Prussian blue analogues(PBAs) with inherent ordered structures and abundant metal ion sites are widely explored as precursors for various electrochemical applications,including oxygen evolution reaction(OER).Using a r...Prussian blue analogues(PBAs) with inherent ordered structures and abundant metal ion sites are widely explored as precursors for various electrochemical applications,including oxygen evolution reaction(OER).Using a range of characterization techniques including Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD) and energy dispersive spectroscopy(EDS),this work discloses the process of replacement of K^(+)by NH4^(+)in the interstitial spaces of the CoFe PBA by a hot aqueous urea solution,which influences the transformation of PBAs under further heat treatment and the OER performance of the deriva tives.After heat treatment at 400℃ under Ar flow,high-resolution transmission electron microscopy(HRTEM) images reveal that CoFe alloy nanoparticles grew on the crystalline cubes of CoFe PBA with K^(+),while CoFe PBA cubes with NH4^(+)become amorphous.Besides,the derivative of CoFe PBA with NH4^(+)(Ar-U-CoFe PBA) performs better than the derivative of CoFe PBA with K^(+)(Ar-CoFe PBA) in OER,registering a lower overpotential of 305 mV at 10 mA cm^(-2),a smaller Tafel slope of 36.1 mV dec^(-1),and better stability over a testing course of 20 h in 1.0 M KOH.A single-cell alkaline electrolyzer,using Ar-U-CoFe PBA and Pt/C for the anodic and cathodic catalyst,respectively,requires an initial cell voltage of 1.66 V to achieve 100 mA cm^(-2)at 80℃,with negligible degradation after100 h.展开更多
In the applications of large-scale energy storage,aqueous batteries are considered as rivals for organic batteries due to their environmentally friendly and low-cost nature.However,carrier ions always exhibit huge hyd...In the applications of large-scale energy storage,aqueous batteries are considered as rivals for organic batteries due to their environmentally friendly and low-cost nature.However,carrier ions always exhibit huge hydrated radius in aqueous electrolyte,which brings difficulty to find suitable host materials that can achieve highly reversible insertion and extraction of cations.Owing to open threedimensional rigid framework and facile synthesis,Prussian blue analogues(PBAs)receive the most extensive attention among various host candidates in aqueous system.Herein,a comprehensive review on recent progresses of PBAs in aqueous batteries is presented.Based on the application in different aqueous systems,the relationship between electrochemical behaviors(redox potential,capacity,cycling stability and rate performance)and structural characteristics(preparation method,structure type,particle size,morphology,crystallinity,defect,metal atom in highspin state and chemical composition)is analyzed and summarized thoroughly.It can be concluded that the required type of PBAs is different for various carrier ions.In particular,the desalination batteries worked with the same mechanism as aqueous batteries are also discussed in detail to introduce the application of PBAs in aqueous systems comprehensively.This report can help the readers to understand the relationship between physical/chemical characteristics and electrochemical properties for PBAs and find a way to fabricate high-performance PBAs in aqueous batteries and desalination batteries.展开更多
Transition-metal(TM)-based Prussian blue and its analogues(TM-PBAs) have attracted considerable attention as cathode materials owing to their versatile ion storage capability with tunable working voltages. TM-PBAs wit...Transition-metal(TM)-based Prussian blue and its analogues(TM-PBAs) have attracted considerable attention as cathode materials owing to their versatile ion storage capability with tunable working voltages. TM-PBAs with different crystal structures, morphologies, and TM combinations can exhibit excellent electrochemical properties because of their unique and robust host frameworks with well-defined<100> ionic diffusion channels. Nonetheless, there is still a lack of understanding regarding the performance dependence of TM-PBAs on structural changes during charging/discharging processes. In this study, in situ X-ray diffraction and X-ray absorption fine structure analyses elucidate the TMdependent structural changes in a series of TM-PBAs during the charging and discharging processes.During the discharging process, the lattice volume of Fe-PBA increased while those of Ni-and Cu-PBAs decreased. This discrepancy is attributed to the extent of size reduction of the cyanometallate complex([Fe(CN)_(6)]) via pi-backbonding from Fe to C due to redox flips of the low-spin Fe^(3+/2+) ion. This study presents a comprehensive understanding of how TM selection affects capacity acquisition and phase transition in TM-PBAs, a promising class of cathode materials.展开更多
Meeting the continuous glucose monitoring requirements of individuals necessitates the research and development of sensors with high sensitivity and stability.In this study,a straightforward strategy was proposed for ...Meeting the continuous glucose monitoring requirements of individuals necessitates the research and development of sensors with high sensitivity and stability.In this study,a straightforward strategy was proposed for synthesizing ultra-thin oxygen-rich graphitized carbon nanosheets(denoted as GCS-O).These nanosheets are obtained by calcining a topologically two-dimensional indium-based coordination polymer.Subsequently,the growth of FeNi Prussian blue analogue(PBA)on GCS-O effectively introduces active sites and increases the nitrogen content within the carbonaceous matrix.The resulting FeNi-PBA/GCS-O composite exhibits excellent glucose sensing performance with a broad linear range of 1 to 1300μmol·L^(-1).Meanwhile,it also achieves a high sensitivity of 2496μA·mmol^(-1)·L·cm^(-2),a limit of detection of 100nmol·L^(-1)(S/N=3),and commendable long-term durability.The relatively simple synthesis process,exceptional sensitivity,and satisfactory electrochemical sensing performance of FeNi-PBA/GCS-O open up new directions for biosensor applications.展开更多
Mn-based Prussian blue analogues(Mn-PBAs),featuring a three-dimensional(3D)metal-organic framework and multiple redox couples,have gained wide interests in Zn-ion batteries(ZIBs).However,owing to the Jahn-Teller disto...Mn-based Prussian blue analogues(Mn-PBAs),featuring a three-dimensional(3D)metal-organic framework and multiple redox couples,have gained wide interests in Zn-ion batteries(ZIBs).However,owing to the Jahn-Teller distortion and disproportionation reaction of Mn^(3+),these materials suffer from poor electrochemical performances and inferior structural stability.Herein,we prepare a typical high-entropy Prussian blue analogue(HE-PBA)with increased configuration entropy through integrating five transition metal elements of Mn,Co,Ni,Fe and Cu into the nitrogen-coordinated-M-lattice sites.Consequently,the HE-PBA presents enhanced uptake of Zn^(2+)with 80 mAh·g^(−1)compared to those medium-entropy PBAs,low-entropy PBAs and conventional PBAs,which can be assigned to“cocktail”effect of multiple transition metal active redox couples.Furthermore,a phase transition process from monoclinic phase to rhombohedral phase occurs in HE-PBA cathode,resulting in a stable structure of MN6(M=Mn,Co,Fe,Ni,Cu)and ZnN4 co-linked to FeC6 through the cyanide ligands.Additionally,the advantages of entropy-driven stability are also confirmed by the calculated reduction energy and the density of states between HE-PBA and KMn[Fe(CN)6](KMnHCF).This work not only presents a high-performance HE-PBA cathode in ZIBs,but also introduces a novel concept of high entropy benefiting for designing advanced materials.展开更多
