Engineering nanomaterials at single-atomic sites could enable unprecedented catalytic properties for broad applications,yet it remains challenging to do so on the surface of multimetallic nanocrystals.Herein,we presen...Engineering nanomaterials at single-atomic sites could enable unprecedented catalytic properties for broad applications,yet it remains challenging to do so on the surface of multimetallic nanocrystals.Herein,we present the multifactorial engineering(size,shape,phase,and composition)of the fully ordered PtBi nanoplates at atomic level,achieving a unique catalyst surface where the face-centered cubic(fcc)Pt edges are modified by the isolated Pd atoms and BiO_(x)adatoms.This Pd_(1)/Pt-BiO_(x)electrocatalyst exhibits an ultrahigh mass activity of 16.01 A mg^(-1)Pt+Pd toward ethanol oxidation in alkaline electrolyte and enables a direct ethanol fuel cell of peak power density of 56.7 mW cm^(−2).The surrounding BiO_(x)adatoms are critical for mitigating CO-poisoning on the Pt surface,and the Pd_(1)/Pt single-atom alloy further facilitates the electrooxidation of CH_(3)CH_(2)OH.This work offers new insights into the rational design and construction of sophisticated catalyst surface at single-atomic sites for highly efficient electrocatalysis.展开更多
Constructing hierarchical nanostructures with highly exposed surfaces is a promising strategy for developing advanced cathode materials in aqueous batteries.Herein,we employed a competitive coordination strategy to op...Constructing hierarchical nanostructures with highly exposed surfaces is a promising strategy for developing advanced cathode materials in aqueous batteries.Herein,we employed a competitive coordination strategy to optimize the characteristics of nickel metal-organic framework(Ni-MOF).Specifically,the acetate ions were employed as precise regulators,exerting a distinct influence on the morphology of the Ni-MOF and leading to a structural transition from a block structure to a two-dimensional(2D)layered structure.The optimized Ni-MOF exhibits a unique superstructure composed of hierarchical 2D layers assembled into flower-like architectures.This distinctive superstructure increases the electrochemically active surface area of Ni-MOF(N-2)and provides abundant pathways for electron/ion transfer,thereby facilitating efficient electrochemical reactions.Remarkably,the assembled aqueous alkaline N-2//Zn battery demonstrated enhanced specific capacity(0.446 mAh·cm^(-2)at 1 mA·cm^(-2))and excellent maximum energy/power density(0.789 mWh·cm^(-2)/17.262 mW·cm^(-2)).This work not only offers valuable insights into regulating MOF morphology,but also makes a contribution toward enhancing the application potential of MOFs in aqueous batteries.展开更多
Machine learning(ML)is transforming material research and development(R&D),driving a fundamental shift from experience-driven approaches to data-driven frameworks.This review systematically highlights the transfor...Machine learning(ML)is transforming material research and development(R&D),driving a fundamental shift from experience-driven approaches to data-driven frameworks.This review systematically highlights the transformative breakthroughs brought by machine learning throughout the entire process of intelligent material innovation.And it provides a comprehensive full chain analysis,from atomic scale design to macroscopic applications,emphasizing multi-scale modeling that combines physical mechanisms with data-driven methods,running through all stages of material innovation.In the design phase,ML promotes performance-oriented structural optimization through inverse design systems and generative models.For synthesis and processing,closed-loop autonomous systems and green controllable synthesis strategies significantly improve efficiency and sustainability.In terms of advanced representation,ML-powered techniques can help proactively tackle key challenges of complex structures.Performance prediction models enable precise correlations between material properties and extreme properties(such as auxiliary structures)by revealing catalytic descriptors and decoding biological interface mechanisms.Ultimately,these ML-driven advancements are unlocking practical applications in key fields,such as energy,biomedicine,environmental remediation,and structural engineering.This article aims to provide a comprehensive technological roadmap for the next generation of smart material development by integrating cross scale insights and autonomous strategies,and to outline future directions for this rapidly developing paradigm.展开更多
The rovibrational spectra of thioanisole(TA)and its halogenated derivatives,3-fluorothioanisole(3FTA)and 3-chlorothioanisole(3ClTA),were measured using synchrotron-based Fourier transform infrared spectroscopy(FTIR)at...The rovibrational spectra of thioanisole(TA)and its halogenated derivatives,3-fluorothioanisole(3FTA)and 3-chlorothioanisole(3ClTA),were measured using synchrotron-based Fourier transform infrared spectroscopy(FTIR)at the Canadian Light Source.Combined with density functional theory calculations,the stable structures and vibrational modes of TA,3FTA,and 3ClTA in their vibrational states were analyzed.The theoretical vibrational mode frequencies were corrected by simulating the rotational structure of a vibrational band.The contributions of the cis-and trans-isomers of 3FTA and 3ClTA to the FTIR spectra at 298 K were estimated using the Boltzmann distribution,revealing their coexistence in the experimental spectra.The results indicate that both fluorine and chlorine substitution significantly affect the vibrational modes,particularly in the benzene ring.Compared to TA,the FTIR spectra of 3FTA and 3ClTA show changes in the frequencies and intensities of some vibrational modes,with halogen substitution causing specific modes to shift to higher wavenumbers.A comparison of the FTIR spectra of TA,3FTA,and 3ClTA highlights the influence of halogen substitution on vibrational properties,emphasizing how the type and position of the substituent affect frequency shifts and spectral intensities.These findings provide deeper insights into how halogenation alters vibrational spectra,which is crucial for further spectral analysis and molecular structure determination.展开更多
