In the present era of genomics, ionomics is one of the major pillars for the structural and functional genomic study. The complete set of ions present in an organism is referred to as the ionome of the organism. Hence...In the present era of genomics, ionomics is one of the major pillars for the structural and functional genomic study. The complete set of ions present in an organism is referred to as the ionome of the organism. Hence, the ionomics is defined as the, “study of quantitative complement of low molecular weight molecules present in cells in a particular physiological and developmental state of the plant” [1]. The complete ionomic profiling of the plants are done by using a number of analytical tools like ICP-MS, ICP-OES, X-Ray crystallography, Neutron Activation Analysis (NAA) etc. All these analytical tools gave complete profile of the ions present in the plants. These data are stored in a database called PiiMS (Purdue Ionomics Information Management System) [2]. The huge data available in the database helps in the forward and reverse genetic approach for studying the structural and functional genomics of the particular organism. This review describes the role of the ionomic study in crop plants like arabidopsis, rice and maize.展开更多
Ionomics is a high-throughput elemental profiling approach to study the molecular mechanistic basis underlying mineral nutrient and trace element composition （also known as the ionome） of living organisms. Since the...Ionomics is a high-throughput elemental profiling approach to study the molecular mechanistic basis underlying mineral nutrient and trace element composition （also known as the ionome） of living organisms. Since the concept of ionomics was first introduced more than 10 years ago, significant progress has been made in the identification of genes and gene networks that control the ionome. In this update, we summa- rize the progress made in using the ionomics approach over the last decade, including the identification of genes by forward genetics and the study of natural ionomic variation. We further discuss the potential application of ionomics to the investigation of the ecological functions of ionomic alleles in adaptation to the environment.展开更多
CO_(2)reduction reaction(CO_(2)RR)electrolyzers based on gas diffusion electrode(GDE)enable the direct mass transfer of CO_(2)to the catalyst surface for participation in the reaction,thereby establishing an efficient...CO_(2)reduction reaction(CO_(2)RR)electrolyzers based on gas diffusion electrode(GDE)enable the direct mass transfer of CO_(2)to the catalyst surface for participation in the reaction,thereby establishing an efficient three-phase reaction interface that significantly enhances current density.However,current hydrophobic modification methods face difficulties in achieving precise and substantial control over wettability,and the hydrophobic modifiers tend to significantly impair the conductivity of the electrode and ion transport capabilities.This study employs Nafion ionomers to hydrophobically modify the threedimensional catalyst layer,revealing the bifunctionality of Nafion.The fluorinated backbone of Nafion ensures the hydrophobicity of the entire catalyst layer,while its sulfonic acid groups promote ion transport,without significantly affecting the conductivity of the electrode.Furthermore,by employing modifiers with distinct wettability characteristics,a highly efficient and large-scale manipulation of the hydrophilic/hydrophobic properties of the catalyst layer was successfully realized.The electrode,constructed with silver nanopowder as a representative catalyst and modified with the hydrophobic ionomer Nafion,exhibits a substantial enhancement in both catalytic activity and durability.The optimized electrode exhibited exceptional electrocatalytic performance in both flow cell and membrane electrode assembly(MEA)configurations.Notably,in the MEA,the electrode achieved a remarkable CO Faradaic efficiency(FE)of 93.3%at a total current density of 200 mA cm^(-2),while maintaining stable operation for over 62 h.展开更多
As the proton transport channel and binder within the catalytic layer(CL),the physicochemical properties of the ionomer can affect the CL microstructure and performance of the membrane electrode assembly.In this paper...As the proton transport channel and binder within the catalytic layer(CL),the physicochemical properties of the ionomer can affect the CL microstructure and performance of the membrane electrode assembly.In this paper,we select ionomers with different side-chain lengths and investigate the effects of the side-chain structure and content of the ionomers on the performance of membrane electrode assembly(MEA).Electrochemical tests show that at a mass ratio of 10 wt.%of ionomer/Ir(I/Ir),long-side-chain(LSC)ionomer exhibits the best performance(2.141 V@2.00 A/cm^(2),while short-side-chain(SSC)ionomer is 2.208 V@2.00 A/cm^(2)).The MEA containing LSC ionomer shows better electrochemical performance than the SSC at the same I/Ir mass ratio,especially at high current density.The MEA containing LSC ionomer has a larger average pore size and porosity,which indicates that it may have better mass-transfer properties.From the analysis of voltage loss,it can be seen that LSC ionomers have a smaller ohmic impedance and mass transfer resistance than SSC ionomers.In conclusion,LSC ionomers are more conducive to water-gas transport,which can provide excellent water electrolysis performance.This article focuses on the optimization of ionomer side chains and content,which can enhance PEM water electrolysis performance at lower cost.展开更多
Sustainable energy technologies,particularly fuel cells,are gaining attraction for their potential to reduce carbon emissions and provide efficient power.Proton exchange membrane fuel cells(PEMFCs)have been central to...Sustainable energy technologies,particularly fuel cells,are gaining attraction for their potential to reduce carbon emissions and provide efficient power.Proton exchange membrane fuel cells(PEMFCs)have been central to this development.However,one persistent issue with lowtemperature PEMFCs is the dehydration of Nafion ionomer at elevated temperatures,which severely limits proton conductivity.Wang et al.tackle this by introducing a covalent organic framework(COF)interwoven with Nafion,addressing the challenge of maintaining proton conductivity and oxygen transport in medium temperatures(100–120℃).展开更多
This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mas...This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mass transport limitations and ionomer-induced catalyst poisoning.The composite architecture strategically positions Pt/V layer with lower ionomer-to-carbon ratio(I/C=0.6)near the proton exchange membrane to maximize surface Pt accessibility and oxygen transport efficiency,whereas Pt/KB layer(I/C=0.9)adjacent to the gas diffusion layer leverages its porous structure to shield Pt from sulfonate group poisoning and enhance proton conduction under low-humidity conditions.This synergistic carbon support engineering achieves a balance between reactant accessibility and catalyst utilization,as demonstrated by improved power density,reduced transport resistance,and higher Pt utilization under dry conditions.These findings establish a new paradigm for low-Pt CCL design through rational carbon support hybridization and ionomer gradient engineering,offering a scalable solution for high-performance PEMFCs in energy-critical applications.展开更多
