Roof plate secretion of bone morphogenetic proteins(BMPs)directs the cellular fate of sensory neurons during spinal cord development,including the formation of the ascending sensory columns,though their biology is not...Roof plate secretion of bone morphogenetic proteins(BMPs)directs the cellular fate of sensory neurons during spinal cord development,including the formation of the ascending sensory columns,though their biology is not well understood.Type-ⅡBMP receptor(BMPRⅡ),the cognate receptor,is expressed by neural precursor cells during embryogenesis;however,an in vitro method of enriching BMPRⅡ^(+)human neural precursor cells(hNPCs)from the fetal spinal cord is absent.Immunofluorescence was undertaken on intact second-trimester human fetal spinal cord using antibodies to BMPRⅡand leukemia inhibitory factor(LIF).Regions of highest BMPRⅡ^(+)immunofluorescence localized to sensory columns.Parenchymal and meningeal-associated BMPRⅡ^(+)vascular cells were identified in both intact fetal spinal cord and cortex by co-positivity with vascular lineage markers,CD34/CD39.LIF immunostaining identified a population of somas concentrated in dorsal and ventral horn interneurons,mirroring the expression of LIF receptor/CD118.A combination of LIF supplementation and high-density culture maintained culture growth beyond 10 passages,while synergistically increasing the proportion of neurospheres with a stratified,cytoarchitecture.These neurospheres were characterized by BMPRⅡ^(+)/MAP2ab^(+/–)/βⅢ-tubulin^(+)/nestin^(–)/vimentin^(–)/GFAP^(–)/NeuN^(–)surface hNPCs surrounding a heterogeneous core ofβⅢ-tubulin^(+)/nestin^(+)/vimentin^(+)/GFAP^(+)/MAP2ab^(–)/NeuN^(–)multipotent precursors.Dissociated cultures from tripotential neurospheres contained neuronal(βⅢ-tubulin^(+)),astrocytic(GFAP+),and oligodendrocytic(O4+)lineage cells.Fluorescence-activated cell sorting-sorted BMPRⅡ^(+)hNPCs were MAP2ab^(+/–)/βⅢ-tubulin^(+)/GFAP^(–)/O4^(–)in culture.This is the first isolation of BMPRⅡ^(+)hNPCs identified and characterized in human fetal spinal cords.Our data show that LIF combines synergistically with high-density reaggregate cultures to support the organotypic reorganization of neurospheres,characterized by surface BMPRⅡ^(+)hNPCs.Our study has provided a new methodology for an in vitro model capable of amplifying human fetal spinal cord cell numbers for>10 passages.Investigations of the role BMPRⅡplays in spinal cord development have primarily relied upon mouse and rat models,with interpolations to human development being derived through inference.Because of significant species differences between murine biology and human,including anatomical dissimilarities in central nervous system(CNS)structure,the findings made in murine models cannot be presumed to apply to human spinal cord development.For these reasons,our human in vitro model offers a novel tool to better understand neurodevelopmental pathways,including BMP signaling,as well as spinal cord injury research and testing drug therapies.展开更多
Transition metal carbides and nitrides(MXenes)nanosheets are attractive two-dimensional(2D)materials,but they suffer from oxidation/degradation issues during storage and/or applications due to their sensitivity to wat...Transition metal carbides and nitrides(MXenes)nanosheets are attractive two-dimensional(2D)materials,but they suffer from oxidation/degradation issues during storage and/or applications due to their sensitivity to water and oxygen.Despite the great research progress,the exact oxidation kinetics of Ti_(3)C_(2)T_(x)(MXene)and their final products after oxidation are not fully understood.Herein,we systematically tracked the oxidation process of few-layer Ti_(3)C_(2)T_(x) nanosheets in an aqueous solution at room temperature over several weeks.We also studied the oxidation effects on the electrocatalytic properties of Ti_(3)C_(2)T_(x) for hydrogen evolution reaction and found that the overpotential to achieve a current density of 10 mA cm^(-2)increases from 0.435 to 0.877 V after three weeks of degradation,followed by improvement to stabilized values of around 0.40 V after eight weeks.These results suggest that severely oxidized MXene could be a promising candidate for designing efficient catalysts.According to our detailed experimental characterization and theoretical calculations,unlike previous studies,black titanium oxide is formed as the final product in addition to white Ti(IV)oxide and disordered carbons after the complete oxidation of Ti_(3)C_(2)T_(x).This work presents significant advancements in better understanding of 2D Ti_(3)C_(2)T_(x)(MXene)oxidation and enhances the prospects of this material for various applications.展开更多
One of the most unique properties of two-dimensional carbides and nitrides of transition metals(MXenes)is their excellent water dispersibility and yet possessing superior electrical conductivity but their industrial-s...One of the most unique properties of two-dimensional carbides and nitrides of transition metals(MXenes)is their excellent water dispersibility and yet possessing superior electrical conductivity but their industrial-scale application is limited by their costly chemical synthesis methods.In this work,the niche feature of MXenes was capitalized in the packed-bed electrochemical reactor to produce MXenes at an unprecedented reaction rate and yield with minimal chemical waste.A simple NH4F solution was employed as the green electrolyte,which could be used repeatedly without any loss in its efficacy.Surprisingly,both fluoride and ammonium were found to play critical roles in the electrochemical etching,functionalization,and expansion of the layered parent materials(MAXs)through which the liberation of ammonia gas was observed.The electrochemically produced MXenes with excellent conductivity,applied as supercapacitor electrodes,could deliver an ultrahigh volumetric capacity(1408 F cm^(−3))and a volumetric energy density(75.8 Wh L^(−1)).This revolutionary green,energy-efficient,and scalable electrochemical route will not only pave the way for industrial-scale production of MXenes but also open up a myriad of versatile electrochemical modifications for improved functional MXenes.展开更多
This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB)production and its effects on soil properties,plant growth,immobilization of heavy metals,reduction of nutrient leaching and...This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB)production and its effects on soil properties,plant growth,immobilization of heavy metals,reduction of nutrient leaching and mitigation of greenhouse gas emissions.The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agro-industrial wastes.RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio,which suggests the presence of higher aromatic carbon compounds.The increase of pyrolysis temperature also results in production of RHBs with higher ash content,lower yield and higher surface area.RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions.Although it depends on soil type,RHB application can improve soil organic carbon content,cation exchange capacity,available K concentration,bulk density and microbial activity.The effect of RHB on soil aggregation mainly depends on soil texture.The growth of different crops is also enhanced by application of RHB.RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability.RHB application shows a significant capacity in reduction of nitrate leaching,although its magnitude depends on the biochar application rate and soil biogeochemical characteristics.Use of RHB,especially in paddy fields,shows a promising mitigation effect on greenhouse gas(CH4,CO2 and N2O)emissions.Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time,its performance for specific applications(e.g.carbon sequestration,pH amendment)can be manipulated by adjusting the pyrolysis temperature.More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment.展开更多
