Water often presents significant challenges in catalysts by deactivating active sites,poisoning the reaction,and even degrading composite structure.These challenges are amplified when the water participates as a react...Water often presents significant challenges in catalysts by deactivating active sites,poisoning the reaction,and even degrading composite structure.These challenges are amplified when the water participates as a reactant and is fed as a liquid phase,such as trickle bed-type reactors in a hydrogen-water isotope exchange(HIE)reaction.The key balance in such multiphase reactions is the precise control of catalyst design to repel bulk liquid water while diffusing water vapor.Herein,a platinum-incorporated metal-organic framework(MIL-101)based bifunctional hydrophobic catalyst functionalized with long alkyl chains(C_(12),dodecylamine)and further manufactured with poly(vinylidene fluoride),Pt@MIL-101-12/PVDF,has been developed which can show dramatically improved catalytic activity under multi-phase reactions involving hydrogen gas and liquid water.Pt@MIL-101-12/PVDF demonstrates enhanced macroscopic water-blocking properties,with a notable reduction of over 65%in water adsorption capacity and newly introduced liquid water repellency.while exhibiting a negligible increase in mass transfer resistance,i.e.,bifunctional hydrophobicity.Excellent catalytic activity,evaluated via HIE reaction,and its durability underscore the impact of bifunctional hydrophobicity.In situ DRIFTS analysis elucidates water adsorption/desorption dynamics within the catalyst composite,highlighting reinforced water diffusion at the microscopic level,affirming the catalyst's bifunctionality in different length scales.With demonstrated radiation resistance,Pt@MIL-101-12/PVDF emerges as a promising candidate for isotope exchange reactions.展开更多
High-entropy alloy(HEA)nanoparticles(NPs)have attracted great attention in electrocatalysis due to their tailorable complex compositions and unique properties.Herein,we introduce Fe,Co,Ni,Cr and Mn into the metal-poly...High-entropy alloy(HEA)nanoparticles(NPs)have attracted great attention in electrocatalysis due to their tailorable complex compositions and unique properties.Herein,we introduce Fe,Co,Ni,Cr and Mn into the metal-polyphenol coordination system to prepare HEA NPs enclosed in N-doped carbon(FeCoNiCrMn)with great potential for catalyzing oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).The unique high-entropy structural characteristics in FeCoNiCrMn facilitate effective interplay between metal species,leading to improved ORR(E_(1/2)=0.89 V)and OER(η=330 mV,j=10 mA·cm^(−2))activity.Additionally,FeCoNiCrMn exhibits excellent open-circuit voltage(1.523 V),power density(110 mW·cm^(−2))and long-term durability,outperforming Pt/C+IrO_(2) electrodes as a cathode catalyst in Zn-air batteries(ZABs).Such polyphenol-assisted alloying method broadens and simplifies the development of HEA electrocatalysts for high-performance ZABs.展开更多
Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree c...Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying degree.The optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline electrolyte.The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co species.When the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based device.In particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions.Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.展开更多
Herein,a luminescent europium-based metal-organic framework(Eu-MOF,[Eu_(3)(L)(HL)(NO_(3))_(2)(DMF)_(2)]·4DMF·5H_(2)O,H_(4)L=5,5′-(pyrazine-2,6-diyl)diisophthalic acid,DMF=N,N-dimethylformamide)was developed...Herein,a luminescent europium-based metal-organic framework(Eu-MOF,[Eu_(3)(L)(HL)(NO_(3))_(2)(DMF)_(2)]·4DMF·5H_(2)O,H_(4)L=5,5′-(pyrazine-2,6-diyl)diisophthalic acid,DMF=N,N-dimethylformamide)was developed for the dual-functional detection of environmental pollutants.This fluorescence-quenching-based sensor exhibited excep-tional sensitivity for both 2,4,6-trinitrophenol(TNP)and tetracycline(TC),achieving remarkably low detection lim-its of 1.96×10^(-6)and 1.71×10^(-7)mol·L^(-1),respectively.Notably,the system exhibited 99%fluorescence quenching ef-ficiency for TC,indicating ultra-efficient analyte recognition.The detection performance surpasses most reported lu-minescent MOF sensors,attributed to synergistic mechanisms of fluorescence resonance energy transfer(FRET)and photoinduced electron transfer(PET).CCDC:2446483.展开更多
The tert-butyl nitrite as a bifunctional reagent mediated radical alkene difunctionalization has emerged as a powerful strategy for synthesis of structurally diverse oxime-containing compounds.However,the phosphorus-c...The tert-butyl nitrite as a bifunctional reagent mediated radical alkene difunctionalization has emerged as a powerful strategy for synthesis of structurally diverse oxime-containing compounds.However,the phosphorus-centered radical initiated transformations remain largely elusive.Herein,a visible-lightinduced radical phosphinoyloximation of alkenes with secondary phosphine oxides and tert-butyl nitrite has been developed under photocatalyst-and metal-free conditions.This protocol features mild conditions,broad substrate scope,good functional tolerance,and operational simplicity,yielding a diverse array ofα-phosphinoyl oximes in moderate to good yields with high stereoselectivities.The photomediated homolytic cleavage of O–NO bond of tert-butyl nitrite generates the reactive tert-butoxyl radical and persistent NO radical to act as both HAT reagent and the source of oximes.展开更多
The continuous depletion of fossil fuels and the effects of climate change have encouraged prompt action to attain carbon neutrality.Technologies that transform and store renewable energy are crucial for creating a su...The continuous depletion of fossil fuels and the effects of climate change have encouraged prompt action to attain carbon neutrality.Technologies that transform and store renewable energy are crucial for creating a sustainable society,which is independent of fossil fuels.In this regard,electrochemical water splitting based on the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is an attractive technique for producing carbon-free hydrogen fuels.Additionally,rechargeable metal–air batteries(MABs)are another intriguing way for renewable energy storage through reversible oxygen reactions(OER and the oxygen reduction reaction,ORR).Herein,we comprehensively review bifunctional electrocatalysts for water splitting(HER and OER)and MABs(OER and ORR),particularly 2D carbon material-derived heterostructures.The synthesis and properties of 2D carbon materials and their energy conversion and storage mechanisms are discussed to highlight the bifunc-tionality of the heterostructures.Recent studies on bifunctional electrocatalysts based on 2D carbon-derived heterostructures are also reviewed.Finally,perspectives for future studies and multifunctional catalysts are presented.展开更多