With the development of renewable energy,electrochemical carbon dioxide reduction reaction(CO_(2)RR)has become a potential solution for achieving carbon neutrality.However,until now,due to issues with salt precipitate...With the development of renewable energy,electrochemical carbon dioxide reduction reaction(CO_(2)RR)has become a potential solution for achieving carbon neutrality.However,until now,due to issues with salt precipitate and regeneration of the electrolyte,this technology faces challenges such as difficulty in maintaining long-term stable operation and excessive costs.The pure water CO_(2)electrolyzers are believed to be the ultimate solution to eliminate the salt depreciation and electrolyte issues.This study develops an in-situ method tailored for CO_(2)reduction in pure water.By employing distribution of relaxation times(DRT)analysis and in-situ electrochemical active surface area(ECSA)measurements,we carried out a comprehensive investigation into the mass transport and electrochemical active surface area of gas diffusion electrodes(GDE)under pure water conditions.The maximum 89%CO selectivity and high selectivity(>80%)in the range of 0-300 mA/cm^(2)were achieved using commercial Ag nanoparticles by rational design of catalyst layer.We found that ionomers influence the CO_(2)electrolyzers performance via affecting local pH,GDE-membrane interface,and CO_(2)transport,while catalyst loading mainly influences the active area and CO_(2)transport.This work provides benchmark and insights for future pure water CO_(2)electrolyzers development.展开更多
Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)represents an advanced technology for converting CO_(2)into highly valuable chemicals.Although significant progress has been achieved in producing multi-carbon chemic...Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)represents an advanced technology for converting CO_(2)into highly valuable chemicals.Although significant progress has been achieved in producing multi-carbon chemicals such as ethylene(C2H4),addressing(bi)carbonate salt formation and precipitation in alkaline electrolytes remains a critical challenge for achieving longterm stability during industrialization.We developed a Cu_(2)(OH)_(2)CO_(3)/Mg^(2+)/C pre-catalyst,which transforms into a catalytically active Cu0/Cu^(2+)/Mg^(2+)composite by electroreduction.Crucially,the application of different ionomers(specifically Sustainion XA-9)on this composite catalyst effectively alleviates salt precipitation issues,thereby enabling high-selectivity,durable CO_(2)-to-C^(2+)conversion.In a membrane electrode assembly,the maximum Faradaic efficiency for C^(2+)products reaches 80%,with stable operation at 200 mA cm^(−2)for 50 h.In situ Raman spectroscopy reveals that only top-type*CO intermediate exists on the Cu0/Cu^(2+)/Nafion cathode,whereas both bridge-type and top-type of*CO sites coexist on the Cu^(0)/Cu^(2+)/Mg^(2+)/Sustainion XA-9 cathode.This dual adsorption configuration facilitates the C─C coupling kinetics on the catalyst,inducing a favorable microenvironment for selective C^(2+)formation.Therefore,strategic optimization of catalyst architectures and ionomer engineering enables CO_(2)RR with improved efficiency and durability,advancing green chemistry and carbon-neutral technologies.展开更多
Urgent requirements of the renewable energy boost the development of stable and clean hydrogen,which could effectively displace fossil fuels in mitigating climate changes.The efficient interconversion of hydrogen and ...Urgent requirements of the renewable energy boost the development of stable and clean hydrogen,which could effectively displace fossil fuels in mitigating climate changes.The efficient interconversion of hydrogen and electronic is highly based on polymer electrolyte membrane fuel cells(PEMFCs)and water electrolysis(PEMWEs).However,the high cost continues to impede large-scale commercialization of both PEMFC and PEMWE technologies,with the expense primarily attributed to noble catalysts serving as a major bottleneck.The reduction of Pt loading in PEMFCs is essential but limited by the oxygen transport resistance in the cathode catalyst layers(CCLs),while the oxygen transport in anode catalyst layers(ACLs)in PEMWEs also being focused as the Ir/IrO_(x) catalyst reduced.The pore structure and the catalyst-ionomer agglomerates play important roles in the oxygen transport process of both PEMFCs and PEMWEs due to the similarity of membrane electrode assembly(MEA).Herein,the oxygen transport mechanism of PEMFCs in pore structure and ionomer thin films in CCLs is systematically reviewed,while state-of-the-art strategies are presented for enhancing oxygen transport and performance through materials and structural design.The deeply research opens avenues for exploring similar key scientific problems in oxygen transport process of PEMWEs and their further development.展开更多
Liquid phosphoric acid(PA),as the proton carrier for high temperature polymer electrolyte membrane fuel cells(HT-PEMFCs),presents challenges such as catalyst poisoning,high gas transport resistance and electrolyte los...Liquid phosphoric acid(PA),as the proton carrier for high temperature polymer electrolyte membrane fuel cells(HT-PEMFCs),presents challenges such as catalyst poisoning,high gas transport resistance and electrolyte loss.These issues significantly impede the performance and durability of HT-PEMFCs,thereby limiting their potential for further application.In this study,poly(2,3,5,6-tetrafluorostylene-4-phosphonic acid)(PWN)with intrinsic proton conduction ability was employed as catalyst layer binder to reveal the impacts of the ionomer's molecular structure on mass transport within the catalyst layer.Our findings demonstrated that increasing the phosphorylation degree of PWN could enhance both pore formation at the catalyst layer and electrode acidophilic capability while improving proton conduction ability and reducing cells'internal resistance.However,adverse effects included increased local oxygen transport resistance and decreased catalyst utilization resulting from electrode acidophilic capability.This research offers valuable insights for the relationships between micro-scale molecule structure,mesoscale electrode architecture,and membrane electrode assembly design in HT-PEMFCs.展开更多
