The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts rem...The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.展开更多
Ferroelectric materials are gaining increasing attention for the development of advanced catalytic technologies due to their field-responsive polarization states.However,achieving dynamic optimization of catalytic act...Ferroelectric materials are gaining increasing attention for the development of advanced catalytic technologies due to their field-responsive polarization states.However,achieving dynamic optimization of catalytic activity using ferroelectrics remains a fundamental challenge.Inspired by the force-adaptive mechanisms of fish scales,we introduce an intracrystalline force regulation strategy to dynamically control cobalt spin states and enhance peroxymonosulfate(PMS)activation in Fenton-like processes.This approach utilizes BaTi_(0.92)Co_(0.08)O_(3-δ)(BTC-8)nano-ferroelectrics,where ultrasound irradiation generates a built-in electric field that drives electrons towards cobalt sites.This electron transfer is further facilitated by electronegativity differences between cobalt and barium/titanium ions.The resulting piezo-driven electron flow promotes continuous regeneration of high-spin Co^(2+),enhancing PMS adsorption and SO_(4)^(-)-OH bond cleavage,leading to increased production of⋅SO_(4)^(-)and singlet oxygen(^(1)O_(2))for organic pollutant degradation.Consequently,BTC-8 achieves a reaction rate(k=1.7960 min^(-1))28.93 times higher than that of pure barium titanate,surpassing previously reported PMS activation and piezocatalytic systems.This work represents a shift from static electronic structure design to dynamic electronic engineering in the development of advanced catalytic strategies for water remediation.展开更多
Inspired by molecular catalysts,researchers developed atomically precise nitrogen-coordinated single or dual metal sites imbedded in graphitized carbon(M-N-C)to fully utilize metallic sites for 02activation.These cata...Inspired by molecular catalysts,researchers developed atomically precise nitrogen-coordinated single or dual metal sites imbedded in graphitized carbon(M-N-C)to fully utilize metallic sites for 02activation.These catalysts performed remarkably well in the electrocatalytic oxygen reduction reaction(ORR)due to their distinct coordination and electrical structures,Nonetheless,their maximum efficacy in practical applications has yet to be achieved.This agenda identifies tailoring the coordination environment,spin states,intersite distance,and metal-metal interaction as innovative approaches to regulate the ORR performance of these catalysts.However,it is necessary to undertake a precise assessment of these methodologies and the knowledge obtained to be implemented in the design of future M-N-C catalysts for ORR.Therefore,this review aims to analyze recent progress in M-N-C ORR catalysts,emphasizing their innovative engineering with aspects such as alteration in intersite distance,metal-metal interaction,coordination environment,and spin states.Additionally,we critically discuss how to logically monitor the atomic structure,local coordination,spin,and electronic states of M-N-C catalysts to modulate their ORR activity.We have also highlighted the challenges associated with M-N-C catalysts and proposed suggestions for their future design and fabrication.展开更多
Dual-atom catalysts(DACs),a natural extension of single-atom catalysts(SACs),have emerged as a prominent focal point in the field of heterogeneous catalysis,particularly in the context of chemical and energy conversio...Dual-atom catalysts(DACs),a natural extension of single-atom catalysts(SACs),have emerged as a prominent focal point in the field of heterogeneous catalysis,particularly in the context of chemical and energy conversion processes.Despite the fact that the catalytic activity of DACs is significantly modulated by the electronic structure of the catalyst,understanding how electron spin states are affected by variations in topology and geometric structure remains challenging and relatively unexplored.Herein,we propose the rational design of stable DACs composed of two iron atoms anchored on pristine graphdiyne(GDY),Fe_(2)-GDYn.A comprehensive and systematic investigation was carried out to elucidate the electronic configuration and spin states involved in the deliberate convergence towards the magnetic ground state,with the aim of uncovering the structure-spin relationship.Through an in-depth analysis of spin populations,electronic localization/delocalization,and the chemical bonding characteristics of the central metal atoms and the GDY skeleton,it was revealed that the spin coupling between the two iron atoms is preponderantly dictated by adjacent short-range Fe-Fe interactions.Conversely,spin decoupling can be attributed to the long-rangeπ-bond component within the linkage.Moreover,geometric and chemical bonding asymmetries were found to induce orbital and spin splitting in iron atoms possessing an electronic configuration of d8.These findings provide important insights into the relationship between topology and spin,thereby presenting novel strategies for the rational design of spin-manipulated DACs.展开更多