Developing high-performance and low-cost electrocatalysts for oxygen evolution reaction(OER)is still a great challenge for water-splitting technologies.Herein,an innovative metal-organic frameworks(MOFs)hybrid-assiste...Developing high-performance and low-cost electrocatalysts for oxygen evolution reaction(OER)is still a great challenge for water-splitting technologies.Herein,an innovative metal-organic frameworks(MOFs)hybrid-assisted strategy is reported to synthesize core-shell Co/Mn-ZIF@Fe-Co-Mn Prussian blue analogues(PBAs)toward highly efficient OER electrocatalysts in alkaline electrolyte.Physical characterization indicates that the amorphous hydroxide transformed from Co/Mn-ZIF@Fe-Co-Mn PBA(ZIF:zeolitic imidazolate frameworks)during the electrochemical process acted as the electroactive species.Benefiting from these structural and compositional features,the developed composite delivers a remarkably low overpotential of 270 mV with a current density of 10 mA·cm^(−2)in 1.0 M KOH solution.Moreover,water splitting is catalyzed to reach a current density of 10 mA·cm^(−2)at 1.62 V.展开更多
Prussian blue analogues(PBAs)have gained significant popularity as cathode materials for sodium-ion batteries(SIBs)due to their remarkable features such as high capacity and convenient synthesis.However,PBAs usually s...Prussian blue analogues(PBAs)have gained significant popularity as cathode materials for sodium-ion batteries(SIBs)due to their remarkable features such as high capacity and convenient synthesis.However,PBAs usually suffer from kinetic problems during the electrochemical reactions due to sluggish Na~+diffusion in the large crystals,resulting in low-capacity utilization and inferior rate capability.In this study,we present a facile etching method aiming at activating the sodium storage sites and accelerating the Na~+transport of Na_2NiFe(CN)_6(denoted as NaNiHCF)by precisely controlling its morphologies.A progressive corner passivation phenomenon occurred in NaNiHCF during the etching process,which led to a substantial augmentation of the specific surface area as the morphology transitioned from a standard cube to a dice shape.Notably,by controlling the etching time,the obtained NaNiHCF-3 electrode exhibited boosted electrochemical performance with high reversible capacity of 83.5mAh g~(-1)(98.2%of its theoretical capacity),superior rate capability(71.2 mAh g~(-1)at 10 C),and stable cycling life-span at different temperatures.Both experimental and computational methods reveal the remarkably reversible structural evolution process and improved Na~+diffusion coefficient.We believe that this work can serve as an indispensable reference to tailor the structure of PBAs to obtain improved electrochemical performance.展开更多
The design of electrode materials with specific structures is considered a promising approach for improving the performance of lithium-ion batteries(LIBs).In this paper,FeO/CoO hollow nanocages coated with a N-doped c...The design of electrode materials with specific structures is considered a promising approach for improving the performance of lithium-ion batteries(LIBs).In this paper,FeO/CoO hollow nanocages coated with a N-doped carbon layer(FCO@NC)was prepared using Fe-Co-based Prussian blue analogs(PBA)as a precursor.During the synthesis,dopamine was the carbon and nitrogen source.The reducing atmosphere was assured via NH_3/Ar,which regulated the vacancies in the structure of FCO@NC as well as increased its conductivity.When used as anode materials for LIBs,the FCO@NC nanocages deliver a high reversible capacity of 774.89 mAh·g^(-1)at 0.3 A·g^(-1)after200 cycles with a capacity retention rate of 80.4%and426.76 mAh·g^(-1)after 500 cycles at a high current density of 1 A·g^(-1).It is demonstrated that the hollow nanocage structure can effectively enhance the cycle stability,and the heat treatment in NH_(3)/Ar atmosphere contributes to the oxygen vacancy content of the electrode materials,further facilitating its conductivity and electrochemical performance.展开更多
Prussian blue analogues(PBAs) with open frameworks have drawn much attention in energy storage fields due to their tridimensional ionic diffusion path, easy preparation, and low cost. This review summarizes the recent...Prussian blue analogues(PBAs) with open frameworks have drawn much attention in energy storage fields due to their tridimensional ionic diffusion path, easy preparation, and low cost. This review summarizes the recent progress of using PBAs and their derivatives as energy storage materials in alkali ions,multi-valent ions, and metal-air batteries. The key factors to improve the electrochemical performance of PBAs as cathode materials in rechargeable batteries were firstly discussed. Several approaches for performance enhancement such as controlling the amounts of vacancies and coordinated water, optimizing morphologies, and depositing carbon coating are described in details. Then, we highlighted the significance of their diverse architectures and morphologies in anode materials for lithium/sodium ion batteries. Finally, the applications of Prussian blue derivatives as catalysts in metal-air batteries are also reviewed, providing insights into the origin of favorable morphologies and structures of catalyst for the optimal performance.展开更多
Aqueous batteries have engendered increasing attention as promising solutions for stationary energy storage due to their potentially low cost and innate safety.In various aqueous battery systems,Prussian blue analogue...Aqueous batteries have engendered increasing attention as promising solutions for stationary energy storage due to their potentially low cost and innate safety.In various aqueous battery systems,Prussian blue analogues(PBAs)represent a class of promising electrode materials with fascinating electrochemical performance,owing to their large open frameworks,abundant ion insertion sites,and facile preparation.To date,PBAs have shown substantial progress towards storage of alkali metal ions(Li^(+),Na^(+),and K^(+)),H^(+),and NH4^(+) in aqueous electrolytes,which,however,has yet not been specifically summarized.This review selects some representative research to introduce the progress of PBAs in these battery systems and aims to discuss the crucial role of ionic charge carrier in affecting the overall electrode performance.Besides,some critical knowledge gaps and challenges of PBA materials have been pointed out for future development.展开更多
