Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters ...Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters with well-defined structures and diverse properties.Therefore,the design and synthesis of a POM-based material for proton conduction is extremely vital.Herein,a dimeric four tartaric acid-bridged tetra-Zr-incorporated arsenotungstate.展开更多
Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)...Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)(H_(2)O)_(21){Ca(H_(2)O)_(2)@Sb_(12)O_(18)[Ni_(2)(OH)(A-α-Si W_(10)O_(37))]_(3)}_(2)·40H_(2)O(1),was constructed using Keggintype polyoxotungstate A-α-Si W_(10)O_(37),along with Ni and Sb elements.The structure features a Tdsymmetric Sb_(12)O_(18)({Sb_(12)})cage that encapsulates an 8-coordinate Ca^(2+)ion at its face.Additionally,the{Sb_(12)}cage forms an 18-nuclear 3d-5p heterometallic cluster by connecting with three di-nuclear nickel clusters through shared oxygen atoms.Electrochemical impedance spectra studies reveal that the single crystal of 1 achieves a proton conductivity of 1.11×10^(-1)S/cm along the[110]direction and 1.04×10^(-1)S/cm along the[100]direction at 85℃ and 98%relative humidity(RH).Furthermore,the powder form of 1 exhibits a proton conductivity of 3.00×10^(-2)S/cm.These findings suggest that compound 1 holds promise as a practical proton conducting material.展开更多
Lanthanide metal-organic frameworks(Ln-MOFs)are widely used for fluorescence detection of ions and organic small molecules due to their excellent fluorescence properties.An aqueous stable europiumbased metal-organic f...Lanthanide metal-organic frameworks(Ln-MOFs)are widely used for fluorescence detection of ions and organic small molecules due to their excellent fluorescence properties.An aqueous stable europiumbased metal-organic framework,{I(CH_(3))_(2)NH_(2)]_(2)[Eu(TTDI)H_(2)O]_(2)·2H_(2)O·7DMF}_(n)(Eu-MOF,TTDI=5,5'-(thieno[3,2-b]-2,5-diphenyl)terephthalic)was synthesized and characterized,which demonstrates high selectivity and sensitivity fluorescence sensing of uric acid(UA)with a detection limit of 0.062μmol/L.Moreover,it also exhibits good proton conductivity with a maximum value of 3.34×10^(-3)S/cm at 55℃ under 98% relative humidity owing to its abundant hydrogen-bonding network.Therefore,this Eu-MOF is a potentially important multifunctional bioassay material.展开更多
To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D...To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D frameworks,designated as[La(HPO_(3))(C_(2)O_(4))0.5(H_(2)O)_(2)](La‑1)and(C_(6)H_(16)N_(2))(H_(3)O)[La_(2)(H_(2)PO_(3))_(3)(C_(2)O_(4))_(3)(H_(2)O)](La‑2)(C_(6)H_(14)N_(2)=cis-2,6-dimethylpiperazine),were prepared by hydrothermal and solvothermal conduction,respectively.La‑1 was constructed with lanthanum phosphite 2D layers and C_(2)O_(4)^(2-)groups,whereas La‑2 was constructed with lanthanum oxalate 2D layers and H_(2)PO^(3-)groups.Alternating current(AC)impedance spectra indicate that the pro-ton conductivities of both compounds could reach 10^(-4)S·cm^(-1)and remain highly durable at 75℃and 98%of rela-tive humidity(RH).Due to the abundance of H-bonds in La‑2,theσof La‑2 was higher than that of La‑1.La‑1 exhibited excellent water and pH stability.CCDC:2439965,La‑1;443776,La‑2.展开更多
Highly reduced molybdenum red(MR)clusters have emerged as a new type of polyoxomolybdates(POMos)and showed great potential as electron/proton reservoirs for energy conversion and storage,as well as for catalysis.Howev...Highly reduced molybdenum red(MR)clusters have emerged as a new type of polyoxomolybdates(POMos)and showed great potential as electron/proton reservoirs for energy conversion and storage,as well as for catalysis.However,the limited structural diversity of MR clusters significantly hinders further exploration of their potential as functional materials.Herein,we describe the synthesis of a novel highly reduced MR cluster{Mo_(49)}(compound 1)based on rational assembly of a variety of basic building blocks(BBs).In addition to the well-established BBs found in the family of MR clusters,the unique tetrahedral{MoVI 4}BB plays a key role in directing the assembly to afford trigonal pyramid-like structure of compound 1,which consists of 49 Mo and 148 O atoms with a high reduction degree of 73%.Moreover,at 80℃and 98%relative humidity(RH),the pellet sample of compound 1 displays good proton conductivity of 7.88×10^(-3)S/cm owing to the efficient hydrogen-bonded network built from the surface oxygen atoms,protons and vip water molecules.This research offers new insights into the assembly and synthesis of MR clusters through a BB strategy and manifests their significant potential for advanced applications.展开更多
The development of core-shell nanoclusters with controllable composition is of utmost importance as the material properties depend on their constituent elements.However,precisely tuning their compositions at the atomi...The development of core-shell nanoclusters with controllable composition is of utmost importance as the material properties depend on their constituent elements.However,precisely tuning their compositions at the atomic scale is not easily achieved because of the difficulty of using limited macroscopic synthetic methods for atomic-level modulation.In this work,we report an interesting example of precisely regulating the core composition of an inorganic core-shell-type cobalt polyoxoniobate[Co_(26)Nb_(36)O_(140)]^(32−)by controlling reaction conditions,in which the inner Co-core composition could be tune while retaining the outer Nb-shell composition of resulting product,leading to a series of isostructural species with a general formula of{Co_(26-n)Nb_(36+n)O_(140)}(n=0–2).These rare species not only can display good powder and single-crystal proton conductivities,but also might provide helpful and atomic-level insights into the syntheses,structures and composition modifications of inorganic amorphous core-shell heterometal oxide nanoparticles.展开更多