Aqueous zinc-based batteries(ZBBs)are promising for grid-scale energy storage owing to their safety and cost-effectiveness;however,their practical application is hindered by rapid capacity fading and unstable cathodes...Aqueous zinc-based batteries(ZBBs)are promising for grid-scale energy storage owing to their safety and cost-effectiveness;however,their practical application is hindered by rapid capacity fading and unstable cathodes caused by sluggish Zn^(2+)kinetics and structural degradation in alkaline electrolytes.Herein,to address these challenges,we utilize amphiphilic polymer(PVP)to realize the composite of nickel-based complexes and ZIF-67.The hierarchical nickel-cobalt layered double hydroxide(NiCo-LDH)was prepared by metal ion exchange strategy.PVP-mediated-mediated suppression of agglomeration,combined with Ni^(2+)-induced framework reconstruction,synergistically modulated the morphology,resulting in mesoporous nanosheets with hydroxyl-rich surfaces.This design generated high-valence Co^(3+)species through charge-compensation-driven oxidation,thereby significantly accelerating Zn^(2+)ion diffusion and reducing the interfacial resistance.The optimized NiCo-LDH-100cathode(Ni:Co=3:1)achieves cycling stability and exceptional energy/power densities(0.49 mWh cm^(-2)/49.1 mW cm^(-2)).This study provides a solution for the cathode instability of Ni-Zn batteries through a coordination-derivatiz ation strategy,which is promising for advancing sustainable energy storage technologies.展开更多
The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper re...The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper reviews the speciation,forms and distribution of sulfur in coal,the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis,and the sulfur regulation during coal-blending coking of high organic-sulfur coals.It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization,which raises the need of a combination of current or newly adopted characterization methods.Different from the removal of inorganic sulfur from coal,the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property,particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes.Based on the interactions among the sulfur radicals,sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char,regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is,the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals,and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals.Wherein,the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.展开更多
Molecularly thin water layer, with a hydrogen bonding network different from those in bulk water and ice, has unique properties and is generally involved in many important processes such as wetting, erosion, atmospher...Molecularly thin water layer, with a hydrogen bonding network different from those in bulk water and ice, has unique properties and is generally involved in many important processes such as wetting, erosion, atmosphere chemical reaction, protein folding and biomolecular interaction. Here, we report a new water layer structure at room temperature, which is found inside nanobubbles by using synchrotron based scanning transmission soft X-ray microscopy(STXM). The three peaks 535.0, 536.8 and 540.9 e V at O K edge inside the nanobubbles show a novel characteristics of very thin water layers, which has never been observed before.展开更多
Relationship between atomic local structures and Curie temperature of NdFeB permanent magnets was investigated semi-quantitatively using synchrotron radiation technique. Fe K-edge X-ray absorption spectroscopy(XAS) wa...Relationship between atomic local structures and Curie temperature of NdFeB permanent magnets was investigated semi-quantitatively using synchrotron radiation technique. Fe K-edge X-ray absorption spectroscopy(XAS) was employed to study the local structure of Fe atoms for samples before and after doping Dy, Tb or Gd. It is found that the bond lengths and coordination numbers are changed. Thus, the exchange interaction between Fe atoms increases with Dy, Tb or Gd doping, resulting in the improvement of Curie temperature of NdFeB permanent magnets. The doping effect is proven by experimental measurement of the magnetic properties. Microstructural characterization using scanning electron microscopy(SEM) was also used to further analyze the effect of different rare earth elements doping on Curie temperature of NdFeB permanent magnets.展开更多
The electroreduction reaction of CO_(2)(ECO_(2)RR)requires high-performance catalysts to convert CO_(2)into useful chemicals.Transition metal-based atomically dispersed catalysts are promising for the high selectivity...The electroreduction reaction of CO_(2)(ECO_(2)RR)requires high-performance catalysts to convert CO_(2)into useful chemicals.Transition metal-based atomically dispersed catalysts are promising for the high selectivity and activity in ECO_(2)RR.This work presents a series of atomically dispersed Co,Fe bimetallic catalysts by carbonizing the Fe-introduced Co-zeolitic-imidazolate-framework(C-Fe-Co-ZIF)for the syngas generation from ECO_(2)RR.The synergistic effect of the bimetallic catalyst promotes CO production.Compared to the pure C-Co-ZiF,C-Fe-Co-ZIF facilitates CO production with a CO Faradaic efficiency(FE)boost of 10%,with optimal FE_(CO)of 51.9%,FE_(H_(2))of 42.4%at-0.55 V,and CO current density of 8.0 mA cm^(-2)at-0.7 V versus reversible hydrogen electrode(RHE).The H_(2)/CO ratio is tunable from 0.8 to 4.2 in a wide potential window of-0.35 to-0.8 V versus RHE.The total FE_(CO+H_(2))maintains as high as 93%over 10 h.The proper adding amount of Fe could increase the number of active sites and create mild distortions for the nanoscopic environments of Co and Fe,which is essential for the enhancement of the CO production in ECO_(2)RR.The positive impacts of Cu-Co and Ni-Co bimetallic catalysts demonstrate the versatility and potential application of the bimetallic strategy for ECO_(2)RR.展开更多