This work examines the origin of the abnormal magnetism exhibited by Cu Mn Fe-PBAs modified with multi-walled carbon nanotubes(MWCNTs).The system of Cu Mn Fe-PBAs@MWCNTs coexists with both large and small clusters.Cu ...This work examines the origin of the abnormal magnetism exhibited by Cu Mn Fe-PBAs modified with multi-walled carbon nanotubes(MWCNTs).The system of Cu Mn Fe-PBAs@MWCNTs coexists with both large and small clusters.Cu Mn Fe-PBAs clusters have an average particle size of 28 nm,and some of the smaller particles are adsorbed on the surface of MWCNTs.Surprisingly,the magnitude of magnetization increases linearly with decreasing temperature.When above the Curie temperature,the magnitude of magnetization is significantly greater than that of PBAs without being modified.This phenomenon can be attributed to magnetostatic interactions between ultra-fine magnetic nanoparticles adsorbed on the surface of MWCNTs.Using the Monte Carlo method,we simulated the magnetostatic interaction of cylindrical adsorbed particles,and the simulation results are almost identical to those observed experimentally.The results indicate that 0.089Cu Mn Fe-PBAs clusters per 1 nm^(2)can be adsorbed onto the surface area of MWCNTs.We demonstrate that MWCNTs adsorbing magnetic particles exhibit magnetic behavior,and suggest a method for producing ultrafine materials.It also introduces a new method of calculating the adsorption efficiency of carbon nanotubes,offering theoretical guidance for future research on nanomaterials with enhanced adsorption efficiency.展开更多
The low intrinsic activity of Fenton catalytic site and high demand for light-energy input inhibit the organic-pollution control efficiency of photo-Fenton process.Here,through structural design with density functiona...The low intrinsic activity of Fenton catalytic site and high demand for light-energy input inhibit the organic-pollution control efficiency of photo-Fenton process.Here,through structural design with density functional theory(DFT)calculations,Ce is predicted to enable the construction of coordinatively unsaturated metal centers(CUCs)in Prussian blue analogue(PBA),which can strongly adsorb H_(2)O_(2)and donate sufficient electrons for directly splitting the O-O bond to produceOH.Using a substitution-co-assembly strategy,binary Ce-Fe PBA is then prepared,which rapidly degrades sulfamethoxazole with the pseudo-first-order kinetic rate constant exceeding reported values by 1-2 orders of magnitude.Meanwhile,the photogenerated electrons reduce Fe(Ⅲ)and Ce(Ⅳ)to promote the metal valence cycle in CUCs and make sulfamethoxazole degradation efficiency only lose 6.04%in 5 runs.Overall,by introducing rare earth metals into transition metal-organic frameworks,this work guides the whole process for highly active CUCs from design and construction to mechanism exploration with DFT calculations,enabling ultrafast and stable photo-Fenton catalysis.展开更多
Supercapacitors(SCs)with high power output have attracted increasing attention as efficient and environmentally friendly energy storage devices.Prussian blue and its analogues(PB/PBAs)are simple coordination polymers ...Supercapacitors(SCs)with high power output have attracted increasing attention as efficient and environmentally friendly energy storage devices.Prussian blue and its analogues(PB/PBAs)are simple coordination polymers with tunable chemical compositions and open framework.Prussian blue can act as electrode materials in its pristine form and has also been utilized to derive various metallic nanostructures for electrochemical applications due to their simple fabrication process,non-toxic characteristics,and low price.Here,we firstly describe the charge storage mechanisms of SCs briefly followed by an introduction of the fabrication methods of PB/PBAs and their derivatives.Then,a comprehensive review on recent studies of the use of PB/PBAs and their derivatives as the electrode materials for SCs are given with a focus on strategies to improve their electrochemical performances.Finally,we discuss critical challenges in this research area and propose some general ideas for future research.展开更多
To meet the current energy needs of society,the highly efficient and continuous production of clean energy is required.One of the key issues facing the green hydrogen evolution is the construction of efficient,low-cos...To meet the current energy needs of society,the highly efficient and continuous production of clean energy is required.One of the key issues facing the green hydrogen evolution is the construction of efficient,low-cost electrocatalysts.Prussian blue(PB),Prussian blue analogs(PBAs),and their derivatives have tunable metal centers and have attracted significant interest as novel photo-and electrochemical catalysts.In this review,recent research progress into PB/PBA-based hollow structures,substrate-supported nanostructures,and their derivatives for green water splitting is discussed and summarized.First,several remarkable examples of nanostructured PB/PBAs supported on substrates(copper foil,carbon cloth,and nickel foam)and hollow structures(such as single-shelled hollow boxes,open hollow cages,and intricate hollow structures(multi-shell and yolk-shell))are discussed in detail,including their synthesis and formation mechanisms.Subsequently,the applications of PB/PBA derivatives((hydr)oxides,phosphides,chalcogenides,and carbides)for water splitting are discussed.Finally,the limitations in this research area and the most urgent challenges are summarized.We hope that this review will stimulate more researchers to develop technologies based on these intricate PB/PBA structures and their derivatives for highly efficient,green water splitting.展开更多
Prussian blue analogue Na2Ni[Fe(CN)6](Ni-PB)has been widely studied as a cathode material for sodium-ion battery due to its excellent cycling performance.However,Ni-PB has a low theoretical capacity of 85 mAh g^(−1) b...Prussian blue analogue Na2Ni[Fe(CN)6](Ni-PB)has been widely studied as a cathode material for sodium-ion battery due to its excellent cycling performance.However,Ni-PB has a low theoretical capacity of 85 mAh g^(−1) because of the electrochemical inertness of Ni.Herein,ternary Ni-PB is successfully synthesized by double doping with Co and Fe at Ni-site,and the effect of doping with Co and Fe on the electrochemical performance of Ni-PB is systematically investigated through theoretical calculations and electrochemical tests.The first principles calculations confirm that double doping with Co and Fe can significantly reduce the energy barrier and bandgap of Ni-PB.X-ray diffraction and composition analysis results indicate that ternary NiCoFe-PB composite not only has good crystallinity and high Na content but also has low defects and crystal water.Electrochemical tests reveal that,besides the capacity contribution of high-spin Co/Fe and low-spin Fe,Co-doping enhances the electrochemical activity of low-spin Fe and Fe-doping improves the activity of high-spin Co;moreover,double doping can decrease the diffusion resistance of Na+ions through solid electrolyte interface film,accelerate the kinetics for both ion diffusion process and Faradic reaction,and increase active sites.Under the synergistic effect of Co and Fe,this ternary NiCoFe-PB exhibits outstanding electrochemical performance with a high initial discharge capacity of 120.4 mAh g^(−1) at 20mA g^(−1) and an extremely low capacity fading rate of 0.0044%per cycle at a high current density of 2 A g^(−1) even after 10,000 cycles,showing great application potential of ternary NiCoFe-PB in the field of large-scale energy storage.展开更多