Metal-organic frameworks(MOFs)with inherent porosity and suspended acidic groups are promising proton conducting materials in water or aqua-ammonia media.Herein we report a new lanthanide phosphonate,namely,Dy_(2)(amp...Metal-organic frameworks(MOFs)with inherent porosity and suspended acidic groups are promising proton conducting materials in water or aqua-ammonia media.Herein we report a new lanthanide phosphonate,namely,Dy_(2)(amp_(2)H_(2))_(2)(mal)(H_(2)O)_(2)·5H2O(MDAF-6).It possesses a 3D open-framework structure,and shows a high NH_(3)adsorption capacity of 142.4 cm^(3)/g at P/P0=0.98 at 298 K due to acid-base interaction.Interestingly,the proton conductivity of MDAF-6-NH3 is enhanced by five orders of magnitude compared to MDAF-6 after 8.5 h exposure in saturated NH_(3)-H_(2)O vapor,indicating the importance of coexistent conjugate acid-base pairs of H_(3)O+-H_(2)O and NH_(4)^(+)-NH_(3)in promoting proton conduction.Magnetic studies of MDAF-6 revealed slow magnetization relaxation under zero dc field,characteristic of singlemolecule magnet behavior.This work provides not only a new multifunctional MOF material,but also a new strategy to improve proton conduction in aqua-ammonia medium.展开更多
To attain the objectives of carbon peaking and carbon neutrality,the development of stable and highperformance ion-conducting materials holds enormous relevance in various energy storage and conversion devices.Particu...To attain the objectives of carbon peaking and carbon neutrality,the development of stable and highperformance ion-conducting materials holds enormous relevance in various energy storage and conversion devices.Particularly,crystalline porous materials possessing built-in ordered nanochannels exhibit remarkable superiority in comprehending the ion transfer mechanisms with precision.In this regard,covalent organic frameworks(COFs)are highly regarded as a promising alternative due to their preeminent structural tunability,accessible well-defined pores,and excellent thermal/chemical stability under hydrous/anhydrous conditions.By the availability of organic units and the diversity of topologies and connections,advances in COFs have been increasing rapidly over the last decade and they have emerged as a new field of proton-conducting materials.Therefore,a comprehensive summary and discussion are urgently needed to provide an"at a glance"understanding of the prospects and challenges in the development of proton-conducting COFs.In this review,we target a comprehensive review of COFs in the field of proton conductivity from the aspects of design strategies,the proton conducting mechanism/features,the relationships of structure-function,and the application of research.The relevant content of theoretical simulation,advanced structural characterizations,prospects,and challenges are also presented elaborately and critically.More importantly,we sincerely hope that this progress report will form a consistent view of this field and provide inspiration for future research.展开更多
Through the mechanochemical method,sulfamic acid(SA)is successfully introduced into UiO-66-NH_(2)to form SA@UiO-66-NH_(2).In SA@UiO-66-NH_(2),the acidic cationic sulfiliminium(—S=NH_(2)^(+))moiety formed by the bridg...Through the mechanochemical method,sulfamic acid(SA)is successfully introduced into UiO-66-NH_(2)to form SA@UiO-66-NH_(2).In SA@UiO-66-NH_(2),the acidic cationic sulfiliminium(—S=NH_(2)^(+))moiety formed by the bridging bidentate binding mode between SA and the zirconium metal center can release protons,and SA actively participates in the construction of hydrogen-bonded network,thereby accelerating the proton conduction.At 95%RH(relative humidity)and 358 K,the proton conductivity of SA@UiO-66-NH_(2)can reach 1.42×10^(-2)S·cm^(-1),which is four orders of magnitude higher than that of the parent framework UiO-66-NH_(2).Meanwhile,this high proton conductivity can be maintained for at least 90 h.展开更多
The study of anisotropic proton conduction(APC)on a layered-structured vanadium selenite single crystal,namely[H_(3)O][(VO_(2))_(3)(SeO_(3))_(2)](1),reveals the proton conductivity(σ)ratio(σ_([100])/σ_([001])=188)a...The study of anisotropic proton conduction(APC)on a layered-structured vanadium selenite single crystal,namely[H_(3)O][(VO_(2))_(3)(SeO_(3))_(2)](1),reveals the proton conductivity(σ)ratio(σ_([100])/σ_([001])=188)at 80℃ under 70%relative humidity(RH)and the proton conduction mechanisms of Grotthuss and Vehicle along the[100]and[001]directions,respectively.展开更多
A new coordination compound [Mg（L）（H2 O）5·H2 O]（NKU-109, H2 L=5-（4 H-1,2,4-triazol-4-yl）benzene-1,3-dicarboxylic acid） was solvothermally synthesized, featuring a supramolecular hydrogen-bonding network. ...A new coordination compound [Mg（L）（H2 O）5·H2 O]（NKU-109, H2 L=5-（4 H-1,2,4-triazol-4-yl）benzene-1,3-dicarboxylic acid） was solvothermally synthesized, featuring a supramolecular hydrogen-bonding network. A good proton conductivity of 5.87×10^-4S/cm was recorded at 70℃ and a relative humidity of75% in alternating current（AC） impedance experiment, which sheds a new light on the design of proton conduction materials based on coordination compounds.展开更多
Multifunctional materials with proton conduction,circularly polarized luminescence(CPL)and a magneto-optical Faraday effect would provide a great opportunity for applications in luminescent,electrical,magneto-optical ...Multifunctional materials with proton conduction,circularly polarized luminescence(CPL)and a magneto-optical Faraday effect would provide a great opportunity for applications in luminescent,electrical,magneto-optical and optical-electronic smart devices.However,such types of multifunctional systems have rarely been reported.Herein,by introducing a chiral amine-phenol ligand,a pair of Cd(Ⅱ)-Tb(Ⅲ)enantiomers,[Cd_(2)Tb(RR/SS-H_(2)L)_(2)(H_(2)O)_(6)](ClO_(4))_(3)·2H_(2)O(R-1 and S-1)[H_(2)L=((SS/RR)-cyclohexane-1,2-diylbis(azanediyl)-bis(methylene)-bis(2-methoxyphenol))],were obtained.R-1 and S-1 feature the homochiral molecules of trinuclear Cd2Tb structures,which contain abundant H-bonds to form threedimensional(3D)supermolecular frameworks.They are chiral multifunctional materials showing strong Tb(Ⅲ)characteristic emissions,a moderate proton conductivity of 1.17×10^(-4) S cm^(-1) at 333 K and 100%RH for R-1,CPL with a luminescence dissymmetry factor value of over 10^(-3) for R-1 and S-1 and a strong magneto-optical Faraday effect,and they are the first known materials simultaneously showing CPL,proton conduction and the Faraday effect.展开更多