Modulating the electronic structure has emerged as an effective strategy for optimizing the adsorption and catalytic capabilities of electrocatalysts in lithium-sulfur(Li-S)batteries.However,the regulation of electron...Modulating the electronic structure has emerged as an effective strategy for optimizing the adsorption and catalytic capabilities of electrocatalysts in lithium-sulfur(Li-S)batteries.However,the regulation of electronic structure involving spin-related charge transfer and orbital interactions has been largely underexplored in sulfur electrocatalysts.Herein,selenium-deficient bimetallic selenides embedded in a coaxial carbon layer(CoSe_(2-x)/ZnSe)were meticulously fabricated as electrocatalysts,aiming to modulate the electron spin state of Co catalytic sites to enhance the bidirectional lithium polysulfides(LiPSs)conversion kinetics and suppress the LiPSs shuttling effect.Density functional theory(DFT)calculations and experimental results indicate that the selenium vacancies at the CoSe_(2-x)/ZnSe heterointerfaces weaken the ligand fields and drive the Co 3d orbital electronic structure transition from low-spin to high-spin states.Such tailored spin state configuration generates more unpaired electrons and upshifts the dband center,thus accelerating the charge transfer and strengthening the orbital interactions between LiPSs and Co catalytic sites.As a consequence,the assembled Li-S batteries with CoSe_(2-x)/ZnSe electrocatalysts exhibit an ultralow average decay rate of 0.028%per cycle at 1 C over 1000 cycles.This work presents a novel strategy for manipulating ligand fields to realize electron spin state modulation in sulfur electrocatalysts.展开更多
Oxygen reduction reaction(ORR)in neutral electrolyte is urgently needed in various areas,such as metalair batteries.However,the N-coordinated transition-metal single-atom electrocatalysts confront sluggish catalytic k...Oxygen reduction reaction(ORR)in neutral electrolyte is urgently needed in various areas,such as metalair batteries.However,the N-coordinated transition-metal single-atom electrocatalysts confront sluggish catalytic kinetics due to the inappropriate electronic structure and the as-resulted unreasonable adsorption strength towards oxygen-containing intermediates.In this work,we develop a strategy to tune the Fe d-orbital spin state by introducing inert Si atom into the first coordination sphere of Fe-N_(4)moieties.The experimental and theoretical results suggest that Si atom generates the coordination field distortion of Fe and induces the Fe d-orbital spin state transforming from low to medium spin state.The optimized spin-electron filled state(t2g^(4)eg^(1))of Fe sites weakens the adsorption strength to intermediates and reduces the energy barrier of^(∗)OH desorption.Consequently,Fe-Si/NC catalyst exhibits superior ORR performance compared with that of Fe-NC and commercial Pt/C,showing a more positive half-wave potential of 0.753 V(vs.RHE)in 0.1 mol/L phosphate buffered saline.In addition,Fe-Si/NC-based neutral zinc-air batteries show a maximum power density of 108.9 mW cm^(−2)and long-term stability for 200 h.This work represents the possibility of constructing distorted coordination configurations of single-atom catalysts to modulate electronic structure and enhance ORR activity in neutral electrolyte.展开更多
By the first-principles calculations, most studies indicated that the （1102）-CoO2 termination of LaCoO3 cannot be stabilized, which disagrees with the experimental observation. Besides the crystal structure, we foun...By the first-principles calculations, most studies indicated that the （1102）-CoO2 termination of LaCoO3 cannot be stabilized, which disagrees with the experimental observation. Besides the crystal structure, we found that the spin states of Co3＋ ions could affect surface stability, which previously were not well considered. By examining the different states of Co3＋ ions in hexagonal-phase LaCoO3, including low spin, intermediate spin, and high spin states, the surface grand potentials of these facets are calculated and compared. The results show that the spin states of Co3＋ ions have an important influence on stability of the LaCoO3 facets. Different from the previous results, the stability diagrams demonstrate that the （1102）- CoO2 termination can stably exist under O-rich condition, which can get an agreement with the experimental ones. Furthermore, the surface oxygen vacancy formation energies （Eov） of stable facets are computed in different spin states. The Eov of these possible exposed terminations strongly depend on the spin state of Co3＋ ions： in particular, the Eov of the HS states is lower than that of other spin states. This indicates that one can tune the properties of LaCoO3 by directly tuning the spin states of Co3＋ ions.展开更多
Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sph...Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.展开更多
Photocatalysis is considered as one of the most promising technologies to generate renewable energy and degrade environmental pollutants.Tremendous efforts have been made to improve photocatalytic efficiency.Among the...Photocatalysis is considered as one of the most promising technologies to generate renewable energy and degrade environmental pollutants.Tremendous efforts have been made to improve photocatalytic efficiency.Among these,tuning spin polarization and introducing an external magnetic field are considered two promising strategies to boost photocatalytic performance.Herein this review highlights the recent breakthroughs through manipulating spin states and applying external magnetic fields for enhancing photocatalytic reactions.The relevant characterization techniques and fundamental mechanisms are summarized.Spin polarization states of photocatalysts have received considerable attention due to their unique roles,including inhibiting the recombination of photoexcited carriers owing to spin orientation constraint,enhancing the reaction product selectivity,and reducing the reaction barriers via optimizing the absorption energy and binding strength.As for the effects of external magnetic field on photocatalytic performance,we mainly discuss the separation enhancement of photoinduced carriers under static and time-varying magnetic fields and the magneto-hydrodynamic effect of charged particles.Lastly,the negative magnetoresistance effect is discussed due to the synergistic effects of the electron spin state and an external magnetic field.These discussions in this review may provide new insights into designing new semiconductors for boosting photocatalytic performance in internal and external magnetic fields.展开更多
Silicate perovskites（（Mg, Fe）SiO 3 and CaS iO 3） are believed to be the major constituent minerals in the lower mantle. The phase relation, solid solution, spin state of iron and water solubility related to the lo...Silicate perovskites（（Mg, Fe）SiO 3 and CaS iO 3） are believed to be the major constituent minerals in the lower mantle. The phase relation, solid solution, spin state of iron and water solubility related to the lower mantle perovskite are of great effect on the geodynamics of the Earth＇s interior and on ore mineralization. Previous studies indicate that a large amount of iron coupled with aluminum can incorporate into magnesium perovskite, but this is discordant with the disproportionation of（Mg,Fe）SiO 3 perovskite into iron-free MgS i O3 perovskite and hexagonal phase（Mg0.6Fe0.4）SiO 3 in the Earth＇s lower mantle. MnS iO 3 is the first chemical component confirmed to form wide range solid solution with Ca SiO 3 perovskite and complete solid solution with MgS i O3 perovskite at the P-T conditions in the lower mantle, and addition of Mn Si O3 will strongly affects the mutual solubility between Mg Si O3 and CaS iO 3. The spin state of iron is deeply depends on the site occupation of the Fe3＋or Fe2＋, the synthesis and the annealing conditions of the sample. It seems that the spin state of Fe2＋ in the lower mantle perovskite can be settled as high spin, however, the existence of intermediate spin or low spin state of Fe2＋ in perovskite has not been clarified. Moreover, different results have also been reported for the spin state of Fe3＋ in perovskite. The water solubility of the lower mantle perovskite is related with its composition. In pure Mg SiO 3 perovskite, only less than 500 ppm water was reported. Al–Mg Si O3 perovskite or Al–Fe–MgS iO 3 perovskite in the lower mantle accommodates water of 1100 to 1800 ppm. Further experiments are necessary to clarify the detailed conditions for perovskite solid solution, to reliably analyze the valence and spin states of iron in the coexisting iron-bearing phases, and to compare the water solubility of different phases at different layers for deeply understanding the geodynamics of the Earth＇s interior and ore mineralization.展开更多
We investigate phase diffusion of a two-component Bose--Einstein condensates prepared initially in arbitrary coherent spin state ｜θ0,φ0｜. Analytical expression of the phase-diffusion time is presented for θ0～π/...We investigate phase diffusion of a two-component Bose--Einstein condensates prepared initially in arbitrary coherent spin state ｜θ0,φ0｜. Analytical expression of the phase-diffusion time is presented for θ0～π/2 case. In comparison with the symmetrical case （i.e., θ0=π/2）, we find that the diffusion process becomes slow due to the reduced atom number variance.展开更多
