Central venous catheterization(CVC)is a fundamental clinical procedure widely performed across medical specialties.However,the complication rate of subclavian vein catheterization ranges from 6%to 11%.[1]Common compli...Central venous catheterization(CVC)is a fundamental clinical procedure widely performed across medical specialties.However,the complication rate of subclavian vein catheterization ranges from 6%to 11%.[1]Common complications include hemothorax,pneumothorax,air embolism,arterial puncture,and aortic perforation.[2]Herein,we report a rare case of accidental puncture of the aorta during subclavian CVC,which was successfully managed with a ventricular septal defect(VSD)occluder.展开更多
Water splitting by electricity is believed to be a promising approach to obtain high-purity H2 on a large scale.Highly efficient electrocatalysts are of great importance for the electrocatalytic hydrogen evolution rea...Water splitting by electricity is believed to be a promising approach to obtain high-purity H2 on a large scale.Highly efficient electrocatalysts are of great importance for the electrocatalytic hydrogen evolution reaction(HER).Herein,we designed a highly efficient electrocatalyst(Ru@Ni_(3)S_(2))for the HER by immersing Ni_(3)S_(2)nanorod arrays into a RuCl3 aqueous solution.展开更多
Electrochemical reduction offers a carbon-neutral process for energy-saving NH_(3) synthesis under ambient conditions,but this process involves difficulty in breaking the strong NuN bond of inert N_(2) and the challen...Electrochemical reduction offers a carbon-neutral process for energy-saving NH_(3) synthesis under ambient conditions,but this process involves difficulty in breaking the strong NuN bond of inert N_(2) and the challenge of N_(2) activation,underlining the need for high-performance electrocatalysts for the nitrogen reduction reaction(NRR).Herein,we report our recent effort in this direction by in situ hydrothermally growing a Nb_(2)O_(5) nanowire array on carbon cloth(Nb_(2)O_(5)/CC)as a self-standing NRR catalyst electrode toward artificial N_(2) fixation with high selectivity under ambient conditions.In 0.1 M Na_(2)SO_(4),such Nb_(2)O_(5)/CC achieves an NH_(3) formation rate of 1.58×10^(-10) mol s^(-1) cm^(-2) and a high faradaic efficiency of 2.26%at-0.60 V,rivaling the performances of most reported non-noble metal NRR electrocatalysts in neutral medium.Notably,this catalyst also shows high electrochemical stability during electrolysis and recycling tests.Density functional theory calculations reveal that a distal associative route is involved in the reaction pathways during the NRR over the Nb_(2)O_(5)(001)facet.This work would open up an exciting new avenue to explore the design of self-standing 3D electrodes made of transition metal oxides for the NRR and other applications.展开更多
Rapid capacity degradation caused by poor structural stability and slow reaction kinetics is the main obstacle faced by the cathode materials of current aqueous magnesium ion hybrid supercapacitors(MHSs).Herein,we pro...Rapid capacity degradation caused by poor structural stability and slow reaction kinetics is the main obstacle faced by the cathode materials of current aqueous magnesium ion hybrid supercapacitors(MHSs).Herein,we propose and evaluate Co-doped MnO_(2)(Co-MnO_(2))with abundant oxygen vacancies as the cathode material for MHSs.Comprehensive studies show that the decrease in the combined valence of Mn caused by Co doping leads to more oxygen vacancies,which improves the electronic conductivity,exposes more active sites,and promotes the adsorption/desorption behavior of Mg^(2+).In addition,Co intercalating between the MnO_(2)layers improves the stability of the electrode material by enhancing the strength of the interlayer framework.Consequently,an MHS based on the Co-MnO_(2)cathode and AC anode exhibits an excellent energy density of 79.6 W h kg^(-1)at a power density of 360 W kg^(-1)and amazing long-term cycling life with 94.8%capacity retention after 15000 cycles.This work demonstrates that the Co doping strategy can enhance the electrochemical performance of MnO_(2)and opens up a new horizon for developing high-performance candidate cathodes in aqueous MHSs.展开更多