The large-scale commercialization of proton exchange membrane fuel cells(PEMFCs)has been hindered by the high demand of platinum(Pt)in the cathode due to the sluggish kinetics of the oxygen reduction reaction.Reducing...The large-scale commercialization of proton exchange membrane fuel cells(PEMFCs)has been hindered by the high demand of platinum(Pt)in the cathode due to the sluggish kinetics of the oxygen reduction reaction.Reducing the amount of Pt would worsen the problems caused by the adsorption of perfluorinated sulfonic acid(PFSA)ionomers to Pt via the side chains,namely,blocking the active sites of Pt and inducing densely packed layers of fluorocarbon backbones on Pt surface to obstruct local O_(2)transport at the Pt/PFSA interfaces.This work aims at optimizing the Pt/ionomer interface to mitigate the sulfonate adsorption and in the meantime to reduce the local O_(2)transport resistance(R_(local)),by using a porous composite of 1-butyl-3-methylimidazolium hydrogen sulfate ionic liquid(IL)modified MOF-808(BMImHSO_(4)@MOF-808)as additive in cathodic catalyst layer(CCL).Through detailed physical,spectroscopic and electrochemical characterizations,we demonstrate a three-fold optimization mechanism of Pt/ionomer interface structure by BMImHSO_(4)@MOF-808:the unsaturated metal sites in MOF-808 effectively inhibit the sulfonate adsorption on Pt through coordination with the sulfonates of PFSA,thereby improving catalyst utilization;the pores in MOF-808 establish efficient transport channels for gaseous oxygen,significantly reducing R_(local);the IL modification layers facilitate the formation of continuous proton transport networks,increasing proton conductivity.The incorporation of BMImHSO_(4)@MOF-808 in a low-Pt CCL(0.1 mg_(Pt)cm^(-2))yields a peak power density of 1.9 W cm^(-2)for PEMFC under H_(2)-O_(2)condition,and ca.20%increase of power density under H_(2)-air condition as compared with conventional CCL,indicating the prospect of IL-MOF composites as an efficient additive to enhance the performance of PEMFCs.展开更多
Anion exchange membrane fuel cells(AEMFCs)are considered a more affordable technology compared to proton exchange membrane fuel cells(PEMFCs),but the performance and durability of AEMFCs are still not competent with P...Anion exchange membrane fuel cells(AEMFCs)are considered a more affordable technology compared to proton exchange membrane fuel cells(PEMFCs),but the performance and durability of AEMFCs are still not competent with PEMFCs owing to the more challenging water management,which severely hinders its development and real-life applications.In this study,we introduce the strategy to boost the performance and stability of the membrane electrode assembly(MEA)of AEMFCs by regulating the hydrophilicity of the anode and cathode ionomers.Two poly(biphenyl alkylene)ionomers with different hydrophilicity are synthesized and used to fabricate MEAs with asymmetric or symmetric ionomer configurations in the anodic and cathodic catalyst layers(CLs)for AEMFCs.Molecular dynamics(MD)simulations have revealed different diffusion rates of water in the hydrophobic anode and the hydrophilic cathode,which show the potential of this design to improve water management in AEMFCs,The effectiveness of this design is also confirmed by experimental results that the MEA with this asymmetric configuration exhibits the highest power and current densities of 1.58 W cm^(-2)or 5.58 A cm^(-2),respectively,among all configurations.Furthermore,this configuration also enhances the durability,with the MEA showing a voltage decay rate of only 313.1μV h^(-1)after 500 h of in-situ durability test at 0.2 A cm^(-2).This study provides new insights into the rational design of more efficient water management in MEA for high-performance AEMFCs.展开更多
Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-nob...Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-noble metal catalysts and hydrocarbon-based ionomers as membrane[1].However,despite of extensive researches on non-noble metal catalysts such as Co[2].展开更多
Arsenite(As(III))as the most toxic and mobile form is the dominant arsenic(As)species in flooded paddy fields,resulting in higher accumulation of As in paddy rice than other terrestrial crops.Mitigation of As toxicity...Arsenite(As(III))as the most toxic and mobile form is the dominant arsenic(As)species in flooded paddy fields,resulting in higher accumulation of As in paddy rice than other terrestrial crops.Mitigation of As toxicity to rice plant is an important way to safeguard food production and safety.In the current study,As(III)-oxidizing bacteria Pseudomonas sp.strain SMS11 was inoculated with rice plants to accelerate conversion of As(III)into lower toxic arsenate(As(V)).Meanwhile,additional phosphate was supplemented to restrict As(V)uptake by the rice plants.Growth of rice plant was significantly inhibited under As(III)stress.The inhibition was alleviated by the introduction of additional P and SMS11.Arsenic speciation showed that additional P restricted As accumulation in the rice roots via competing common uptake pathways,while inoculation with SMS11 limited As translocation from root to shoot.Ionomic profiling revealed specific characteristics of the rice tissue samples from different treatment groups.Compared to the roots,ionomes of the rice shoots were more sensitive to environmental perturbations.Both extraneous P and As(III)-oxidizing bacteria SMS11 could alleviate As(III)stress to the rice plants through promoting growth and regulating ionome homeostasis.展开更多
Maize is one of the most nutrient demanding staple crops. Tissue nutrient diagnosis of maize is currently conducted using critical nutrient concentration or dual ratio ranges, but such diagnoses are pathological as bi...Maize is one of the most nutrient demanding staple crops. Tissue nutrient diagnosis of maize is currently conducted using critical nutrient concentration or dual ratio ranges, but such diagnoses are pathological as biased by data redundancy, sub-compositional incoherence and non-normal distribution. The use of orthogonal balances, a compositional data analysis technique, avoids such biases. Our objective was to develop foliar nutrient balance standards for maize. We collected 758 grain yields (15.5% moisture content) and foliar samples at silk stage in maize fields of southern Quebec, Canada, and analyzed ten nutrients in tissues (N, P, K, Ca, Mg, B, Cu, Zn, Mn, Fe). Nutrients were arranged into ad hoc balances and computed as isometric log ratios (ilr). An optimized binary classification performed by a customized receiver operating characteristic procedure showed that a critical Mahalanobis distance of 4.21 separated balanced from imbalanced specimens about yield cut-off of 11.83 Mg grain·ha-1 with test performance of 86%. Quebec maize balance standards differed from published standards computed from DRIS norms collected in other agroecosystems. The Redfield N/P ratio in maize leaves was found to be the least variable balance across regions of the world. The DRIS dual ratios and raw concentration values were found to be geometrically inadequate for conducting diagnosis. The unbiased nutrient balance diagnosis combined the critical Mahalanobis distance and a mobile representation of nutrient balances with ilr means of true negative (TN) specimens centered at fulcrums and back-transformed ilr values of TN specimens into raw concentrations loading the buckets below. Nutrients can be appreciated as relative shortage, adequacy or excess in the concentration domain following statistical analysis and diagnosis in the unbiased balance domain.展开更多