Metal-air batteries face a great challenge in developing efficient and durable low-cost oxygen reduction reaction(ORR)electrocatalysts.Single-atom iron catalysts embedded into nitrogen doped carbon(Fe-N-C)have emerged...Metal-air batteries face a great challenge in developing efficient and durable low-cost oxygen reduction reaction(ORR)electrocatalysts.Single-atom iron catalysts embedded into nitrogen doped carbon(Fe-N-C)have emerged as attractive materials for potential replacement of Pt in ORR,but their catalytic performance was limited by the symmetrical electronic structure distribution around the single-atom Fe site.Here,we report our findings in significantly enhancing the ORR performance of Fe-N-C by moderate Fe_(2)O_(3) integration via the strong electronic interaction.Remarkably,the optimized catalyst(M-Fe_(2)O_(3)/Fe_(SA)@NC)exhibits excellent activity,durability and good tolerance to methanol,outperforming the benchmark Pt/C catalyst.When M-Fe_(2)O_(3)/Fe_(SA)@NC catalyst was used in a practical zinc-air battery assembly,peak power density of 155 mW cm^(-2)and specific capacity of 762 mA h g_(Zn)^(-1)were achieved and the battery assembly has shown superior cycling stability over a period of 200 h.More importantly,theoretical studies suggest that the introduction of Fe_(2)O_(3) can evoke the crystal field alteration and electron redistribution on single Fe atoms,which can break the symmetric charge distribution of Fe-N_(4) and thereby optimize the corresponding adsorption energy of intermediates to promote the O_(2)reduction.This study provides a new pathway to promote the catalytic performance of single-atom catalysts.展开更多
Parkinson's disease(PD) has a complex and multifactorial pathophysiology. Various studies, conducted both in pre-clinical models and PD patients, have reported a link between the disruption of calcium(Ca^(2+)) hom...Parkinson's disease(PD) has a complex and multifactorial pathophysiology. Various studies, conducted both in pre-clinical models and PD patients, have reported a link between the disruption of calcium(Ca^(2+)) homeostasis and the subsequent development of PD. Ca^(2+) regulation is crucial for neuronal survival, differentiation,exocytosis at synapses,gene transcription,and proliferation.展开更多
Nickel(Ni)-rich cathode materials have become promising candidates for the next-generation electrical vehicles due to their high specific capacity.However,the poor thermodynamic stability(including cyclic performance ...Nickel(Ni)-rich cathode materials have become promising candidates for the next-generation electrical vehicles due to their high specific capacity.However,the poor thermodynamic stability(including cyclic performance and safety performance or thermal stability)will restrain their wide commercial application.Herein,a single-crystal Ni-rich Li Ni_(0.83)Co_(0.12)Mn_(0.05)O_(2) cathode material is synthesized and modified by a dual-substitution strategy in which the high-valence doping element improves the structural stability by forming strong metal–oxygen binding forces,while the low-valence doping element eliminates high Li^(+)/Ni^(2+)mixing.As a result,this synergistic dual substitution can effectively suppress H2-H3 phase transition and generation of microcracks,thereby ultimately improving the thermodynamic stability of Ni-rich cathode material.Notably,the dual-doped Ni-rich cathode delivers an extremely high capacity retention of 81%after 250 cycles(vs.Li/Li+)in coin-type half cells and 87%after 1000 cycles(vs.graphite/Li^(+))in pouch-type full cells at a high temperature of 55℃.More impressively,the dual-doped sample exhibits excellent thermal stability,which demonstrates a higher thermal runaway temperature and a lower calorific value.The synergetic effects of this dual-substitution strategy pave a new pathway for addressing the critical challenges of Ni-rich cathode at high temperatures,which will significantly advance the high-energy-density and high-safety cathodes to the subsequent commercialization.展开更多
BiVO_(4)is one of the most promising photoanode materials for photoelectrochemical(PEC)solar energy conversion,but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency(LHE),...BiVO_(4)is one of the most promising photoanode materials for photoelectrochemical(PEC)solar energy conversion,but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency(LHE),weak photogenerated charge separation efficiency(Φ_(Sep)),and low water oxidation efficiency(Φ_(OX)).Herein,we tackle these challenges of the BiVO_(4)photoanodes using systematic engineering,including catalysis engineering,bandgap engineering,and morphology engineering.In particular,we deposit a NiCoO_(x)layer onto the BiVO_(4)photoanode as the oxygen evolution catalyst to enhance theΦ_(OX)of Fe‐g‐C_(3)N_(4)/BiVO_(4)for PEC water oxidation,and incorporate Fe‐doped graphite‐phase C_(3)N_(4)(Fe‐g‐C_(3)N_(4))into the BiVO_(4)photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm,increase the LHE andΦ_(Sep),and further improve the oxygen evolution reaction activity of the NiCoO_(x)catalytic layer.Consequently,the maximum photocurrent density of the as‐prepared NiCoO_(x)/Fe‐g‐C_(3)N_(4)/BiVO_(4)is remarkably boosted from 4.6 to 7.4 mA cm^(−2).This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE,Φ_(Sep),andΦ_(OX)of BiVO_(4)‐based photoanodes,which will substantially benefit the design,preparation,and large‐scale application of next‐generation high‐performance photoanodes.展开更多
This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts...This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts such as improved efficiency,selectivity,and flexibility due to their distinct electronic structure and unique properties.The review discusses the critical elements in the design of SACs,including the choice of metal atom,host material,and coordination environment,and how these elements impact the catalytic activity.The role of single atoms in photocatalytic H_(2)O_(2)production is also analysed,focusing on enhancing light absorption and charge generation,improving the migration and separation of charge carriers,and lowering the energy barrier of adsorption and activation of reactants.Despite these advantages,several challenges,including H_(2)O_(2)decomposition,stability of SACs,unclear mechanism,and low selectivity,need to be overcome.Looking towards the future,the review suggests promising research directions such as direct utilization of H_(2)O_(2),high-throughput synthesis and screening,the creation of dual active sites,and employing density functional theory for investigating the mechanisms of SACs in H_(2)O_(2)photosynthesis.This review provides valuable insights into the potential of single atom catalysts for advancing the field of photocatalytic H_(2)O_(2)production.展开更多
Carbon nitrides(including CN,C2N,C3N,C3N4,C4N,and C5N)are a unique family of nitrogen-rich carbon materials with multiple beneficial properties in crystalline structures,morphologies,and electronic configurations.In t...Carbon nitrides(including CN,C2N,C3N,C3N4,C4N,and C5N)are a unique family of nitrogen-rich carbon materials with multiple beneficial properties in crystalline structures,morphologies,and electronic configurations.In this review,we provide a comprehensive review on these materials properties,theoretical advantages,the synthesis and modification strategies of different carbon nitride-based materials(CNBMs)and their application in existing and emerging rechargeable battery systems,such as lithium-ion batteries,sodium and potassium-ion batteries,lithium sulfur batteries,lithium oxygen batteries,lithium metal batteries,zinc-ion batteries,and solid-state batteries.The central theme of this review is to apply the theoretical and computational design to guide the experimental synthesis of CNBMs for energy storage,i.e.,facilitate the application of first-principle studies and density functional theory for electrode material design,synthesis,and characterization of different CNBMs for the aforementioned rechargeable batteries.At last,we conclude with the challenges,and prospects of CNBMs,and propose future perspectives and strategies for further advancement of CNBMs for rechargeable batteries.展开更多
Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar r...Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar regions.We used a global climate model(GCM)to investigate the impact on atmospheric chemistry from a change to the contemporary DMS fl ux to that which has been projected for the late 21 st century.The perturbed simulation corresponded to conditions that pertained to a tripling of equivalent CO 2,which was estimated to occur by year 2090 based on current worst-case greenhouse gas emission scenarios.The changes in zonal mean DMS fl ux were applied to 50°S–70°S Antarctic(ANT)and 65°N–80°N Arctic(ARC)regions.The results indicate that there are clearly diff erent impacts after perturbation in the southern and northern polar regions.Most quantities related to the sulfur cycle show a higher increase in ANT.However,most sulfur compounds have higher peaks in ARC.The perturbation in DMS fl ux leads to an increase of atmospheric DMS of about 45%in ANT and 33.6%in ARC.The sulfur dioxide(SO 2)vertical integral increases around 43%in ANT and 7.5%in ARC.Sulfate(SO 4)vertical integral increases by 17%in ANT and increases around 6%in ARC.Sulfur emissions increases by 21%in ANT and increases by 9.7%in ARC.However,oxidation of DMS by OH increases by 38.2%in ARC and by 15.17%in ANT.Aerosol optical depth(AOD)increases by 4%in the ARC and by 17.5%in the ANT,and increases by 22.8%in austral summer.The importance of the perturbation of the biogenic source to future aerosol burden in polar regions leads to a cooling in surface temperature of 1 K in the ANT and 0.8 K in the ARC.Generally,polar regions in the Antarctic Ocean will have a higher off setting eff ect on warming after DMS fl ux perturbation.展开更多
In order to efficiently produce H_(2),conventional methanol‐water thermocatalytic(TC)reforming requires a very high temperature due to high Gibbs free energy,while the energy conversion efficiency of methanol‐water ...In order to efficiently produce H_(2),conventional methanol‐water thermocatalytic(TC)reforming requires a very high temperature due to high Gibbs free energy,while the energy conversion efficiency of methanol‐water photocatalytic(PC)reforming is far from satisfaction because of the kinetic limitation.To address these issues,herein,we incorporate PC and TC processes together in a specially designed reactor and realize simultaneous photocatalytic/thermocatalytic(PC‐TC)reforming of methanol in an aqueous phase.Such a design facilitates the synergetic effect of the PC and TC process for H_(2) production due to a lower energy barrier and faster reaction kinetics.The methanol‐water reforming based on the optimized 0.05%Pt@TiO_(2) catalyst delivers an outstanding H_(2) production rate in the PC‐TC process(5.66μmol H_(2)·g^(‒1) catalyst·s^(‒1)),which is about 3 and 7 times than those of the TC process(1.89μmol H_(2)·g^(‒1) catalyst·s^(‒1))and the PC process(0.80μmol H_(2)·g^(‒1) catalyst·s^(‒1)),respectively.Isotope tracer experiments,active intermediate trapping experiments,and theoretical calculations demonstrate that the photo‐generated holes and hydroxyl radicals could enhance the methanol dehydrogenation,water molecule splitting,and water‐gas shift reaction,while high temperature accelerates reaction kinetics.The proposed PC‐TC reforming of methanol for hydrogen production can be a promising technology to solve the energy and environmental issue in the closed‐loop hydrogen economy in the near future.展开更多
Electrochemistry has emerged as a major route for graphene and graphene oxide synthesis from graphite.Anodic graphite oxidation is commonly used with dilute mineral acid or aqueous salt electrolytes.In this system,the...Electrochemistry has emerged as a major route for graphene and graphene oxide synthesis from graphite.Anodic graphite oxidation is commonly used with dilute mineral acid or aqueous salt electrolytes.In this system,the electrolyte acid concentration appears to be a critical parameter.However,the effect of the acid concentration,particularly at low concentrations,is still not fully understood.To address this issue,we used a packed bed electrochemical reactor to synthesize seven different electrochemical graphite oxide(EGO)products in 2–16M sulfuric acid.Detailed XRD,XPS,Raman,conductivity and optical microscopy analysis of the products was carried out.We found dilute acid(<10 M)graphite oxides were less crystalline and less oxidized than those produced in stronger acids.The oxygen evolution reaction at the graphite surface appears to affect the structural changes,oxidation mechanism,and electrochemical corrosion of the anode.EGO conductivity is also strongly affected by the electrolyte’s acidity.We show that well oxidized,yet reasonably conductive,single layer graphene oxide can be produced from 7.1M acid.These results broaden our understanding of graphite electrochemistry and will serve to inform future electrochemical graphene synthesis efforts.展开更多
Owing to the inherent advantages of low cost and high capacity,cobalt(Co)-free lithium(Li)-rich layered oxides have become one of the most promising cathodes for next-generation high-energy lithium-ion batteries.Howev...Owing to the inherent advantages of low cost and high capacity,cobalt(Co)-free lithium(Li)-rich layered oxides have become one of the most promising cathodes for next-generation high-energy lithium-ion batteries.However,these familial cathodes suffer from serious voltage decay due to many reasons,such as oxygen release and transition metal(TM)migration,which are closely related to nanoscale strain evolution.Here,by combining the synergistic effects of surface integration,bulk doping,and concentration gradient,we successfully construct a Co-free Li-rich layered cathode with a very small volumetric strain(1.05%)between 2.0 and 4.8 V,approaching the critical value of zero strain.Various characterizations indicate that the constructed zero-strain cathode can significantly suppress the TM migration,interfacial reactions,and structural degradation including cracks,lattice defects,phase evolution,and nanovoids,leading to improved voltage stability of Co-free Li-rich layered oxides during the prolonged cycles.This work provides a strategy to eliminate the lattice strain of Li-rich layered cathodes and facilitates the up-scaled application of the as-prepared cathode materials.展开更多
An environmentally benign,sustainable,and cost-effective supply of H_(2)O_(2)as a rapidly expanding consumption raw material is highly desired for chemical industries,medical treatment,and household disinfection.The e...An environmentally benign,sustainable,and cost-effective supply of H_(2)O_(2)as a rapidly expanding consumption raw material is highly desired for chemical industries,medical treatment,and household disinfection.The electrocatalytic production route via electrochemical oxygen reduction reaction(ORR)offers a sustainable avenue for the onsite production of H_(2)O_(2)from O2 and H2O.The most crucial and innovative part of such technology lies in the availability of suitable electrocatalysts that promote two-electron(2e^(–))ORR.In recent years,tremendous progress has been achieved in designing efficient,robust,and cost-effective catalyst materials,including noble metals and their alloys,metalfree carbon-based materials,single-atom catalysts,and molecular catalysts.Meanwhile,innovative cell designs have significantly advanced electrochemical applications at the industrial level.This review summarizes fundamental basics and recent advances in H_(2)O_(2)production via 2e^(–)-ORR,including catalyst design,mechanistic explorations,theoretical computations,experimental evaluations,and electrochemical cell designs.Perspectives on addressing remaining challenges are also presented with an emphasis on the large-scale synthesis of H_(2)O_(2)via the electrochemical route.展开更多