Oxygen reduction/evolution reactions(ORR/OERs)catalysts play a key role in the metal‐air battery and water‐splitting process.Herein,we developed a facile template‐free method to fabricate a new type of non–noble m...Oxygen reduction/evolution reactions(ORR/OERs)catalysts play a key role in the metal‐air battery and water‐splitting process.Herein,we developed a facile template‐free method to fabricate a new type of non–noble metal‐based hybrid catalyst which consists of binary FeNi alloy/nitride nanocrystals with graphitic‐shell and biomass‐derived N‐doped carbon(NC)(FexNiyN@C/NC).This novel nanostructure exhibits superior performance for ORR/OER,which can be attributed to the strong interactions between the graphitic‐shell encapsulated FeNi alloy/nitride nanocrystals and the N‐doped porous carbon substrate.The X‐ray absorption spectroscopy technique was employed to reveal the underlying mechanisms for the excellent performance.The assembled Zn‐air battery device exhibits outstanding charging/discharging performance and cycling stability,indicating the great potential of this type of novel catalysts.展开更多
Biomolecules with a broad range of structure and heteroatom-containing groups offer a great opportunity for rational design of promising electrocatalysts via versatile chemistry.In this study,uniform folic acid-Co nan...Biomolecules with a broad range of structure and heteroatom-containing groups offer a great opportunity for rational design of promising electrocatalysts via versatile chemistry.In this study,uniform folic acid-Co nanotubes(FA-Co NTs) were hydrothermally prepared as sacrificial templates for highly porous Co and N co-doped carbon nanotubes(Co-N/CNTs) with well-controlled size and morphology.The formation mechanism of FA-Co NTs was investigated and FA-Co-hydrazine coordination interaction together with the H-bond interaction between FA molecules was characterized to be the driving force for growth of one-dimensional nanotubes.Such distinct metal-ligand interaction afforded the resultant CNTs rich Co-N_x sites,hierarchically porous structure and Co nanoparticle-embedded conductive network,thus an overall good electrocatalytic activity for oxygen reduction.Electrochemical tests showed that Co-N/CNTs-900 promoted an efficient 4 e ORR process with an onset potential of 0.908 V vs.RHE,a limiting current density of 5.66 mA cm^(-2) at 0.6 V and a H_2 O_2 yield lower than 5%,comparable to that of 20%Pt/C catalyst.Moreover,the catalyst revealed very high stability upon continuous operation and remarkable tolerance to methanol.展开更多
Constructing the efficacious and applicable bifunctional electrocatalysts and establishing out the mechanisms of organic electro-oxidation by replacing anodic oxygen evolution reaction(OER) are critical to the develop...Constructing the efficacious and applicable bifunctional electrocatalysts and establishing out the mechanisms of organic electro-oxidation by replacing anodic oxygen evolution reaction(OER) are critical to the development of electrochemicallydriven technologies for efficient hydrogen production and avoid CO_(2) emission. Herein, the hetero-nanocrystals between monodispersed Pt(~ 2 nm) and Ni_(3)S_(2)(~ 9.6 nm) are constructed as active electrocatalysts through interfacial electronic modulation, which exhibit superior bi-functional activities for methanol selective oxidation and H_(2) generation. The experimental and theoretical studies reveal that the asymmetrical charge distribution at Pt–Ni_(3)S_(2) could be modulated by the electronic interaction at the interface of dual-monodispersed heterojunctions, which thus promote the adsorption/desorption of the chemical intermediates at the interface. As a result, the selective conversion from CH_(3)OH to formate is accomplished at very low potentials(1.45 V) to attain 100 m A cm^(-2) with high electronic utilization rate(~ 98%) and without CO_(2) emission. Meanwhile, the Pt–Ni_(3)S_(2) can simultaneously exhibit a broad potential window with outstanding stability and large current densities for hydrogen evolution reaction(HER) at the cathode. Further, the excellent bi-functional performance is also indicated in the coupled methanol oxidation reaction(MOR)//HER reactor by only requiring a cell voltage of 1.60 V to achieve a current density of 50 m A cm^(-2) with good reusability.展开更多
Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures(350–650°C),feed concentrations(15–30 wt%)and reaction times(15–60 min).Nickel-impregnate...Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures(350–650°C),feed concentrations(15–30 wt%)and reaction times(15–60 min).Nickel-impregnated activated carbon(Ni/AC)was synthesized as a catalyst for enhancing syngas yields at optimal gasification conditions(650°C,15 wt%and 60 min).Structural chemistry of precursors and chars developed at different gasification temperatures was studied using physicochemical and synchrotronbased approaches such as carbon–hydrogen–nitrogen–sulfur(CHNS)analysis,thermogravimetric and differential thermogravimetric analysis(TGA/DTA),scanning electron microscopy(SEM),Fourier-Transform Infrared spectroscopy(FTIR),Raman spectroscopy,X-ray diffraction(XRD)and X-ray absorption spectroscopy(XAS).Asphaltene testified to be a better precursor for catalytic hydrothermal gasification leading to 11.97 mmol/g of total gas yield compared to petroleum coke(8.04 mmol/g).In particular,supercritical water gasification using 5 wt%Ni/AC at 650°C with 15 wt%feed concentration for 60 min resulted in 4.17 and 2.98 mmol/g of H_2from asphaltene and petroleum coke,respectively.Under the same conditions,the respective CH_4yields from catalytic gasification of asphaltene and petroleum coke were 2.54and 1.07 mmol/g.Nonetheless,asphaltene also seemed to an attractive feedstock for the production of highly aromatic chars through hydrothermal gasification.展开更多
