperature.展开更多
Application of sodium-ion batteries is suppressed due to the lack of appropriate electrolytes matching cathode and anode simultaneously.Ether-based electrolytes,preference of anode materials,cannot match with high-pot...Application of sodium-ion batteries is suppressed due to the lack of appropriate electrolytes matching cathode and anode simultaneously.Ether-based electrolytes,preference of anode materials,cannot match with high-potential cathodes failing to apply in full cells.Herein,vinylene carbonate(VC)as an additive into NaCF_(3) SO_(3)-Diglyme(DGM)could make sodium-ion full cells applicable without preactivation of cathode and anode.The assembled FeS@C||Na3 V2(PO_(4))_(3)@C full cell with this electrolyte exhibits long term cycling stability and high capacity retention.The deduced reason is additive VC,whose HOMO level value is close to that of DGM,not only change the solvent sheath structure of Na^(+),but also is synergistically oxidized with DGM to form integrity and consecutive cathode electrolyte interphase on Na3 V2(PO_(4))_(3)@C cathode,which could effectively improve the oxidative stability of electrolyte and prevent the electrolyte decomposition.This work displays a new way to optimize the sodium-ion full cell seasily with bright practical application potential.展开更多
A series of soluble poly(p-phenylene vinylene)(PPV)derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials.The electronic characteristics of PPV derivatives were studied.
A new strategy is developed for the synthesis of 1-aminoisoquinoline derivatives.This Rh(III)-catalyzed[4+2]annulation reaction employs benzamidines as efficient directing groups and the vinylene carbonate as an acety...A new strategy is developed for the synthesis of 1-aminoisoquinoline derivatives.This Rh(III)-catalyzed[4+2]annulation reaction employs benzamidines as efficient directing groups and the vinylene carbonate as an acetylene surrogate.Additionally,the reaction features broad substrate scopes and good yields,only producing carbonate anion as byproduct.展开更多
It was found that traces of water in the reaction medium would result in a great increase of gel and a decrease of Molecular weight of the poly(2-methoxy,5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) during the pol...It was found that traces of water in the reaction medium would result in a great increase of gel and a decrease of Molecular weight of the poly(2-methoxy,5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) during the polymerization, which ultimately led to inferior film qualities and device properties. The device (ITO/PEDOT/MEH-PPV/Ba/Al) with MEH-PPV prepared under dry conditions has an external quantum efficiency of above 2.0%.展开更多
Ionic liquids have been paid much attention and are considered to replace the conventional organic electrolyte and solve the safety issues by virtue of nonvolatility,non-flammability,high ionic conductivity and extend...Ionic liquids have been paid much attention and are considered to replace the conventional organic electrolyte and solve the safety issues by virtue of nonvolatility,non-flammability,high ionic conductivity and extended electrochemical steady window.The paper introduces ionic liquids electrolyte on basis of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI),which shows a wide electrochemical window (0.5-4.5 V vs.Li+/Li),and is theoretically feasible as an electrolyte for Li/LiFePO4batteries to improve the safety.Linear sweep voltammetry (LSV) was performed to investigate the electrochemical stability window of the polymer electrolyte.Interfacial resistance for Li/electrolyte/Li symmetric cells and Li/electrolyte/LiFePO4 cells were studied by electrochemical impedance spectroscopy (EIS).The results showed that additive vinylene carbonate (VC) enhances the formation of solid electrolyte interphase film to protect lithium anodes from corrosion and improves the compatibility of ionic liquid electrolyte towards lithium anodes.Accordingly,Li/LiFePO4cells delivers the initial discharge capacity of 124 mAh g-1 at a current rate of 0.1C in the ionic liquid electrolyte (EMITFSI+0.8 mol L-1LiTFSI+5 wt%VC),and shows better cyclability than in the ionic liquid electrolyte without VC.展开更多