Binders could play crucial or even decisive roles in the fabrication of low-cost, stable and high-capacity electrodes. This is especially the case for the silicon (Si) anodes and sulfur (S) cathodes that undergo large...Binders could play crucial or even decisive roles in the fabrication of low-cost, stable and high-capacity electrodes. This is especially the case for the silicon (Si) anodes and sulfur (S) cathodes that undergo large volume change and active material loss in lithium-ion batteries during prolonged cycles. Herein, a hydrophilic polymer poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was explored as a dual-functional aqueous binder for the preparation of high-performance silicon anode and sulfur cathode. Benefiting from the dual functions of PMVEMA, i.e., the excellent dispersion ability and strong binding forces, the as-prepared electrodes exhibit improved capacity, rate capability and long-term cycling performance. In particular, the as-prepared Si electrode delivers a high initial discharge capacity of 1346.5 mAh g^(−1) at a high rate of 8.4 A/g and maintains 834.5 mAh g^(−1) after 300 cycles at 4.2 A/g, while the as-prepared S cathode exhibits enhanced cycling performance with high remaining discharge capacities of 663.4 mAh g^(−1) after 100 cycles at 0.2 C and 487.07 mAh g^(−1) after 300 cycles at 1 C, respectively. These encouraging results suggest that PMVEMA could be a universal binder to facilitate the green manufacture of both anode and cathode for high-capacity energy storage systems.展开更多
Solid polymer electrolytes(SPEs)have become increasingly attractive in solid-state lithium-ion batteries(SSLIBs)in recent years because of their inherent properties of flexibility,processability,and interfacial compat...Solid polymer electrolytes(SPEs)have become increasingly attractive in solid-state lithium-ion batteries(SSLIBs)in recent years because of their inherent properties of flexibility,processability,and interfacial compatibility.However,the commercialization of SPEs remains challenging for flexible and high-energy-density LIBs.The incorporation of functional additives into SPEs could significantly improve the electrochemical and mechanical properties of SPEs and has created some historical milestones in boosting the development of SPEs.In this study,we review the roles of additives in SPEs,highlighting the working mechanisms and functionalities of the additives.The additives could afford significant advantages in boosting ionic conductivity,increasing ion transference number,improving high-voltage stability,enhancing mechanical strength,inhibiting lithium dendrite,and reducing flammability.Moreover,the application of functional additives in high-voltage cathodes,lithium-sulfur batteries,and flexible lithiumion batteries is summarized.Finally,future research perspectives are proposed to overcome the unresolved technical hurdles and critical issues in additives of SPEs,such as facile fabrication process,interfacial compatibility,investigation of the working mechanism,and special functionalities.展开更多
Low cost and green fabrication of high-performance electrocatalysts with earth-abundant resources for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)are crucial for the large-scale application of rech...Low cost and green fabrication of high-performance electrocatalysts with earth-abundant resources for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)are crucial for the large-scale application of rechargeable Zn-air batteries(ZABs).In this work,our density functional theory calculations on the electrocatalyst suggest that the rational construction of interfacial structure can induce local charge redistribution,improve the electronic conductivity and enhance the catalyst stability.In order to realize such a structure,we spatially immobilize heterogeneous CoS/CoO nanocrystals onto N-doped graphene to synthesize a bifunctional electrocatalyst(CoS/CoO@NGNs).The optimization of the composition,interfacial structure and conductivity of the electrocatalyst is conducted to achieve bifunctional catalytic activity and deliver outstanding efficiency and stability for both ORR and OER.The aqueous ZAB with the as-prepared CoS/CoO@NGNs cathode displays a high maximum power density of 137.8 mW cm^−2,a specific capacity of 723.9 mAh g^−1 and excellent cycling stability(continuous operating for 100 h)with a high round-trip efficiency.In addition,the assembled quasi-solid-state ZAB also exhibits outstanding mechanical flexibility besides high battery performances,showing great potential for applications in flexible and wearable electronic devices.展开更多
Aqueous zinc-ion batteries(AZIBs)can be one of the most promising electrochemical energy storage devices for being non-flammable,low-cost,and sustainable.However,the challenges of AZIBs,including dendrite growth,hydro...Aqueous zinc-ion batteries(AZIBs)can be one of the most promising electrochemical energy storage devices for being non-flammable,low-cost,and sustainable.However,the challenges of AZIBs,including dendrite growth,hydrogen evolution,corrosion,and passivation of zinc anode during charging and discharging processes,must be overcome to achieve high cycling performance and stability in practical applications.In this work,we utilize a dual-func-tional organic additive cyclohexanedodecol(CHD)to firstly establish[Zn(H2O)5(CHD)]2+complex ion in an aqueous Zn electrolyte and secondly build a robust protection layer on the Zn surface to overcome these dilemmas.Systematic experiments and theoretical calculations are carried out to interpret the working mechanism of CHD.At a very low concentration of 0.1 mg mL^(−1) CHD,long-term reversible Zn plating/stripping could be achieved up to 2200 h at 2 mA cm^(−2),1000 h at 5 mA cm^(−2),and 650 h at 10 mA cm^(−2) at the fixed capacity of 1 mAh cm^(−2).When matched with V_(2)O_(5) cathode,the resultant AZIBs full cell with the CHD-modified electrolyte presents a high capacity of 175 mAh g^(−1) with the capacity retention of 92%after 2000 cycles under 2 A g^(−1).Such a performance could enable the commercialization of AZIBs for applications in grid energy storage and industrial energy storage.展开更多
Sustainable,conductive,and porous carbon materials are ideal for energy storage materials.In this study,honeycomb-like carbon materials(HCM)are synthesized via a“salty”thermal treatment of abundant and sustainable c...Sustainable,conductive,and porous carbon materials are ideal for energy storage materials.In this study,honeycomb-like carbon materials(HCM)are synthesized via a“salty”thermal treatment of abundant and sustainable coffee extract.Systematic materials characterization indicates that the as-prepared HCM consists of heteroatoms(N and O,etc.)doped ultra-thin carbon framework,possesses remarkable specific surface area,and excellent electrical conductivity.Such properties bestow HCM outstanding materials to be the blocking layer for Li-I2 battery,significantly eliminating the dissolution of I2 in the cathode region and stopping the I2 from shutting to anode compartment.Furthermore,our electrochemical investigation suggests that HCM could incur surface pseudo-capacitive iodine-ions charge storage and contribute additional energy storage capacity.As a result,the resultant Li-I2 battery achieves a robust and highly reversible capacity of 224.5 mAh·g−1 at the rate of 10 C.Even under a high rate of 50 C,the remarkable capacity of the as-prepared Li-I2 battery can still be maintained at 120.2 mAh·g−1 after 4000 cycles.展开更多
基金supported by grants from the National Health and Medical Research Council(NHMRC)of Australia(Nos.571100 and 1048082)the Baxter Charitable Foundation(to TCL)+1 种基金Medical Research grants from the Rebecca L.Cooper Medical Research Foundation(to MWW,TCL,and MDL)supported by a Charles D.Kelman,M.D.Postdoctoral Award(2010)from the International Retinal Research Foundation(USA)。