Owing to the distinctive structural characteristics,vanadium nitride(VN)is highly regarded as a catalyst for oxygen reduction reaction(ORR)in zinc-air batteries(ZABs).However,VN exhibits limited intrinsic ORR activity...Owing to the distinctive structural characteristics,vanadium nitride(VN)is highly regarded as a catalyst for oxygen reduction reaction(ORR)in zinc-air batteries(ZABs).However,VN exhibits limited intrinsic ORR activity due to the weak adsorption ability to O-containing species.Here,the S-doped VN anchored on N,S-doped multi-dimensional carbon(S-VN/Co/NS-MC)was constructed using the solvothermal and in-situ doping methods.Incorporating sulfur atoms into VN species alters the electron spin state of vanadium in the S-VN/Co/NS-MC for regulating the adsorption energy of vanadium sites to oxygen molecules.The introduced sulfur atoms polarize the V 3d_(z)^(2) electrons,shifting spin-down electrons closer to the Fermi level in the S-VN/Co/NS-MC.Consequently,the introduction of sulfur atoms into VN species enhances the adsorption energy of vanadium sites for oxygen molecules.The*OOH dissociation transitions from being unspontaneous on the VN surface to a spontaneous state on the S-doped VN surface.Then,the ORR barrier on the S-VN/Co/NS-MC surface is reduced.The S-VN/Co/NS-MC demonstrates a higher half-wave potential and limiting current density compared to the VN/Co/N-MC.The S-VN/Co/NS-MC-based liquid ZABs display a power density of 195.7 m W cm^(-2),a specific capacity of 815.7 m A h g^(-1),and a cycling stability exceeding 250 h.The S-VN/Co/NS-MC-based flexible ZABs are successfully employed to charge both a smart watch and a mobile phone.This approach holds promise for advancing the commercial utilization of VN-based catalysts in ZABs.展开更多
Since the use of a quantum channel is very expensive for transmitting large messages, it is vital to develop an effective quantum compression encoding scheme that is easy to implement. Given that, with the single-phot...Since the use of a quantum channel is very expensive for transmitting large messages, it is vital to develop an effective quantum compression encoding scheme that is easy to implement. Given that, with the single-photon spin-orbit entanglement, we propose a quantum secret sharing scheme using orbital angular momentum onto multiple spin states based on Fibonacci compression encoding. In our proposed scheme, we can represent the frequency of any secret message which is typically collection of bits encodings of text or integers as a bitstring using the base Fibonacci sequence, which is encoded multiple spin states for secret shares transmitted to participants. We demonstrate that Fibonacci compression encoding carries excellent properties that enable us to achieve more robust quantum secret sharing schemes with fewer number of photons.展开更多
We propose a different entanglement concentration protocol （ECP） for nonlocal N-electron systems in a partially entangled Bell-type pure state using the CNOT gates and the projection measurements on an additional el...We propose a different entanglement concentration protocol （ECP） for nonlocal N-electron systems in a partially entangled Bell-type pure state using the CNOT gates and the projection measurements on an additional electron. For each nonlocal N-electron system, Alice first entangles it with the additional electron, and then she projects the additional electron onto an orthogonal basis for dividing the N-electron systems into two groups. In the first group, the N parties obtain a subset of N-electron systems in a maximally entangled state directly. In the second group, they obtain some less-entangled N-electron systems, which are the resource for the entanglement concentration in the next round. By iterating the entanglement concentration process several times, the present ECP has the maximal success probability, which is the theoretical limit of an ECP, equal to the entanglement of the partially entangled state, and higher than the others. This ECP may be useful in quantum computers based on electron-spin systems in the future.展开更多