Rechargeable metal-air batteries have gained significant interest due to their high energy density and environmental benignity.However,these batteries face significant challenges,particularly related to the air-breath...Rechargeable metal-air batteries have gained significant interest due to their high energy density and environmental benignity.However,these batteries face significant challenges,particularly related to the air-breathing electrode,resulting in poor cycle life,low efficiency,and catalyst degradation.Developing a robust bifunctional electrocatalyst remains difficult,as oxygen electrocatalysis involves sluggish kinetics and follows different reaction pathways,often requiring distinct active sites.Consequently,the poorly understood mechanisms and irreversible surface reconstruction in the catalyst’s microenvironment,such as atomic modulation,nano-/microscale,and surface interfaces,lead to accelerated degradation during charge and discharge cycles.Overcoming these barriers requires advancements in the development and understanding of bifunctional electrocatalysts.In this review,the critical components of metal-air batteries,the associated challenges,and the current engineering approaches to address these issues are discussed.Additionally,the mechanisms of oxygen electrocatalysis on the air electrodes are examined,along with insights into how chemical characteristics of materials influence these mechanisms.Furthermore,recent advances in bifunctional electrocatalysts are highlighted,with an emphasis on the synthesis strategies,microenvironmental modulations,and stabilized systems demonstrating efficient performance,particularly zinc-and lithium-air batteries.Finally,perspectives and future research directions are provided for designing efficient and durable bifunctional electrocatalysts for metal-air batteries.展开更多
Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtai...Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtained in high yields(up to 95%)and excellent enantioselectivities(up to 99%).In terms of synthetic utility,the reaction can be performed on a gram scale,and the product can be converted into potential biological nucleoside analog.展开更多
The advancement of high-performance zinc-air battery systems necessitates the development of highly effective non-precious metal-based bifunctional electrocatalysts capable of synergistically enhancing both oxygen red...The advancement of high-performance zinc-air battery systems necessitates the development of highly effective non-precious metal-based bifunctional electrocatalysts capable of synergistically enhancing both oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).To address the critical limitations of conventional non-precious catalysts in balancing multiple active sites and structural stability,we introduce an innovative in situ synthesis approach for constructing Fe_(2)P/FeNi bimetallic heterogeneous nanoparticles encapsulated within nitrogen-phosphorus dual-doped carbon matrices featuring interconnected leaf-like nanostructures(Fe_(2)P/FeNi@NPC).This architecturally optimized configuration not only mitigates transition metal degradation through protective carbon confinement but also facilitates rapid charge transfer kinetics and efficient mass diffusion pathways,substantially improving both catalytic efficiency and operational durability.Through comprehensive characterizations combining insitu monitoring and ex-situ analysis,the dynamic evolution of active sites during electrochemical operations is systematically tracked,and the genuine catalytic centers and spin state are identified.The optimized Fe_(2)P/FeNi@NPC composite exhibited remarkable electrochemical performance in alkaline media,achieving a superior ORR half-wave potential of 0.83 V and requiring only 1.62 V to achieve a current density of 10 mA cm^(-2)for OER.Notably,the assembled rechargeable zinc-air batteries(ZABs)exhibited a high specific capacity of 755.08 mAh g^(-1),a low charge-discharge voltage difference of 0.79 V,and exceptional cycling stability of over 1400 h.Furthermore,the flexible ZAB maintains excellent cycling performance even when subjected to various bending conditions.This work provides valuable insights into atomic-and electronic-scale dual-regulation strategy,offering a promising pathway to overcome current limitations in non-precious metal-based electrocatalysts for practical applications in metal-air battery systems.展开更多
The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives.However,both the mechanistic activation mode and the...The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives.However,both the mechanistic activation mode and the substrate scopes of this type of radical difunctionalizations are still limited.We demonstrate herein a modular photoredox strategy for the difunctionalization of alkenes,employing arylsulfonyl acetate as the bifunctional reagent.This approach involves a radical addition/Smiles rearrangement cascade process,offering a robust alternative for the synthesis of valuableγ,γ-diaryl andγ-aryl esters.A complementary oxidative bifunctional reagents activation mode is identified to govern the radical cascade reactions,facilitating the simultaneous incorporation of aryl and carboxylate-bearing alkyl groups into the alkenes with excellent diastereoselectivity.Noteworthy features of this method include mild reaction conditions,organophotocatalysis,high atom-and step-economy,excellent functional group compatibility and great structural diversity.展开更多
The simplification of the process of electrolytic water catalyst preparation and the exploitation of highly active catalysts represent a meaningful but challenging task.Meanwhile,bifunctional electrolytic water cataly...The simplification of the process of electrolytic water catalyst preparation and the exploitation of highly active catalysts represent a meaningful but challenging task.Meanwhile,bifunctional electrolytic water catalysts are of great significance in improving electrolysis efficiency and simplifying catalyst preparation processes.In this study,we introduce Ru and V into CoTe,which exhibits intrinsic oxygenophilic properties,and couple it with hydrophilic and well-conducting MXene to overcome the sluggish alkaline kinetics of hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The synthesized Ru,V co-doped CoTe@MXene(RVCTM)catalysts exhibited HER overpotentials of 34 and 116 mV and OER overpotentials of 249 and 320 mV at 10 and 100 mA cm^(-2) current densities,respectively.Moreover,the catalysts demonstrated remarkable stability.Theoretical calculations demonstrated that the incorporation of Ru and V had a profound impact on the local electronic environments of Co and Te.In addition,the coupling with MXene resulted in charge redistribution at the heterogeneous interface.The combined effect of doping and heterostructure construction effectively optimizes the d-band center of the catalyst and reduces the adsorption energy barrier of reaction intermediates.This approach offers deep insights into the development of multifunctional catalysts.展开更多
In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to sign...In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].展开更多