文摘Roof plate secretion of bone morphogenetic proteins(BMPs)directs the cellular fate of sensory neurons during spinal cord development,including the formation of the ascending sensory columns,though their biology is not well understood.Type-ⅡBMP receptor(BMPRⅡ),the cognate receptor,is expressed by neural precursor cells during embryogenesis;however,an in vitro method of enriching BMPRⅡ^(+)human neural precursor cells(hNPCs)from the fetal spinal cord is absent.Immunofluorescence was undertaken on intact second-trimester human fetal spinal cord using antibodies to BMPRⅡand leukemia inhibitory factor(LIF).Regions of highest BMPRⅡ^(+)immunofluorescence localized to sensory columns.Parenchymal and meningeal-associated BMPRⅡ^(+)vascular cells were identified in both intact fetal spinal cord and cortex by co-positivity with vascular lineage markers,CD34/CD39.LIF immunostaining identified a population of somas concentrated in dorsal and ventral horn interneurons,mirroring the expression of LIF receptor/CD118.A combination of LIF supplementation and high-density culture maintained culture growth beyond 10 passages,while synergistically increasing the proportion of neurospheres with a stratified,cytoarchitecture.These neurospheres were characterized by BMPRⅡ^(+)/MAP2ab^(+/–)/βⅢ-tubulin^(+)/nestin^(–)/vimentin^(–)/GFAP^(–)/NeuN^(–)surface hNPCs surrounding a heterogeneous core ofβⅢ-tubulin^(+)/nestin^(+)/vimentin^(+)/GFAP^(+)/MAP2ab^(–)/NeuN^(–)multipotent precursors.Dissociated cultures from tripotential neurospheres contained neuronal(βⅢ-tubulin^(+)),astrocytic(GFAP+),and oligodendrocytic(O4+)lineage cells.Fluorescence-activated cell sorting-sorted BMPRⅡ^(+)hNPCs were MAP2ab^(+/–)/βⅢ-tubulin^(+)/GFAP^(–)/O4^(–)in culture.This is the first isolation of BMPRⅡ^(+)hNPCs identified and characterized in human fetal spinal cords.Our data show that LIF combines synergistically with high-density reaggregate cultures to support the organotypic reorganization of neurospheres,characterized by surface BMPRⅡ^(+)hNPCs.Our study has provided a new methodology for an in vitro model capable of amplifying human fetal spinal cord cell numbers for>10 passages.Investigations of the role BMPRⅡplays in spinal cord development have primarily relied upon mouse and rat models,with interpolations to human development being derived through inference.Because of significant species differences between murine biology and human,including anatomical dissimilarities in central nervous system(CNS)structure,the findings made in murine models cannot be presumed to apply to human spinal cord development.For these reasons,our human in vitro model offers a novel tool to better understand neurodevelopmental pathways,including BMP signaling,as well as spinal cord injury research and testing drug therapies.
基金supported by the Australian Research Council (DE220100521 and DP200101217)supported by Fellow research grant of National University of Mongolia (No.P2021-4197)+2 种基金the support of Griffith University internal grantssupport from King Abdullah University of Science and Technology (KAUST)through the Ibn Rushd Postdoctoral Fellowship Awardsupport from the US Office of Naval Research (ONR),Office of Naval Research Global (ONRG)under the grant N62909-23-1-2035。
文摘Transition metal carbides and nitrides(MXenes)nanosheets are attractive two-dimensional(2D)materials,but they suffer from oxidation/degradation issues during storage and/or applications due to their sensitivity to water and oxygen.Despite the great research progress,the exact oxidation kinetics of Ti_(3)C_(2)T_(x)(MXene)and their final products after oxidation are not fully understood.Herein,we systematically tracked the oxidation process of few-layer Ti_(3)C_(2)T_(x) nanosheets in an aqueous solution at room temperature over several weeks.We also studied the oxidation effects on the electrocatalytic properties of Ti_(3)C_(2)T_(x) for hydrogen evolution reaction and found that the overpotential to achieve a current density of 10 mA cm^(-2)increases from 0.435 to 0.877 V after three weeks of degradation,followed by improvement to stabilized values of around 0.40 V after eight weeks.These results suggest that severely oxidized MXene could be a promising candidate for designing efficient catalysts.According to our detailed experimental characterization and theoretical calculations,unlike previous studies,black titanium oxide is formed as the final product in addition to white Ti(IV)oxide and disordered carbons after the complete oxidation of Ti_(3)C_(2)T_(x).This work presents significant advancements in better understanding of 2D Ti_(3)C_(2)T_(x)(MXene)oxidation and enhances the prospects of this material for various applications.
基金Australian Research Council,Grant/Award Numbers:DP190100120,FT200100015National Key Research and Development Program,Grant/Award Number:2021YFA1600800Shenzhen Science and Technology Program,Grant/Award Numbers:RCJC20200714114434086,JCYJ20190808142001745,JCYJ20200812160737002,20180921273B。
文摘One of the most unique properties of two-dimensional carbides and nitrides of transition metals(MXenes)is their excellent water dispersibility and yet possessing superior electrical conductivity but their industrial-scale application is limited by their costly chemical synthesis methods.In this work,the niche feature of MXenes was capitalized in the packed-bed electrochemical reactor to produce MXenes at an unprecedented reaction rate and yield with minimal chemical waste.A simple NH4F solution was employed as the green electrolyte,which could be used repeatedly without any loss in its efficacy.Surprisingly,both fluoride and ammonium were found to play critical roles in the electrochemical etching,functionalization,and expansion of the layered parent materials(MAXs)through which the liberation of ammonia gas was observed.The electrochemically produced MXenes with excellent conductivity,applied as supercapacitor electrodes,could deliver an ultrahigh volumetric capacity(1408 F cm^(−3))and a volumetric energy density(75.8 Wh L^(−1)).This revolutionary green,energy-efficient,and scalable electrochemical route will not only pave the way for industrial-scale production of MXenes but also open up a myriad of versatile electrochemical modifications for improved functional MXenes.
文摘This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB)production and its effects on soil properties,plant growth,immobilization of heavy metals,reduction of nutrient leaching and mitigation of greenhouse gas emissions.The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agro-industrial wastes.RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio,which suggests the presence of higher aromatic carbon compounds.The increase of pyrolysis temperature also results in production of RHBs with higher ash content,lower yield and higher surface area.RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions.Although it depends on soil type,RHB application can improve soil organic carbon content,cation exchange capacity,available K concentration,bulk density and microbial activity.The effect of RHB on soil aggregation mainly depends on soil texture.The growth of different crops is also enhanced by application of RHB.RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability.RHB application shows a significant capacity in reduction of nitrate leaching,although its magnitude depends on the biochar application rate and soil biogeochemical characteristics.Use of RHB,especially in paddy fields,shows a promising mitigation effect on greenhouse gas(CH4,CO2 and N2O)emissions.Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time,its performance for specific applications(e.g.carbon sequestration,pH amendment)can be manipulated by adjusting the pyrolysis temperature.More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment.