Proton-conducting materials have become highly desirable for clean energy-related applications,and the design and synthesis of stable and efficient proton-conduction materials have become increasingly important but ch...Proton-conducting materials have become highly desirable for clean energy-related applications,and the design and synthesis of stable and efficient proton-conduction materials have become increasingly important but challenging.Three stable porous metal-organic frameworks(MOFs)based on the aluminum(III)cation(Al-MOFs),DUT-5(1),DUT-4(2),and NOTT-300(3),were selected as imidazole(Im)supporters and were successfully used to obtain three proton conduction composites(namely Im@1,Im@2,and Im@3)with excellent proton conductivities(σ).At 80℃ and 100%RH,the proton conductivity values of 1-3 were respectively 1.39×10^(-2),2.98×10^(-2),and 5.57×10^(-2) S cm^(-1),which increased significantly with the decrease in their aperture sizes(1,11.1Å;2,8.5Å;3,6.5Å).The proton conductivity values of Im@1-3 were significantly higher than those of the original MOFs 1-3.Especially,3 has a suitable aperture size for loading imidazole molecules and restricting them in a limited space,which made it difficult for the imidazole molecules of Im@3 to escape from the pores of 3,eventually leading to the formation of strong continuous hydrogen-bonding networks.Therefore,at 80℃ and 100%RH,the proton conductivities(σ)of Im@3 can reach up to 2.55×10^(-1) S cm^(-1),which is close to the σ of the commercial benchmark Nafion under the same conditions.Finally,the related molecular simulation was accomplished to elucidate the proton conduction mechanism by using the Grand Canonical Monte Carlo(GCMC)method.All the above features make Im@3 one of the most promising candidates for further practical applications in fuel cells.展开更多
Hydrogen bonds play a pivotal role in governing both proton conduction and dielectric properties in functional materials.However,the direct mechanistic relationship between these two properties,as mediated by hydrogen...Hydrogen bonds play a pivotal role in governing both proton conduction and dielectric properties in functional materials.However,the direct mechanistic relationship between these two properties,as mediated by hydrogen bonds,remains poorly understood.Here,we address this gap by investigating the role of hydrogen-bonded motifs in coordination polymers(CPs),focusing on how their structural dynamics influence both proton transport and dielectric relaxation.To this end,two CPs,{(H_(3)tren)_(2)[Zn_(3)(PO_(4))_(4)]·6H_(2)O}(ZnPO_(4)-H_(3)tren-H_(2)O)and{(H_(3)tren)_(2)[Zn_(3)(PO_(4))_(4)]·2H_(2)ta}(ZnPO_(4)-H_(3)tren-H_(2)ta,tren=tri(2-aminoethyl)amine and H_(2)ta=terephthalic acid),featuring analogous host frameworks but distinct hydrogenbonded networks,were rationally designed and synthesized by modulating the vip molecules through substituent effects.Despite their structural similarity,ZnPO_(4)-H_(3)tren-H_(2)O and ZnPO_(4)-H_(3)tren-H_(2)ta exhibit markedly different proton conductivities of 4.55×10^(-4) and 3.41×10^(-3 )S cm^(-1),respectively,at 353 K and~97%relative humidity(RH).The nearly one-order-of-magnitude difference is attributed to the dissociation of the H_(2)ta molecule,which provides a more acidic proton source.Moreover,we found that the pronounced non-Debye relaxation behavior at low temperatures in ZnPO_(4)-H_(3)tren-H_(2)O leads to an increased activation energy for proton conduction,in contrast to the relaxation-free behavior of ZnPO_(4)-H_(3)tren-H_(2)ta.The difference is attributed to variations in the dynamics of their hydrogen-bonded motifs.Furthermore,dielectric relaxation of H_(3)tren^(3+)ions at high temperatures was also observed in both materials.Molecular dynamics simulations corroborate these findings,capturing the distinct dynamic behaviors of water clusters and H_(3)tren^(3+)ions.Beyond fundamental insights,both CPs exhibit high dielectric constants and moderate conductivities under ambient conditions,highlighting their potential as dispersed-phase components in electrorheological fluids.This study unveils a mechanistic link between dielectric relaxation and proton conduction,offering design principles for multifunctional materials that integrate proton conductivity with desirable dielectric properties.展开更多
We report the design and synthesis of a 1D Dy(III)coordination polymer,comprised of sulfonate functionalised ligand 8-hydroxyquinoline-5-sulfonic acid(H_(2)SQ)and Dy3+ions,with a hydrogen-bonded supramolecular 3D stru...We report the design and synthesis of a 1D Dy(III)coordination polymer,comprised of sulfonate functionalised ligand 8-hydroxyquinoline-5-sulfonic acid(H_(2)SQ)and Dy3+ions,with a hydrogen-bonded supramolecular 3D structure.Interestingly,the coordination compound can exhibit reversible structural transformation from a trihydrate(1·3H_(2)O)to a monohydrate(1·H_(2)O)phase during partial desorption/adsorption processes of water molecules in a single-crystal-to-single-crystal(SC-SC)fashion.Importantly,the field-induced slow magnetic relaxation behaviour and proton conduction performance were both switched during the dynamic structural transformation,giving rise to a proton conductive SIM of 1·3H_(2)O and a SIM-insulator of 1·H_(2)O.Variable temperature single-crystal structural analyses reveal that the non-coordinated water molecules play a vital role in the changes in primary coordination environments around the Dy^(3+) ions,and the global hydrogen-bonding networks,resulting in the modification of magnetic properties and proton transport pathways in 1·3H_(2)O and 1·H_(2)O,respectively.The previous results not only provide the first example of a Dy(III)sulfonate showing switched single-ion magnetism and proton conduction behaviour but also highlight a promising way to use water for dynamic control of magnetic and electrical properties.展开更多