Element profile was investigated for their use to trace the geographical origin of rice （Oryza sativa L.） samples. The concentrations of 13 elements （calcium （Ca）, potassium （K）, magnesium （Mg）, phosphorus （...Element profile was investigated for their use to trace the geographical origin of rice （Oryza sativa L.） samples. The concentrations of 13 elements （calcium （Ca）, potassium （K）, magnesium （Mg）, phosphorus （P）, boron （B）, manganese （Mn）, iron （Fe）, nickel （Ni）, copper （Cu）, arsenic （As）, selenium （Se）, molybdenum （Mo）, and cadmium （Cd）） were determined in the rice samples by inductively coupled plasma optical emission and mass spectrometry. Most of the essential elements for human health in rice were within normal ranges except for Mo and Se. Mo concentrations were twice as high as those in rice from Vietnam and Spain. Meanwhile, Se concentrations were three times lower in the whole province compared to the Chinese average level of 0.088 mg/kg. About 12% of the rice samples failed the Chinese national food safety standard of 0.2 mg/kg for Cd. Combined with the multi-elemental profile in rice, the principal component analysis （PCA）, discriminant function analysis （DFA） and Fibonacci index analysis （FIA） were applied to discriminate geographical origins of the samples. Results indicated that the FIA method could achieve a more effective geographical origin classification compared with PCA and DFA, due to its efficiency in making the grouping even when the elemental variability was so high that PCA and DFA showed little discriminatory power. Furthermore, some elements were identified as the most powerful indicators of geographical origin： Ca, Ni, Fe and Cd. This suggests that the newly established methodology of FIA based on the ionome profile can be applied to determine the geographical origin of rice.展开更多
Imidazolium-based elastomeric ionomers （i-BIIR） were facilely synthesized by ionically modified brominated poly（isobutylene-co-isoprene） （BIIR） with different alkyl chain imidazole and thoroughly explored as nov...Imidazolium-based elastomeric ionomers （i-BIIR） were facilely synthesized by ionically modified brominated poly（isobutylene-co-isoprene） （BIIR） with different alkyl chain imidazole and thoroughly explored as novel toughening agents for poly（lactic acid） （PLA）. The miscibility, thermal behavior, phase morphology and mechanical property of ionomers and blends were investigated through dynamic mechanical analyses （DMA）, differential scanning calorimetry （DSC）, scanning electron microscopy （SEM）, tensile and impact testing. DMA and SEM results showed that better compatibility between the PLA and i-BIIR was achieved compared to the PLA/unmodified BIIR elastomer. A remarkable improvement in ductility with an optimum elongation at break up to 235% was achieved for the PLA/i-BIIR blends with 1-dodecylimidazole alkyl chain （i-BIIR-12）, more than 10 times higher than that of pure PLA. The impact strengths of PLA were enhanced from 1.9 kJ/m2 to 4.1 k J/m2 for the PLA/10 wt% i-BIIR-12 blend. Toughening mechanism had been established by systematical analysis of the compatibility, intermolecular interaction and phase structures of the blends. Interracial cavitations initiated massive shear yielding of the PLA matrix owing to a suitable interfacial adhesion which played a key role in the enormous toughening effect in these blends. We believed that introducing imidazolium group into the BIIR elastomer was vital for the formation of a suitable interfacial adhesion.展开更多
SMPU （shape memory polyurethane） non-ionomers and ionomers, synthesized with poly（c-caprolactone） （PCL）, 4, 4＇-diphenylmethane diisocyanate （MDI）, 1,4-butanediol （BDO）, dimethylolpropionic acid （DMPA） wer...SMPU （shape memory polyurethane） non-ionomers and ionomers, synthesized with poly（c-caprolactone） （PCL）, 4, 4＇-diphenylmethane diisocyanate （MDI）, 1,4-butanediol （BDO）, dimethylolpropionic acid （DMPA） were measured with cyclic tensile test and strain recovery test. The relations between the structure and shape memory effect of these two series were studied with respect to the ionic group content and the effect of neutralization. The resulting data indicate that, with the introduction of asymmetrical extender, the stress at 100% elongation is decreased for PU non-ionomer and ionomer series, especially lowered sharply for non-ionomer series; the fixation ratio of ionomer series is not affected obviously by the ionic group content; the total recovery ratio of ionomer series is decreased greatly. After sufficient relaxation time for samples stretched beforehand, the switching temperature is raised slightly, whereas the recovery ratio measured with strain recovery test method is lowered with increased DMPA content. The characterization with FT-IR, DSC, DMA elucidated that, the ordered hard domain of the two series is disrupted with the introduction of DMPA which causes more hard segments to dissolve in soft phase; ionic groups on hard segment enhance the cohesion between hard segments especially at high ionic group content and significantly facilitate the phase separation compared with the corresponding non-ionomer at moderate ionic group content.展开更多
High transparency and toughness are prerequisites for sustainable polymers if they are to find wide application as alternatives to petroleum-based polymers.However,the utility of sustainable polymers such as commercia...High transparency and toughness are prerequisites for sustainable polymers if they are to find wide application as alternatives to petroleum-based polymers.However,the utility of sustainable polymers such as commercially available polylactide(PLA)is limited by their inherent brittleness and high cost.Unfortunately,toughening PLA-based materials via cost-effective blending strategies without sacrificing transparency remains a challenge.Herein,we report a novel strategy involving active refractive index matching for creation of highly transparent and tough PLA blends.Specifically,we engineered the refractive index of a promising renewable poly(epichlorohydrin-co-ethylene oxide)elastomer by introducing polar ionic moieties via a simple chemical method,and we blended the resulting ionomers with PLA.The best blend showed an impact strength of>80 kJ/m2,an elongation at break of 400%,and high transparency(90%).These characteristics are of great importance for potential applications such as packaging.Our strategy offers a versatile new way to prepare high-performance sustainable polymer materials with excellent transparency.展开更多
文摘In the present era of genomics, ionomics is one of the major pillars for the structural and functional genomic study. The complete set of ions present in an organism is referred to as the ionome of the organism. Hence, the ionomics is defined as the, “study of quantitative complement of low molecular weight molecules present in cells in a particular physiological and developmental state of the plant” [1]. The complete ionomic profiling of the plants are done by using a number of analytical tools like ICP-MS, ICP-OES, X-Ray crystallography, Neutron Activation Analysis (NAA) etc. All these analytical tools gave complete profile of the ions present in the plants. These data are stored in a database called PiiMS (Purdue Ionomics Information Management System) [2]. The huge data available in the database helps in the forward and reverse genetic approach for studying the structural and functional genomics of the particular organism. This review describes the role of the ionomic study in crop plants like arabidopsis, rice and maize.