Exploring earth-abundant,highly active bifunctional electrocatalysts for efficient hydrogen and oxygen evolution is crucial for water splitting.However,due to their distinct free energies and conducting behaviors(elec...Exploring earth-abundant,highly active bifunctional electrocatalysts for efficient hydrogen and oxygen evolution is crucial for water splitting.However,due to their distinct free energies and conducting behaviors(electron/hole),balancing the catalytic efficiency between hydrogen and oxygen evolution remains challenging for achieving bifunctional electrocatalysts.Here,we report a locally-doped MoS_(2)monolayer with an in-plane heterostructure acting as a bifunctional electrocatalyst and apply it to the overall water splitting.In this heterostructure,the core region contains Mo/S vacancies,while the ring region was doped by Fe atoms(in two substitution configurations:1FeMo and 3FeMo-VS clusters)with a p-type conductive characteristic.Our micro-cell measurements,combined with density functional theory(DFT)calculations,reveal that the vacancies-rich core region presents remarkable hydrogen evolution reaction(HER)activity while the Fe-doped ring gives an excellent oxygen evolution reaction(OER)activity,thus forming an in-plane bifunctional electrocatalyst.Finally,as a proof-of-concept for overall water splitting,we constructed a full-cell configuration based on a locally-doped MoS_(2)monolayer,which achieved a cell voltage of 1.87 V at 10 mA·cm^(-2),demonstrating outstanding performance in strong acid electrolytes.Our work provides insight into the hetero-integration of bifunctional electrocatalysts at the atomic level,paving the way for designing transition metal dichalcogenide catalysts with activity-manipulated regions capable of multiple reactions.展开更多
Regulating lithium(Li)plating/stripping behavior in three-dimensional(3D)conductive scaffolds is critical to stabilizing Li metal batteries(LMBs).Surface protrusions and roughness in these scaffolds can induce uneven ...Regulating lithium(Li)plating/stripping behavior in three-dimensional(3D)conductive scaffolds is critical to stabilizing Li metal batteries(LMBs).Surface protrusions and roughness in these scaffolds can induce uneven distributions of the electric fields and ionic concentrations,forming“hot spots.”Hot spots may cause uncontrollable Li dendrites growth,presenting significant challenges to the cycle stability and safety of LMBs.To address these issues,we construct a Li ionic conductive-dielectric gradient bifunctional interlayer(ICDL)onto a 3D Li-injected graphene/carbon nanotube scaffold(LGCF)via in situ reaction of exfoliated hexagonal boron nitride(fhBN)and molten Li.Microscopic and spectroscopic analyses reveal that ICDL consists of fhBN-rich outer layer and inner layer enriched with Li_(3)N and Li-boron composites(Li-B).The outer layer utilizes dielectric properties to effectively homogenize the electric field,while the inner layer ensures high Li ion conductivity.Moreover,DFT calculations indicate that ICDL can effectively adsorb Li and decrease the Li diffusion barrier,promoting enhanced Li ion transport.The modulation of Li kinetics by ICDL increases the critical length of the Li nucleus,enabling suppression of Li dendrite growth.Attributing to these advantages,the ICDL-coated LGCF(ICDL@LGCF)demonstrates impressive long-term cycle performances in both symmetric cells and full cells.展开更多
Defect engineering and interface engineering exhibit remarkable potential in the quest for efficient and stable bifunctional catalysts for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Herein,...Defect engineering and interface engineering exhibit remarkable potential in the quest for efficient and stable bifunctional catalysts for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Herein,we innovatively designed a Ni-MoO_(2)/NiMoO_(4-x) heterojunction electrocatalyst enriched with lattice defects using a novel thermal reduction strategy.For this catalyst,the strain effect induced by the lattice defects optimizes the electronic structure,while the heterogeneous interface significantly accelerates the electron transport efficiency,thereby substantially enhancing catalytic activity and pro-moting reaction kinetics.Using advanced spherical aberration-corrected transmission electron microscopy(AC-TEM)combined with geometric phase analysis(GPA)simulations,we directly visualized and con-firmed the presence of strain effects and heterostructures,which are pivotal factors in improving catalytic performance.In an alkaline seawater environment,the Ni-MoO_(2)/NiMoO_(4-x) catalyst exhibited exceptional performance with the HER overpotential as low as 27 mV and the OER overpotential of 216 mV at a cur-rent density of 10 mA cm^(-2).Furthermore,in a membrane electrode assembly(MEA)electrolyzer,the het-erojunction catalyst can drive a current density of 147 mA cm^(-2) at a voltage of only 1.82 V,and maintain stable operation for over 100 h without degradation.In-depth theoretical simulations and experimen-tal analyses revealed that the enriched Ni defect sites optimized the adsorption energy of hydrogen and oxygen intermediates,thereby boosting the catalytic efficiency for both HER and OER.This study not only pioneers a new approach to optimizing the performance of transition metal oxide catalysts but also pro-vides robust theoretical support and experimental foundations for the practical application of hydrogen production technology through electrolytic water splitting in the future.展开更多
The key to obtaining high intrinsic catalytic activity of Me-N_(x)-C electrocatalysts for Zn-air batteries is to form high-density bifunctional Me-N_(x) active sites during the pyrolysis of the precursor while maintai...The key to obtaining high intrinsic catalytic activity of Me-N_(x)-C electrocatalysts for Zn-air batteries is to form high-density bifunctional Me-N_(x) active sites during the pyrolysis of the precursor while maintaining structural stability.In this study,a host-vip spatial confinement strategy was utilized to synthesize a composite catalyst consisting of Co_(3)Fe_(7) nanoparticles confined in an N-doped carbon network.The coupling between the host(MIL-88B)and vip(cobalt porphyrin,CoPP)produces highdensity bimetallic atomic active sites.By controlling the mass of vip molecules,it is possible to construct precursors with the highest activity potential.The Co_(3)Fe_(7)/NC material with a certain amount of the vip displays a better electrocatalytic performance for both oxygen reduction reaction and oxygen evolution reaction with a half-wave potential(E_(1/2))of 0.85 V and an overpotential of 1.59 V at 10 mAcm^(-2),respectively.The specific structure of bimetallic active centers is verified to be FeN2-CoN_(4) using experimental characterizations,and the oxygen reaction mechanism is explored by in-situ characterization techniques and first-principles calculations.The Zn-air battery assembled with Co_(3)Fe_(7)/NC cathode exhibits a remarkable open-circuit voltage of 1.52 V,an exceptional peak power density of 248.1mWcm^(-2),and stable cycling stability over 1000 h.Particularly,the corresponding flexible Zn-air battery affords prominent cycling performance under different bending angles.This study supplies the idea and method of designing catalysts with specific structures at the atomic and electronic scales for breaking through the large-scale application of electrocatalysts based on oxygen reactions in fuel cells/metal-air batteries.展开更多