In this study,we have synthesized Prussian blue analogue nanocrystals of copper hexacyanocobaltate(CuHCC),and their derivatives via a facile stepwise encapsulation of 1,3-diaza-2,4-cyclopentadiene(Im;Im@CuHCC)and acet...In this study,we have synthesized Prussian blue analogue nanocrystals of copper hexacyanocobaltate(CuHCC),and their derivatives via a facile stepwise encapsulation of 1,3-diaza-2,4-cyclopentadiene(Im;Im@CuHCC)and acetic acid(HAc;Im-HAc@CuHCC)into the CuHCC framework.These materials were characterized by powder X-ray diffraction,thermogravimetric analysis,infrared spectroscopy,N_(2)adsorption/desorption and scanning electron microscopy.Im-HAc@CuHCC shows humidity dependent proton conduction with conductivity(σ)in the 0.933-8.55×10^(-2)S cm^(-1)range at 98%relative humidity(RH)whileσ≈10^(-6)-10^(-5)S cm^(-1)at 25%RH in the 298-353 K range.We further prepared and characterized a series of composites of Im-HAc@CuHCC with a polyvinyl alcohol(PVA)hydrogel,labeled Im-HAc@CuHCC-PVA-X(X=0,2,5 and 10%,and represents the mass ratio of Im-HAc@CuHCC and the hydrogel).Regarding PVA hydrogel,the tensile strength of composites is enhanced at least 1.5 times.Importantly,the X=10%composite shows superior proton conduction withσ=0.81-6.5×10^(-2)S cm^(-1)at 25%RH in the 298-353 K range,confirming that the formation of the hydrogel composite is a facile but efficient strategy to enhance the water-retention capacity and proton conduction at low humidity for porous proton conductors.展开更多
Two novel nickel cluster substituted polyoxometalates(POMs),H_(7)Na_(19)(H_(2)O)_(26){Ni_(12)(OH)_(9)(PO_(4))_(4)(A-α-SiW_(9)O_(34))[W_(4)O_(10)(OH)(PO_(2)(OH)_(2))_(2)(A-α-SiW_(9)O_(34))_(2)]}·4C_(2)H_(8)N...Two novel nickel cluster substituted polyoxometalates(POMs),H_(7)Na_(19)(H_(2)O)_(26){Ni_(12)(OH)_(9)(PO_(4))_(4)(A-α-SiW_(9)O_(34))[W_(4)O_(10)(OH)(PO_(2)(OH)_(2))_(2)(A-α-SiW_(9)O_(34))_(2)]}·4C_(2)H_(8)N·27H_(2)O(1)and H_(26.5)K_(2.5)Na(H_(2)O)_(16)[Ni_(6)(OH)(BO_(3))_(2)(dien)_(2)(B-α-SiW_(10)O_(37))_(2)]_(2)·24H_(2)O(2)(dien=diethylenetriamine),have been successfully prepared.1 is a Ni_(12)-substituted POM comprised of a novel{Ni_(12)(OH)_(9)(PO_(4))_(4)}core,an A-α-{SiW_(9)O_(34)}unit and an uncommon{W_(4)O_(10)(OH)[PO_(2)(OH)_(2)]_(2)(A-α-SiW_(9)O_(34))_(2)}fragment.2 is a Ni_(6)-substituted sandwich-type POM constructed from two B-α-{SiW_(10)O_(37)}units and an unusual boat-like{Ni_(6)(OH)(BO_(3))_(2)(dien)_(2)}cluster.Photocatalytic study reveals that 2 shows a moderate catalytic activity in visible-light-driven CO_(2)reduction reactions.Additionally,the magnetic behaviors and the proton conduction performances of the compounds were investigated.展开更多
Using the new Schiff base ligands condensed from 2-hydroxy-1-naphthalenecarboxaldehyde and(1R,2R)/(1S,2S)-2-aminocyclohexanol(R-H_(3)L/S-H_(3)L),a pair of homochiral Cu_(6)Dy_(3) heterometallic cluster complexes[Cu_(6...Using the new Schiff base ligands condensed from 2-hydroxy-1-naphthalenecarboxaldehyde and(1R,2R)/(1S,2S)-2-aminocyclohexanol(R-H_(3)L/S-H_(3)L),a pair of homochiral Cu_(6)Dy_(3) heterometallic cluster complexes[Cu_(6)Dy_(3)(R-L)_(6)(OH)_(6)(H_(2)O)_(6)](ClO_(4))(NO_(3))_(2)·4.75H_(2)O·8.5MeOH(R-1)and[Cu_(6)Dy_(3)(S-L)_(6)(OH)_(6)(H_(2)O)_(6)](ClO_(4))(NO_(3))_(2)·5.5H_(2)O·8MeOH(S-1)were synthesized at room temperature,which exhibit an interesting topology of triangular corner-sharing cubanes.Magnetic measurements revealed that they are zero-field single-molecule magnets(SMMs),with different Ueff/k values of 19.5(0.6)K for R-1 and 21.4(0.4)K for S-1,owing to solvent magnetic effects.Meanwhile,the chiral enantiomers show proton conductivity caused by hydrogen bonding networks.Furthermore,the circular dichroism(CD)spectra of R-1 and S-1 confirmed their enantiomeric nature,and the magnetic circular dichroism(MCD)study indicated that both R-1 and S-1 have strong magneto-optical Faraday effects at room temperature,with a large|g_(max(MCD))|value of 0.58 T^(−1).展开更多
Rapid dynamics and remarkable proton conduction induced by confined water in nanospaces have attracted much attentions from researchers,which is crucial for advancing the development of innovative proton conductors an...Rapid dynamics and remarkable proton conduction induced by confined water in nanospaces have attracted much attentions from researchers,which is crucial for advancing the development of innovative proton conductors and deepening comprehension of proton and water transport mechanisms within biological systems.In this aspect,carbon nanotubes(CNTs)are frequently employed as a research platform.However,they possess certain limitations,such as their inherent electronic conductivity and extreme hydrophobicity,which can impede the accurate assessment and precise regulation of proton conduction.We herein prepared two 2D COFs with different hydrophilic fragment,and obtained maximum acid-free proton conductivity of 3.04×10^(–4) S·cm^(–1) at 70℃ and 100%RH with Grotthuss type activation energy of 0.14 eV.This is mainly due to that the water molecules in the center of channel form strong hydrogen bonds,enhancing proton dissociation and guiding fast directional diffusion.展开更多
We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventiona...We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventional quaternary ammonium-crosslinked benzimidazole membranes,the introduction of phenyl groups significantly increases the free volume within the membrane.After phosphoric acid doping,the benzimidazole membrane with larger free volume retains more phosphoric acid compared to conventional quaternary ammonium-crosslinked membranes,forming an extensive hydrogen-bonding network that effectively enhances its anhydrous proton conductivity.The anhydrous proton conductivity reaches 91 mS·cm^(-1)at 160℃,substantially higher than that of conventional quaternary ammonium-crosslinked membranes with the same mass fraction.Benefiting from the improved conductivity,the membrane electrode assembly exhibits reduced ohmic polarization,achieving a peak power density of 792 mW·cm^(-2)at 160℃.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22071043 and 22203027)Shanxi Province Science Foundation(No.202303021211194)the program for the(Reserved)Discipline Leaders of Taiyuan Institute of Technology.