Different sizes of layered CoOOH were synthesized by the molten-salt-assisted method at different temperatures.X-ray diffraction and scanning electron microscope studies reveal that CoOOH grew at(003)with increasing t...Different sizes of layered CoOOH were synthesized by the molten-salt-assisted method at different temperatures.X-ray diffraction and scanning electron microscope studies reveal that CoOOH grew at(003)with increasing temperature,and its size can reach dozens of microns.X-ray absorption near edge structure and XPS studies demonstrate that the Co valence state of CoOOH-750 is trivalent,and X-ray Absorption Fine Structure shows that it had a higher symmetry and lower disorder degree,indicating that CoOOH-750 has higher crystallinity and Co3+.The results of electrochemical tests show that CoOOH-750 exhibited the best oxygen-evolution-reaction(OER)catalytic activity.展开更多
Nowadays,searching for the materials with multiple magneto-functional properties and good mechanical properties is vital in various fields,such as solid-state refrigeration,magnetic actuators,magnetic sensors and inte...Nowadays,searching for the materials with multiple magneto-functional properties and good mechanical properties is vital in various fields,such as solid-state refrigeration,magnetic actuators,magnetic sensors and intelligent/smart devices.In this work,the magnetic-field-induced metamagnetic reverse martensitic transformation(MFIRMT)from paramagnetic martensite to ferromagnetic austenite with multiple magneto-responsive effects is realized in Fe-doped Co-V-Ga Heusler alloys by manipulating the magnetic ordering.The martensitic transformation temperature Tmreduces quasi-linearly with increasing Fe-content.In strikingly contrast with the Fe-free alloys,the magnetization difference(M')across martensitic transformation increases by three orders of magnitude for Fe-doped alloys.The increased M'should be ascribed to the reduction of Tm,almost unchanged Curie temperature of austenite and the increased magnetic moment in the samples with higher Fe-content.The large M'provides strong driving force to realize the MFIRMT and accordingly multiple magneto-responsive effects,such as magnetocaloric,magnetoresistance and magnetostriction effects.Meanwhile,giant Vickers hardness of 518 HV and compressive strength of 1423 MPa are achieved.Multiple magneto-responsive effects with exceptional mechanical properties make these alloys great potential candidates for applications in many fields.展开更多
Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configura...Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configurations,we designed a new type of binary-atom catalyst,through engineering Fe-N_(4)electronic structure with adjacent Co-N_(2)C_(2)and nitrogen-coordinated Co nanoclusters,as oxygen electrocatalysts.The resultant optimized electronic structure of the Fe-N_(4)active center favors the binding capability of intermediates and enhances oxygen reduction reaction(ORR)activity in both alkaline and acid conditions.In addition,anchoring M-N-C atomic sites on highly graphitized carbon supports guarantees of efficient charge-and mass-transports,and escorts the high bifunctional catalytic activity of the entire catalyst.Further,through the combination of electrochemical studies and in-situ X-ray absorption spectroscopy analyses,the ORR degradation mechanisms under highly oxidative conditions during oxygen evolution reaction processes were revealed.This work developed a new binary-atom catalyst and systematically investigates the effect of highly oxidative environments on ORR electrochemical behavior.It demonstrates the strategy for facilitating oxygen electrocatalytic activity and stability of the atomically dispersed M-N-C catalysts.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.22475132 and 52101259)the Shenzhen Science and Technology Innovation Committee(Grant No.JCYJ20210324105008022)financially supported by the Shenzhen Science and Technology Innovation Program(Nos.KQTD20190929173914967 and ZDSYS20220527171401003).
文摘Engineering nanomaterials at single-atomic sites could enable unprecedented catalytic properties for broad applications,yet it remains challenging to do so on the surface of multimetallic nanocrystals.Herein,we present the multifactorial engineering(size,shape,phase,and composition)of the fully ordered PtBi nanoplates at atomic level,achieving a unique catalyst surface where the face-centered cubic(fcc)Pt edges are modified by the isolated Pd atoms and BiO_(x)adatoms.This Pd_(1)/Pt-BiO_(x)electrocatalyst exhibits an ultrahigh mass activity of 16.01 A mg^(-1)Pt+Pd toward ethanol oxidation in alkaline electrolyte and enables a direct ethanol fuel cell of peak power density of 56.7 mW cm^(−2).The surrounding BiO_(x)adatoms are critical for mitigating CO-poisoning on the Pt surface,and the Pd_(1)/Pt single-atom alloy further facilitates the electrooxidation of CH_(3)CH_(2)OH.This work offers new insights into the rational design and construction of sophisticated catalyst surface at single-atomic sites for highly efficient electrocatalysis.