Retaining satisfactory electrocatalytic performance under high current density plays a crucial role in industrial water splitting but is still limited to the enormous energy loss because of insufficient exposure of ac...Retaining satisfactory electrocatalytic performance under high current density plays a crucial role in industrial water splitting but is still limited to the enormous energy loss because of insufficient exposure of active sites caused by the blocked mass/charge transportation at this condition.Herein,we present a freestanding lamellar nanoporous Ni-Co-Mn alloy electrode(Lnp-NCM)designed by a refined variant of the“dealloying-coarsening-dealloying”protocol for highly efficient bifunctional electrocatalyst,where large porous channels distribute on the surface and small porous channels at the interlayer.With its 3D lamellar architecture regulating,the electrocatalytic properties of the electrodes with different distances between lamellas are compared,and faster energy conversion kinetics is achieved with efficient bubble transport channels and abundant electroactive sites.Note that the optimized sample(Lnp-NCM4)is expected to be a potential bifunctional electrocatalyst with low overpotentials of 258 and 439 mV at high current densities of 1000 and 900 mA·cm^(-2)for hydrogen and oxygen evolution reactions(HER and OER),respectively.During overall water splitting in a two-electrode cell with Lnp-NCM4 as cathode and anode,it only needs an ultralow cell voltage of 1.75 V to produce 100 mA·cm^(-2)with remarkable long-term stability over 50 h.This study on lamellar nanoporous electrode design approaches industrial water splitting requirements and paves a way for developing other catalytic systems.展开更多
Rational design of complex hollow nanostructures offers a great opportunity to construct various functional nanostructures.A novel in situ disassembly-polymerization-pyrolysis approach was developed to synthesize atom...Rational design of complex hollow nanostructures offers a great opportunity to construct various functional nanostructures.A novel in situ disassembly-polymerization-pyrolysis approach was developed to synthesize atomically dispersed Fe single atoms(Fe SAs)and tiny Co nanoparticles(Co NPs)binary sites embedded in double-shelled hollow carbon nanocages(Co NPs/Fe SAs DSCNs)without removing excess templates.The Co NPs/Fe SAs DSCNs displayed excellent bifunctional activity,boosting the realistic rechargeable zinc-air batteries with high efficiency,long-term durability,and reversibility,which is comparable to noble metal catalysts(Pt/C and RuO_(2)).The enhanced catalytic activity should be attributed to as well as the strong interactions between Fe SAs and Co NPs with the nitrogen-doped carbon matrix,the exposure of more active sites,and the high-flux mass transportation.In addition,the confinement effect between the double C–N shells prevented the aggregation and corrosion of metal atoms,thus improving the durability of the Co NPs/Fe SAs DSCNs,further highlighting the structural advantages of carbon nanoreactor.This work provides guidance for further rational design and preparation of complex hollow structure materials with advanced bifunctional air cathodes.展开更多
Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains...Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains a great challenge to avoid the inhomogeneous distribution and aggregation of metal single-atomic active centers in the construction of bifunctional electrocatalysts with atomically dispersed multimetallic sites because of the common calcination method.Herein,we report a novel catalyst with phthalocyanine-assembled Fe-Co-Ni single-atomic triple sites dispersed on sulfur-doped graphene using a simple ultrasonic procedure without calcination,and X-ray absorption fine structure(XAFS),aberration-corrected scanning transmission electron microscopy(AC-STEM),and other detailed characterizations are performed to demonstrate the successful synthesis.The novel catalyst shows extraordinary bifunctional ORR/OER activities with a fairly low potential difference(ΔE=0.621 V)between the OER overpotential(Ej10=315 mV at 10 m A cm^(-2))and the ORR half-wave potential(Ehalf-wave=0.924 V).Moreover,the above catalyst shows excellent ZAB performance,with an outstanding specific capacity(786 mAh g^(-1)),noteworthy maximum power density(139 mW cm^(-2)),and extraordinary rechargeability(discharged and charged at 5 mA cm^(-2) for more than 1000 h).Theoretical calculations reveal the vital importance of the preferable synergetic coupling effect between adjacent active sites in the Fe-Co-Ni trimetallic single-atomic sites during the ORR/OER processes.This study provides a new avenue for the investigation of bifunctional electrocatalysts with atomically dispersed trimetallic sites,which is intended for enhancing the ORR/OER performance in ZABs.展开更多
The development of highly efficient and durable bifunctional catalysts with minimal precious metal usage is critical for advancing proton exchange membrane water electrolysis(PEMWE).We present an iridium-platinum nano...The development of highly efficient and durable bifunctional catalysts with minimal precious metal usage is critical for advancing proton exchange membrane water electrolysis(PEMWE).We present an iridium-platinum nanoalloy(IrPt)supported on lanthanum and nickel co-doped cobalt oxide,featuring a core-shell architecture with an amorphous IrPtOx shell and an IrPt core.This catalyst exhibits exceptional bifunctional activity for oxygen and hydrogen evolution reactions in acidic media,achieving 2 A cm^(-2)at 1.72 V in a PEMWE device with ultralow loadings of 0.075 mgIr cm^(-2)and 0.075 mgPt cm^(-2)at anode and cathode,respectively.It demonstrates outstanding durability,sustaining water splitting for over 646 h with a degradation rate of only 5μV h^(-1),outperforming state-of-the-art Ir-based catalysts.In situ X-ray absorption spectroscopy and density functional theory simulations reveal that the optimized charge redistribution between Ir and Pt,along with the IrPt core-IrPtOx shell structure,enhances performance.The Ir-O-Pt active sites enable a bi-nuclear mechanism for oxygen evolution reaction and a Volmer-Tafel mechanism for hydrogen evolution reaction,reducing kinetic barriers.Hierarchical porosity,abundant oxygen vacancies,and a high electrochemical surface area further improve electron and mass transfer.This work offers a cost-effective solution for green hydrogen production and advances the design of highperformance bifunctional catalysts for PEMWE.展开更多
基金supported by grants from the National Research Foundation of Korea(NRF)under grant No.RS-2022-00155422 and No.2021R1C1C102014。
文摘Water often presents significant challenges in catalysts by deactivating active sites,poisoning the reaction,and even degrading composite structure.These challenges are amplified when the water participates as a reactant and is fed as a liquid phase,such as trickle bed-type reactors in a hydrogen-water isotope exchange(HIE)reaction.The key balance in such multiphase reactions is the precise control of catalyst design to repel bulk liquid water while diffusing water vapor.Herein,a platinum-incorporated metal-organic framework(MIL-101)based bifunctional hydrophobic catalyst functionalized with long alkyl chains(C_(12),dodecylamine)and further manufactured with poly(vinylidene fluoride),Pt@MIL-101-12/PVDF,has been developed which can show dramatically improved catalytic activity under multi-phase reactions involving hydrogen gas and liquid water.Pt@MIL-101-12/PVDF demonstrates enhanced macroscopic water-blocking properties,with a notable reduction of over 65%in water adsorption capacity and newly introduced liquid water repellency.while exhibiting a negligible increase in mass transfer resistance,i.e.,bifunctional hydrophobicity.Excellent catalytic activity,evaluated via HIE reaction,and its durability underscore the impact of bifunctional hydrophobicity.In situ DRIFTS analysis elucidates water adsorption/desorption dynamics within the catalyst composite,highlighting reinforced water diffusion at the microscopic level,affirming the catalyst's bifunctionality in different length scales.With demonstrated radiation resistance,Pt@MIL-101-12/PVDF emerges as a promising candidate for isotope exchange reactions.