Exploring highly efficient bifunctional photocatalysts for simultaneous H2 evolution and organic chemical production in pure water represents a green route for sustainable solar energy storage and conversion.Herein,a ...Exploring highly efficient bifunctional photocatalysts for simultaneous H2 evolution and organic chemical production in pure water represents a green route for sustainable solar energy storage and conversion.Herein,a facile strategy was explored for preparing a hierarchical porous heterostructure of Fe_(4)Ni_(5)S_(8)@ZnIn_(2)S_(4)(FNS@ZIS)by the in situ growth of ZIS nanosheets on Prussian blue analogue(PBA)-derived bimetallic FNS sulfides.A series of FNS@ZIS hierarchical structures were facilely prepared by adjusting the loading amount(n%)of FNS(n=19,26,and 32 for FNS@ZIS-1-3).These structures can efficiently drive the solar co-production of H_(2) and organic chemicals.The optimal co-production was achieved with FNS@ZIS-2,affording a H_(2) evolution rate of 10465μmol·g^(-1)·h^(-1),along with high selectivity for the oxidation of benzyl alcohol to benzaldehyde(>99.9%).The performance was 22 and 31 times higher than that of FNS and ZIS,respectively,and even superior to the state-of-the-art results achieved using various sacrificial agents.Further mechanistic study indicated that the unique hierarchical core/shell architecture can facilitate interfacial charge separation,afford bimetallic synergy,abundant active sites and excellent photostability.This work highlights a simple and efficient method for preparing porous multimetallic hierarchical structures for the solar co-production of organic chemicals and H_(2) fuel.展开更多
Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion...Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion batteries(AIBs)including sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs).Owing to larger ion sizes of Na^(+)and K^(+)compared with Li^(+),nanocomposites with excellent crystallinity orientation and well-developed porosity show unprecedented potential for advanced lithium/sodium/potassium storage.With enticing open rigid framework structures,Prussian blue analogues(PBAs)remain promising self-sacrificial templates for the preparation of various nanocomposites,whose appeal originates from the well-retained porous structures and exceptional electrochemical activities after thermal decomposition.This review focuses on the recent progress of PBA-derived nanocomposites from their fabrication,lithium/sodium/potassium storage mechanism,and applications in AIBs(LIBs,SIBs,and PIBs).To distinguish various PBA derivatives,the working mechanism and applications of PBA-templated metal oxides,metal chalcogenides,metal phosphides,and other nanocomposites are systematically evaluated,facilitating the establishment of a structure–activity correlation for these materials.Based on the fruitful achievements of PBA-derived nanocomposites,perspectives for their future development are envisioned,aiming to narrow down the gap between laboratory study and industrial reality.展开更多
The unique components and architecture of Prussian blue analogous(PBAs) offer great potential for the construction of various functional nanostructures. Herein, we reported the preparation of a series of Mn–Fe oxides...The unique components and architecture of Prussian blue analogous(PBAs) offer great potential for the construction of various functional nanostructures. Herein, we reported the preparation of a series of Mn–Fe oxides-based hybrids using Mn–Fe PBA as a template and an organic carbon source by calcination.The study focuses on revealing the interaction between the microstructure and electrochemical performance of the products obtained at different calcination temperatures. Notably, the as-derived porous Fe–Fe0.33Mn0.67O/C nanocubes(i.e., M600) exhibited the best rate capability and cycle life compared with other samples(~890 m Ah/g at 0.1 A/g, 626.8 m Ah/g after 1000 cycles at 1.0 A/g with a 99% capacity retention). These can be attributed to the fact that the porous structure provides shorter Li+diffusion path and promotes the penetration of electrolyte. Besides, the N-doped C formed by the carbonization of organic ligands can buffer the volume change and prevent the aggregation of Fe_(0.33)Mn_(0.67)O nanoparticles during the discharge/charge cycles. Moreover, the presence of metallic Fe enhances the conductivity and the electrochemical activity, which accelerates the electrochemical reactions. Therefore, reasonable design of microstructure and compositions of functional nanocomposites is the key to obtain ideal electrochemical properties.展开更多
The control of thermal expansion is essential in applications where thermal stability is required from fiber optics coatings,high performance fuel cell cathodes to tooth fillings.Negative thermal expansion(NTE)materia...The control of thermal expansion is essential in applications where thermal stability is required from fiber optics coatings,high performance fuel cell cathodes to tooth fillings.Negative thermal expansion(NTE)materials,although rare,are fundamental for this purpose.This work focuses on studying tetracyanidoborate salt CuB(CN)_(4),an interesting cubicstructure material that displays large isotropic NTE.A joint study of synchrotron x-ray diffraction,temperature-dependent Raman spectroscopy,and lattice dynamics calculations was conducted,showing that not only low-frequency optical modes(transverse thermal vibrations of N and C atoms)but also the acoustic modes(the vibrations of Cu atoms as a collective torsion of the neighboring atoms),contribute to NTE.As a result,new insights were gained into the NTE mechanism of CuB(CN)_(4) and related framework materials.展开更多
The magnetic susceptibility of ternary metal Prussian blue analogues with orthorhombic structure is studied using Ising model. Within the frame work of effective-field theory with correlations, the roles of the mole f...The magnetic susceptibility of ternary metal Prussian blue analogues with orthorhombic structure is studied using Ising model. Within the frame work of effective-field theory with correlations, the roles of the mole fraction y, uniaxial magnetic anisotropy, transverse and longitudinal magnetic field are discussed in detabls. The temperature dependence of the magnetic susceptibility is also investigated. The interesting phenomenon of the inverted magnetic hysteresis loop has been found. The results can help to understand the experimental work of the molecule-based ferri- ferrimagnet.展开更多
基金Financial support from the China Scholarship Council(201806220068,201806650009) to F.Dthe Villum Experiment(grant No.35844) to X.X.