Exploration of a new type of water-stable proton conducting material is of great interest owing to its applications as an electrolytic material in proton exchange membrane fuel cells(PEMFC).Herein,we report four such ...Exploration of a new type of water-stable proton conducting material is of great interest owing to its applications as an electrolytic material in proton exchange membrane fuel cells(PEMFC).Herein,we report four such new metal organic frameworks of Cd(Ⅱ)and Co(Ⅱ)containing a new linear bis-pyridyltris-amide ligand(L)and angular dicarboxylates 4,4’-oxybisbenzoic acid(OBA)and benzene-1,3-diacrylic acid(BDA)as linkers.The MOFs are found to exhibit a general formula of{[M(L)(dicarboxylate)]·xDMF·yH_(2)O}_(n)with varying amounts of solvent.Two MOFs containing BDA exhibited twodimensional rectangular grid-like networks with grid dimensions of 25×23Å^(2),while those with OBA exhibited 3D-networks consisting of the mab topology with rectangular channels of dimensions 31×21Å^(2)and 31×17Å^(2).All four exhibited a solvent accessible volume of 36–49%.AC impedance analyses on MOFs 1–4 reveal that they exhibit appreciable proton conductivities(PC):σ=2.2×10^(−3),9.5×10^(−4),1.2×10^(−3)and 6.6×10^(−4)S cm^(−1),respectively,at 353 K and 98%relative humidity(RH).The high PC values could be attributed to the hydrogen bonding between water molecules and also with amides and carboxylates of the framework.Furthermore,a gas sorption study revealed that MOFs 1–4 show preferential adsorption of water vapor(195–330 cc g^(−1)at p/p0∼1)over nitrogen given the hydrophilic nature of the channels and the stability of MOFs under humid conditions.In addition,all these materials have shown capability in selectively adsorbing cationic dyes(methylene blue,MB and crystal violet,CV).展开更多
Improving the electrocatalytic performance of molybdenum phosphide-based(MoP)electrocatalysts through structure design has become a feasible method to use MoP to supersede noble metallic electrocatalysts for the hydro...Improving the electrocatalytic performance of molybdenum phosphide-based(MoP)electrocatalysts through structure design has become a feasible method to use MoP to supersede noble metallic electrocatalysts for the hydrogen evolution reaction(HER).Herein,we demonstrated a two-step calcining strategy to synthesize a new excellent HER catalyst consisting of MoP nanoparticles loaded on a nitrogen-doped carbon hybrid framework substrate(MoP@NCF),for which acetone was used as the carbon source of the MoP-based electrocatalysts for the first time.The MoP@NCF exhibits an outstanding electrocatalytic performance for the HER with a low overpotential(only 121.8 mV in acid and 129.5 mV in alkaline electrolytes,respectively)at a current density of 10 mA cm^(-2),which is ascribed to the unique porous nanostructure with an enormous special surface area of 247.43 m^(2) g^(-1),and the ultrasmall size and homogeneous distribution of the MoP nanoparticles.Our work provides a rational method to reinforce the HER activity of molybdenum phosphide through structure design,and the therein useful strategy has the possibility of being applied to a range of other metal-based electrocatalyst materials.展开更多