基金supported by the Fundamental Research Funds for the Central Universities(No.22120230104).
文摘High-entropy alloy(HEA)nanoparticles(NPs)have attracted great attention in electrocatalysis due to their tailorable complex compositions and unique properties.Herein,we introduce Fe,Co,Ni,Cr and Mn into the metal-polyphenol coordination system to prepare HEA NPs enclosed in N-doped carbon(FeCoNiCrMn)with great potential for catalyzing oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).The unique high-entropy structural characteristics in FeCoNiCrMn facilitate effective interplay between metal species,leading to improved ORR(E_(1/2)=0.89 V)and OER(η=330 mV,j=10 mA·cm^(−2))activity.Additionally,FeCoNiCrMn exhibits excellent open-circuit voltage(1.523 V),power density(110 mW·cm^(−2))and long-term durability,outperforming Pt/C+IrO_(2) electrodes as a cathode catalyst in Zn-air batteries(ZABs).Such polyphenol-assisted alloying method broadens and simplifies the development of HEA electrocatalysts for high-performance ZABs.
基金financially supported by the National Natural Science Foundation of China(No.22279047)the Instrumental Analysis Center of Jiangsu University of Science and Technology。
文摘Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying degree.The optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline electrolyte.The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co species.When the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based device.In particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions.Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.
文摘Herein,a luminescent europium-based metal-organic framework(Eu-MOF,[Eu_(3)(L)(HL)(NO_(3))_(2)(DMF)_(2)]·4DMF·5H_(2)O,H_(4)L=5,5′-(pyrazine-2,6-diyl)diisophthalic acid,DMF=N,N-dimethylformamide)was developed for the dual-functional detection of environmental pollutants.This fluorescence-quenching-based sensor exhibited excep-tional sensitivity for both 2,4,6-trinitrophenol(TNP)and tetracycline(TC),achieving remarkably low detection lim-its of 1.96×10^(-6)and 1.71×10^(-7)mol·L^(-1),respectively.Notably,the system exhibited 99%fluorescence quenching ef-ficiency for TC,indicating ultra-efficient analyte recognition.The detection performance surpasses most reported lu-minescent MOF sensors,attributed to synergistic mechanisms of fluorescence resonance energy transfer(FRET)and photoinduced electron transfer(PET).CCDC:2446483.
基金the financial support from the National Natural Science Foundation of China(Nos.22201265,22201264)the China Postdoctoral Science Foundation(Nos.2022M710133,2022TQ0287)。
文摘The tert-butyl nitrite as a bifunctional reagent mediated radical alkene difunctionalization has emerged as a powerful strategy for synthesis of structurally diverse oxime-containing compounds.However,the phosphorus-centered radical initiated transformations remain largely elusive.Herein,a visible-lightinduced radical phosphinoyloximation of alkenes with secondary phosphine oxides and tert-butyl nitrite has been developed under photocatalyst-and metal-free conditions.This protocol features mild conditions,broad substrate scope,good functional tolerance,and operational simplicity,yielding a diverse array ofα-phosphinoyl oximes in moderate to good yields with high stereoselectivities.The photomediated homolytic cleavage of O–NO bond of tert-butyl nitrite generates the reactive tert-butoxyl radical and persistent NO radical to act as both HAT reagent and the source of oximes.
基金supported by National R&D Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(Nos.2022R1F1A1072420 and NRF-2020R1A3B2079803).
文摘The continuous depletion of fossil fuels and the effects of climate change have encouraged prompt action to attain carbon neutrality.Technologies that transform and store renewable energy are crucial for creating a sustainable society,which is independent of fossil fuels.In this regard,electrochemical water splitting based on the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is an attractive technique for producing carbon-free hydrogen fuels.Additionally,rechargeable metal–air batteries(MABs)are another intriguing way for renewable energy storage through reversible oxygen reactions(OER and the oxygen reduction reaction,ORR).Herein,we comprehensively review bifunctional electrocatalysts for water splitting(HER and OER)and MABs(OER and ORR),particularly 2D carbon material-derived heterostructures.The synthesis and properties of 2D carbon materials and their energy conversion and storage mechanisms are discussed to highlight the bifunc-tionality of the heterostructures.Recent studies on bifunctional electrocatalysts based on 2D carbon-derived heterostructures are also reviewed.Finally,perspectives for future studies and multifunctional catalysts are presented.
基金the National Key Research and Development Program of China(no.2021YFA1600800 and 2021YFA1501000)the Fundamental Research Funds for the Central Universities(YCJJ20242227)+3 种基金the Research Plan of International Collaboration Fund for Creative Research Teams(ICFCRT)of NSFC(No.W2441008)the open research fund of Suzhou Laboratory(No.SZLAB-1308-2024-ZD010)the Innovation and Talent Recruitment Base of New Energy Chemistry and Devices(B21003)supported by the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement(Grant No.101102946 and Grant No.945422).
文摘Rechargeable metal-air batteries have gained significant interest due to their high energy density and environmental benignity.However,these batteries face significant challenges,particularly related to the air-breathing electrode,resulting in poor cycle life,low efficiency,and catalyst degradation.Developing a robust bifunctional electrocatalyst remains difficult,as oxygen electrocatalysis involves sluggish kinetics and follows different reaction pathways,often requiring distinct active sites.Consequently,the poorly understood mechanisms and irreversible surface reconstruction in the catalyst’s microenvironment,such as atomic modulation,nano-/microscale,and surface interfaces,lead to accelerated degradation during charge and discharge cycles.Overcoming these barriers requires advancements in the development and understanding of bifunctional electrocatalysts.In this review,the critical components of metal-air batteries,the associated challenges,and the current engineering approaches to address these issues are discussed.Additionally,the mechanisms of oxygen electrocatalysis on the air electrodes are examined,along with insights into how chemical characteristics of materials influence these mechanisms.Furthermore,recent advances in bifunctional electrocatalysts are highlighted,with an emphasis on the synthesis strategies,microenvironmental modulations,and stabilized systems demonstrating efficient performance,particularly zinc-and lithium-air batteries.Finally,perspectives and future research directions are provided for designing efficient and durable bifunctional electrocatalysts for metal-air batteries.