文摘Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters with well-defined structures and diverse properties.Therefore,the design and synthesis of a POM-based material for proton conduction is extremely vital.Herein,a dimeric four tartaric acid-bridged tetra-Zr-incorporated arsenotungstate.
基金the financial support from the National Natural Science Foundation of China(Nos.22109164 and 22371046)the Key Program of the Natural Science Foundation of Fujian Province(No.2021J02007)。
文摘Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)(H_(2)O)_(21){Ca(H_(2)O)_(2)@Sb_(12)O_(18)[Ni_(2)(OH)(A-α-Si W_(10)O_(37))]_(3)}_(2)·40H_(2)O(1),was constructed using Keggintype polyoxotungstate A-α-Si W_(10)O_(37),along with Ni and Sb elements.The structure features a Tdsymmetric Sb_(12)O_(18)({Sb_(12)})cage that encapsulates an 8-coordinate Ca^(2+)ion at its face.Additionally,the{Sb_(12)}cage forms an 18-nuclear 3d-5p heterometallic cluster by connecting with three di-nuclear nickel clusters through shared oxygen atoms.Electrochemical impedance spectra studies reveal that the single crystal of 1 achieves a proton conductivity of 1.11×10^(-1)S/cm along the[110]direction and 1.04×10^(-1)S/cm along the[100]direction at 85℃ and 98%relative humidity(RH).Furthermore,the powder form of 1 exhibits a proton conductivity of 3.00×10^(-2)S/cm.These findings suggest that compound 1 holds promise as a practical proton conducting material.
基金Project supported by the National Natural Science Foundation of China(22365018)Jiangxi Provincial Key Laboratory of Functional Crystalline Materials Chemistry(2024SSY05161)Scientific Research Foundation of Jiangxi Provincial Education Department(GJJ210808)。
文摘Lanthanide metal-organic frameworks(Ln-MOFs)are widely used for fluorescence detection of ions and organic small molecules due to their excellent fluorescence properties.An aqueous stable europiumbased metal-organic framework,{I(CH_(3))_(2)NH_(2)]_(2)[Eu(TTDI)H_(2)O]_(2)·2H_(2)O·7DMF}_(n)(Eu-MOF,TTDI=5,5'-(thieno[3,2-b]-2,5-diphenyl)terephthalic)was synthesized and characterized,which demonstrates high selectivity and sensitivity fluorescence sensing of uric acid(UA)with a detection limit of 0.062μmol/L.Moreover,it also exhibits good proton conductivity with a maximum value of 3.34×10^(-3)S/cm at 55℃ under 98% relative humidity owing to its abundant hydrogen-bonding network.Therefore,this Eu-MOF is a potentially important multifunctional bioassay material.
文摘To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D frameworks,designated as[La(HPO_(3))(C_(2)O_(4))0.5(H_(2)O)_(2)](La‑1)and(C_(6)H_(16)N_(2))(H_(3)O)[La_(2)(H_(2)PO_(3))_(3)(C_(2)O_(4))_(3)(H_(2)O)](La‑2)(C_(6)H_(14)N_(2)=cis-2,6-dimethylpiperazine),were prepared by hydrothermal and solvothermal conduction,respectively.La‑1 was constructed with lanthanum phosphite 2D layers and C_(2)O_(4)^(2-)groups,whereas La‑2 was constructed with lanthanum oxalate 2D layers and H_(2)PO^(3-)groups.Alternating current(AC)impedance spectra indicate that the pro-ton conductivities of both compounds could reach 10^(-4)S·cm^(-1)and remain highly durable at 75℃and 98%of rela-tive humidity(RH).Due to the abundance of H-bonds in La‑2,theσof La‑2 was higher than that of La‑1.La‑1 exhibited excellent water and pH stability.CCDC:2439965,La‑1;443776,La‑2.
基金National Natural Science Foundation of China(Nos.92161111 and 21901038)Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,ChinaInternational Cooperation Fund of Science and Technology Commission of Shanghai Municipality,China(No.21130750100)。
文摘Highly reduced molybdenum red(MR)clusters have emerged as a new type of polyoxomolybdates(POMos)and showed great potential as electron/proton reservoirs for energy conversion and storage,as well as for catalysis.However,the limited structural diversity of MR clusters significantly hinders further exploration of their potential as functional materials.Herein,we describe the synthesis of a novel highly reduced MR cluster{Mo_(49)}(compound 1)based on rational assembly of a variety of basic building blocks(BBs).In addition to the well-established BBs found in the family of MR clusters,the unique tetrahedral{MoVI 4}BB plays a key role in directing the assembly to afford trigonal pyramid-like structure of compound 1,which consists of 49 Mo and 148 O atoms with a high reduction degree of 73%.Moreover,at 80℃and 98%relative humidity(RH),the pellet sample of compound 1 displays good proton conductivity of 7.88×10^(-3)S/cm owing to the efficient hydrogen-bonded network built from the surface oxygen atoms,protons and vip water molecules.This research offers new insights into the assembly and synthesis of MR clusters through a BB strategy and manifests their significant potential for advanced applications.
基金the financial support from the National Natural Science Foundation of China(Nos.21971039 and 22171045)and the Key Program of Natural Science Foundation of Fujian Province(No.2021J02007).
文摘The development of core-shell nanoclusters with controllable composition is of utmost importance as the material properties depend on their constituent elements.However,precisely tuning their compositions at the atomic scale is not easily achieved because of the difficulty of using limited macroscopic synthetic methods for atomic-level modulation.In this work,we report an interesting example of precisely regulating the core composition of an inorganic core-shell-type cobalt polyoxoniobate[Co_(26)Nb_(36)O_(140)]^(32−)by controlling reaction conditions,in which the inner Co-core composition could be tune while retaining the outer Nb-shell composition of resulting product,leading to a series of isostructural species with a general formula of{Co_(26-n)Nb_(36+n)O_(140)}(n=0–2).These rare species not only can display good powder and single-crystal proton conductivities,but also might provide helpful and atomic-level insights into the syntheses,structures and composition modifications of inorganic amorphous core-shell heterometal oxide nanoparticles.
基金the National Natural Science Foundation of China(No.21731003).