文摘Ionomics is a high-throughput elemental profiling approach to study the molecular mechanistic basis underlying mineral nutrient and trace element composition （also known as the ionome） of living organisms. Since the concept of ionomics was first introduced more than 10 years ago, significant progress has been made in the identification of genes and gene networks that control the ionome. In this update, we summa- rize the progress made in using the ionomics approach over the last decade, including the identification of genes by forward genetics and the study of natural ionomic variation. We further discuss the potential application of ionomics to the investigation of the ecological functions of ionomic alleles in adaptation to the environment.
基金National Key R&D Program of China(2023YFA1507902,2021YFA1500804)the National Natural Science Foundation of China(22121004,22038009,22250008)+2 种基金the Haihe Laboratory of Sustainable Chemical Transformations(CYZC202107)the Program of Introducing Talents of Discipline to Universities,China(No.BP0618007)the Xplorer Prize,China,for their financial support。
文摘CO_(2)reduction reaction(CO_(2)RR)electrolyzers based on gas diffusion electrode(GDE)enable the direct mass transfer of CO_(2)to the catalyst surface for participation in the reaction,thereby establishing an efficient three-phase reaction interface that significantly enhances current density.However,current hydrophobic modification methods face difficulties in achieving precise and substantial control over wettability,and the hydrophobic modifiers tend to significantly impair the conductivity of the electrode and ion transport capabilities.This study employs Nafion ionomers to hydrophobically modify the threedimensional catalyst layer,revealing the bifunctionality of Nafion.The fluorinated backbone of Nafion ensures the hydrophobicity of the entire catalyst layer,while its sulfonic acid groups promote ion transport,without significantly affecting the conductivity of the electrode.Furthermore,by employing modifiers with distinct wettability characteristics,a highly efficient and large-scale manipulation of the hydrophilic/hydrophobic properties of the catalyst layer was successfully realized.The electrode,constructed with silver nanopowder as a representative catalyst and modified with the hydrophobic ionomer Nafion,exhibits a substantial enhancement in both catalytic activity and durability.The optimized electrode exhibited exceptional electrocatalytic performance in both flow cell and membrane electrode assembly(MEA)configurations.Notably,in the MEA,the electrode achieved a remarkable CO Faradaic efficiency(FE)of 93.3%at a total current density of 200 mA cm^(-2),while maintaining stable operation for over 62 h.
基金Project(52271013)supported by the National Natural Science Foundation of ChinaProject(23DZ1200600)supported by the Science and Technology Innovation Action Plan of Shanghai,China。
文摘As the proton transport channel and binder within the catalytic layer(CL),the physicochemical properties of the ionomer can affect the CL microstructure and performance of the membrane electrode assembly.In this paper,we select ionomers with different side-chain lengths and investigate the effects of the side-chain structure and content of the ionomers on the performance of membrane electrode assembly(MEA).Electrochemical tests show that at a mass ratio of 10 wt.%of ionomer/Ir(I/Ir),long-side-chain(LSC)ionomer exhibits the best performance(2.141 V@2.00 A/cm^(2),while short-side-chain(SSC)ionomer is 2.208 V@2.00 A/cm^(2)).The MEA containing LSC ionomer shows better electrochemical performance than the SSC at the same I/Ir mass ratio,especially at high current density.The MEA containing LSC ionomer has a larger average pore size and porosity,which indicates that it may have better mass-transfer properties.From the analysis of voltage loss,it can be seen that LSC ionomers have a smaller ohmic impedance and mass transfer resistance than SSC ionomers.In conclusion,LSC ionomers are more conducive to water-gas transport,which can provide excellent water electrolysis performance.This article focuses on the optimization of ionomer side chains and content,which can enhance PEM water electrolysis performance at lower cost.
基金financial support from the National Natural Science Foundation of China(No.22301139)the Natural Science Foundation of Jiangsu Province(No.BK 20230375).
文摘Sustainable energy technologies,particularly fuel cells,are gaining attraction for their potential to reduce carbon emissions and provide efficient power.Proton exchange membrane fuel cells(PEMFCs)have been central to this development.However,one persistent issue with lowtemperature PEMFCs is the dehydration of Nafion ionomer at elevated temperatures,which severely limits proton conductivity.Wang et al.tackle this by introducing a covalent organic framework(COF)interwoven with Nafion,addressing the challenge of maintaining proton conductivity and oxygen transport in medium temperatures(100–120℃).
基金financially supported by National Natural Science Foundation of China(22202124 and UA22A20429)Shanxi Scholarship Council of China(2023-008 and 2023-009)+4 种基金Shanxi Outstanding Project Selection and Support Program for Overseas Scientific and Technological Activities(20230002)Science and Technology Innovation Teams of Shanxi Province(202304051001023)the Key Research and Development Program of Shanxi Province(No.202302060301009)Qingdao New Energy Shandong Laboratory Open Project(QNESL OP)Shandong Provincial Natural Science Foundation(Nos.ZR2024QB175 and ZR2023LFG005).