The surface conductivity of poly [ 2-methoxy-5-（3＇-methyl） butoxy]-p-phenylene vinylene （PMOMBOPV） films doped with FeCl3 and H2SO4 by chemical method and implanted by N^＋ ions was studied and the comparison of ...The surface conductivity of poly [ 2-methoxy-5-（3＇-methyl） butoxy]-p-phenylene vinylene （PMOMBOPV） films doped with FeCl3 and H2SO4 by chemical method and implanted by N^＋ ions was studied and the comparison of environmental stability of conductive behavior was also investigated. The energy and dose of N^＋ ions were in the rang 15～35 keV and 3. 8×10^15～9. 6×10^16 ions/cm^2, respectively. The conductivity of PMOMBOPV film was enhanced remarkably with the increases of the energy and dose of N^＋ ions. For example, the conductivity of PMOMBOPV film was 3. 2×10^-2S/cm when ion implantation was performed with an energy of 35 keV at a dose of 9. 6 × 10^14 ions/cm^2 , which was almost seven orders of magnitude higher than that of film unimplanted. The environmental stability of conductive behavior for ionimplanted film was much better than that of chemical doped films. Moreover, the conductive activation energy of ion-implanted films was measured to be about 0.17 eV.展开更多
Solid polymer electrolytes(SPEs)have attracted considerable attention for solid-state lithium-metal batteries(LMBs)with high energy density and enhanced safety for future applications.In this study,an SPE was devel-op...Solid polymer electrolytes(SPEs)have attracted considerable attention for solid-state lithium-metal batteries(LMBs)with high energy density and enhanced safety for future applications.In this study,an SPE was devel-oped based on a poly(ethyl acrylate)(PEA)polymer matrix with the vinylene carbonate(VC)additive(defined as PEA-VC)for high-voltage solid-state LMBs.Results show that introducing the VC additive into the PEA-based SPE leads to high lithium-ion conductivity(1.57 mS/cm at 22°C),a high lithium-ion transference number(0.73),and a wide electrochemical stability window(up to 4.9 V vs.Li/Li^(+)).The remarkable compatibil-ity of the PEA-VC SPE with lithium metal anodes and high-voltage cathodes was demonstrated in Li//Li symmetric cells(800 h lifetime at a current density of 0.1 mA/cm^(2) at 22°C)and Li//LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)full cells(with a capacity retention of 77.8%after 100 cycles at 0.2C).The improved stability is attributed to the introduction of the VC additive,which helps form a robust cathode–electrolyte interphase,effectively suppressing parasitic interface side reactions.Overall,this study highlights the role of VC addi-tives in high-voltage and solid-state LMBs,offering a general yet effective approach for addressing the interfa-cial instability issue through an additive-engineering strategy.展开更多
Methacrylic acid first was neutralized with an aqueous solution of NaOH to pH = 6.0 similar to 7.0, vinylene carbonate (VCA) was added to the solution, then monomers were copolymerized in paraffin oil by means of reve...Methacrylic acid first was neutralized with an aqueous solution of NaOH to pH = 6.0 similar to 7.0, vinylene carbonate (VCA) was added to the solution, then monomers were copolymerized in paraffin oil by means of reverse-phase suspension polymerization and hydrophilic copolymeric supports were prepared. The properties of the supports were determined using trypsin and results show that the amount of enzymes coupled to the supports and the specific activity of immobilized trypsin are related to the content of VCA structure units, reaction time and concentration of enzyme solution, etc.展开更多
Bulk polymerization of vinylene carbonate using t-butylperoxypivalate at 40℃gave colourless, high molecular weight poly(vinylene carbonate) (PVCA). Solutions of PVCA in acetone and DMF are not stable at 25℃and this ...Bulk polymerization of vinylene carbonate using t-butylperoxypivalate at 40℃gave colourless, high molecular weight poly(vinylene carbonate) (PVCA). Solutions of PVCA in acetone and DMF are not stable at 25℃and this degradation was studied. From measurements in DMF with unfractionated PVCA a Mark-Houwink equation was obtained:展开更多
Photocatalytic hydrogen(H_(2))evolution using covalent organic frameworks(COFs)is an attractive and promising avenue for exploration,but one of its big challenges is low photo-induced charge separation.In this study,w...Photocatalytic hydrogen(H_(2))evolution using covalent organic frameworks(COFs)is an attractive and promising avenue for exploration,but one of its big challenges is low photo-induced charge separation.In this study,we present a straightforward and facile dipole polarization engineering strategy to enhance charge separation efficiency,achieved through atomic modulation(O,S,and Se)of the COF monomer.Our findings demonstrate that incorporating atoms with varying electronegativities into the COF matrix significantly influences the local dipole moment,thereby affecting charge separation efficiency and photostability,which in turn affects the rates of photocatalytic H_(2) evolution.As a result,the newly developed TMT-BO-COF,which contains highly electronegative O atoms,exhibits the lowest exciton binding energy,the highest efficiency in charge separation and transportation,and the longest lifetime of the active charges.This leads to an impressive average H_(2) production rate of 23.7 mmol g^(−1) h^(−1),which is 2.5 and 24.5 times higher than that of TMT-BS-COF(containing S atoms)and TMT-BSe-COF(containing Se atoms),respectively.A novel photocatalytic hydrogen evolution mechanism based on proton-coupled electron transfer on N in the structure of triazine rings in vinylene-linked COFs is proposed by theoretical calculations.Our findings provide new insights into the design of highly photoactive organic framework materials for H_(2) evolution and beyond.展开更多