文摘Metal-organic frameworks(MOFs)with inherent porosity and suspended acidic groups are promising proton conducting materials in water or aqua-ammonia media.Herein we report a new lanthanide phosphonate,namely,Dy_(2)(amp_(2)H_(2))_(2)(mal)(H_(2)O)_(2)·5H2O(MDAF-6).It possesses a 3D open-framework structure,and shows a high NH_(3)adsorption capacity of 142.4 cm^(3)/g at P/P0=0.98 at 298 K due to acid-base interaction.Interestingly,the proton conductivity of MDAF-6-NH3 is enhanced by five orders of magnitude compared to MDAF-6 after 8.5 h exposure in saturated NH_(3)-H_(2)O vapor,indicating the importance of coexistent conjugate acid-base pairs of H_(3)O+-H_(2)O and NH_(4)^(+)-NH_(3)in promoting proton conduction.Magnetic studies of MDAF-6 revealed slow magnetization relaxation under zero dc field,characteristic of singlemolecule magnet behavior.This work provides not only a new multifunctional MOF material,but also a new strategy to improve proton conduction in aqua-ammonia medium.
基金financial support from the National Natural Science Foundation of China(21978024)the Beijing Natural Science Foundation(2202034)。
文摘To attain the objectives of carbon peaking and carbon neutrality,the development of stable and highperformance ion-conducting materials holds enormous relevance in various energy storage and conversion devices.Particularly,crystalline porous materials possessing built-in ordered nanochannels exhibit remarkable superiority in comprehending the ion transfer mechanisms with precision.In this regard,covalent organic frameworks(COFs)are highly regarded as a promising alternative due to their preeminent structural tunability,accessible well-defined pores,and excellent thermal/chemical stability under hydrous/anhydrous conditions.By the availability of organic units and the diversity of topologies and connections,advances in COFs have been increasing rapidly over the last decade and they have emerged as a new field of proton-conducting materials.Therefore,a comprehensive summary and discussion are urgently needed to provide an"at a glance"understanding of the prospects and challenges in the development of proton-conducting COFs.In this review,we target a comprehensive review of COFs in the field of proton conductivity from the aspects of design strategies,the proton conducting mechanism/features,the relationships of structure-function,and the application of research.The relevant content of theoretical simulation,advanced structural characterizations,prospects,and challenges are also presented elaborately and critically.More importantly,we sincerely hope that this progress report will form a consistent view of this field and provide inspiration for future research.
基金supported by the National Natural Science Foundation of China(22071019 and 21872021)the Basic Scientific Research Project of Liaoning Provincial Department of Education(LJKMZ20220968)
文摘Through the mechanochemical method,sulfamic acid(SA)is successfully introduced into UiO-66-NH_(2)to form SA@UiO-66-NH_(2).In SA@UiO-66-NH_(2),the acidic cationic sulfiliminium(—S=NH_(2)^(+))moiety formed by the bridging bidentate binding mode between SA and the zirconium metal center can release protons,and SA actively participates in the construction of hydrogen-bonded network,thereby accelerating the proton conduction.At 95%RH(relative humidity)and 358 K,the proton conductivity of SA@UiO-66-NH_(2)can reach 1.42×10^(-2)S·cm^(-1),which is four orders of magnitude higher than that of the parent framework UiO-66-NH_(2).Meanwhile,this high proton conductivity can be maintained for at least 90 h.
基金the National Science Foundation of China(No.21771183)NSF of Fujian Province(No.2018J01027)FJIRSM&IUE Joint Research Fund(No.RHZX-2018-005)for financial support.
文摘The study of anisotropic proton conduction(APC)on a layered-structured vanadium selenite single crystal,namely[H_(3)O][(VO_(2))_(3)(SeO_(3))_(2)](1),reveals the proton conductivity(σ)ratio(σ_([100])/σ_([001])=188)at 80℃ under 70%relative humidity(RH)and the proton conduction mechanisms of Grotthuss and Vehicle along the[100]and[001]directions,respectively.
基金supported by the 973 Program of China (No. 2014CB845600)the National Natural Science Foundation of China (Nos. 21421001 and 21531005)the Natural Science Foundation of Tianjin(No. 15JCZDJC38800)
文摘A new coordination compound [Mg（L）（H2 O）5·H2 O]（NKU-109, H2 L=5-（4 H-1,2,4-triazol-4-yl）benzene-1,3-dicarboxylic acid） was solvothermally synthesized, featuring a supramolecular hydrogen-bonding network. A good proton conductivity of 5.87×10^-4S/cm was recorded at 70℃ and a relative humidity of75% in alternating current（AC） impedance experiment, which sheds a new light on the design of proton conduction materials based on coordination compounds.
基金the NSF of China(21661005,22161002 and 21761012).
文摘Multifunctional materials with proton conduction,circularly polarized luminescence(CPL)and a magneto-optical Faraday effect would provide a great opportunity for applications in luminescent,electrical,magneto-optical and optical-electronic smart devices.However,such types of multifunctional systems have rarely been reported.Herein,by introducing a chiral amine-phenol ligand,a pair of Cd(Ⅱ)-Tb(Ⅲ)enantiomers,[Cd_(2)Tb(RR/SS-H_(2)L)_(2)(H_(2)O)_(6)](ClO_(4))_(3)·2H_(2)O(R-1 and S-1)[H_(2)L=((SS/RR)-cyclohexane-1,2-diylbis(azanediyl)-bis(methylene)-bis(2-methoxyphenol))],were obtained.R-1 and S-1 feature the homochiral molecules of trinuclear Cd2Tb structures,which contain abundant H-bonds to form threedimensional(3D)supermolecular frameworks.They are chiral multifunctional materials showing strong Tb(Ⅲ)characteristic emissions,a moderate proton conductivity of 1.17×10^(-4) S cm^(-1) at 333 K and 100%RH for R-1,CPL with a luminescence dissymmetry factor value of over 10^(-3) for R-1 and S-1 and a strong magneto-optical Faraday effect,and they are the first known materials simultaneously showing CPL,proton conduction and the Faraday effect.
基金supported by the National Natural Science Foundation of China(21401095,21801107,22178157)the Natural Science Foundation of Shandong Province(ZR2022MB010,ZR2019MB068,ZR2021QB123)+5 种基金Project of Shandong Province Higher Educational Science and Technology Program(KJ2018BZC043,J18KA113)the Liaocheng University Start-up Fund for Doctoral Scientific Research(318050104,318052017)the Scientific Research Fund of Liaocheng University(318011913)the Youth Innovation Team of Shandong Colleges and Universities(2019KJC027,2020KJC012)the Open Fund of Liaocheng University(2020CESNCTKL02)the Shandong Students Innovation and Entrepreneurship Training Program(319260210).