Maximizing the reaction kinetics of Pd catalysts for oxygen reduction reaction(ORR)while minimizing CO poisoning during the methanol oxidation reaction(MOR)remains a key challenge for advancing direct methanol fuel ce...Maximizing the reaction kinetics of Pd catalysts for oxygen reduction reaction(ORR)while minimizing CO poisoning during the methanol oxidation reaction(MOR)remains a key challenge for advancing direct methanol fuel cells(DMFCs).Herein,we synthesize an anatase/rutile TiO_(2) homojunction(A/R-TiO_(2))through energy band alignment and oxygen vacancy engineering,providing support for Pd nanoparticles to decipher the strong correlation between this unique structure and the electrocatalytic properties of Pd/A/R-TiO_(2) catalysts.Combined experimental results and theoretical calculations demonstrate that the near perfect energy band alignment and abundant oxygen vacancies in A/R-TiO_(2) not only accelerate electron transfer to the Pd surface,thereby maximizing the reaction kinetics and catalytic efficiency,but also optimize the electronic structure of Pd active sites to reduce the adsorption energy of key intermediates(*OH,*CH_(2)OH,*CO)during the ORR and MOR.Consequently,the Pd/A/R-TiO_(2) catalyst delivers a remarkably positive E_(1/2) of 0.929 V and an enhanced mass activity of 4.27 A mg_(Pd)^(-1) at 0.85 V for ORR,respectively,nearly 13 and 27 times greater than those of Pt/C and Pd/C catalysts commercially available at present.The Pd/A/R-TiO_(2) catalyst displays high selectivity for an effective four-electron transfer pathway,a lower H_(2)O_(2) yield(1.66%),and excellent methanol crossover tolerance.Importantly,the catalyst demonstrates exceptional stability,exhibiting minimal activity decay and negligible structural degradation after 10000 cycles.Furthermore,the as-synthesized catalyst achieves superior MOR activity(4.10 A mgPd^(-1) and 8.85 A cm^(-2))and enhanced CO tolerance,surpassing commercial Pt/C and Pd/C catalysts.These bifunctional catalysts thus hold great potential for large-scale and industry-orientated use of DMFCs.展开更多
The recent development of the two-photon technique offers a unique opportunity to improve the depth of imaging and treatment in photodynamic therapy(PDT).Herein,we designed a fluorescence resonance energy transfer(FRE...The recent development of the two-photon technique offers a unique opportunity to improve the depth of imaging and treatment in photodynamic therapy(PDT).Herein,we designed a fluorescence resonance energy transfer(FRET)based AceDAN-porphyrin(Zn)dyad for two-photon excited fluorescence imaging and PDT of cancer cells simultaneously,in which the AceDAN moiety was selected as the two-photon absorption donor and the porphyrin(Zn)moiety served as the energy acceptor.Upon one-photon or two-photon excitation,the excited state energy of the AceDAN donor was transferred to the porphyrin(Zn)acceptor with high efficiency(η_(EET)=98%),where red fluorescence and singlet oxygen were generated.Dyad 1 exhibited high photocytotoxicity towards A549 cells(IC_(50)=4.3μM)with rapid cellular uptake while displaying low dark-cytotoxicity.Furthermore,by combining the advantages of two-photon excitation with a porphyrin(Zn)photosensitizer,the AceDAN-porphyrin(Zn)dyad has been successfully applied to A549 cells for imaging and photodynamic therapy under two-photon laser irradiation.展开更多
Single-ion magnets(SIMs)are prominent candidates for promoting new technologies in quantum information processing(QIP).Herein,we present two new isostructural oxamato derivatives,namely,{n-Bu_(4)N[Ln(H_(2)edpba)_(2)]}...Single-ion magnets(SIMs)are prominent candidates for promoting new technologies in quantum information processing(QIP).Herein,we present two new isostructural oxamato derivatives,namely,{n-Bu_(4)N[Ln(H_(2)edpba)_(2)]}_(n),Ln=Tb^(3+)(1)and Gd^(3+)(2)[H_(2)edpba^(2-)=N,N’-2,2’-ethylenediphenylenebis(oxamate)],that are thermostable up to∼290℃.Single-crystal X-ray diffraction reveals that 1 and 2 are one-dimensional coordination polymers with a ribbon-like structure,and their metal centers are eight-coordinated with a D_(4d) symmetry.Cryomagnetic studies disclose the presence of slow magnetic relaxation(SMR)behavior for 1 and 2.For 1,the Raman effect dominates the SMR at a zero magnetic field,while Raman,Orbach,and reciprocating thermal behavior(RTB)mechanisms arise at higher