文摘This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mass transport limitations and ionomer-induced catalyst poisoning.The composite architecture strategically positions Pt/V layer with lower ionomer-to-carbon ratio(I/C=0.6)near the proton exchange membrane to maximize surface Pt accessibility and oxygen transport efficiency,whereas Pt/KB layer(I/C=0.9)adjacent to the gas diffusion layer leverages its porous structure to shield Pt from sulfonate group poisoning and enhance proton conduction under low-humidity conditions.This synergistic carbon support engineering achieves a balance between reactant accessibility and catalyst utilization,as demonstrated by improved power density,reduced transport resistance,and higher Pt utilization under dry conditions.These findings establish a new paradigm for low-Pt CCL design through rational carbon support hybridization and ionomer gradient engineering,offering a scalable solution for high-performance PEMFCs in energy-critical applications.
基金supported by the National Natural Science Foundation of China(No.52394204)by the Shanghai Municipal Science and Technology Major Project。
文摘With the development of renewable energy,electrochemical carbon dioxide reduction reaction(CO_(2)RR)has become a potential solution for achieving carbon neutrality.However,until now,due to issues with salt precipitate and regeneration of the electrolyte,this technology faces challenges such as difficulty in maintaining long-term stable operation and excessive costs.The pure water CO_(2)electrolyzers are believed to be the ultimate solution to eliminate the salt depreciation and electrolyte issues.This study develops an in-situ method tailored for CO_(2)reduction in pure water.By employing distribution of relaxation times(DRT)analysis and in-situ electrochemical active surface area(ECSA)measurements,we carried out a comprehensive investigation into the mass transport and electrochemical active surface area of gas diffusion electrodes(GDE)under pure water conditions.The maximum 89%CO selectivity and high selectivity(>80%)in the range of 0-300 mA/cm^(2)were achieved using commercial Ag nanoparticles by rational design of catalyst layer.We found that ionomers influence the CO_(2)electrolyzers performance via affecting local pH,GDE-membrane interface,and CO_(2)transport,while catalyst loading mainly influences the active area and CO_(2)transport.This work provides benchmark and insights for future pure water CO_(2)electrolyzers development.
基金supported by the National Natural Science Foundation of China(No.22303087)the Joint Fund of the Technical R&D Program of Henan Province(No.232301420049)the Natural Science Foundation of Henan Province(No.212300410281).
文摘Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)represents an advanced technology for converting CO_(2)into highly valuable chemicals.Although significant progress has been achieved in producing multi-carbon chemicals such as ethylene(C2H4),addressing(bi)carbonate salt formation and precipitation in alkaline electrolytes remains a critical challenge for achieving longterm stability during industrialization.We developed a Cu_(2)(OH)_(2)CO_(3)/Mg^(2+)/C pre-catalyst,which transforms into a catalytically active Cu0/Cu^(2+)/Mg^(2+)composite by electroreduction.Crucially,the application of different ionomers(specifically Sustainion XA-9)on this composite catalyst effectively alleviates salt precipitation issues,thereby enabling high-selectivity,durable CO_(2)-to-C^(2+)conversion.In a membrane electrode assembly,the maximum Faradaic efficiency for C^(2+)products reaches 80%,with stable operation at 200 mA cm^(−2)for 50 h.In situ Raman spectroscopy reveals that only top-type*CO intermediate exists on the Cu0/Cu^(2+)/Nafion cathode,whereas both bridge-type and top-type of*CO sites coexist on the Cu^(0)/Cu^(2+)/Mg^(2+)/Sustainion XA-9 cathode.This dual adsorption configuration facilitates the C─C coupling kinetics on the catalyst,inducing a favorable microenvironment for selective C^(2+)formation.Therefore,strategic optimization of catalyst architectures and ionomer engineering enables CO_(2)RR with improved efficiency and durability,advancing green chemistry and carbon-neutral technologies.
基金supported by the National Key Research and Development Program of China(No.2021YFB4001305).
文摘Urgent requirements of the renewable energy boost the development of stable and clean hydrogen,which could effectively displace fossil fuels in mitigating climate changes.The efficient interconversion of hydrogen and electronic is highly based on polymer electrolyte membrane fuel cells(PEMFCs)and water electrolysis(PEMWEs).However,the high cost continues to impede large-scale commercialization of both PEMFC and PEMWE technologies,with the expense primarily attributed to noble catalysts serving as a major bottleneck.The reduction of Pt loading in PEMFCs is essential but limited by the oxygen transport resistance in the cathode catalyst layers(CCLs),while the oxygen transport in anode catalyst layers(ACLs)in PEMWEs also being focused as the Ir/IrO_(x) catalyst reduced.The pore structure and the catalyst-ionomer agglomerates play important roles in the oxygen transport process of both PEMFCs and PEMWEs due to the similarity of membrane electrode assembly(MEA).Herein,the oxygen transport mechanism of PEMFCs in pore structure and ionomer thin films in CCLs is systematically reviewed,while state-of-the-art strategies are presented for enhancing oxygen transport and performance through materials and structural design.The deeply research opens avenues for exploring similar key scientific problems in oxygen transport process of PEMWEs and their further development.
基金supported by The National Key Research and Development Program of China(2021YFB4001204)National Natural Science Foundation of China(22179130,22379143,22479145)。
文摘Liquid phosphoric acid(PA),as the proton carrier for high temperature polymer electrolyte membrane fuel cells(HT-PEMFCs),presents challenges such as catalyst poisoning,high gas transport resistance and electrolyte loss.These issues significantly impede the performance and durability of HT-PEMFCs,thereby limiting their potential for further application.In this study,poly(2,3,5,6-tetrafluorostylene-4-phosphonic acid)(PWN)with intrinsic proton conduction ability was employed as catalyst layer binder to reveal the impacts of the ionomer's molecular structure on mass transport within the catalyst layer.Our findings demonstrated that increasing the phosphorylation degree of PWN could enhance both pore formation at the catalyst layer and electrode acidophilic capability while improving proton conduction ability and reducing cells'internal resistance.However,adverse effects included increased local oxygen transport resistance and decreased catalyst utilization resulting from electrode acidophilic capability.This research offers valuable insights for the relationships between micro-scale molecule structure,mesoscale electrode architecture,and membrane electrode assembly design in HT-PEMFCs.