基金supported by the Australian Research Council Australian Laureate Fellowship(No.FL200100049)the support of Natural Science Foundation for Young Scholars of Jiangsu Province(No.BK20220879)+1 种基金National Natural Science Foundation for Young Scholars of China(No.22209072)Monash University for a PhD scholarship as part of the university support for establishment of the ARC Research Hub for Energy-efficient Separation(H170100009)。
文摘Metal-air batteries face a great challenge in developing efficient and durable low-cost oxygen reduction reaction(ORR)electrocatalysts.Single-atom iron catalysts embedded into nitrogen doped carbon(Fe-N-C)have emerged as attractive materials for potential replacement of Pt in ORR,but their catalytic performance was limited by the symmetrical electronic structure distribution around the single-atom Fe site.Here,we report our findings in significantly enhancing the ORR performance of Fe-N-C by moderate Fe_(2)O_(3) integration via the strong electronic interaction.Remarkably,the optimized catalyst(M-Fe_(2)O_(3)/Fe_(SA)@NC)exhibits excellent activity,durability and good tolerance to methanol,outperforming the benchmark Pt/C catalyst.When M-Fe_(2)O_(3)/Fe_(SA)@NC catalyst was used in a practical zinc-air battery assembly,peak power density of 155 mW cm^(-2)and specific capacity of 762 mA h g_(Zn)^(-1)were achieved and the battery assembly has shown superior cycling stability over a period of 200 h.More importantly,theoretical studies suggest that the introduction of Fe_(2)O_(3) can evoke the crystal field alteration and electron redistribution on single Fe atoms,which can break the symmetric charge distribution of Fe-N_(4) and thereby optimize the corresponding adsorption energy of intermediates to promote the O_(2)reduction.This study provides a new pathway to promote the catalytic performance of single-atom catalysts.
文摘Parkinson's disease(PD) has a complex and multifactorial pathophysiology. Various studies, conducted both in pre-clinical models and PD patients, have reported a link between the disruption of calcium(Ca^(2+)) homeostasis and the subsequent development of PD. Ca^(2+) regulation is crucial for neuronal survival, differentiation,exocytosis at synapses,gene transcription,and proliferation.
基金financially supported by the Natural Science Foundation of Jiangsu Province,China (BK20210887)the Jiangsu Provincial Double Innovation Program,China (JSSCB20210984)+1 种基金the Natural Science Fund for Colleges and Universities of Jiangsu Province,China (21KJB450003)the Jiangsu University of Science and Technology Doctoral Research Start-up Fund,China (120200012)。
文摘Nickel(Ni)-rich cathode materials have become promising candidates for the next-generation electrical vehicles due to their high specific capacity.However,the poor thermodynamic stability(including cyclic performance and safety performance or thermal stability)will restrain their wide commercial application.Herein,a single-crystal Ni-rich Li Ni_(0.83)Co_(0.12)Mn_(0.05)O_(2) cathode material is synthesized and modified by a dual-substitution strategy in which the high-valence doping element improves the structural stability by forming strong metal–oxygen binding forces,while the low-valence doping element eliminates high Li^(+)/Ni^(2+)mixing.As a result,this synergistic dual substitution can effectively suppress H2-H3 phase transition and generation of microcracks,thereby ultimately improving the thermodynamic stability of Ni-rich cathode material.Notably,the dual-doped Ni-rich cathode delivers an extremely high capacity retention of 81%after 250 cycles(vs.Li/Li+)in coin-type half cells and 87%after 1000 cycles(vs.graphite/Li^(+))in pouch-type full cells at a high temperature of 55℃.More impressively,the dual-doped sample exhibits excellent thermal stability,which demonstrates a higher thermal runaway temperature and a lower calorific value.The synergetic effects of this dual-substitution strategy pave a new pathway for addressing the critical challenges of Ni-rich cathode at high temperatures,which will significantly advance the high-energy-density and high-safety cathodes to the subsequent commercialization.
基金Natural Science Foundation of China,Grant/Award Number:22108042Guangzhou(202201020147)。
文摘BiVO_(4)is one of the most promising photoanode materials for photoelectrochemical(PEC)solar energy conversion,but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency(LHE),weak photogenerated charge separation efficiency(Φ_(Sep)),and low water oxidation efficiency(Φ_(OX)).Herein,we tackle these challenges of the BiVO_(4)photoanodes using systematic engineering,including catalysis engineering,bandgap engineering,and morphology engineering.In particular,we deposit a NiCoO_(x)layer onto the BiVO_(4)photoanode as the oxygen evolution catalyst to enhance theΦ_(OX)of Fe‐g‐C_(3)N_(4)/BiVO_(4)for PEC water oxidation,and incorporate Fe‐doped graphite‐phase C_(3)N_(4)(Fe‐g‐C_(3)N_(4))into the BiVO_(4)photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm,increase the LHE andΦ_(Sep),and further improve the oxygen evolution reaction activity of the NiCoO_(x)catalytic layer.Consequently,the maximum photocurrent density of the as‐prepared NiCoO_(x)/Fe‐g‐C_(3)N_(4)/BiVO_(4)is remarkably boosted from 4.6 to 7.4 mA cm^(−2).This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE,Φ_(Sep),andΦ_(OX)of BiVO_(4)‐based photoanodes,which will substantially benefit the design,preparation,and large‐scale application of next‐generation high‐performance photoanodes.
基金This work was financially supported by the Guangdong Basic and Applied Basic Research Foundation(2020A1515010982)the National Natural Science Foundation of China(21805191)+2 种基金Shenzhen Science and Technology Program(JCYJ20210324094000001,20190808142001745,20200812122947002)Shenzhen Peacock Plan(20210802524B and 20180921273B)the Australian Research Council(FT200100015)。
文摘This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts such as improved efficiency,selectivity,and flexibility due to their distinct electronic structure and unique properties.The review discusses the critical elements in the design of SACs,including the choice of metal atom,host material,and coordination environment,and how these elements impact the catalytic activity.The role of single atoms in photocatalytic H_(2)O_(2)production is also analysed,focusing on enhancing light absorption and charge generation,improving the migration and separation of charge carriers,and lowering the energy barrier of adsorption and activation of reactants.Despite these advantages,several challenges,including H_(2)O_(2)decomposition,stability of SACs,unclear mechanism,and low selectivity,need to be overcome.Looking towards the future,the review suggests promising research directions such as direct utilization of H_(2)O_(2),high-throughput synthesis and screening,the creation of dual active sites,and employing density functional theory for investigating the mechanisms of SACs in H_(2)O_(2)photosynthesis.This review provides valuable insights into the potential of single atom catalysts for advancing the field of photocatalytic H_(2)O_(2)production.
基金the Australia Research Council Discovery Projects(DP160102627 and DP1701048343)of AustraliaShenzhen Peacock Plan of China(KQTD2016112915051055)the 111 Project(D20015)of China Three Gorges University.