基金supported by the National Natural Science Foundation of China(No.52371240)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_3510).
文摘Constructing hierarchical nanostructures with highly exposed surfaces is a promising strategy for developing advanced cathode materials in aqueous batteries.Herein,we employed a competitive coordination strategy to optimize the characteristics of nickel metal-organic framework(Ni-MOF).Specifically,the acetate ions were employed as precise regulators,exerting a distinct influence on the morphology of the Ni-MOF and leading to a structural transition from a block structure to a two-dimensional(2D)layered structure.The optimized Ni-MOF exhibits a unique superstructure composed of hierarchical 2D layers assembled into flower-like architectures.This distinctive superstructure increases the electrochemically active surface area of Ni-MOF(N-2)and provides abundant pathways for electron/ion transfer,thereby facilitating efficient electrochemical reactions.Remarkably,the assembled aqueous alkaline N-2//Zn battery demonstrated enhanced specific capacity(0.446 mAh·cm^(-2)at 1 mA·cm^(-2))and excellent maximum energy/power density(0.789 mWh·cm^(-2)/17.262 mW·cm^(-2)).This work not only offers valuable insights into regulating MOF morphology,but also makes a contribution toward enhancing the application potential of MOFs in aqueous batteries.
基金Foundation of China(Nos.NSFC-22509178 and 52371240)the Changjiang Scholars Program of the Ministry of Education(No.Q2018270)+1 种基金China Postdoctoral Science Foundation(No.2025M770225)Yangzhou Innovation Capability Enhancement Program(No.YZ2022170).
文摘Machine learning(ML)is transforming material research and development(R&D),driving a fundamental shift from experience-driven approaches to data-driven frameworks.This review systematically highlights the transformative breakthroughs brought by machine learning throughout the entire process of intelligent material innovation.And it provides a comprehensive full chain analysis,from atomic scale design to macroscopic applications,emphasizing multi-scale modeling that combines physical mechanisms with data-driven methods,running through all stages of material innovation.In the design phase,ML promotes performance-oriented structural optimization through inverse design systems and generative models.For synthesis and processing,closed-loop autonomous systems and green controllable synthesis strategies significantly improve efficiency and sustainability.In terms of advanced representation,ML-powered techniques can help proactively tackle key challenges of complex structures.Performance prediction models enable precise correlations between material properties and extreme properties(such as auxiliary structures)by revealing catalytic descriptors and decoding biological interface mechanisms.Ultimately,these ML-driven advancements are unlocking practical applications in key fields,such as energy,biomedicine,environmental remediation,and structural engineering.This article aims to provide a comprehensive technological roadmap for the next generation of smart material development by integrating cross scale insights and autonomous strategies,and to outline future directions for this rapidly developing paradigm.
基金supported by the National Natural Science Foundation of China(No.223B2306)the Innovation Capability Support Program of Shaanxi Province(2023-CX-TD-49)the Natural Science Basic Research Program of Shaanxi Province(2025JC-JCQN-043).
文摘The rovibrational spectra of thioanisole(TA)and its halogenated derivatives,3-fluorothioanisole(3FTA)and 3-chlorothioanisole(3ClTA),were measured using synchrotron-based Fourier transform infrared spectroscopy(FTIR)at the Canadian Light Source.Combined with density functional theory calculations,the stable structures and vibrational modes of TA,3FTA,and 3ClTA in their vibrational states were analyzed.The theoretical vibrational mode frequencies were corrected by simulating the rotational structure of a vibrational band.The contributions of the cis-and trans-isomers of 3FTA and 3ClTA to the FTIR spectra at 298 K were estimated using the Boltzmann distribution,revealing their coexistence in the experimental spectra.The results indicate that both fluorine and chlorine substitution significantly affect the vibrational modes,particularly in the benzene ring.Compared to TA,the FTIR spectra of 3FTA and 3ClTA show changes in the frequencies and intensities of some vibrational modes,with halogen substitution causing specific modes to shift to higher wavenumbers.A comparison of the FTIR spectra of TA,3FTA,and 3ClTA highlights the influence of halogen substitution on vibrational properties,emphasizing how the type and position of the substituent affect frequency shifts and spectral intensities.These findings provide deeper insights into how halogenation alters vibrational spectra,which is crucial for further spectral analysis and molecular structure determination.