Among various perylenediimide(PDI)-based small molecular non-fullerene acceptors(NFAs),PDI dimer can effectively avoid the excessive aggregation of single PDI and improve the photovoltaic performance.However,the twist...Among various perylenediimide(PDI)-based small molecular non-fullerene acceptors(NFAs),PDI dimer can effectively avoid the excessive aggregation of single PDI and improve the photovoltaic performance.However,the twist of perylene core in PDI dimer will destroy the effective conjugation.Thus,ring annulation of PDI dimer is a feasible method to balance the film quality and electron transport,but the systematic study has attracted few attentions.Herein,we choose a simple vinylene linked PDI dimer,V-PDI2,and then conduct further studies on the structure-property-performance relationship of four kinds of derived fused-PDI dimers,namely V-TDI2,V-FDI2,V-PDIS2 and V-PDISe2 respectively.The former two are incorporated thianaphthene and benzofuran at the inside bay positions,and the latter two are fused thiophene and selenophene at the outside bay positions,respectively.Theoretical calculations reveal the inside-and outside-fused structures largely affect the skeleton configuration,the former two tend to be planar structure and the latter two maintain the distorted backbone.The photovoltaic characterizations show that the inside-fused PDI dimers offer high open circuit voltage(VOC),while the outside-fused PDI dimers afford large short-circuit current density(JSC).This variation tendency results from the reasonably tunable energy levels,light absorption,molecular crystallinity and film morphology.As a result,PBDB-T:V-PDISe2 device exhibits the highest power conversion efficiency(PCE)of 6.51%,and PBDB-T:VFDI2 device realizes the highest VOC of 1.00 V.This contribution indicates that annulation of PDI dimers in outside or inside bay regions is a feasible method to modulate the properties of PDI-based non-fullerene acceptors.展开更多
Soluble poly(3-hexyl-2,5-thienylene vinylene) (PHTV) was readily synthesized from thiophene in a yield better than that of the precursor method to prepare poly(thienylene vinylene) (PTV). The bandgap of the polymer is...Soluble poly(3-hexyl-2,5-thienylene vinylene) (PHTV) was readily synthesized from thiophene in a yield better than that of the precursor method to prepare poly(thienylene vinylene) (PTV). The bandgap of the polymer is about 1.8 eV, which is comparable with that of PTV. Owing to the introduction of alkyl side groups onto the backbone of the polymer, it can be dissolved in common organic solvents such as chloroform, THF and toluene. The synthesis of soluble PHTV is a very important approach to preventing oxidation and to improving the properties and the processbility of the PTV. The existence of alkyl side groups in PHTV does not affect its, bandgap and thermal properties as compared with PTV. After doping with FeCl3, the conductivity of PHTV is as high as 1.1 x 10(-2) S/cm. The soluble PHTV can be easily transformed into thin film with much better quality than that of the PTV film prepared by the traditional precursor method, which is very important for fabricating devices with good properties.展开更多
Based on an analysis of the 1H NMR,FT-IR,UV-vis spectra,a chiral trimeric phenylene vinylene derivative（ChTPV） synthesized by a Wittig reaction was determined to have a trans-cis configuration, and it could be isome...Based on an analysis of the 1H NMR,FT-IR,UV-vis spectra,a chiral trimeric phenylene vinylene derivative（ChTPV） synthesized by a Wittig reaction was determined to have a trans-cis configuration, and it could be isomerized to the trans-trans isomer when treated with iodine.The melting point of ChTPV with a trans-trans configuration increased by 162.1℃compared to the trans-cis isomer,and the ChTPV with trans-trans configuration exhibited the typical liquid-crystalline texture of the smectic A in the heating process.The results indicated that the molecular configuration can influence the formation of the liquid crystalline phase of ChTPV.展开更多