文摘Carbon nitrides(including CN,C2N,C3N,C3N4,C4N,and C5N)are a unique family of nitrogen-rich carbon materials with multiple beneficial properties in crystalline structures,morphologies,and electronic configurations.In this review,we provide a comprehensive review on these materials properties,theoretical advantages,the synthesis and modification strategies of different carbon nitride-based materials(CNBMs)and their application in existing and emerging rechargeable battery systems,such as lithium-ion batteries,sodium and potassium-ion batteries,lithium sulfur batteries,lithium oxygen batteries,lithium metal batteries,zinc-ion batteries,and solid-state batteries.The central theme of this review is to apply the theoretical and computational design to guide the experimental synthesis of CNBMs for energy storage,i.e.,facilitate the application of first-principle studies and density functional theory for electrode material design,synthesis,and characterization of different CNBMs for the aforementioned rechargeable batteries.At last,we conclude with the challenges,and prospects of CNBMs,and propose future perspectives and strategies for further advancement of CNBMs for rechargeable batteries.
文摘Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar regions.We used a global climate model(GCM)to investigate the impact on atmospheric chemistry from a change to the contemporary DMS fl ux to that which has been projected for the late 21 st century.The perturbed simulation corresponded to conditions that pertained to a tripling of equivalent CO 2,which was estimated to occur by year 2090 based on current worst-case greenhouse gas emission scenarios.The changes in zonal mean DMS fl ux were applied to 50°S–70°S Antarctic(ANT)and 65°N–80°N Arctic(ARC)regions.The results indicate that there are clearly diff erent impacts after perturbation in the southern and northern polar regions.Most quantities related to the sulfur cycle show a higher increase in ANT.However,most sulfur compounds have higher peaks in ARC.The perturbation in DMS fl ux leads to an increase of atmospheric DMS of about 45%in ANT and 33.6%in ARC.The sulfur dioxide(SO 2)vertical integral increases around 43%in ANT and 7.5%in ARC.Sulfate(SO 4)vertical integral increases by 17%in ANT and increases around 6%in ARC.Sulfur emissions increases by 21%in ANT and increases by 9.7%in ARC.However,oxidation of DMS by OH increases by 38.2%in ARC and by 15.17%in ANT.Aerosol optical depth(AOD)increases by 4%in the ARC and by 17.5%in the ANT,and increases by 22.8%in austral summer.The importance of the perturbation of the biogenic source to future aerosol burden in polar regions leads to a cooling in surface temperature of 1 K in the ANT and 0.8 K in the ARC.Generally,polar regions in the Antarctic Ocean will have a higher off setting eff ect on warming after DMS fl ux perturbation.
文摘In order to efficiently produce H_(2),conventional methanol‐water thermocatalytic(TC)reforming requires a very high temperature due to high Gibbs free energy,while the energy conversion efficiency of methanol‐water photocatalytic(PC)reforming is far from satisfaction because of the kinetic limitation.To address these issues,herein,we incorporate PC and TC processes together in a specially designed reactor and realize simultaneous photocatalytic/thermocatalytic(PC‐TC)reforming of methanol in an aqueous phase.Such a design facilitates the synergetic effect of the PC and TC process for H_(2) production due to a lower energy barrier and faster reaction kinetics.The methanol‐water reforming based on the optimized 0.05%Pt@TiO_(2) catalyst delivers an outstanding H_(2) production rate in the PC‐TC process(5.66μmol H_(2)·g^(‒1) catalyst·s^(‒1)),which is about 3 and 7 times than those of the TC process(1.89μmol H_(2)·g^(‒1) catalyst·s^(‒1))and the PC process(0.80μmol H_(2)·g^(‒1) catalyst·s^(‒1)),respectively.Isotope tracer experiments,active intermediate trapping experiments,and theoretical calculations demonstrate that the photo‐generated holes and hydroxyl radicals could enhance the methanol dehydrogenation,water molecule splitting,and water‐gas shift reaction,while high temperature accelerates reaction kinetics.The proposed PC‐TC reforming of methanol for hydrogen production can be a promising technology to solve the energy and environmental issue in the closed‐loop hydrogen economy in the near future.
基金support from the Australian Research Council (LP160101521 and DP190100120)
文摘Electrochemistry has emerged as a major route for graphene and graphene oxide synthesis from graphite.Anodic graphite oxidation is commonly used with dilute mineral acid or aqueous salt electrolytes.In this system,the electrolyte acid concentration appears to be a critical parameter.However,the effect of the acid concentration,particularly at low concentrations,is still not fully understood.To address this issue,we used a packed bed electrochemical reactor to synthesize seven different electrochemical graphite oxide(EGO)products in 2–16M sulfuric acid.Detailed XRD,XPS,Raman,conductivity and optical microscopy analysis of the products was carried out.We found dilute acid(<10 M)graphite oxides were less crystalline and less oxidized than those produced in stronger acids.The oxygen evolution reaction at the graphite surface appears to affect the structural changes,oxidation mechanism,and electrochemical corrosion of the anode.EGO conductivity is also strongly affected by the electrolyte’s acidity.We show that well oxidized,yet reasonably conductive,single layer graphene oxide can be produced from 7.1M acid.These results broaden our understanding of graphite electrochemistry and will serve to inform future electrochemical graphene synthesis efforts.
基金the funding supports of National Natural Science Foundation of China(Project 52004070,51874104)Key Technology and Supporting Platform of Genetic Engineering of Materials under States Key Project of Research and Development Plan of China(Project 2016YFB0700600)。
文摘Owing to the inherent advantages of low cost and high capacity,cobalt(Co)-free lithium(Li)-rich layered oxides have become one of the most promising cathodes for next-generation high-energy lithium-ion batteries.However,these familial cathodes suffer from serious voltage decay due to many reasons,such as oxygen release and transition metal(TM)migration,which are closely related to nanoscale strain evolution.Here,by combining the synergistic effects of surface integration,bulk doping,and concentration gradient,we successfully construct a Co-free Li-rich layered cathode with a very small volumetric strain(1.05%)between 2.0 and 4.8 V,approaching the critical value of zero strain.Various characterizations indicate that the constructed zero-strain cathode can significantly suppress the TM migration,interfacial reactions,and structural degradation including cracks,lattice defects,phase evolution,and nanovoids,leading to improved voltage stability of Co-free Li-rich layered oxides during the prolonged cycles.This work provides a strategy to eliminate the lattice strain of Li-rich layered cathodes and facilitates the up-scaled application of the as-prepared cathode materials.
基金supported by an Australian Research Council(ARC)Discovery Project(DP210103266)This research was supported by an AINSE Ltd.Postgraduate Research Award(PGRA).
文摘An environmentally benign,sustainable,and cost-effective supply of H_(2)O_(2)as a rapidly expanding consumption raw material is highly desired for chemical industries,medical treatment,and household disinfection.The electrocatalytic production route via electrochemical oxygen reduction reaction(ORR)offers a sustainable avenue for the onsite production of H_(2)O_(2)from O2 and H2O.The most crucial and innovative part of such technology lies in the availability of suitable electrocatalysts that promote two-electron(2e^(–))ORR.In recent years,tremendous progress has been achieved in designing efficient,robust,and cost-effective catalyst materials,including noble metals and their alloys,metalfree carbon-based materials,single-atom catalysts,and molecular catalysts.Meanwhile,innovative cell designs have significantly advanced electrochemical applications at the industrial level.This review summarizes fundamental basics and recent advances in H_(2)O_(2)production via 2e^(–)-ORR,including catalyst design,mechanistic explorations,theoretical computations,experimental evaluations,and electrochemical cell designs.Perspectives on addressing remaining challenges are also presented with an emphasis on the large-scale synthesis of H_(2)O_(2)via the electrochemical route.