文摘Prussian blue analogues(PBAs) with inherent ordered structures and abundant metal ion sites are widely explored as precursors for various electrochemical applications,including oxygen evolution reaction(OER).Using a range of characterization techniques including Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD) and energy dispersive spectroscopy(EDS),this work discloses the process of replacement of K^(+)by NH4^(+)in the interstitial spaces of the CoFe PBA by a hot aqueous urea solution,which influences the transformation of PBAs under further heat treatment and the OER performance of the deriva tives.After heat treatment at 400℃ under Ar flow,high-resolution transmission electron microscopy(HRTEM) images reveal that CoFe alloy nanoparticles grew on the crystalline cubes of CoFe PBA with K^(+),while CoFe PBA cubes with NH4^(+)become amorphous.Besides,the derivative of CoFe PBA with NH4^(+)(Ar-U-CoFe PBA) performs better than the derivative of CoFe PBA with K^(+)(Ar-CoFe PBA) in OER,registering a lower overpotential of 305 mV at 10 mA cm^(-2),a smaller Tafel slope of 36.1 mV dec^(-1),and better stability over a testing course of 20 h in 1.0 M KOH.A single-cell alkaline electrolyzer,using Ar-U-CoFe PBA and Pt/C for the anodic and cathodic catalyst,respectively,requires an initial cell voltage of 1.66 V to achieve 100 mA cm^(-2)at 80℃,with negligible degradation after100 h.
基金This work was sponsored by NSAF Joint Fund(U1830106)Science and Technology Innovation 2025 Major Program of Ningbo(2018B10061)K.C.Wong Magna Fund in Ningbo University.
文摘In the applications of large-scale energy storage,aqueous batteries are considered as rivals for organic batteries due to their environmentally friendly and low-cost nature.However,carrier ions always exhibit huge hydrated radius in aqueous electrolyte,which brings difficulty to find suitable host materials that can achieve highly reversible insertion and extraction of cations.Owing to open threedimensional rigid framework and facile synthesis,Prussian blue analogues(PBAs)receive the most extensive attention among various host candidates in aqueous system.Herein,a comprehensive review on recent progresses of PBAs in aqueous batteries is presented.Based on the application in different aqueous systems,the relationship between electrochemical behaviors(redox potential,capacity,cycling stability and rate performance)and structural characteristics(preparation method,structure type,particle size,morphology,crystallinity,defect,metal atom in highspin state and chemical composition)is analyzed and summarized thoroughly.It can be concluded that the required type of PBAs is different for various carrier ions.In particular,the desalination batteries worked with the same mechanism as aqueous batteries are also discussed in detail to introduce the application of PBAs in aqueous systems comprehensively.This report can help the readers to understand the relationship between physical/chemical characteristics and electrochemical properties for PBAs and find a way to fabricate high-performance PBAs in aqueous batteries and desalination batteries.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(Ministry of Science and ICT)(NRF-2021R1G1A1092280 and NRF2019R1A6A3A03031343)the Dongil Culture and Scholarship Foundationthe technical support provided at 1-D(KIST-PAL XRD and XAFS)and 7-D beamlines(XAFS)of the Pohang Light Source-II at the Pohang Accelerating Laboratory。
文摘Transition-metal(TM)-based Prussian blue and its analogues(TM-PBAs) have attracted considerable attention as cathode materials owing to their versatile ion storage capability with tunable working voltages. TM-PBAs with different crystal structures, morphologies, and TM combinations can exhibit excellent electrochemical properties because of their unique and robust host frameworks with well-defined<100> ionic diffusion channels. Nonetheless, there is still a lack of understanding regarding the performance dependence of TM-PBAs on structural changes during charging/discharging processes. In this study, in situ X-ray diffraction and X-ray absorption fine structure analyses elucidate the TMdependent structural changes in a series of TM-PBAs during the charging and discharging processes.During the discharging process, the lattice volume of Fe-PBA increased while those of Ni-and Cu-PBAs decreased. This discrepancy is attributed to the extent of size reduction of the cyanometallate complex([Fe(CN)_(6)]) via pi-backbonding from Fe to C due to redox flips of the low-spin Fe^(3+/2+) ion. This study presents a comprehensive understanding of how TM selection affects capacity acquisition and phase transition in TM-PBAs, a promising class of cathode materials.
基金financially supported by the National Natural Science Foundation of China(No.21601137)Natural Science Foundation of Zhejiang Province(No.LQ16B010003)+2 种基金Basic Science and Technology Research Project of Wenzhou,Zhejiang Province(No.H20220001)the Special Basic Cooperative Research Programs of Yunnan Provincial Undergraduate Universities Association(No.202101BA070001-042)the Yunnan Province Young and Middle-aged Academic and Technical Leaders Reserve Talent Project(202105AC 160060)。
文摘Meeting the continuous glucose monitoring requirements of individuals necessitates the research and development of sensors with high sensitivity and stability.In this study,a straightforward strategy was proposed for synthesizing ultra-thin oxygen-rich graphitized carbon nanosheets(denoted as GCS-O).These nanosheets are obtained by calcining a topologically two-dimensional indium-based coordination polymer.Subsequently,the growth of FeNi Prussian blue analogue(PBA)on GCS-O effectively introduces active sites and increases the nitrogen content within the carbonaceous matrix.The resulting FeNi-PBA/GCS-O composite exhibits excellent glucose sensing performance with a broad linear range of 1 to 1300μmol·L^(-1).Meanwhile,it also achieves a high sensitivity of 2496μA·mmol^(-1)·L·cm^(-2),a limit of detection of 100nmol·L^(-1)(S/N=3),and commendable long-term durability.The relatively simple synthesis process,exceptional sensitivity,and satisfactory electrochemical sensing performance of FeNi-PBA/GCS-O open up new directions for biosensor applications.
基金Foundation of China(Nos.21908204,52074244,2022TQ0285 and 52206282)and the Center of Advanced Analysis&Computational Science,Zhengzhou University for their characterization。
文摘Mn-based Prussian blue analogues(Mn-PBAs),featuring a three-dimensional(3D)metal-organic framework and multiple redox couples,have gained wide interests in Zn-ion batteries(ZIBs).However,owing to the Jahn-Teller distortion and disproportionation reaction of Mn^(3+),these materials suffer from poor electrochemical performances and inferior structural stability.Herein,we prepare a typical high-entropy Prussian blue analogue(HE-PBA)with increased configuration entropy through integrating five transition metal elements of Mn,Co,Ni,Fe and Cu into the nitrogen-coordinated-M-lattice sites.Consequently,the HE-PBA presents enhanced uptake of Zn^(2+)with 80 mAh·g^(−1)compared to those medium-entropy PBAs,low-entropy PBAs and conventional PBAs,which can be assigned to“cocktail”effect of multiple transition metal active redox couples.Furthermore,a phase transition process from monoclinic phase to rhombohedral phase occurs in HE-PBA cathode,resulting in a stable structure of MN6(M=Mn,Co,Fe,Ni,Cu)and ZnN4 co-linked to FeC6 through the cyanide ligands.Additionally,the advantages of entropy-driven stability are also confirmed by the calculated reduction energy and the density of states between HE-PBA and KMn[Fe(CN)6](KMnHCF).This work not only presents a high-performance HE-PBA cathode in ZIBs,but also introduces a novel concept of high entropy benefiting for designing advanced materials.