文摘The large-scale commercialization of proton exchange membrane fuel cells(PEMFCs)has been hindered by the high demand of platinum(Pt)in the cathode due to the sluggish kinetics of the oxygen reduction reaction.Reducing the amount of Pt would worsen the problems caused by the adsorption of perfluorinated sulfonic acid(PFSA)ionomers to Pt via the side chains,namely,blocking the active sites of Pt and inducing densely packed layers of fluorocarbon backbones on Pt surface to obstruct local O_(2)transport at the Pt/PFSA interfaces.This work aims at optimizing the Pt/ionomer interface to mitigate the sulfonate adsorption and in the meantime to reduce the local O_(2)transport resistance(R_(local)),by using a porous composite of 1-butyl-3-methylimidazolium hydrogen sulfate ionic liquid(IL)modified MOF-808(BMImHSO_(4)@MOF-808)as additive in cathodic catalyst layer(CCL).Through detailed physical,spectroscopic and electrochemical characterizations,we demonstrate a three-fold optimization mechanism of Pt/ionomer interface structure by BMImHSO_(4)@MOF-808:the unsaturated metal sites in MOF-808 effectively inhibit the sulfonate adsorption on Pt through coordination with the sulfonates of PFSA,thereby improving catalyst utilization;the pores in MOF-808 establish efficient transport channels for gaseous oxygen,significantly reducing R_(local);the IL modification layers facilitate the formation of continuous proton transport networks,increasing proton conductivity.The incorporation of BMImHSO_(4)@MOF-808 in a low-Pt CCL(0.1 mg_(Pt)cm^(-2))yields a peak power density of 1.9 W cm^(-2)for PEMFC under H_(2)-O_(2)condition,and ca.20%increase of power density under H_(2)-air condition as compared with conventional CCL,indicating the prospect of IL-MOF composites as an efficient additive to enhance the performance of PEMFCs.
基金supported by the National Key R&D Program of China(No.2023YFB4004700)。
文摘Anion exchange membrane fuel cells(AEMFCs)are considered a more affordable technology compared to proton exchange membrane fuel cells(PEMFCs),but the performance and durability of AEMFCs are still not competent with PEMFCs owing to the more challenging water management,which severely hinders its development and real-life applications.In this study,we introduce the strategy to boost the performance and stability of the membrane electrode assembly(MEA)of AEMFCs by regulating the hydrophilicity of the anode and cathode ionomers.Two poly(biphenyl alkylene)ionomers with different hydrophilicity are synthesized and used to fabricate MEAs with asymmetric or symmetric ionomer configurations in the anodic and cathodic catalyst layers(CLs)for AEMFCs.Molecular dynamics(MD)simulations have revealed different diffusion rates of water in the hydrophobic anode and the hydrophilic cathode,which show the potential of this design to improve water management in AEMFCs,The effectiveness of this design is also confirmed by experimental results that the MEA with this asymmetric configuration exhibits the highest power and current densities of 1.58 W cm^(-2)or 5.58 A cm^(-2),respectively,among all configurations.Furthermore,this configuration also enhances the durability,with the MEA showing a voltage decay rate of only 313.1μV h^(-1)after 500 h of in-situ durability test at 0.2 A cm^(-2).This study provides new insights into the rational design of more efficient water management in MEA for high-performance AEMFCs.
基金supported by the National Natural Science Foundation of China(Nos.22162014 and U24A2044).
文摘Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-noble metal catalysts and hydrocarbon-based ionomers as membrane[1].However,despite of extensive researches on non-noble metal catalysts such as Co[2].
基金This work was supported by the National Natural Science Foundation of China(No.41977351)the Natural Science Foundation of Hunan Province,China(No.2020JJ4698).
文摘Arsenite(As(III))as the most toxic and mobile form is the dominant arsenic(As)species in flooded paddy fields,resulting in higher accumulation of As in paddy rice than other terrestrial crops.Mitigation of As toxicity to rice plant is an important way to safeguard food production and safety.In the current study,As(III)-oxidizing bacteria Pseudomonas sp.strain SMS11 was inoculated with rice plants to accelerate conversion of As(III)into lower toxic arsenate(As(V)).Meanwhile,additional phosphate was supplemented to restrict As(V)uptake by the rice plants.Growth of rice plant was significantly inhibited under As(III)stress.The inhibition was alleviated by the introduction of additional P and SMS11.Arsenic speciation showed that additional P restricted As accumulation in the rice roots via competing common uptake pathways,while inoculation with SMS11 limited As translocation from root to shoot.Ionomic profiling revealed specific characteristics of the rice tissue samples from different treatment groups.Compared to the roots,ionomes of the rice shoots were more sensitive to environmental perturbations.Both extraneous P and As(III)-oxidizing bacteria SMS11 could alleviate As(III)stress to the rice plants through promoting growth and regulating ionome homeostasis.
文摘Maize is one of the most nutrient demanding staple crops. Tissue nutrient diagnosis of maize is currently conducted using critical nutrient concentration or dual ratio ranges, but such diagnoses are pathological as biased by data redundancy, sub-compositional incoherence and non-normal distribution. The use of orthogonal balances, a compositional data analysis technique, avoids such biases. Our objective was to develop foliar nutrient balance standards for maize. We collected 758 grain yields (15.5% moisture content) and foliar samples at silk stage in maize fields of southern Quebec, Canada, and analyzed ten nutrients in tissues (N, P, K, Ca, Mg, B, Cu, Zn, Mn, Fe). Nutrients were arranged into ad hoc balances and computed as isometric log ratios (ilr). An optimized binary classification performed by a customized receiver operating characteristic procedure showed that a critical Mahalanobis distance of 4.21 separated balanced from imbalanced specimens about yield cut-off of 11.83 Mg grain·ha-1 with test performance of 86%. Quebec maize balance standards differed from published standards computed from DRIS norms collected in other agroecosystems. The Redfield N/P ratio in maize leaves was found to be the least variable balance across regions of the world. The DRIS dual ratios and raw concentration values were found to be geometrically inadequate for conducting diagnosis. The unbiased nutrient balance diagnosis combined the critical Mahalanobis distance and a mobile representation of nutrient balances with ilr means of true negative (TN) specimens centered at fulcrums and back-transformed ilr values of TN specimens into raw concentrations loading the buckets below. Nutrients can be appreciated as relative shortage, adequacy or excess in the concentration domain following statistical analysis and diagnosis in the unbiased balance domain.