基金This work was financially supported by the Australian Research Council(ARC)Discovery Projects(DP210103266 and DPI 701048343)the Griffith University Ph.D.Scholarships.
文摘Binders could play crucial or even decisive roles in the fabrication of low-cost, stable and high-capacity electrodes. This is especially the case for the silicon (Si) anodes and sulfur (S) cathodes that undergo large volume change and active material loss in lithium-ion batteries during prolonged cycles. Herein, a hydrophilic polymer poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was explored as a dual-functional aqueous binder for the preparation of high-performance silicon anode and sulfur cathode. Benefiting from the dual functions of PMVEMA, i.e., the excellent dispersion ability and strong binding forces, the as-prepared electrodes exhibit improved capacity, rate capability and long-term cycling performance. In particular, the as-prepared Si electrode delivers a high initial discharge capacity of 1346.5 mAh g^(−1) at a high rate of 8.4 A/g and maintains 834.5 mAh g^(−1) after 300 cycles at 4.2 A/g, while the as-prepared S cathode exhibits enhanced cycling performance with high remaining discharge capacities of 663.4 mAh g^(−1) after 100 cycles at 0.2 C and 487.07 mAh g^(−1) after 300 cycles at 1 C, respectively. These encouraging results suggest that PMVEMA could be a universal binder to facilitate the green manufacture of both anode and cathode for high-capacity energy storage systems.
基金supported by the Australian Research Council(ARC)Discovery Projects(DP210103266 and DP1701048343)the Griffith University Ph.D.Scholarships.
文摘Solid polymer electrolytes(SPEs)have become increasingly attractive in solid-state lithium-ion batteries(SSLIBs)in recent years because of their inherent properties of flexibility,processability,and interfacial compatibility.However,the commercialization of SPEs remains challenging for flexible and high-energy-density LIBs.The incorporation of functional additives into SPEs could significantly improve the electrochemical and mechanical properties of SPEs and has created some historical milestones in boosting the development of SPEs.In this study,we review the roles of additives in SPEs,highlighting the working mechanisms and functionalities of the additives.The additives could afford significant advantages in boosting ionic conductivity,increasing ion transference number,improving high-voltage stability,enhancing mechanical strength,inhibiting lithium dendrite,and reducing flammability.Moreover,the application of functional additives in high-voltage cathodes,lithium-sulfur batteries,and flexible lithiumion batteries is summarized.Finally,future research perspectives are proposed to overcome the unresolved technical hurdles and critical issues in additives of SPEs,such as facile fabrication process,interfacial compatibility,investigation of the working mechanism,and special functionalities.
基金the National Natural Science Foundation of China(Grant Numbers 21506081)the Provincial Natural Science Foundation of Jiangsu(Grant Numbers BK20191430)+2 种基金Six Talent Peaks Project of Jiangsu Province[Grant Numbers XNY-009]High-tech research key laboratory of Zhenjiang(Grant Numbers SS2018002)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions and the Research Foundation of Jiangsu University(Grant Numbers 17JDG007).
文摘Low cost and green fabrication of high-performance electrocatalysts with earth-abundant resources for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)are crucial for the large-scale application of rechargeable Zn-air batteries(ZABs).In this work,our density functional theory calculations on the electrocatalyst suggest that the rational construction of interfacial structure can induce local charge redistribution,improve the electronic conductivity and enhance the catalyst stability.In order to realize such a structure,we spatially immobilize heterogeneous CoS/CoO nanocrystals onto N-doped graphene to synthesize a bifunctional electrocatalyst(CoS/CoO@NGNs).The optimization of the composition,interfacial structure and conductivity of the electrocatalyst is conducted to achieve bifunctional catalytic activity and deliver outstanding efficiency and stability for both ORR and OER.The aqueous ZAB with the as-prepared CoS/CoO@NGNs cathode displays a high maximum power density of 137.8 mW cm^−2,a specific capacity of 723.9 mAh g^−1 and excellent cycling stability(continuous operating for 100 h)with a high round-trip efficiency.In addition,the assembled quasi-solid-state ZAB also exhibits outstanding mechanical flexibility besides high battery performances,showing great potential for applications in flexible and wearable electronic devices.
基金financial support from the Australia Research Council Discovery Projects(DP210103266)of Australiasupported by computational resources provided by the Australian Government through the National Computational Infrastructure(NCI)under the National Computational Merit Allocation Scheme and the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia。
文摘Aqueous zinc-ion batteries(AZIBs)can be one of the most promising electrochemical energy storage devices for being non-flammable,low-cost,and sustainable.However,the challenges of AZIBs,including dendrite growth,hydrogen evolution,corrosion,and passivation of zinc anode during charging and discharging processes,must be overcome to achieve high cycling performance and stability in practical applications.In this work,we utilize a dual-func-tional organic additive cyclohexanedodecol(CHD)to firstly establish[Zn(H2O)5(CHD)]2+complex ion in an aqueous Zn electrolyte and secondly build a robust protection layer on the Zn surface to overcome these dilemmas.Systematic experiments and theoretical calculations are carried out to interpret the working mechanism of CHD.At a very low concentration of 0.1 mg mL^(−1) CHD,long-term reversible Zn plating/stripping could be achieved up to 2200 h at 2 mA cm^(−2),1000 h at 5 mA cm^(−2),and 650 h at 10 mA cm^(−2) at the fixed capacity of 1 mAh cm^(−2).When matched with V_(2)O_(5) cathode,the resultant AZIBs full cell with the CHD-modified electrolyte presents a high capacity of 175 mAh g^(−1) with the capacity retention of 92%after 2000 cycles under 2 A g^(−1).Such a performance could enable the commercialization of AZIBs for applications in grid energy storage and industrial energy storage.
基金This study was financially supported by the Australia Research Council Discovery Projects(DP170103721 andDP180102003)We also acknowledge the computational support from the Australian Government through the National Computational Infrastructure(NCI)under the National Computational Merit Allocation Scheme and the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia.
文摘Sustainable,conductive,and porous carbon materials are ideal for energy storage materials.In this study,honeycomb-like carbon materials(HCM)are synthesized via a“salty”thermal treatment of abundant and sustainable coffee extract.Systematic materials characterization indicates that the as-prepared HCM consists of heteroatoms(N and O,etc.)doped ultra-thin carbon framework,possesses remarkable specific surface area,and excellent electrical conductivity.Such properties bestow HCM outstanding materials to be the blocking layer for Li-I2 battery,significantly eliminating the dissolution of I2 in the cathode region and stopping the I2 from shutting to anode compartment.Furthermore,our electrochemical investigation suggests that HCM could incur surface pseudo-capacitive iodine-ions charge storage and contribute additional energy storage capacity.As a result,the resultant Li-I2 battery achieves a robust and highly reversible capacity of 224.5 mAh·g−1 at the rate of 10 C.Even under a high rate of 50 C,the remarkable capacity of the as-prepared Li-I2 battery can still be maintained at 120.2 mAh·g−1 after 4000 cycles.