A series of new silicon-containing poly（p-arylene vinylene）s （PAVs） with anthracene units in the main chain were synthesized by hydrosilylation reaction. The introduction of organosilicon units improved the solubi...A series of new silicon-containing poly（p-arylene vinylene）s （PAVs） with anthracene units in the main chain were synthesized by hydrosilylation reaction. The introduction of organosilicon units improved the solubility of the polymers, and the π-π conjugation of polymeric chains was interrupted. These polymers behaved as blue-green light emitters with their fluorescence maximum at 447-499 nm and quantum yields in the range of 0.28-0.30 in solution.展开更多
We report the electrosynthesis of a novel semiconductor polymer based on alkyl vinylthiophene derivative in the presence of an ionic liquid (IL). The polymerization was performed under galvanostatic conditions and the...We report the electrosynthesis of a novel semiconductor polymer based on alkyl vinylthiophene derivative in the presence of an ionic liquid (IL). The polymerization was performed under galvanostatic conditions and the polymer was studied as potential donor component of a multilayer heterojunction organic solar cell (OSC). The monomer used was (E)-1,2-di-(3-octyl-2-thienyl) vinylene (OTV) and the IL used for the electropolymerization was 1-octyl-3-methylimidazole hexafluorophosphate C8mimPF6. Optical properties, stability and morphology of the polymer were analyzed using FT-IR, UV-vis, Raman and XPS spectroscopy. Voltammetry analysis and scanning electron microscopy (SEM-EDX) were also performed on the polymer. The OSC assembled with the polymer of OTV was used as electro donor and C60 as acceptor. Molybdenum trioxide (MoO3) and bathocuproine (BCP) were used as buffer layer between anode and cathode respectively. I-V curves, in the dark and under AM 1.5 solar simulator were performed to measure its efficiency.展开更多
Cholesteryl trimeric phenylene vinylene （ChoI-TPV） has been synthesized and characterized. The self- assembly behaviors of ChoI-TPV in THF/H20 system at different water content （water content： 40% and 80%） and di...Cholesteryl trimeric phenylene vinylene （ChoI-TPV） has been synthesized and characterized. The self- assembly behaviors of ChoI-TPV in THF/H20 system at different water content （water content： 40% and 80%） and different solute concentration （solute concentration： 1.0 ×10^-5 mol/L and saturated concentration） were studied using UV-vis spectrophotometry, photoluminescence spectrophotometry, and circular dichroism spectroscopy. Based on an analysis of the UV-vis and photoluminescence spectra, Chol-TPV shows the typical H-type aggregation at saturated concentration in 80% aqueous THF. However, ChoI-TPV shows the non-typical H-type aggregation under other conditions. The circular dichroism signal suggests that the Chol-TPV exists in the right handed helical architectures with high water content at a concentration of 1.0 × 10^-5 mol/L, and a helix inversion was found at saturated concentration.展开更多
At present,most of state-of-the-art power conversion efficiencies(PCEs)of organic solar cells(OSCs)are achieved from the photoactive materials involving donor–acceptor(D–A)copolymer donors.It is well known that the ...At present,most of state-of-the-art power conversion efficiencies(PCEs)of organic solar cells(OSCs)are achieved from the photoactive materials involving donor–acceptor(D–A)copolymer donors.It is well known that the complicated molecular structure of D–A copolymers means the tedious synthesis,which brings about severe cost issue and poor scalability for the industrial production.Therefore,to develop application-oriented OSCs,considerable attention should be paid on simplifying the chemical structures of polymer donors.Polythiophene(PT)and poly(thiophene vinylene)(PTV)derivatives should be among the simplest polymer donors,and OSCs based on them have made some breakthroughs in past 2 years.Here,we briefly introduce the recent advances of OSCs based on low-cost polymers including poly(3-hexylthiophene)(P3HT),PT derivatives,and PTV derivatives,respectively,and emphasize the importance of modulating energy levels,preaggregation effect,and D/A miscibility for the past progress as well as the future development.At last,we also propose some challenges demanding prompt solution for realizing practical application of OSCs,aiming at providing guidance and stimulating new ideas for further research.展开更多
文摘Indoles and their derivatives are an important class of N-heterocycles.In this article,iridium-catalyzed annulation reactions of N-aryl-2-aminopyridines to synthesize indole derivatives are designed and developed,which utilize vinylene carbonate as a new C2 synthon.This protocol is expected to provide a facile and useful access to various indole derivatives.