基金supported by the National Natural Science Foundation of China(Nos.82130103,82151525 and 81903465)the Central Plains Scholars and Scientists Studio Fund(2018002)+1 种基金the Natural Science Foundation of Henan Province(No.212300410051)the Science and Technology Major Project of Henan Province(No.221100310300)。
文摘Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtained in high yields(up to 95%)and excellent enantioselectivities(up to 99%).In terms of synthetic utility,the reaction can be performed on a gram scale,and the product can be converted into potential biological nucleoside analog.
基金supported by the National Natural Science Foundation of China(Nos.22008058,No 22279135)the Natural Science Foundation of Hubei Province(No.2023AFB1010)+1 种基金the Key Project of Scientific Plan of Education Department of Hubei Province(No.D20232501)the CAS Strategic Leading Science&Technology Program(B)(XDB1040203)。
文摘The advancement of high-performance zinc-air battery systems necessitates the development of highly effective non-precious metal-based bifunctional electrocatalysts capable of synergistically enhancing both oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).To address the critical limitations of conventional non-precious catalysts in balancing multiple active sites and structural stability,we introduce an innovative in situ synthesis approach for constructing Fe_(2)P/FeNi bimetallic heterogeneous nanoparticles encapsulated within nitrogen-phosphorus dual-doped carbon matrices featuring interconnected leaf-like nanostructures(Fe_(2)P/FeNi@NPC).This architecturally optimized configuration not only mitigates transition metal degradation through protective carbon confinement but also facilitates rapid charge transfer kinetics and efficient mass diffusion pathways,substantially improving both catalytic efficiency and operational durability.Through comprehensive characterizations combining insitu monitoring and ex-situ analysis,the dynamic evolution of active sites during electrochemical operations is systematically tracked,and the genuine catalytic centers and spin state are identified.The optimized Fe_(2)P/FeNi@NPC composite exhibited remarkable electrochemical performance in alkaline media,achieving a superior ORR half-wave potential of 0.83 V and requiring only 1.62 V to achieve a current density of 10 mA cm^(-2)for OER.Notably,the assembled rechargeable zinc-air batteries(ZABs)exhibited a high specific capacity of 755.08 mAh g^(-1),a low charge-discharge voltage difference of 0.79 V,and exceptional cycling stability of over 1400 h.Furthermore,the flexible ZAB maintains excellent cycling performance even when subjected to various bending conditions.This work provides valuable insights into atomic-and electronic-scale dual-regulation strategy,offering a promising pathway to overcome current limitations in non-precious metal-based electrocatalysts for practical applications in metal-air battery systems.
基金the National Natural Science Foundation of China(No.21901199)National Training Program of Innovation and Entrepreneurship for Undergraduates(No.S202310698011)Xi’an Jiaotong University(No.7121192002)for financial support.
文摘The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives.However,both the mechanistic activation mode and the substrate scopes of this type of radical difunctionalizations are still limited.We demonstrate herein a modular photoredox strategy for the difunctionalization of alkenes,employing arylsulfonyl acetate as the bifunctional reagent.This approach involves a radical addition/Smiles rearrangement cascade process,offering a robust alternative for the synthesis of valuableγ,γ-diaryl andγ-aryl esters.A complementary oxidative bifunctional reagents activation mode is identified to govern the radical cascade reactions,facilitating the simultaneous incorporation of aryl and carboxylate-bearing alkyl groups into the alkenes with excellent diastereoselectivity.Noteworthy features of this method include mild reaction conditions,organophotocatalysis,high atom-and step-economy,excellent functional group compatibility and great structural diversity.
基金the National Natural Science Foundation of China(No.52222408)the China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202302)for their financial support.
文摘The simplification of the process of electrolytic water catalyst preparation and the exploitation of highly active catalysts represent a meaningful but challenging task.Meanwhile,bifunctional electrolytic water catalysts are of great significance in improving electrolysis efficiency and simplifying catalyst preparation processes.In this study,we introduce Ru and V into CoTe,which exhibits intrinsic oxygenophilic properties,and couple it with hydrophilic and well-conducting MXene to overcome the sluggish alkaline kinetics of hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The synthesized Ru,V co-doped CoTe@MXene(RVCTM)catalysts exhibited HER overpotentials of 34 and 116 mV and OER overpotentials of 249 and 320 mV at 10 and 100 mA cm^(-2) current densities,respectively.Moreover,the catalysts demonstrated remarkable stability.Theoretical calculations demonstrated that the incorporation of Ru and V had a profound impact on the local electronic environments of Co and Te.In addition,the coupling with MXene resulted in charge redistribution at the heterogeneous interface.The combined effect of doping and heterostructure construction effectively optimizes the d-band center of the catalyst and reduces the adsorption energy barrier of reaction intermediates.This approach offers deep insights into the development of multifunctional catalysts.
基金funded by the Master,PhD Scholarship Programme of Vingroup Innovation Foundation(VINIF),code VINIF.2024.TS.035funded by Vietnam National University,Ho Chi Minh City(VNUHCM)under grant number NCM2024-18-01。
文摘In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].
基金supported by the National Natural Science Foundation of China(Nos.22175060 and 22376062)JSPS Grant-in-Aid for Scientific Research(Nos.JP21H05235,JP22H05478 and JP22F22358)+1 种基金China Postdoctoral Science Foundation(No.2022M722867)the Key Research Project of Higher Education Institutions in Henan Province(No.23A530001).
文摘Exploring earth-abundant,highly active bifunctional electrocatalysts for efficient hydrogen and oxygen evolution is crucial for water splitting.However,due to their distinct free energies and conducting behaviors(electron/hole),balancing the catalytic efficiency between hydrogen and oxygen evolution remains challenging for achieving bifunctional electrocatalysts.Here,we report a locally-doped MoS_(2)monolayer with an in-plane heterostructure acting as a bifunctional electrocatalyst and apply it to the overall water splitting.In this heterostructure,the core region contains Mo/S vacancies,while the ring region was doped by Fe atoms(in two substitution configurations:1FeMo and 3FeMo-VS clusters)with a p-type conductive characteristic.Our micro-cell measurements,combined with density functional theory(DFT)calculations,reveal that the vacancies-rich core region presents remarkable hydrogen evolution reaction(HER)activity while the Fe-doped ring gives an excellent oxygen evolution reaction(OER)activity,thus forming an in-plane bifunctional electrocatalyst.Finally,as a proof-of-concept for overall water splitting,we constructed a full-cell configuration based on a locally-doped MoS_(2)monolayer,which achieved a cell voltage of 1.87 V at 10 mA·cm^(-2),demonstrating outstanding performance in strong acid electrolytes.Our work provides insight into the hetero-integration of bifunctional electrocatalysts at the atomic level,paving the way for designing transition metal dichalcogenide catalysts with activity-manipulated regions capable of multiple reactions.