fields.Conversely,RTB and the bottleneck effect were observed at 2.Solid-state photoluminescent data display a remarkable green luminescence emission,with intense and sharp bands ranging from 480 to 700 nm in the spectra,which are attributed to the ^(5)D_(4)→^(7)F_(J)(J=6-0)transitions of terbium(Ⅲ)ions.By monitoring the temperaturedependent lifetime of the ^(5)D_(4) state after the intensity decay of the emission band attributed to the ^(5)D_(4)→^(7)F_(5)(546 nm)transition,the complex shows a reasonable thermometric performance with a relative sensitivity of 2.77%K^(-1) at 448 K.1 behaves as a zero-field SIM and as a photoluminescent thermometer.展开更多
Covalent organic frameworks(COFs)have emerged as highly versatile platforms for the spatially controlled immobilization of metals in heterogeneous photocatalytic hydrogen evolution reactions(HERs).Herein,we have integ...Covalent organic frameworks(COFs)have emerged as highly versatile platforms for the spatially controlled immobilization of metals in heterogeneous photocatalytic hydrogen evolution reactions(HERs).Herein,we have integrated both a Cu(I)diimine-based photosensitizer unit and a Co(II)bipyridine-based catalyst unit into a two-dimensional COF,TpBpy,which serves as a macro-ligand scaffold.The resulting hybrid material,TpBpy–Cu/Co,achieves an optimized photocatalytic H2 evolution rate of 12.16 mmol g^(-1) h^(-1),representing a 25-fold enhancement relative to the pristine TpBpy framework.To elucidate the origin of this enhancement,ultrafast transient optical spectroscopy,electrochemical measurements,and photoluminescence studies were employed.These studies reveal that the incorporation of the Cu(I)diimine unit enhances the photosensitizing capability of the framework,while the excited-state lifetime of the photosensitizer is prolonged due to the confinement effects within COF structure.Furthermore,comparative invetigations demonstrate that the TpBpy–Cu/Co outperformes the system consisting of separate TpBpy–Cu and Co(bpy)Cl2,highlighting the critical role of metal coordination in facilitating intra-framework charge transfer from photosensitizers to catalysts.This study provides strategic insights into the design of COF–metal coordination systems,emphasizing the importance of integrating multifunctional units to tailor and enhance photocatalytic performance.展开更多
基金supported by a grant from the Beijing Union Medical College Foundation-Rui E Emergency Medicine Research Fund in 2025。
文摘Central venous catheterization(CVC)is a fundamental clinical procedure widely performed across medical specialties.However,the complication rate of subclavian vein catheterization ranges from 6%to 11%.[1]Common complications include hemothorax,pneumothorax,air embolism,arterial puncture,and aortic perforation.[2]Herein,we report a rare case of accidental puncture of the aorta during subclavian CVC,which was successfully managed with a ventricular septal defect(VSD)occluder.
基金financially supported by the National Natural Science Foundation of China(U1904195 and U1804138)the Program for Science&Technology Innovative Research Team in University of Henan Province(20IRTSTHN007)+1 种基金the Science&Technology Innovation Talents in Universities of Henan Province(22HASTIT028)the Key Scientific Research Project of Colleges and Universities in Henan Province(21B150015).
文摘Water splitting by electricity is believed to be a promising approach to obtain high-purity H2 on a large scale.Highly efficient electrocatalysts are of great importance for the electrocatalytic hydrogen evolution reaction(HER).Herein,we designed a highly efficient electrocatalyst(Ru@Ni_(3)S_(2))for the HER by immersing Ni_(3)S_(2)nanorod arrays into a RuCl3 aqueous solution.
基金supported by the National Natural Science Foundation of China(No.21575071 and 21575137)Qingdao Science&Technology Planning Project(17-6-3-15-gx)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.Kycx18_1122).