基金financially supported by the National Natural Science Foundation of China(No.52371240)
文摘Aqueous zinc-based batteries(ZBBs)are promising for grid-scale energy storage owing to their safety and cost-effectiveness;however,their practical application is hindered by rapid capacity fading and unstable cathodes caused by sluggish Zn^(2+)kinetics and structural degradation in alkaline electrolytes.Herein,to address these challenges,we utilize amphiphilic polymer(PVP)to realize the composite of nickel-based complexes and ZIF-67.The hierarchical nickel-cobalt layered double hydroxide(NiCo-LDH)was prepared by metal ion exchange strategy.PVP-mediated-mediated suppression of agglomeration,combined with Ni^(2+)-induced framework reconstruction,synergistically modulated the morphology,resulting in mesoporous nanosheets with hydroxyl-rich surfaces.This design generated high-valence Co^(3+)species through charge-compensation-driven oxidation,thereby significantly accelerating Zn^(2+)ion diffusion and reducing the interfacial resistance.The optimized NiCo-LDH-100cathode(Ni:Co=3:1)achieves cycling stability and exceptional energy/power densities(0.49 mWh cm^(-2)/49.1 mW cm^(-2)).This study provides a solution for the cathode instability of Ni-Zn batteries through a coordination-derivatiz ation strategy,which is promising for advancing sustainable energy storage technologies.
基金financial support of National Natural Science Foundation of China(U1910201,21878208)Transformation of Scientific and Technological Achievements Programs of Higher Education Institutions in Shanxi(TSTAP)Shanxi Province Science Foundation for Key Program(201901D111001(ZD))。
文摘The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper reviews the speciation,forms and distribution of sulfur in coal,the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis,and the sulfur regulation during coal-blending coking of high organic-sulfur coals.It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization,which raises the need of a combination of current or newly adopted characterization methods.Different from the removal of inorganic sulfur from coal,the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property,particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes.Based on the interactions among the sulfur radicals,sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char,regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is,the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals,and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals.Wherein,the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.
基金Supported by the National Natural Science Foundation of China(Nos.11079050,11290165 and 11305252)the National Basic Research Program of China(No.2013CB932801)+1 种基金the Program of the Chinese Academy of Sciences(Nos.KJCX2-EW-W09 and KJZD-EW-M03)the Key Laboratory of Interfacial Physics and Technology of the Chinese Academy of Sciences,and the Open Research Project of the Large Scientific Facility of the Chinese Academy of Sciences:Study on Self-assembly Technology and Nanometer Array with Ultra-high Density
文摘Molecularly thin water layer, with a hydrogen bonding network different from those in bulk water and ice, has unique properties and is generally involved in many important processes such as wetting, erosion, atmosphere chemical reaction, protein folding and biomolecular interaction. Here, we report a new water layer structure at room temperature, which is found inside nanobubbles by using synchrotron based scanning transmission soft X-ray microscopy(STXM). The three peaks 535.0, 536.8 and 540.9 e V at O K edge inside the nanobubbles show a novel characteristics of very thin water layers, which has never been observed before.
基金financially supported by State High-Tech Development Plan (No. 2011AA061901)the TechnologyLanding Project of Jiangxi Province (No.KJLD13041)+1 种基金the Science and Technology Plan of Ganzhou (No.[2014]131)the Research Support Plan of Jiangxi University of Science and Technology(No. jxxjbs15001)
文摘Relationship between atomic local structures and Curie temperature of NdFeB permanent magnets was investigated semi-quantitatively using synchrotron radiation technique. Fe K-edge X-ray absorption spectroscopy(XAS) was employed to study the local structure of Fe atoms for samples before and after doping Dy, Tb or Gd. It is found that the bond lengths and coordination numbers are changed. Thus, the exchange interaction between Fe atoms increases with Dy, Tb or Gd doping, resulting in the improvement of Curie temperature of NdFeB permanent magnets. The doping effect is proven by experimental measurement of the magnetic properties. Microstructural characterization using scanning electron microscopy(SEM) was also used to further analyze the effect of different rare earth elements doping on Curie temperature of NdFeB permanent magnets.
基金This work is supported financially by the Natural Sciences and Engineering Research Council of Canada(NSERC),the Fonds de Recherche du Québec-Nature et Technologies(FRQNT)Centre Québécois sur les Materiaux Fonctionnels(CQMF),the Canada Foundation for Innovation(CFI)+1 种基金Institut National de la Recherche Scientifique(INRS).The XAS characterizations were performed at the Canadian Light Source(CLS),which is financially supported by NSERC,CFIthe University of Saskatchewan,the Government of Saskatchewan,Western Economic Diversification Canada,the National Research Council of Canada,and the Canadian Institutes of Health Research。
文摘The electroreduction reaction of CO_(2)(ECO_(2)RR)requires high-performance catalysts to convert CO_(2)into useful chemicals.Transition metal-based atomically dispersed catalysts are promising for the high selectivity and activity in ECO_(2)RR.This work presents a series of atomically dispersed Co,Fe bimetallic catalysts by carbonizing the Fe-introduced Co-zeolitic-imidazolate-framework(C-Fe-Co-ZIF)for the syngas generation from ECO_(2)RR.The synergistic effect of the bimetallic catalyst promotes CO production.Compared to the pure C-Co-ZiF,C-Fe-Co-ZIF facilitates CO production with a CO Faradaic efficiency(FE)boost of 10%,with optimal FE_(CO)of 51.9%,FE_(H_(2))of 42.4%at-0.55 V,and CO current density of 8.0 mA cm^(-2)at-0.7 V versus reversible hydrogen electrode(RHE).The H_(2)/CO ratio is tunable from 0.8 to 4.2 in a wide potential window of-0.35 to-0.8 V versus RHE.The total FE_(CO+H_(2))maintains as high as 93%over 10 h.The proper adding amount of Fe could increase the number of active sites and create mild distortions for the nanoscopic environments of Co and Fe,which is essential for the enhancement of the CO production in ECO_(2)RR.The positive impacts of Cu-Co and Ni-Co bimetallic catalysts demonstrate the versatility and potential application of the bimetallic strategy for ECO_(2)RR.