基金financially supported by the Natural Science Foundation of Hunan Province(2023JJ40608,2024JJ6413)the Majoy Project of the Education Department of Hunan Province(24A0610).
文摘Proton exchange membrane water electrolysis(PEMWE)technology is widely recognized as a cornerstone for green hydrogen production,offering high operational current densities exceeding 1.0 A cm^(-2),rapid dynamic response capabilities,and zero-carbon emission characteristics[1].However,the sluggish kinetics of oxygen evolution reaction(OER)at the anode presents a critical bottleneck for large-scale commercial deployment(Fig.1(a)).Despite significant advancements through electronic structure modulation[2]and coordination environment optimization[3],the deprotonation energy barrier of oxygen-containing intermediates and the stability of active sites under acidic conditions remain unresolved challenges.
基金Project(2007BAE12B01)supported by the National Key Technology Research and Development Program of ChinaProject(20803095)supported by the National Natural Science Foundation of China
文摘Effects of film-forming additive on stability of electrode and cycling performance of LiFePO4/graphite cell at elevated temperature were studied. Two 18650 cells with and without VC additive were investigated by galvanostatic cycling, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis and Raman spectroscopy. The results show that in the presence of VC additive, dissolution of Fe from LiFePO4 material is greatly depressed and stability of graphite structure is improved; the additive can not only reduce reaction of electrolyte on surface of LiFePO4 electrode but also suppress reduction of solvent and thickening of the solid electrolyte interface （SEI） layer on graphite surface. Electrolyte with VC is considered to be a good candidate for improving cycling performance of the LiFePOa/graphite cell at elevated temperature.
基金supported by the National Natural Science Foundation of China(Nos.U1804129,21771164,21671205,U1804126)Zhongyuan Youth Talent Support Program of Henan ProvinceZhengzhou University Youth Innovation Program。
文摘Application of sodium-ion batteries is suppressed due to the lack of appropriate electrolytes matching cathode and anode simultaneously.Ether-based electrolytes,preference of anode materials,cannot match with high-potential cathodes failing to apply in full cells.Herein,vinylene carbonate(VC)as an additive into NaCF_(3) SO_(3)-Diglyme(DGM)could make sodium-ion full cells applicable without preactivation of cathode and anode.The assembled FeS@C||Na3 V2(PO_(4))_(3)@C full cell with this electrolyte exhibits long term cycling stability and high capacity retention.The deduced reason is additive VC,whose HOMO level value is close to that of DGM,not only change the solvent sheath structure of Na^(+),but also is synergistically oxidized with DGM to form integrity and consecutive cathode electrolyte interphase on Na3 V2(PO_(4))_(3)@C cathode,which could effectively improve the oxidative stability of electrolyte and prevent the electrolyte decomposition.This work displays a new way to optimize the sodium-ion full cell seasily with bright practical application potential.
文摘A series of soluble poly(p-phenylene vinylene)(PPV)derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials.The electronic characteristics of PPV derivatives were studied.
基金the support from the National Natural Science Foundation of China(NSFC,Nos.81602954,81573286,81373259 and 81773577).
文摘A new strategy is developed for the synthesis of 1-aminoisoquinoline derivatives.This Rh(III)-catalyzed[4+2]annulation reaction employs benzamidines as efficient directing groups and the vinylene carbonate as an acetylene surrogate.Additionally,the reaction features broad substrate scopes and good yields,only producing carbonate anion as byproduct.
基金This work were supported by the National Natural Science Foundation of China (Project No29992530-6) and the Natural Science Foundation of Guangdong Province (Grant No. 990623).
文摘It was found that traces of water in the reaction medium would result in a great increase of gel and a decrease of Molecular weight of the poly(2-methoxy,5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) during the polymerization, which ultimately led to inferior film qualities and device properties. The device (ITO/PEDOT/MEH-PPV/Ba/Al) with MEH-PPV prepared under dry conditions has an external quantum efficiency of above 2.0%.