文摘Electrochemical reduction offers a carbon-neutral process for energy-saving NH_(3) synthesis under ambient conditions,but this process involves difficulty in breaking the strong NuN bond of inert N_(2) and the challenge of N_(2) activation,underlining the need for high-performance electrocatalysts for the nitrogen reduction reaction(NRR).Herein,we report our recent effort in this direction by in situ hydrothermally growing a Nb_(2)O_(5) nanowire array on carbon cloth(Nb_(2)O_(5)/CC)as a self-standing NRR catalyst electrode toward artificial N_(2) fixation with high selectivity under ambient conditions.In 0.1 M Na_(2)SO_(4),such Nb_(2)O_(5)/CC achieves an NH_(3) formation rate of 1.58×10^(-10) mol s^(-1) cm^(-2) and a high faradaic efficiency of 2.26%at-0.60 V,rivaling the performances of most reported non-noble metal NRR electrocatalysts in neutral medium.Notably,this catalyst also shows high electrochemical stability during electrolysis and recycling tests.Density functional theory calculations reveal that a distal associative route is involved in the reaction pathways during the NRR over the Nb_(2)O_(5)(001)facet.This work would open up an exciting new avenue to explore the design of self-standing 3D electrodes made of transition metal oxides for the NRR and other applications.
基金the Shanghai Domestic Science and Technology Cooperation Project(21015801000)is gratefully acknowledged.
文摘Rapid capacity degradation caused by poor structural stability and slow reaction kinetics is the main obstacle faced by the cathode materials of current aqueous magnesium ion hybrid supercapacitors(MHSs).Herein,we propose and evaluate Co-doped MnO_(2)(Co-MnO_(2))with abundant oxygen vacancies as the cathode material for MHSs.Comprehensive studies show that the decrease in the combined valence of Mn caused by Co doping leads to more oxygen vacancies,which improves the electronic conductivity,exposes more active sites,and promotes the adsorption/desorption behavior of Mg^(2+).In addition,Co intercalating between the MnO_(2)layers improves the stability of the electrode material by enhancing the strength of the interlayer framework.Consequently,an MHS based on the Co-MnO_(2)cathode and AC anode exhibits an excellent energy density of 79.6 W h kg^(-1)at a power density of 360 W kg^(-1)and amazing long-term cycling life with 94.8%capacity retention after 15000 cycles.This work demonstrates that the Co doping strategy can enhance the electrochemical performance of MnO_(2)and opens up a new horizon for developing high-performance candidate cathodes in aqueous MHSs.
基金We acknowledge DST(SERB)(SR/S1/IC-08/2013),New Delhi,India,for financial support and DST-FIST for the single crystal X-ray diffractometer.
文摘Exploration of a new type of water-stable proton conducting material is of great interest owing to its applications as an electrolytic material in proton exchange membrane fuel cells(PEMFC).Herein,we report four such new metal organic frameworks of Cd(Ⅱ)and Co(Ⅱ)containing a new linear bis-pyridyltris-amide ligand(L)and angular dicarboxylates 4,4’-oxybisbenzoic acid(OBA)and benzene-1,3-diacrylic acid(BDA)as linkers.The MOFs are found to exhibit a general formula of{[M(L)(dicarboxylate)]·xDMF·yH_(2)O}_(n)with varying amounts of solvent.Two MOFs containing BDA exhibited twodimensional rectangular grid-like networks with grid dimensions of 25×23Å^(2),while those with OBA exhibited 3D-networks consisting of the mab topology with rectangular channels of dimensions 31×21Å^(2)and 31×17Å^(2).All four exhibited a solvent accessible volume of 36–49%.AC impedance analyses on MOFs 1–4 reveal that they exhibit appreciable proton conductivities(PC):σ=2.2×10^(−3),9.5×10^(−4),1.2×10^(−3)and 6.6×10^(−4)S cm^(−1),respectively,at 353 K and 98%relative humidity(RH).The high PC values could be attributed to the hydrogen bonding between water molecules and also with amides and carboxylates of the framework.Furthermore,a gas sorption study revealed that MOFs 1–4 show preferential adsorption of water vapor(195–330 cc g^(−1)at p/p0∼1)over nitrogen given the hydrophilic nature of the channels and the stability of MOFs under humid conditions.In addition,all these materials have shown capability in selectively adsorbing cationic dyes(methylene blue,MB and crystal violet,CV).