基金supported by the National Natural Science Foundation of China(Nos.51922008,52072114,and 51872075)the 111 Project(No.D17007)+1 种基金Henan Center for Outstanding Overseas Scientists(No.GZS2022017)Xinxiang Major Science and Technology Projects(No.21ZD001).
文摘Developing high-performance and low-cost electrocatalysts for oxygen evolution reaction(OER)is still a great challenge for water-splitting technologies.Herein,an innovative metal-organic frameworks(MOFs)hybrid-assisted strategy is reported to synthesize core-shell Co/Mn-ZIF@Fe-Co-Mn Prussian blue analogues(PBAs)toward highly efficient OER electrocatalysts in alkaline electrolyte.Physical characterization indicates that the amorphous hydroxide transformed from Co/Mn-ZIF@Fe-Co-Mn PBA(ZIF:zeolitic imidazolate frameworks)during the electrochemical process acted as the electroactive species.Benefiting from these structural and compositional features,the developed composite delivers a remarkably low overpotential of 270 mV with a current density of 10 mA·cm^(−2)in 1.0 M KOH solution.Moreover,water splitting is catalyzed to reach a current density of 10 mA·cm^(−2)at 1.62 V.
基金financially supported from the National Natural Science Foundation of China(U20A20249,21972108,and 22209125)。
文摘Prussian blue analogues(PBAs)have gained significant popularity as cathode materials for sodium-ion batteries(SIBs)due to their remarkable features such as high capacity and convenient synthesis.However,PBAs usually suffer from kinetic problems during the electrochemical reactions due to sluggish Na~+diffusion in the large crystals,resulting in low-capacity utilization and inferior rate capability.In this study,we present a facile etching method aiming at activating the sodium storage sites and accelerating the Na~+transport of Na_2NiFe(CN)_6(denoted as NaNiHCF)by precisely controlling its morphologies.A progressive corner passivation phenomenon occurred in NaNiHCF during the etching process,which led to a substantial augmentation of the specific surface area as the morphology transitioned from a standard cube to a dice shape.Notably,by controlling the etching time,the obtained NaNiHCF-3 electrode exhibited boosted electrochemical performance with high reversible capacity of 83.5mAh g~(-1)(98.2%of its theoretical capacity),superior rate capability(71.2 mAh g~(-1)at 10 C),and stable cycling life-span at different temperatures.Both experimental and computational methods reveal the remarkably reversible structural evolution process and improved Na~+diffusion coefficient.We believe that this work can serve as an indispensable reference to tailor the structure of PBAs to obtain improved electrochemical performance.
基金financially supported by the National Natural Science Foundation of China (No.52274294)the Fundamental Research Funds for the Central Universities (No.N2124007-1)。
文摘The design of electrode materials with specific structures is considered a promising approach for improving the performance of lithium-ion batteries(LIBs).In this paper,FeO/CoO hollow nanocages coated with a N-doped carbon layer(FCO@NC)was prepared using Fe-Co-based Prussian blue analogs(PBA)as a precursor.During the synthesis,dopamine was the carbon and nitrogen source.The reducing atmosphere was assured via NH_3/Ar,which regulated the vacancies in the structure of FCO@NC as well as increased its conductivity.When used as anode materials for LIBs,the FCO@NC nanocages deliver a high reversible capacity of 774.89 mAh·g^(-1)at 0.3 A·g^(-1)after200 cycles with a capacity retention rate of 80.4%and426.76 mAh·g^(-1)after 500 cycles at a high current density of 1 A·g^(-1).It is demonstrated that the hollow nanocage structure can effectively enhance the cycle stability,and the heat treatment in NH_(3)/Ar atmosphere contributes to the oxygen vacancy content of the electrode materials,further facilitating its conductivity and electrochemical performance.
基金supports from the National 1000 Young Talents Program of Chinathe National Nature Science Foundation of China(21603078)+3 种基金National Materials Genome Project(2016YFB0700600)the start-up funding from the University at Buffalo(Buffalo,New York,United States)The State University of New York(SUNY)along with the National Science Foundation(CBET-1511528 and 1604392)United States
文摘Prussian blue analogues(PBAs) with open frameworks have drawn much attention in energy storage fields due to their tridimensional ionic diffusion path, easy preparation, and low cost. This review summarizes the recent progress of using PBAs and their derivatives as energy storage materials in alkali ions,multi-valent ions, and metal-air batteries. The key factors to improve the electrochemical performance of PBAs as cathode materials in rechargeable batteries were firstly discussed. Several approaches for performance enhancement such as controlling the amounts of vacancies and coordinated water, optimizing morphologies, and depositing carbon coating are described in details. Then, we highlighted the significance of their diverse architectures and morphologies in anode materials for lithium/sodium ion batteries. Finally, the applications of Prussian blue derivatives as catalysts in metal-air batteries are also reviewed, providing insights into the origin of favorable morphologies and structures of catalyst for the optimal performance.
基金support from U.S.National Science Foundation Award No.DMR 2004636.