文摘Proton-conducting materials have become highly desirable for clean energy-related applications,and the design and synthesis of stable and efficient proton-conduction materials have become increasingly important but challenging.Three stable porous metal-organic frameworks(MOFs)based on the aluminum(III)cation(Al-MOFs),DUT-5(1),DUT-4(2),and NOTT-300(3),were selected as imidazole(Im)supporters and were successfully used to obtain three proton conduction composites(namely Im@1,Im@2,and Im@3)with excellent proton conductivities(σ).At 80℃ and 100%RH,the proton conductivity values of 1-3 were respectively 1.39×10^(-2),2.98×10^(-2),and 5.57×10^(-2) S cm^(-1),which increased significantly with the decrease in their aperture sizes(1,11.1Å;2,8.5Å;3,6.5Å).The proton conductivity values of Im@1-3 were significantly higher than those of the original MOFs 1-3.Especially,3 has a suitable aperture size for loading imidazole molecules and restricting them in a limited space,which made it difficult for the imidazole molecules of Im@3 to escape from the pores of 3,eventually leading to the formation of strong continuous hydrogen-bonding networks.Therefore,at 80℃ and 100%RH,the proton conductivities(σ)of Im@3 can reach up to 2.55×10^(-1) S cm^(-1),which is close to the σ of the commercial benchmark Nafion under the same conditions.Finally,the related molecular simulation was accomplished to elucidate the proton conduction mechanism by using the Grand Canonical Monte Carlo(GCMC)method.All the above features make Im@3 one of the most promising candidates for further practical applications in fuel cells.
基金support from the National Natural Science Foundation of China(21401147,21403048 and 21771047)the Natural Science Basic Research Program of Shaanxi Province(2024JC-YBMS-084)the Xi’an City Project of Scientific and Technical Personnel in University and Institute Servicing Enterprises(24GXFW0019).
文摘Hydrogen bonds play a pivotal role in governing both proton conduction and dielectric properties in functional materials.However,the direct mechanistic relationship between these two properties,as mediated by hydrogen bonds,remains poorly understood.Here,we address this gap by investigating the role of hydrogen-bonded motifs in coordination polymers(CPs),focusing on how their structural dynamics influence both proton transport and dielectric relaxation.To this end,two CPs,{(H_(3)tren)_(2)[Zn_(3)(PO_(4))_(4)]·6H_(2)O}(ZnPO_(4)-H_(3)tren-H_(2)O)and{(H_(3)tren)_(2)[Zn_(3)(PO_(4))_(4)]·2H_(2)ta}(ZnPO_(4)-H_(3)tren-H_(2)ta,tren=tri(2-aminoethyl)amine and H_(2)ta=terephthalic acid),featuring analogous host frameworks but distinct hydrogenbonded networks,were rationally designed and synthesized by modulating the vip molecules through substituent effects.Despite their structural similarity,ZnPO_(4)-H_(3)tren-H_(2)O and ZnPO_(4)-H_(3)tren-H_(2)ta exhibit markedly different proton conductivities of 4.55×10^(-4) and 3.41×10^(-3 )S cm^(-1),respectively,at 353 K and~97%relative humidity(RH).The nearly one-order-of-magnitude difference is attributed to the dissociation of the H_(2)ta molecule,which provides a more acidic proton source.Moreover,we found that the pronounced non-Debye relaxation behavior at low temperatures in ZnPO_(4)-H_(3)tren-H_(2)O leads to an increased activation energy for proton conduction,in contrast to the relaxation-free behavior of ZnPO_(4)-H_(3)tren-H_(2)ta.The difference is attributed to variations in the dynamics of their hydrogen-bonded motifs.Furthermore,dielectric relaxation of H_(3)tren^(3+)ions at high temperatures was also observed in both materials.Molecular dynamics simulations corroborate these findings,capturing the distinct dynamic behaviors of water clusters and H_(3)tren^(3+)ions.Beyond fundamental insights,both CPs exhibit high dielectric constants and moderate conductivities under ambient conditions,highlighting their potential as dispersed-phase components in electrorheological fluids.This study unveils a mechanistic link between dielectric relaxation and proton conduction,offering design principles for multifunctional materials that integrate proton conductivity with desirable dielectric properties.
基金supported by a start-up fund from Huanggang Normal University(Grant No.2042021033)the Disciplinary Team Project of Huanggang Normal University,and the Open Foundation of State Key Laboratory of Coordination Chemistry(Grant No.SKLCC2208)+3 种基金XQW acknowledges the financial support of the Science and Technology Innovation Program of Shanxi Universities(Grant No.2020L0592)the Doctoral Fund of Jinzhong University(Grant No.jzxybsjjxm2019020)the Basic Research Program of Shanxi Province(Free Exploration)(Grant No.20210302123355)SKS acknowledges a generous seed grant from the IIT Hyderabad and the Department of Science and Technology for the Startup-Research Grant(Grant No.SRG/2020/001323).
文摘We report the design and synthesis of a 1D Dy(III)coordination polymer,comprised of sulfonate functionalised ligand 8-hydroxyquinoline-5-sulfonic acid(H_(2)SQ)and Dy3+ions,with a hydrogen-bonded supramolecular 3D structure.Interestingly,the coordination compound can exhibit reversible structural transformation from a trihydrate(1·3H_(2)O)to a monohydrate(1·H_(2)O)phase during partial desorption/adsorption processes of water molecules in a single-crystal-to-single-crystal(SC-SC)fashion.Importantly,the field-induced slow magnetic relaxation behaviour and proton conduction performance were both switched during the dynamic structural transformation,giving rise to a proton conductive SIM of 1·3H_(2)O and a SIM-insulator of 1·H_(2)O.Variable temperature single-crystal structural analyses reveal that the non-coordinated water molecules play a vital role in the changes in primary coordination environments around the Dy^(3+) ions,and the global hydrogen-bonding networks,resulting in the modification of magnetic properties and proton transport pathways in 1·3H_(2)O and 1·H_(2)O,respectively.The previous results not only provide the first example of a Dy(III)sulfonate showing switched single-ion magnetism and proton conduction behaviour but also highlight a promising way to use water for dynamic control of magnetic and electrical properties.