基金Sponsored by the Natural Science Foundation of Heilongjiang Province of China (Grant No.B2007-05)the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology (Grant No.HIT.NSRIF.2009121)
文摘Ionic liquids have been paid much attention and are considered to replace the conventional organic electrolyte and solve the safety issues by virtue of nonvolatility,non-flammability,high ionic conductivity and extended electrochemical steady window.The paper introduces ionic liquids electrolyte on basis of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI),which shows a wide electrochemical window (0.5-4.5 V vs.Li+/Li),and is theoretically feasible as an electrolyte for Li/LiFePO4batteries to improve the safety.Linear sweep voltammetry (LSV) was performed to investigate the electrochemical stability window of the polymer electrolyte.Interfacial resistance for Li/electrolyte/Li symmetric cells and Li/electrolyte/LiFePO4 cells were studied by electrochemical impedance spectroscopy (EIS).The results showed that additive vinylene carbonate (VC) enhances the formation of solid electrolyte interphase film to protect lithium anodes from corrosion and improves the compatibility of ionic liquid electrolyte towards lithium anodes.Accordingly,Li/LiFePO4cells delivers the initial discharge capacity of 124 mAh g-1 at a current rate of 0.1C in the ionic liquid electrolyte (EMITFSI+0.8 mol L-1LiTFSI+5 wt%VC),and shows better cyclability than in the ionic liquid electrolyte without VC.
基金National Natural Science Foundation of China (60277002) Scientific Research Foundation of Xi’an JiaotongUniversity
文摘The surface conductivity of poly [ 2-methoxy-5-（3＇-methyl） butoxy]-p-phenylene vinylene （PMOMBOPV） films doped with FeCl3 and H2SO4 by chemical method and implanted by N^＋ ions was studied and the comparison of environmental stability of conductive behavior was also investigated. The energy and dose of N^＋ ions were in the rang 15～35 keV and 3. 8×10^15～9. 6×10^16 ions/cm^2, respectively. The conductivity of PMOMBOPV film was enhanced remarkably with the increases of the energy and dose of N^＋ ions. For example, the conductivity of PMOMBOPV film was 3. 2×10^-2S/cm when ion implantation was performed with an energy of 35 keV at a dose of 9. 6 × 10^14 ions/cm^2 , which was almost seven orders of magnitude higher than that of film unimplanted. The environmental stability of conductive behavior for ionimplanted film was much better than that of chemical doped films. Moreover, the conductive activation energy of ion-implanted films was measured to be about 0.17 eV.
基金supported by the startup funding of HLX and the Assistant Secretary for Energy Efficiency and Renewable Energy,Vehicle Technology Office of the U.S.Department of Energy(DOE)through the Advanced Battery Materials Research Program under contract No.DE-SC0012704.
文摘Solid polymer electrolytes(SPEs)have attracted considerable attention for solid-state lithium-metal batteries(LMBs)with high energy density and enhanced safety for future applications.In this study,an SPE was devel-oped based on a poly(ethyl acrylate)(PEA)polymer matrix with the vinylene carbonate(VC)additive(defined as PEA-VC)for high-voltage solid-state LMBs.Results show that introducing the VC additive into the PEA-based SPE leads to high lithium-ion conductivity(1.57 mS/cm at 22°C),a high lithium-ion transference number(0.73),and a wide electrochemical stability window(up to 4.9 V vs.Li/Li^(+)).The remarkable compatibil-ity of the PEA-VC SPE with lithium metal anodes and high-voltage cathodes was demonstrated in Li//Li symmetric cells(800 h lifetime at a current density of 0.1 mA/cm^(2) at 22°C)and Li//LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)full cells(with a capacity retention of 77.8%after 100 cycles at 0.2C).The improved stability is attributed to the introduction of the VC additive,which helps form a robust cathode–electrolyte interphase,effectively suppressing parasitic interface side reactions.Overall,this study highlights the role of VC addi-tives in high-voltage and solid-state LMBs,offering a general yet effective approach for addressing the interfa-cial instability issue through an additive-engineering strategy.
文摘Methacrylic acid first was neutralized with an aqueous solution of NaOH to pH = 6.0 similar to 7.0, vinylene carbonate (VCA) was added to the solution, then monomers were copolymerized in paraffin oil by means of reverse-phase suspension polymerization and hydrophilic copolymeric supports were prepared. The properties of the supports were determined using trypsin and results show that the amount of enzymes coupled to the supports and the specific activity of immobilized trypsin are related to the content of VCA structure units, reaction time and concentration of enzyme solution, etc.