文摘Improving the electrocatalytic performance of molybdenum phosphide-based(MoP)electrocatalysts through structure design has become a feasible method to use MoP to supersede noble metallic electrocatalysts for the hydrogen evolution reaction(HER).Herein,we demonstrated a two-step calcining strategy to synthesize a new excellent HER catalyst consisting of MoP nanoparticles loaded on a nitrogen-doped carbon hybrid framework substrate(MoP@NCF),for which acetone was used as the carbon source of the MoP-based electrocatalysts for the first time.The MoP@NCF exhibits an outstanding electrocatalytic performance for the HER with a low overpotential(only 121.8 mV in acid and 129.5 mV in alkaline electrolytes,respectively)at a current density of 10 mA cm^(-2),which is ascribed to the unique porous nanostructure with an enormous special surface area of 247.43 m^(2) g^(-1),and the ultrasmall size and homogeneous distribution of the MoP nanoparticles.Our work provides a rational method to reinforce the HER activity of molybdenum phosphide through structure design,and the therein useful strategy has the possibility of being applied to a range of other metal-based electrocatalyst materials.
基金funded by the Young Elite Scientists Sponsorship Program by CAST(2021QNRC001)the Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX0557,cstb2023nscq-msx0979,CSTB2024NSCQ-MSX0764)+2 种基金the New Chongqing Innovative Talent Project(CSTB2024NSCQ-QCXMX0020)the Talent Introduction of Chongqing University of Science and Technology(ckrc2021050,ckrc20230401)the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202401508,KJQN202301542).
文摘Maximizing the reaction kinetics of Pd catalysts for oxygen reduction reaction(ORR)while minimizing CO poisoning during the methanol oxidation reaction(MOR)remains a key challenge for advancing direct methanol fuel cells(DMFCs).Herein,we synthesize an anatase/rutile TiO_(2) homojunction(A/R-TiO_(2))through energy band alignment and oxygen vacancy engineering,providing support for Pd nanoparticles to decipher the strong correlation between this unique structure and the electrocatalytic properties of Pd/A/R-TiO_(2) catalysts.Combined experimental results and theoretical calculations demonstrate that the near perfect energy band alignment and abundant oxygen vacancies in A/R-TiO_(2) not only accelerate electron transfer to the Pd surface,thereby maximizing the reaction kinetics and catalytic efficiency,but also optimize the electronic structure of Pd active sites to reduce the adsorption energy of key intermediates(*OH,*CH_(2)OH,*CO)during the ORR and MOR.Consequently,the Pd/A/R-TiO_(2) catalyst delivers a remarkably positive E_(1/2) of 0.929 V and an enhanced mass activity of 4.27 A mg_(Pd)^(-1) at 0.85 V for ORR,respectively,nearly 13 and 27 times greater than those of Pt/C and Pd/C catalysts commercially available at present.The Pd/A/R-TiO_(2) catalyst displays high selectivity for an effective four-electron transfer pathway,a lower H_(2)O_(2) yield(1.66%),and excellent methanol crossover tolerance.Importantly,the catalyst demonstrates exceptional stability,exhibiting minimal activity decay and negligible structural degradation after 10000 cycles.Furthermore,the as-synthesized catalyst achieves superior MOR activity(4.10 A mgPd^(-1) and 8.85 A cm^(-2))and enhanced CO tolerance,surpassing commercial Pt/C and Pd/C catalysts.These bifunctional catalysts thus hold great potential for large-scale and industry-orientated use of DMFCs.
基金National Natural Science Foundation of China(21471015 and 21631003)Beijing Natural Science FoundationFundamental Research Funds for the Central Universities。
文摘The recent development of the two-photon technique offers a unique opportunity to improve the depth of imaging and treatment in photodynamic therapy(PDT).Herein,we designed a fluorescence resonance energy transfer(FRET)based AceDAN-porphyrin(Zn)dyad for two-photon excited fluorescence imaging and PDT of cancer cells simultaneously,in which the AceDAN moiety was selected as the two-photon absorption donor and the porphyrin(Zn)moiety served as the energy acceptor.Upon one-photon or two-photon excitation,the excited state energy of the AceDAN donor was transferred to the porphyrin(Zn)acceptor with high efficiency(η_(EET)=98%),where red fluorescence and singlet oxygen were generated.Dyad 1 exhibited high photocytotoxicity towards A549 cells(IC_(50)=4.3μM)with rapid cellular uptake while displaying low dark-cytotoxicity.Furthermore,by combining the advantages of two-photon excitation with a porphyrin(Zn)photosensitizer,the AceDAN-porphyrin(Zn)dyad has been successfully applied to A549 cells for imaging and photodynamic therapy under two-photon laser irradiation.