文摘Aqueous batteries have engendered increasing attention as promising solutions for stationary energy storage due to their potentially low cost and innate safety.In various aqueous battery systems,Prussian blue analogues(PBAs)represent a class of promising electrode materials with fascinating electrochemical performance,owing to their large open frameworks,abundant ion insertion sites,and facile preparation.To date,PBAs have shown substantial progress towards storage of alkali metal ions(Li^(+),Na^(+),and K^(+)),H^(+),and NH4^(+) in aqueous electrolytes,which,however,has yet not been specifically summarized.This review selects some representative research to introduce the progress of PBAs in these battery systems and aims to discuss the crucial role of ionic charge carrier in affecting the overall electrode performance.Besides,some critical knowledge gaps and challenges of PBA materials have been pointed out for future development.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11447231 and 12105137)the National Undergraduate Innovation and Entrepreneurship Training Program Support Projects of China+3 种基金the Natural Science Foundation of Hunan Province,China(Grant No.2020JJ4517)the Research Foundation of Education Bureau of Hunan Province,China(Grant Nos.19A434,19A43319C1621)the Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(Grant Nos.2019KFY10 and2019KFY09)。
文摘This work examines the origin of the abnormal magnetism exhibited by Cu Mn Fe-PBAs modified with multi-walled carbon nanotubes(MWCNTs).The system of Cu Mn Fe-PBAs@MWCNTs coexists with both large and small clusters.Cu Mn Fe-PBAs clusters have an average particle size of 28 nm,and some of the smaller particles are adsorbed on the surface of MWCNTs.Surprisingly,the magnitude of magnetization increases linearly with decreasing temperature.When above the Curie temperature,the magnitude of magnetization is significantly greater than that of PBAs without being modified.This phenomenon can be attributed to magnetostatic interactions between ultra-fine magnetic nanoparticles adsorbed on the surface of MWCNTs.Using the Monte Carlo method,we simulated the magnetostatic interaction of cylindrical adsorbed particles,and the simulation results are almost identical to those observed experimentally.The results indicate that 0.089Cu Mn Fe-PBAs clusters per 1 nm^(2)can be adsorbed onto the surface area of MWCNTs.We demonstrate that MWCNTs adsorbing magnetic particles exhibit magnetic behavior,and suggest a method for producing ultrafine materials.It also introduces a new method of calculating the adsorption efficiency of carbon nanotubes,offering theoretical guidance for future research on nanomaterials with enhanced adsorption efficiency.
基金supported by the National Natural Science Foundation of China(No.22072064,51522805,51908273,and 22176086)the State Key Laboratory of Pollution Control and Resource Reuse(PCRR-ZZ-202106)Start-Up Funds for Jiangsu Distinguished Professor.
文摘The low intrinsic activity of Fenton catalytic site and high demand for light-energy input inhibit the organic-pollution control efficiency of photo-Fenton process.Here,through structural design with density functional theory(DFT)calculations,Ce is predicted to enable the construction of coordinatively unsaturated metal centers(CUCs)in Prussian blue analogue(PBA),which can strongly adsorb H_(2)O_(2)and donate sufficient electrons for directly splitting the O-O bond to produceOH.Using a substitution-co-assembly strategy,binary Ce-Fe PBA is then prepared,which rapidly degrades sulfamethoxazole with the pseudo-first-order kinetic rate constant exceeding reported values by 1-2 orders of magnitude.Meanwhile,the photogenerated electrons reduce Fe(Ⅲ)and Ce(Ⅳ)to promote the metal valence cycle in CUCs and make sulfamethoxazole degradation efficiency only lose 6.04%in 5 runs.Overall,by introducing rare earth metals into transition metal-organic frameworks,this work guides the whole process for highly active CUCs from design and construction to mechanism exploration with DFT calculations,enabling ultrafast and stable photo-Fenton catalysis.
基金supported by the National Natural Science Foundation of China(Nos.51672055,51972342,51872656,and 51702275)Taishan Scholar Project of Shandong Province(ts20190922)Key Basic Research Project of Natural Science Foundation of Shandong Province(ZR2019ZD51)
文摘Supercapacitors(SCs)with high power output have attracted increasing attention as efficient and environmentally friendly energy storage devices.Prussian blue and its analogues(PB/PBAs)are simple coordination polymers with tunable chemical compositions and open framework.Prussian blue can act as electrode materials in its pristine form and has also been utilized to derive various metallic nanostructures for electrochemical applications due to their simple fabrication process,non-toxic characteristics,and low price.Here,we firstly describe the charge storage mechanisms of SCs briefly followed by an introduction of the fabrication methods of PB/PBAs and their derivatives.Then,a comprehensive review on recent studies of the use of PB/PBAs and their derivatives as the electrode materials for SCs are given with a focus on strategies to improve their electrochemical performances.Finally,we discuss critical challenges in this research area and propose some general ideas for future research.
文摘To meet the current energy needs of society,the highly efficient and continuous production of clean energy is required.One of the key issues facing the green hydrogen evolution is the construction of efficient,low-cost electrocatalysts.Prussian blue(PB),Prussian blue analogs(PBAs),and their derivatives have tunable metal centers and have attracted significant interest as novel photo-and electrochemical catalysts.In this review,recent research progress into PB/PBA-based hollow structures,substrate-supported nanostructures,and their derivatives for green water splitting is discussed and summarized.First,several remarkable examples of nanostructured PB/PBAs supported on substrates(copper foil,carbon cloth,and nickel foam)and hollow structures(such as single-shelled hollow boxes,open hollow cages,and intricate hollow structures(multi-shell and yolk-shell))are discussed in detail,including their synthesis and formation mechanisms.Subsequently,the applications of PB/PBA derivatives((hydr)oxides,phosphides,chalcogenides,and carbides)for water splitting are discussed.Finally,the limitations in this research area and the most urgent challenges are summarized.We hope that this review will stimulate more researchers to develop technologies based on these intricate PB/PBA structures and their derivatives for highly efficient,green water splitting.
基金National Natural Science Foundation of China,Grant/Award Number:52072217,51802261,51772169National Key R&D Program of China,Grant/Award Number:2018YFB0905400Major Technological Innovation Project of Hubei Science and Technology Department,Grant/Award Number:2019AAA164。
文摘Prussian blue analogue Na2Ni[Fe(CN)6](Ni-PB)has been widely studied as a cathode material for sodium-ion battery due to its excellent cycling performance.However,Ni-PB has a low theoretical capacity of 85 mAh g^(−1) because of the electrochemical inertness of Ni.Herein,ternary Ni-PB is successfully synthesized by double doping with Co and Fe at Ni-site,and the effect of doping with Co and Fe on the electrochemical performance of Ni-PB is systematically investigated through theoretical calculations and electrochemical tests.The first principles calculations confirm that double doping with Co and Fe can significantly reduce the energy barrier and bandgap of Ni-PB.X-ray diffraction and composition analysis results indicate that ternary NiCoFe-PB composite not only has good crystallinity and high Na content but also has low defects and crystal water.Electrochemical tests reveal that,besides the capacity contribution of high-spin Co/Fe and low-spin Fe,Co-doping enhances the electrochemical activity of low-spin Fe and Fe-doping improves the activity of high-spin Co;moreover,double doping can decrease the diffusion resistance of Na+ions through solid electrolyte interface film,accelerate the kinetics for both ion diffusion process and Faradic reaction,and increase active sites.Under the synergistic effect of Co and Fe,this ternary NiCoFe-PB exhibits outstanding electrochemical performance with a high initial discharge capacity of 120.4 mAh g^(−1) at 20mA g^(−1) and an extremely low capacity fading rate of 0.0044%per cycle at a high current density of 2 A g^(−1) even after 10,000 cycles,showing great application potential of ternary NiCoFe-PB in the field of large-scale energy storage.