文摘Bulk polymerization of vinylene carbonate using t-butylperoxypivalate at 40℃gave colourless, high molecular weight poly(vinylene carbonate) (PVCA). Solutions of PVCA in acetone and DMF are not stable at 25℃and this degradation was studied. From measurements in DMF with unfractionated PVCA a Mark-Houwink equation was obtained:
文摘Photocatalytic hydrogen(H_(2))evolution using covalent organic frameworks(COFs)is an attractive and promising avenue for exploration,but one of its big challenges is low photo-induced charge separation.In this study,we present a straightforward and facile dipole polarization engineering strategy to enhance charge separation efficiency,achieved through atomic modulation(O,S,and Se)of the COF monomer.Our findings demonstrate that incorporating atoms with varying electronegativities into the COF matrix significantly influences the local dipole moment,thereby affecting charge separation efficiency and photostability,which in turn affects the rates of photocatalytic H_(2) evolution.As a result,the newly developed TMT-BO-COF,which contains highly electronegative O atoms,exhibits the lowest exciton binding energy,the highest efficiency in charge separation and transportation,and the longest lifetime of the active charges.This leads to an impressive average H_(2) production rate of 23.7 mmol g^(−1) h^(−1),which is 2.5 and 24.5 times higher than that of TMT-BS-COF(containing S atoms)and TMT-BSe-COF(containing Se atoms),respectively.A novel photocatalytic hydrogen evolution mechanism based on proton-coupled electron transfer on N in the structure of triazine rings in vinylene-linked COFs is proposed by theoretical calculations.Our findings provide new insights into the design of highly photoactive organic framework materials for H_(2) evolution and beyond.
基金supported by the National Key Research and Development Program of China (2017YFA0206600)the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH033)the National Natural Science Foundation of China (NSFC, Nos. 51473040, 51673048, 21875052, 51673092)
文摘Among various perylenediimide(PDI)-based small molecular non-fullerene acceptors(NFAs),PDI dimer can effectively avoid the excessive aggregation of single PDI and improve the photovoltaic performance.However,the twist of perylene core in PDI dimer will destroy the effective conjugation.Thus,ring annulation of PDI dimer is a feasible method to balance the film quality and electron transport,but the systematic study has attracted few attentions.Herein,we choose a simple vinylene linked PDI dimer,V-PDI2,and then conduct further studies on the structure-property-performance relationship of four kinds of derived fused-PDI dimers,namely V-TDI2,V-FDI2,V-PDIS2 and V-PDISe2 respectively.The former two are incorporated thianaphthene and benzofuran at the inside bay positions,and the latter two are fused thiophene and selenophene at the outside bay positions,respectively.Theoretical calculations reveal the inside-and outside-fused structures largely affect the skeleton configuration,the former two tend to be planar structure and the latter two maintain the distorted backbone.The photovoltaic characterizations show that the inside-fused PDI dimers offer high open circuit voltage(VOC),while the outside-fused PDI dimers afford large short-circuit current density(JSC).This variation tendency results from the reasonably tunable energy levels,light absorption,molecular crystallinity and film morphology.As a result,PBDB-T:V-PDISe2 device exhibits the highest power conversion efficiency(PCE)of 6.51%,and PBDB-T:VFDI2 device realizes the highest VOC of 1.00 V.This contribution indicates that annulation of PDI dimers in outside or inside bay regions is a feasible method to modulate the properties of PDI-based non-fullerene acceptors.
基金This work was supported by the Chinese Academy of Sciences (No. KJCX2-H1).
文摘Soluble poly(3-hexyl-2,5-thienylene vinylene) (PHTV) was readily synthesized from thiophene in a yield better than that of the precursor method to prepare poly(thienylene vinylene) (PTV). The bandgap of the polymer is about 1.8 eV, which is comparable with that of PTV. Owing to the introduction of alkyl side groups onto the backbone of the polymer, it can be dissolved in common organic solvents such as chloroform, THF and toluene. The synthesis of soluble PHTV is a very important approach to preventing oxidation and to improving the properties and the processbility of the PTV. The existence of alkyl side groups in PHTV does not affect its, bandgap and thermal properties as compared with PTV. After doping with FeCl3, the conductivity of PHTV is as high as 1.1 x 10(-2) S/cm. The soluble PHTV can be easily transformed into thin film with much better quality than that of the PTV film prepared by the traditional precursor method, which is very important for fabricating devices with good properties.