基金supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)Fundacao de Amparoà Pesquisa do Estado de Minas Gerais(FAPEMIG)+3 种基金Fundacao Carlos Chagas Filho de Amparoà Pesquisa do Estado do Rio de Janeiro(FAPERJ)Fundacao de Aperfeiçoamento de Pessoal de Nível Superior(CAPES,Finance Code 001)the Fundacao de AmparoàPesquisa do Estado de Sao Paulo(FAPESP)for the postdoctoral fellowship(2024/00198-0)for RVP,project 2021/08111-2for funding the EMU Project 2023/17024-1.
文摘Single-ion magnets(SIMs)are prominent candidates for promoting new technologies in quantum information processing(QIP).Herein,we present two new isostructural oxamato derivatives,namely,{n-Bu_(4)N[Ln(H_(2)edpba)_(2)]}_(n),Ln=Tb^(3+)(1)and Gd^(3+)(2)[H_(2)edpba^(2-)=N,N’-2,2’-ethylenediphenylenebis(oxamate)],that are thermostable up to∼290℃.Single-crystal X-ray diffraction reveals that 1 and 2 are one-dimensional coordination polymers with a ribbon-like structure,and their metal centers are eight-coordinated with a D_(4d) symmetry.Cryomagnetic studies disclose the presence of slow magnetic relaxation(SMR)behavior for 1 and 2.For 1,the Raman effect dominates the SMR at a zero magnetic field,while Raman,Orbach,and reciprocating thermal behavior(RTB)mechanisms arise at higher fields.Conversely,RTB and the bottleneck effect were observed at 2.Solid-state photoluminescent data display a remarkable green luminescence emission,with intense and sharp bands ranging from 480 to 700 nm in the spectra,which are attributed to the ^(5)D_(4)→^(7)F_(J)(J=6-0)transitions of terbium(Ⅲ)ions.By monitoring the temperaturedependent lifetime of the ^(5)D_(4) state after the intensity decay of the emission band attributed to the ^(5)D_(4)→^(7)F_(5)(546 nm)transition,the complex shows a reasonable thermometric performance with a relative sensitivity of 2.77%K^(-1) at 448 K.1 behaves as a zero-field SIM and as a photoluminescent thermometer.
基金supported by the National Natural Science Foundation of China(22205144).
文摘Covalent organic frameworks(COFs)have emerged as highly versatile platforms for the spatially controlled immobilization of metals in heterogeneous photocatalytic hydrogen evolution reactions(HERs).Herein,we have integrated both a Cu(I)diimine-based photosensitizer unit and a Co(II)bipyridine-based catalyst unit into a two-dimensional COF,TpBpy,which serves as a macro-ligand scaffold.The resulting hybrid material,TpBpy–Cu/Co,achieves an optimized photocatalytic H2 evolution rate of 12.16 mmol g^(-1) h^(-1),representing a 25-fold enhancement relative to the pristine TpBpy framework.To elucidate the origin of this enhancement,ultrafast transient optical spectroscopy,electrochemical measurements,and photoluminescence studies were employed.These studies reveal that the incorporation of the Cu(I)diimine unit enhances the photosensitizing capability of the framework,while the excited-state lifetime of the photosensitizer is prolonged due to the confinement effects within COF structure.Furthermore,comparative invetigations demonstrate that the TpBpy–Cu/Co outperformes the system consisting of separate TpBpy–Cu and Co(bpy)Cl2,highlighting the critical role of metal coordination in facilitating intra-framework charge transfer from photosensitizers to catalysts.This study provides strategic insights into the design of COF–metal coordination systems,emphasizing the importance of integrating multifunctional units to tailor and enhance photocatalytic performance.