基金This study was supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)the National Natural Science Foundation of China(21972017)+2 种基金Canada Foundation for Innovation(CFI)Centre Québécois sur les Materiaux Fonctionnels,Fondsde Recherche du Québec‐Nature et TechnologiesInstitut National de la Recherche Scientifique.Mingjie Wu gratefully acknowledges the scholarships from the China Scholarship Council.
文摘Oxygen reduction/evolution reactions(ORR/OERs)catalysts play a key role in the metal‐air battery and water‐splitting process.Herein,we developed a facile template‐free method to fabricate a new type of non–noble metal‐based hybrid catalyst which consists of binary FeNi alloy/nitride nanocrystals with graphitic‐shell and biomass‐derived N‐doped carbon(NC)(FexNiyN@C/NC).This novel nanostructure exhibits superior performance for ORR/OER,which can be attributed to the strong interactions between the graphitic‐shell encapsulated FeNi alloy/nitride nanocrystals and the N‐doped porous carbon substrate.The X‐ray absorption spectroscopy technique was employed to reveal the underlying mechanisms for the excellent performance.The assembled Zn‐air battery device exhibits outstanding charging/discharging performance and cycling stability,indicating the great potential of this type of novel catalysts.
基金supported by the National Natural Science Foundation of China (Nos. 51902204, 21975163)the Bureau of Industry and Information Technology of Shenzhen (No. 201901171518)the support provided by Instrumental Analysis Center of Shenzhen University (Xili Campus)。
文摘Biomolecules with a broad range of structure and heteroatom-containing groups offer a great opportunity for rational design of promising electrocatalysts via versatile chemistry.In this study,uniform folic acid-Co nanotubes(FA-Co NTs) were hydrothermally prepared as sacrificial templates for highly porous Co and N co-doped carbon nanotubes(Co-N/CNTs) with well-controlled size and morphology.The formation mechanism of FA-Co NTs was investigated and FA-Co-hydrazine coordination interaction together with the H-bond interaction between FA molecules was characterized to be the driving force for growth of one-dimensional nanotubes.Such distinct metal-ligand interaction afforded the resultant CNTs rich Co-N_x sites,hierarchically porous structure and Co nanoparticle-embedded conductive network,thus an overall good electrocatalytic activity for oxygen reduction.Electrochemical tests showed that Co-N/CNTs-900 promoted an efficient 4 e ORR process with an onset potential of 0.908 V vs.RHE,a limiting current density of 5.66 mA cm^(-2) at 0.6 V and a H_2 O_2 yield lower than 5%,comparable to that of 20%Pt/C catalyst.Moreover,the catalyst revealed very high stability upon continuous operation and remarkable tolerance to methanol.
基金the financial support of Guangdong Basic and Applied Basic Research Foundation (No. 2023A1515010940)Shenzhen Natural Science Fund (the Stable Support Plan Program No. 20220809160022001)the Shenzhen Science and Technology Programs (No. ZDSYS20220527171401003, KQTD20190929173914967)。
文摘Constructing the efficacious and applicable bifunctional electrocatalysts and establishing out the mechanisms of organic electro-oxidation by replacing anodic oxygen evolution reaction(OER) are critical to the development of electrochemicallydriven technologies for efficient hydrogen production and avoid CO_(2) emission. Herein, the hetero-nanocrystals between monodispersed Pt(~ 2 nm) and Ni_(3)S_(2)(~ 9.6 nm) are constructed as active electrocatalysts through interfacial electronic modulation, which exhibit superior bi-functional activities for methanol selective oxidation and H_(2) generation. The experimental and theoretical studies reveal that the asymmetrical charge distribution at Pt–Ni_(3)S_(2) could be modulated by the electronic interaction at the interface of dual-monodispersed heterojunctions, which thus promote the adsorption/desorption of the chemical intermediates at the interface. As a result, the selective conversion from CH_(3)OH to formate is accomplished at very low potentials(1.45 V) to attain 100 m A cm^(-2) with high electronic utilization rate(~ 98%) and without CO_(2) emission. Meanwhile, the Pt–Ni_(3)S_(2) can simultaneously exhibit a broad potential window with outstanding stability and large current densities for hydrogen evolution reaction(HER) at the cathode. Further, the excellent bi-functional performance is also indicated in the coupled methanol oxidation reaction(MOR)//HER reactor by only requiring a cell voltage of 1.60 V to achieve a current density of 50 m A cm^(-2) with good reusability.