基金supported by the National Natural Science Foundation of China(No.51173155)the Hebei Province Science Foundation of China(No.E2010001182)
文摘Based on an analysis of the 1H NMR,FT-IR,UV-vis spectra,a chiral trimeric phenylene vinylene derivative（ChTPV） synthesized by a Wittig reaction was determined to have a trans-cis configuration, and it could be isomerized to the trans-trans isomer when treated with iodine.The melting point of ChTPV with a trans-trans configuration increased by 162.1℃compared to the trans-cis isomer,and the ChTPV with trans-trans configuration exhibited the typical liquid-crystalline texture of the smectic A in the heating process.The results indicated that the molecular configuration can influence the formation of the liquid crystalline phase of ChTPV.
基金supported by the National Natural Science Foundation of China(Nos.50673094 and 20774102)
文摘A series of new silicon-containing poly（p-arylene vinylene）s （PAVs） with anthracene units in the main chain were synthesized by hydrosilylation reaction. The introduction of organosilicon units improved the solubility of the polymers, and the π-π conjugation of polymeric chains was interrupted. These polymers behaved as blue-green light emitters with their fluorescence maximum at 447-499 nm and quantum yields in the range of 0.28-0.30 in solution.
文摘We report the electrosynthesis of a novel semiconductor polymer based on alkyl vinylthiophene derivative in the presence of an ionic liquid (IL). The polymerization was performed under galvanostatic conditions and the polymer was studied as potential donor component of a multilayer heterojunction organic solar cell (OSC). The monomer used was (E)-1,2-di-(3-octyl-2-thienyl) vinylene (OTV) and the IL used for the electropolymerization was 1-octyl-3-methylimidazole hexafluorophosphate C8mimPF6. Optical properties, stability and morphology of the polymer were analyzed using FT-IR, UV-vis, Raman and XPS spectroscopy. Voltammetry analysis and scanning electron microscopy (SEM-EDX) were also performed on the polymer. The OSC assembled with the polymer of OTV was used as electro donor and C60 as acceptor. Molybdenum trioxide (MoO3) and bathocuproine (BCP) were used as buffer layer between anode and cathode respectively. I-V curves, in the dark and under AM 1.5 solar simulator were performed to measure its efficiency.
基金supported by the National Science Foundation of China(No.51173155)the Hebei Province Science Foundation of China(No.F2011203160)
文摘Cholesteryl trimeric phenylene vinylene （ChoI-TPV） has been synthesized and characterized. The self- assembly behaviors of ChoI-TPV in THF/H20 system at different water content （water content： 40% and 80%） and different solute concentration （solute concentration： 1.0 ×10^-5 mol/L and saturated concentration） were studied using UV-vis spectrophotometry, photoluminescence spectrophotometry, and circular dichroism spectroscopy. Based on an analysis of the UV-vis and photoluminescence spectra, Chol-TPV shows the typical H-type aggregation at saturated concentration in 80% aqueous THF. However, ChoI-TPV shows the non-typical H-type aggregation under other conditions. The circular dichroism signal suggests that the Chol-TPV exists in the right handed helical architectures with high water content at a concentration of 1.0 × 10^-5 mol/L, and a helix inversion was found at saturated concentration.
基金National Key Research and Development Program of China,Grant/Award Number:2019YFE0116700Basic and Applied Basic Research Major Program of Guangdong Province,Grant/Award Number:2019B030302007National Natural Science Foundation of China,Grant/Award Numbers:21835006,91633301,22075017。
文摘At present,most of state-of-the-art power conversion efficiencies(PCEs)of organic solar cells(OSCs)are achieved from the photoactive materials involving donor–acceptor(D–A)copolymer donors.It is well known that the complicated molecular structure of D–A copolymers means the tedious synthesis,which brings about severe cost issue and poor scalability for the industrial production.Therefore,to develop application-oriented OSCs,considerable attention should be paid on simplifying the chemical structures of polymer donors.Polythiophene(PT)and poly(thiophene vinylene)(PTV)derivatives should be among the simplest polymer donors,and OSCs based on them have made some breakthroughs in past 2 years.Here,we briefly introduce the recent advances of OSCs based on low-cost polymers including poly(3-hexylthiophene)(P3HT),PT derivatives,and PTV derivatives,respectively,and emphasize the importance of modulating energy levels,preaggregation effect,and D/A miscibility for the past progress as well as the future development.At last,we also propose some challenges demanding prompt solution for realizing practical application of OSCs,aiming at providing guidance and stimulating new ideas for further research.