基金the financial support from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2023R1A2C2007699 and 2022R1A6A1A0306303912)the Nano Material Technology Development Program through the NRF funded by the Ministry of Science and ICT (NRF-2015M3A7B6027970)the Technology Innovation Program by the Ministry of Trade, Industry & Energy (RS-202300236794)
文摘Regulating lithium(Li)plating/stripping behavior in three-dimensional(3D)conductive scaffolds is critical to stabilizing Li metal batteries(LMBs).Surface protrusions and roughness in these scaffolds can induce uneven distributions of the electric fields and ionic concentrations,forming“hot spots.”Hot spots may cause uncontrollable Li dendrites growth,presenting significant challenges to the cycle stability and safety of LMBs.To address these issues,we construct a Li ionic conductive-dielectric gradient bifunctional interlayer(ICDL)onto a 3D Li-injected graphene/carbon nanotube scaffold(LGCF)via in situ reaction of exfoliated hexagonal boron nitride(fhBN)and molten Li.Microscopic and spectroscopic analyses reveal that ICDL consists of fhBN-rich outer layer and inner layer enriched with Li_(3)N and Li-boron composites(Li-B).The outer layer utilizes dielectric properties to effectively homogenize the electric field,while the inner layer ensures high Li ion conductivity.Moreover,DFT calculations indicate that ICDL can effectively adsorb Li and decrease the Li diffusion barrier,promoting enhanced Li ion transport.The modulation of Li kinetics by ICDL increases the critical length of the Li nucleus,enabling suppression of Li dendrite growth.Attributing to these advantages,the ICDL-coated LGCF(ICDL@LGCF)demonstrates impressive long-term cycle performances in both symmetric cells and full cells.
基金supported by the National Natural Science Foundation of China(Nos.22103045 and 52273077)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZDKT202108,RZ2000003334,and G2RC202022).
文摘Defect engineering and interface engineering exhibit remarkable potential in the quest for efficient and stable bifunctional catalysts for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Herein,we innovatively designed a Ni-MoO_(2)/NiMoO_(4-x) heterojunction electrocatalyst enriched with lattice defects using a novel thermal reduction strategy.For this catalyst,the strain effect induced by the lattice defects optimizes the electronic structure,while the heterogeneous interface significantly accelerates the electron transport efficiency,thereby substantially enhancing catalytic activity and pro-moting reaction kinetics.Using advanced spherical aberration-corrected transmission electron microscopy(AC-TEM)combined with geometric phase analysis(GPA)simulations,we directly visualized and con-firmed the presence of strain effects and heterostructures,which are pivotal factors in improving catalytic performance.In an alkaline seawater environment,the Ni-MoO_(2)/NiMoO_(4-x) catalyst exhibited exceptional performance with the HER overpotential as low as 27 mV and the OER overpotential of 216 mV at a cur-rent density of 10 mA cm^(-2).Furthermore,in a membrane electrode assembly(MEA)electrolyzer,the het-erojunction catalyst can drive a current density of 147 mA cm^(-2) at a voltage of only 1.82 V,and maintain stable operation for over 100 h without degradation.In-depth theoretical simulations and experimen-tal analyses revealed that the enriched Ni defect sites optimized the adsorption energy of hydrogen and oxygen intermediates,thereby boosting the catalytic efficiency for both HER and OER.This study not only pioneers a new approach to optimizing the performance of transition metal oxide catalysts but also pro-vides robust theoretical support and experimental foundations for the practical application of hydrogen production technology through electrolytic water splitting in the future.
基金supported by the National Natural Science Foundation of China(Nos.22008058)Natural Science Foundation of Hubei Province(No.2023AFB1010,2022CFB958)+5 种基金Key Project of Scientific Plan of Education Department of Hubei Province(No.D20232501)the Natural Science Foundation of Zhejiang Province(LQ23E020002)Wenzhou Key Scientific and Technological Innovation Research Project(ZG2023053)Wenzhou Natural Science Foundation(G20220019)Cooperation between industry and education project of Ministry of Education(220601318235513)Wenzhou Science and Technology Association Serves Scientific and Technological Innovation Projects(KJFW0201).
文摘The key to obtaining high intrinsic catalytic activity of Me-N_(x)-C electrocatalysts for Zn-air batteries is to form high-density bifunctional Me-N_(x) active sites during the pyrolysis of the precursor while maintaining structural stability.In this study,a host-vip spatial confinement strategy was utilized to synthesize a composite catalyst consisting of Co_(3)Fe_(7) nanoparticles confined in an N-doped carbon network.The coupling between the host(MIL-88B)and vip(cobalt porphyrin,CoPP)produces highdensity bimetallic atomic active sites.By controlling the mass of vip molecules,it is possible to construct precursors with the highest activity potential.The Co_(3)Fe_(7)/NC material with a certain amount of the vip displays a better electrocatalytic performance for both oxygen reduction reaction and oxygen evolution reaction with a half-wave potential(E_(1/2))of 0.85 V and an overpotential of 1.59 V at 10 mAcm^(-2),respectively.The specific structure of bimetallic active centers is verified to be FeN2-CoN_(4) using experimental characterizations,and the oxygen reaction mechanism is explored by in-situ characterization techniques and first-principles calculations.The Zn-air battery assembled with Co_(3)Fe_(7)/NC cathode exhibits a remarkable open-circuit voltage of 1.52 V,an exceptional peak power density of 248.1mWcm^(-2),and stable cycling stability over 1000 h.Particularly,the corresponding flexible Zn-air battery affords prominent cycling performance under different bending angles.This study supplies the idea and method of designing catalysts with specific structures at the atomic and electronic scales for breaking through the large-scale application of electrocatalysts based on oxygen reactions in fuel cells/metal-air batteries.
基金supported by the National Natural Science Foundation of China(No.52101251)the Science Research Project of Hebei Education Department(No.BJK2023058)the Natural Science Foundation of Hebei Province(Nos.E2020208069 and B2020208083).