基金supported by the Ministry of Science and Technology,China (No.2009DFB90120)
文摘Element profile was investigated for their use to trace the geographical origin of rice （Oryza sativa L.） samples. The concentrations of 13 elements （calcium （Ca）, potassium （K）, magnesium （Mg）, phosphorus （P）, boron （B）, manganese （Mn）, iron （Fe）, nickel （Ni）, copper （Cu）, arsenic （As）, selenium （Se）, molybdenum （Mo）, and cadmium （Cd）） were determined in the rice samples by inductively coupled plasma optical emission and mass spectrometry. Most of the essential elements for human health in rice were within normal ranges except for Mo and Se. Mo concentrations were twice as high as those in rice from Vietnam and Spain. Meanwhile, Se concentrations were three times lower in the whole province compared to the Chinese average level of 0.088 mg/kg. About 12% of the rice samples failed the Chinese national food safety standard of 0.2 mg/kg for Cd. Combined with the multi-elemental profile in rice, the principal component analysis （PCA）, discriminant function analysis （DFA） and Fibonacci index analysis （FIA） were applied to discriminate geographical origins of the samples. Results indicated that the FIA method could achieve a more effective geographical origin classification compared with PCA and DFA, due to its efficiency in making the grouping even when the elemental variability was so high that PCA and DFA showed little discriminatory power. Furthermore, some elements were identified as the most powerful indicators of geographical origin： Ca, Ni, Fe and Cd. This suggests that the newly established methodology of FIA based on the ionome profile can be applied to determine the geographical origin of rice.
基金financially support by the National Natural Science Foundation of China (No. 51573130)
文摘Imidazolium-based elastomeric ionomers （i-BIIR） were facilely synthesized by ionically modified brominated poly（isobutylene-co-isoprene） （BIIR） with different alkyl chain imidazole and thoroughly explored as novel toughening agents for poly（lactic acid） （PLA）. The miscibility, thermal behavior, phase morphology and mechanical property of ionomers and blends were investigated through dynamic mechanical analyses （DMA）, differential scanning calorimetry （DSC）, scanning electron microscopy （SEM）, tensile and impact testing. DMA and SEM results showed that better compatibility between the PLA and i-BIIR was achieved compared to the PLA/unmodified BIIR elastomer. A remarkable improvement in ductility with an optimum elongation at break up to 235% was achieved for the PLA/i-BIIR blends with 1-dodecylimidazole alkyl chain （i-BIIR-12）, more than 10 times higher than that of pure PLA. The impact strengths of PLA were enhanced from 1.9 kJ/m2 to 4.1 k J/m2 for the PLA/10 wt% i-BIIR-12 blend. Toughening mechanism had been established by systematical analysis of the compatibility, intermolecular interaction and phase structures of the blends. Interracial cavitations initiated massive shear yielding of the PLA matrix owing to a suitable interfacial adhesion which played a key role in the enormous toughening effect in these blends. We believed that introducing imidazolium group into the BIIR elastomer was vital for the formation of a suitable interfacial adhesion.
基金This work was supported by Hong Kong ITF research project (No. ITS 098/02).
文摘SMPU （shape memory polyurethane） non-ionomers and ionomers, synthesized with poly（c-caprolactone） （PCL）, 4, 4＇-diphenylmethane diisocyanate （MDI）, 1,4-butanediol （BDO）, dimethylolpropionic acid （DMPA） were measured with cyclic tensile test and strain recovery test. The relations between the structure and shape memory effect of these two series were studied with respect to the ionic group content and the effect of neutralization. The resulting data indicate that, with the introduction of asymmetrical extender, the stress at 100% elongation is decreased for PU non-ionomer and ionomer series, especially lowered sharply for non-ionomer series; the fixation ratio of ionomer series is not affected obviously by the ionic group content; the total recovery ratio of ionomer series is decreased greatly. After sufficient relaxation time for samples stretched beforehand, the switching temperature is raised slightly, whereas the recovery ratio measured with strain recovery test method is lowered with increased DMPA content. The characterization with FT-IR, DSC, DMA elucidated that, the ordered hard domain of the two series is disrupted with the introduction of DMPA which causes more hard segments to dissolve in soft phase; ionic groups on hard segment enhance the cohesion between hard segments especially at high ionic group content and significantly facilitate the phase separation compared with the corresponding non-ionomer at moderate ionic group content.
基金supported by the National Natural Science Foundation of China(No.51573130)。
文摘High transparency and toughness are prerequisites for sustainable polymers if they are to find wide application as alternatives to petroleum-based polymers.However,the utility of sustainable polymers such as commercially available polylactide(PLA)is limited by their inherent brittleness and high cost.Unfortunately,toughening PLA-based materials via cost-effective blending strategies without sacrificing transparency remains a challenge.Herein,we report a novel strategy involving active refractive index matching for creation of highly transparent and tough PLA blends.Specifically,we engineered the refractive index of a promising renewable poly(epichlorohydrin-co-ethylene oxide)elastomer by introducing polar ionic moieties via a simple chemical method,and we blended the resulting ionomers with PLA.The best blend showed an impact strength of>80 kJ/m2,an elongation at break of 400%,and high transparency(90%).These characteristics are of great importance for potential applications such as packaging.Our strategy offers a versatile new way to prepare high-performance sustainable polymer materials with excellent transparency.