基金financial support from the National Natural Science Foundation of China(21722104,21671032 and 21501072)the Natural Science Foundation of Tianjin City of China(18JCJQJC47700 and 17JCQNJC05100)。
文摘Exploring highly efficient bifunctional photocatalysts for simultaneous H2 evolution and organic chemical production in pure water represents a green route for sustainable solar energy storage and conversion.Herein,a facile strategy was explored for preparing a hierarchical porous heterostructure of Fe_(4)Ni_(5)S_(8)@ZnIn_(2)S_(4)(FNS@ZIS)by the in situ growth of ZIS nanosheets on Prussian blue analogue(PBA)-derived bimetallic FNS sulfides.A series of FNS@ZIS hierarchical structures were facilely prepared by adjusting the loading amount(n%)of FNS(n=19,26,and 32 for FNS@ZIS-1-3).These structures can efficiently drive the solar co-production of H_(2) and organic chemicals.The optimal co-production was achieved with FNS@ZIS-2,affording a H_(2) evolution rate of 10465μmol·g^(-1)·h^(-1),along with high selectivity for the oxidation of benzyl alcohol to benzaldehyde(>99.9%).The performance was 22 and 31 times higher than that of FNS and ZIS,respectively,and even superior to the state-of-the-art results achieved using various sacrificial agents.Further mechanistic study indicated that the unique hierarchical core/shell architecture can facilitate interfacial charge separation,afford bimetallic synergy,abundant active sites and excellent photostability.This work highlights a simple and efficient method for preparing porous multimetallic hierarchical structures for the solar co-production of organic chemicals and H_(2) fuel.
基金financial support from the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds,pdjh2023b0145)the Scientific Research Innovation Project of Graduate School of South China Normal University(2024KYLX047)financial support from the Australian Research Council,Centre for Materials Science,Queensland University of Technology.
文摘Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion batteries(AIBs)including sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs).Owing to larger ion sizes of Na^(+)and K^(+)compared with Li^(+),nanocomposites with excellent crystallinity orientation and well-developed porosity show unprecedented potential for advanced lithium/sodium/potassium storage.With enticing open rigid framework structures,Prussian blue analogues(PBAs)remain promising self-sacrificial templates for the preparation of various nanocomposites,whose appeal originates from the well-retained porous structures and exceptional electrochemical activities after thermal decomposition.This review focuses on the recent progress of PBA-derived nanocomposites from their fabrication,lithium/sodium/potassium storage mechanism,and applications in AIBs(LIBs,SIBs,and PIBs).To distinguish various PBA derivatives,the working mechanism and applications of PBA-templated metal oxides,metal chalcogenides,metal phosphides,and other nanocomposites are systematically evaluated,facilitating the establishment of a structure–activity correlation for these materials.Based on the fruitful achievements of PBA-derived nanocomposites,perspectives for their future development are envisioned,aiming to narrow down the gap between laboratory study and industrial reality.
基金supported by the National Natural Science Foundation of China (NSFC, Nos. 21901222, U1904215 and 21671170)Lvyangjinfeng Talent Program of Yangzhou+2 种基金the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)Program for Young Changjiang Scholars of the Ministry of Education,China (No. Q2018270)Natural Science Foundation of Jiangsu Province (No. BK20200044)。
文摘The unique components and architecture of Prussian blue analogous(PBAs) offer great potential for the construction of various functional nanostructures. Herein, we reported the preparation of a series of Mn–Fe oxides-based hybrids using Mn–Fe PBA as a template and an organic carbon source by calcination.The study focuses on revealing the interaction between the microstructure and electrochemical performance of the products obtained at different calcination temperatures. Notably, the as-derived porous Fe–Fe0.33Mn0.67O/C nanocubes(i.e., M600) exhibited the best rate capability and cycle life compared with other samples(~890 m Ah/g at 0.1 A/g, 626.8 m Ah/g after 1000 cycles at 1.0 A/g with a 99% capacity retention). These can be attributed to the fact that the porous structure provides shorter Li+diffusion path and promotes the penetration of electrolyte. Besides, the N-doped C formed by the carbonization of organic ligands can buffer the volume change and prevent the aggregation of Fe_(0.33)Mn_(0.67)O nanoparticles during the discharge/charge cycles. Moreover, the presence of metallic Fe enhances the conductivity and the electrochemical activity, which accelerates the electrochemical reactions. Therefore, reasonable design of microstructure and compositions of functional nanocomposites is the key to obtain ideal electrochemical properties.
基金supported by the National Natural Science Foundation of China (Grant Nos. 22071221, 21905252, and 11774078)Natural Science Foundation of Henan Province, China (Grant No. 212300410086)+1 种基金Innovation Scientists and Technicians Troop Construction Projects of Henan Province, China (No. 10094100510025)supported by National Supercomputing Center in Zhengzhou
文摘The control of thermal expansion is essential in applications where thermal stability is required from fiber optics coatings,high performance fuel cell cathodes to tooth fillings.Negative thermal expansion(NTE)materials,although rare,are fundamental for this purpose.This work focuses on studying tetracyanidoborate salt CuB(CN)_(4),an interesting cubicstructure material that displays large isotropic NTE.A joint study of synchrotron x-ray diffraction,temperature-dependent Raman spectroscopy,and lattice dynamics calculations was conducted,showing that not only low-frequency optical modes(transverse thermal vibrations of N and C atoms)but also the acoustic modes(the vibrations of Cu atoms as a collective torsion of the neighboring atoms),contribute to NTE.As a result,new insights were gained into the NTE mechanism of CuB(CN)_(4) and related framework materials.
基金Supported by the Excellent Talents Program of the university of Liaoning Province of China under Grant No.LR201031
文摘The magnetic susceptibility of ternary metal Prussian blue analogues with orthorhombic structure is studied using Ising model. Within the frame work of effective-field theory with correlations, the roles of the mole fraction y, uniaxial magnetic anisotropy, transverse and longitudinal magnetic field are discussed in detabls. The temperature dependence of the magnetic susceptibility is also investigated. The interesting phenomenon of the inverted magnetic hysteresis loop has been found. The results can help to understand the experimental work of the molecule-based ferri- ferrimagnet.