文摘Retaining satisfactory electrocatalytic performance under high current density plays a crucial role in industrial water splitting but is still limited to the enormous energy loss because of insufficient exposure of active sites caused by the blocked mass/charge transportation at this condition.Herein,we present a freestanding lamellar nanoporous Ni-Co-Mn alloy electrode(Lnp-NCM)designed by a refined variant of the“dealloying-coarsening-dealloying”protocol for highly efficient bifunctional electrocatalyst,where large porous channels distribute on the surface and small porous channels at the interlayer.With its 3D lamellar architecture regulating,the electrocatalytic properties of the electrodes with different distances between lamellas are compared,and faster energy conversion kinetics is achieved with efficient bubble transport channels and abundant electroactive sites.Note that the optimized sample(Lnp-NCM4)is expected to be a potential bifunctional electrocatalyst with low overpotentials of 258 and 439 mV at high current densities of 1000 and 900 mA·cm^(-2)for hydrogen and oxygen evolution reactions(HER and OER),respectively.During overall water splitting in a two-electrode cell with Lnp-NCM4 as cathode and anode,it only needs an ultralow cell voltage of 1.75 V to produce 100 mA·cm^(-2)with remarkable long-term stability over 50 h.This study on lamellar nanoporous electrode design approaches industrial water splitting requirements and paves a way for developing other catalytic systems.
基金supported by the National Natural Science Foundation of China(NSFC,No.21774045)。
文摘Rational design of complex hollow nanostructures offers a great opportunity to construct various functional nanostructures.A novel in situ disassembly-polymerization-pyrolysis approach was developed to synthesize atomically dispersed Fe single atoms(Fe SAs)and tiny Co nanoparticles(Co NPs)binary sites embedded in double-shelled hollow carbon nanocages(Co NPs/Fe SAs DSCNs)without removing excess templates.The Co NPs/Fe SAs DSCNs displayed excellent bifunctional activity,boosting the realistic rechargeable zinc-air batteries with high efficiency,long-term durability,and reversibility,which is comparable to noble metal catalysts(Pt/C and RuO_(2)).The enhanced catalytic activity should be attributed to as well as the strong interactions between Fe SAs and Co NPs with the nitrogen-doped carbon matrix,the exposure of more active sites,and the high-flux mass transportation.In addition,the confinement effect between the double C–N shells prevented the aggregation and corrosion of metal atoms,thus improving the durability of the Co NPs/Fe SAs DSCNs,further highlighting the structural advantages of carbon nanoreactor.This work provides guidance for further rational design and preparation of complex hollow structure materials with advanced bifunctional air cathodes.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.22305071,52472200,52271176,and52072114)the 111 Project(Grant No.D17007)+3 种基金Henan Center for Outstanding Overseas Scientists(Grant No.GZS2022017)the China Postdoctoral Science Foundation(Grant No.2022M721049)the Henan Province Key Research and Development Project(Grant No.231111520500)the Natural Science Foundation of Henan Province(Grant No.252300421556)。
文摘Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains a great challenge to avoid the inhomogeneous distribution and aggregation of metal single-atomic active centers in the construction of bifunctional electrocatalysts with atomically dispersed multimetallic sites because of the common calcination method.Herein,we report a novel catalyst with phthalocyanine-assembled Fe-Co-Ni single-atomic triple sites dispersed on sulfur-doped graphene using a simple ultrasonic procedure without calcination,and X-ray absorption fine structure(XAFS),aberration-corrected scanning transmission electron microscopy(AC-STEM),and other detailed characterizations are performed to demonstrate the successful synthesis.The novel catalyst shows extraordinary bifunctional ORR/OER activities with a fairly low potential difference(ΔE=0.621 V)between the OER overpotential(Ej10=315 mV at 10 m A cm^(-2))and the ORR half-wave potential(Ehalf-wave=0.924 V).Moreover,the above catalyst shows excellent ZAB performance,with an outstanding specific capacity(786 mAh g^(-1)),noteworthy maximum power density(139 mW cm^(-2)),and extraordinary rechargeability(discharged and charged at 5 mA cm^(-2) for more than 1000 h).Theoretical calculations reveal the vital importance of the preferable synergetic coupling effect between adjacent active sites in the Fe-Co-Ni trimetallic single-atomic sites during the ORR/OER processes.This study provides a new avenue for the investigation of bifunctional electrocatalysts with atomically dispersed trimetallic sites,which is intended for enhancing the ORR/OER performance in ZABs.
基金supported by overseas Outstanding Youth Science Fund Project provided by National Natural Science Foundation of China(NSFC)under contract No.22Z990204807Natural Sciences—Basic Research Special Zone Program provided by shanghai government under contract No.22Z511203738+3 种基金Key Open Fund Project provided by Shaoxing New Energy and Molecular Engineering Research Institute,Shanghai Jiao Tong University under contract No.22H010103236Sinopec Natural Science research project provided by Sinopec research institute of petroleum processing under contract No.23H010100026support from National Science Foundation of China(22309113)Scientific and Technological Project of Yunnan Precious Metals Laboratory(YPML20240502029).
文摘The development of highly efficient and durable bifunctional catalysts with minimal precious metal usage is critical for advancing proton exchange membrane water electrolysis(PEMWE).We present an iridium-platinum nanoalloy(IrPt)supported on lanthanum and nickel co-doped cobalt oxide,featuring a core-shell architecture with an amorphous IrPtOx shell and an IrPt core.This catalyst exhibits exceptional bifunctional activity for oxygen and hydrogen evolution reactions in acidic media,achieving 2 A cm^(-2)at 1.72 V in a PEMWE device with ultralow loadings of 0.075 mgIr cm^(-2)and 0.075 mgPt cm^(-2)at anode and cathode,respectively.It demonstrates outstanding durability,sustaining water splitting for over 646 h with a degradation rate of only 5μV h^(-1),outperforming state-of-the-art Ir-based catalysts.In situ X-ray absorption spectroscopy and density functional theory simulations reveal that the optimized charge redistribution between Ir and Pt,along with the IrPt core-IrPtOx shell structure,enhances performance.The Ir-O-Pt active sites enable a bi-nuclear mechanism for oxygen evolution reaction and a Volmer-Tafel mechanism for hydrogen evolution reaction,reducing kinetic barriers.Hierarchical porosity,abundant oxygen vacancies,and a high electrochemical surface area further improve electron and mass transfer.This work offers a cost-effective solution for green hydrogen production and advances the design of highperformance bifunctional catalysts for PEMWE.