基金the Natural Sciences and Engineering Research Council of Canada (NSERC)Canada Research Chair program for funding this bioenergy research
文摘Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures(350–650°C),feed concentrations(15–30 wt%)and reaction times(15–60 min).Nickel-impregnated activated carbon(Ni/AC)was synthesized as a catalyst for enhancing syngas yields at optimal gasification conditions(650°C,15 wt%and 60 min).Structural chemistry of precursors and chars developed at different gasification temperatures was studied using physicochemical and synchrotronbased approaches such as carbon–hydrogen–nitrogen–sulfur(CHNS)analysis,thermogravimetric and differential thermogravimetric analysis(TGA/DTA),scanning electron microscopy(SEM),Fourier-Transform Infrared spectroscopy(FTIR),Raman spectroscopy,X-ray diffraction(XRD)and X-ray absorption spectroscopy(XAS).Asphaltene testified to be a better precursor for catalytic hydrothermal gasification leading to 11.97 mmol/g of total gas yield compared to petroleum coke(8.04 mmol/g).In particular,supercritical water gasification using 5 wt%Ni/AC at 650°C with 15 wt%feed concentration for 60 min resulted in 4.17 and 2.98 mmol/g of H_2from asphaltene and petroleum coke,respectively.Under the same conditions,the respective CH_4yields from catalytic gasification of asphaltene and petroleum coke were 2.54and 1.07 mmol/g.Nonetheless,asphaltene also seemed to an attractive feedstock for the production of highly aromatic chars through hydrothermal gasification.
基金This work was supported by“Transformational Technologies for Clean Energy and Demonstration”,Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDA21080200).
文摘Different sizes of layered CoOOH were synthesized by the molten-salt-assisted method at different temperatures.X-ray diffraction and scanning electron microscope studies reveal that CoOOH grew at(003)with increasing temperature,and its size can reach dozens of microns.X-ray absorption near edge structure and XPS studies demonstrate that the Co valence state of CoOOH-750 is trivalent,and X-ray Absorption Fine Structure shows that it had a higher symmetry and lower disorder degree,indicating that CoOOH-750 has higher crystallinity and Co3+.The results of electrochemical tests show that CoOOH-750 exhibited the best oxygen-evolution-reaction(OER)catalytic activity.
基金financially supported by the Key Project of Natural Science Foundation of Jiangxi Province(No.20192ACB20004)the National Natural Science Foundation of China(No.51671097)the Open Project awarded by National Key Laboratory State Microstructures Physics(No.M32037)。
文摘Nowadays,searching for the materials with multiple magneto-functional properties and good mechanical properties is vital in various fields,such as solid-state refrigeration,magnetic actuators,magnetic sensors and intelligent/smart devices.In this work,the magnetic-field-induced metamagnetic reverse martensitic transformation(MFIRMT)from paramagnetic martensite to ferromagnetic austenite with multiple magneto-responsive effects is realized in Fe-doped Co-V-Ga Heusler alloys by manipulating the magnetic ordering.The martensitic transformation temperature Tmreduces quasi-linearly with increasing Fe-content.In strikingly contrast with the Fe-free alloys,the magnetization difference(M')across martensitic transformation increases by three orders of magnitude for Fe-doped alloys.The increased M'should be ascribed to the reduction of Tm,almost unchanged Curie temperature of austenite and the increased magnetic moment in the samples with higher Fe-content.The large M'provides strong driving force to realize the MFIRMT and accordingly multiple magneto-responsive effects,such as magnetocaloric,magnetoresistance and magnetostriction effects.Meanwhile,giant Vickers hardness of 518 HV and compressive strength of 1423 MPa are achieved.Multiple magneto-responsive effects with exceptional mechanical properties make these alloys great potential candidates for applications in many fields.
基金funded by the National Natural Science Foundation of China (22208331, 52003300)the Natural Sciences and Engineering Research Council of Canada (NSERC)+4 种基金the Fonds de Recherche du Québec-Nature et Technologies (FRQNT)Centre Québécois sur les Materiaux Fonctionnels (CQMF), McGill Universityécole de Technologie Supérieure (éTS)Institut National de la Recherche Scientifique (INRS)the support from the Marcelle-Gauvreau Engineering Research Chair program
文摘Regulating the local configuration of atomically dispersed transition-metal atom catalysts is the key to oxygen electrocatalysis performance enhancement.Unlike the previously reported singleatom or dual-atom configurations,we designed a new type of binary-atom catalyst,through engineering Fe-N_(4)electronic structure with adjacent Co-N_(2)C_(2)and nitrogen-coordinated Co nanoclusters,as oxygen electrocatalysts.The resultant optimized electronic structure of the Fe-N_(4)active center favors the binding capability of intermediates and enhances oxygen reduction reaction(ORR)activity in both alkaline and acid conditions.In addition,anchoring M-N-C atomic sites on highly graphitized carbon supports guarantees of efficient charge-and mass-transports,and escorts the high bifunctional catalytic activity of the entire catalyst.Further,through the combination of electrochemical studies and in-situ X-ray absorption spectroscopy analyses,the ORR degradation mechanisms under highly oxidative conditions during oxygen evolution reaction processes were revealed.This work developed a new binary-atom catalyst and systematically investigates the effect of highly oxidative environments on ORR electrochemical behavior.It demonstrates the strategy for facilitating oxygen electrocatalytic activity and stability of the atomically dispersed M-N-C catalysts.