基金Priority Academic Program Development of Jiangsu Higher Education InstitutionsNational Natural Science Foundation of China(grant no.21671100)。
文摘In this study,we have synthesized Prussian blue analogue nanocrystals of copper hexacyanocobaltate(CuHCC),and their derivatives via a facile stepwise encapsulation of 1,3-diaza-2,4-cyclopentadiene(Im;Im@CuHCC)and acetic acid(HAc;Im-HAc@CuHCC)into the CuHCC framework.These materials were characterized by powder X-ray diffraction,thermogravimetric analysis,infrared spectroscopy,N_(2)adsorption/desorption and scanning electron microscopy.Im-HAc@CuHCC shows humidity dependent proton conduction with conductivity(σ)in the 0.933-8.55×10^(-2)S cm^(-1)range at 98%relative humidity(RH)whileσ≈10^(-6)-10^(-5)S cm^(-1)at 25%RH in the 298-353 K range.We further prepared and characterized a series of composites of Im-HAc@CuHCC with a polyvinyl alcohol(PVA)hydrogel,labeled Im-HAc@CuHCC-PVA-X(X=0,2,5 and 10%,and represents the mass ratio of Im-HAc@CuHCC and the hydrogel).Regarding PVA hydrogel,the tensile strength of composites is enhanced at least 1.5 times.Importantly,the X=10%composite shows superior proton conduction withσ=0.81-6.5×10^(-2)S cm^(-1)at 25%RH in the 298-353 K range,confirming that the formation of the hydrogel composite is a facile but efficient strategy to enhance the water-retention capacity and proton conduction at low humidity for porous proton conductors.
基金supported by the National Natural Science Foundation of China(No.21671040,21773029 and 21831001)the Natural Science Foundation of Fujian Provice(No.2020J01438).
文摘Two novel nickel cluster substituted polyoxometalates(POMs),H_(7)Na_(19)(H_(2)O)_(26){Ni_(12)(OH)_(9)(PO_(4))_(4)(A-α-SiW_(9)O_(34))[W_(4)O_(10)(OH)(PO_(2)(OH)_(2))_(2)(A-α-SiW_(9)O_(34))_(2)]}·4C_(2)H_(8)N·27H_(2)O(1)and H_(26.5)K_(2.5)Na(H_(2)O)_(16)[Ni_(6)(OH)(BO_(3))_(2)(dien)_(2)(B-α-SiW_(10)O_(37))_(2)]_(2)·24H_(2)O(2)(dien=diethylenetriamine),have been successfully prepared.1 is a Ni_(12)-substituted POM comprised of a novel{Ni_(12)(OH)_(9)(PO_(4))_(4)}core,an A-α-{SiW_(9)O_(34)}unit and an uncommon{W_(4)O_(10)(OH)[PO_(2)(OH)_(2)]_(2)(A-α-SiW_(9)O_(34))_(2)}fragment.2 is a Ni_(6)-substituted sandwich-type POM constructed from two B-α-{SiW_(10)O_(37)}units and an unusual boat-like{Ni_(6)(OH)(BO_(3))_(2)(dien)_(2)}cluster.Photocatalytic study reveals that 2 shows a moderate catalytic activity in visible-light-driven CO_(2)reduction reactions.Additionally,the magnetic behaviors and the proton conduction performances of the compounds were investigated.
基金the National Natural Science Foundation of China(Grant Numbers 21871274 and 22271289).
文摘Using the new Schiff base ligands condensed from 2-hydroxy-1-naphthalenecarboxaldehyde and(1R,2R)/(1S,2S)-2-aminocyclohexanol(R-H_(3)L/S-H_(3)L),a pair of homochiral Cu_(6)Dy_(3) heterometallic cluster complexes[Cu_(6)Dy_(3)(R-L)_(6)(OH)_(6)(H_(2)O)_(6)](ClO_(4))(NO_(3))_(2)·4.75H_(2)O·8.5MeOH(R-1)and[Cu_(6)Dy_(3)(S-L)_(6)(OH)_(6)(H_(2)O)_(6)](ClO_(4))(NO_(3))_(2)·5.5H_(2)O·8MeOH(S-1)were synthesized at room temperature,which exhibit an interesting topology of triangular corner-sharing cubanes.Magnetic measurements revealed that they are zero-field single-molecule magnets(SMMs),with different Ueff/k values of 19.5(0.6)K for R-1 and 21.4(0.4)K for S-1,owing to solvent magnetic effects.Meanwhile,the chiral enantiomers show proton conductivity caused by hydrogen bonding networks.Furthermore,the circular dichroism(CD)spectra of R-1 and S-1 confirmed their enantiomeric nature,and the magnetic circular dichroism(MCD)study indicated that both R-1 and S-1 have strong magneto-optical Faraday effects at room temperature,with a large|g_(max(MCD))|value of 0.58 T^(−1).
基金supported by National Natural Science Foundation of China(52207238)China Postdoctoral Science Foundation(2023M731361)Jiangsu University Senior Talent Launch Fund.
文摘Rapid dynamics and remarkable proton conduction induced by confined water in nanospaces have attracted much attentions from researchers,which is crucial for advancing the development of innovative proton conductors and deepening comprehension of proton and water transport mechanisms within biological systems.In this aspect,carbon nanotubes(CNTs)are frequently employed as a research platform.However,they possess certain limitations,such as their inherent electronic conductivity and extreme hydrophobicity,which can impede the accurate assessment and precise regulation of proton conduction.We herein prepared two 2D COFs with different hydrophilic fragment,and obtained maximum acid-free proton conductivity of 3.04×10^(–4) S·cm^(–1) at 70℃ and 100%RH with Grotthuss type activation energy of 0.14 eV.This is mainly due to that the water molecules in the center of channel form strong hydrogen bonds,enhancing proton dissociation and guiding fast directional diffusion.
基金Funded in part by the National Key Research and Development Program of China(No.2023YFB4006302)。
文摘We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventional quaternary ammonium-crosslinked benzimidazole membranes,the introduction of phenyl groups significantly increases the free volume within the membrane.After phosphoric acid doping,the benzimidazole membrane with larger free volume retains more phosphoric acid compared to conventional quaternary ammonium-crosslinked membranes,forming an extensive hydrogen-bonding network that effectively enhances its anhydrous proton conductivity.The anhydrous proton conductivity reaches 91 mS·cm^(-1)at 160℃,substantially higher than that of conventional quaternary ammonium-crosslinked membranes with the same mass fraction.Benefiting from the improved conductivity,the membrane electrode assembly exhibits reduced ohmic polarization,achieving a peak power density of 792 mW·cm^(-2)at 160℃.