Atomic and electronic structures of adsorbed nickel and vanadium atoms and nanoclusters （Nin and Vn, n = 1-10） on hexagonal h-BN and BC3 lattices were studied using DFT PBE/PBC/PW （Perdew-Burke- Ernzerhof potential...Atomic and electronic structures of adsorbed nickel and vanadium atoms and nanoclusters （Nin and Vn, n = 1-10） on hexagonal h-BN and BC3 lattices were studied using DFT PBE/PBC/PW （Perdew-Burke- Ernzerhof potential of density functional theory/periodic boundary conditions/plane wave basis set） technique. For the sake of comparison the structure and properties of the same nanoclusters deposited on pristine graphene were calculated as well. It was found that for all types of supports an increase of n from 1 to 10 leaded to decrease of coordination types from 776 to r/2 and 771. The h-BN- and BC3-based nanocomposites were characterized by high （up to 18 μ for Ni10/BC3） magnetic moments of the nanoclusters and featured by positive binding energies. The graphene-based nanocomposites revealed energetic stability and, in general, lower magnetic moments per unit cell. The direct potential energy barriers for migration of Ni η2/η21 and η6/η6 types of dimers on graphene were low （10.9-28.9 kJ/mol） with high reverse barriers for η6/η6 dimers, which favored dynamically equilibrated Ni clusterization on graphene.展开更多
Perovskite oxide La1-xSrxCoO3（0≤x≤0.5） series were prepared and effect of oxygen annealing on crystal structure and magnetic susceptibility were studied.High-temperature susceptibility could be well fitted by Curi...Perovskite oxide La1-xSrxCoO3（0≤x≤0.5） series were prepared and effect of oxygen annealing on crystal structure and magnetic susceptibility were studied.High-temperature susceptibility could be well fitted by Curie-Weiss law for all Sr-doped samples.Weiss constant and effective magnetic moment were determined, and their variations with Sr doping and oxygen annealing condition were obtained.The result suggested that by assuming that the Co3＋ ions were in the intermediate-spin（IS） state, most of the Co4＋ ions in the as-prepared samples might be in the high-spin（HS） state, but both the Co3＋ and Co4＋ ions might be in the IS state after oxygen annealing, which indicated that annealing in flowing oxygen could cause transition of the spin state of Co4＋ ions from the HS state to IS state.展开更多
The high-spin states of 141pro nucleus have been studied by using in-beam v-ray spectroscopy technology through the126Te（19F, 4n） reaction at a beam energy of 90 MeV. The previous level scheme has been extended with...The high-spin states of 141pro nucleus have been studied by using in-beam v-ray spectroscopy technology through the126Te（19F, 4n） reaction at a beam energy of 90 MeV. The previous level scheme has been extended with spin up to 49/2 h. Many new levels and transitions are identified. Five collective band structures are observed. Based on systematic comparison with the neighboring nuclei, two bands with strong AI = 1 M1 transitions inside the bands are proposed as the oblate bands with γ--60°, and three bands with large signature splitting have been suggested as the oblate-triaxial deformation with γ--90°. The characteristics for these bands have been discussed.展开更多
Carbon nanofibers(CNFs)have received extensive and in-depth studied as anodes for sodium-ion batteries(SIBs),and yet their initial Coulombic efficiency and rate capability remain enormous challenge at practical level....Carbon nanofibers(CNFs)have received extensive and in-depth studied as anodes for sodium-ion batteries(SIBs),and yet their initial Coulombic efficiency and rate capability remain enormous challenge at practical level.Herein,CNFs anchored with cobalt nanocluster(CNFs-Co)were prepared using chemical vapor deposition and thermal reduction methods.The as-prepared CNFs-Co shows a high initial Coulombic efficiency of 91%and a high specific discharge capacity of 246 mAh/g at 0.1 A/g after 200 cycles as anode for SIBs.Meanwhile,the CNFs-Co anode still delivers a high cycling stability with 108 mAh/g after 1000 cycles at 10 A/g.These excellent electrochemical properties could be attributed to the involved spin state Co,which endows CNFs with large interplanar spacing(0.39 nm)and abundant vacancy defects.Importantly,the spin state Co downshifts the p-band center of carbon and strengthens the Na+adsorption energy from-2.33 eV to-2.64 eV based on density functional theory calculation.This novel strategy of modulating the carbon electronic structure by the spin state of magnetic metals provides a reference for the development of high-performance carbon-based anode materials.展开更多
Four complexes of compositions [Fe2（L^1）2]（1）, [Ni2（L^1）2]（2）, [Ni2（L^2）2]（3） and [Cu2（L^2）2]（4）（H2L^1 = 1-（（（2-hydroxy-2,3-dihydro-1 H-inden-1-yl）imino）methyl）naphthalen-2-ol, H2L^2 = 4-（（2-h...Four complexes of compositions [Fe2（L^1）2]（1）, [Ni2（L^1）2]（2）, [Ni2（L^2）2]（3） and [Cu2（L^2）2]（4）（H2L^1 = 1-（（（2-hydroxy-2,3-dihydro-1 H-inden-1-yl）imino）methyl）naphthalen-2-ol, H2L^2 = 4-（（2-hydroxy-2,3-dihydro-1 H-inden-1-yl）imino）pentan-2-one） were synthesized under solvothermal conditions. The structures of 1~4 were characterized by X-ray single-crystal diffraction analysis. The magnetic properties of these four complexes are investigated. The dc magnetic measurements indicate that the metal ions of 1, 2 and 3 are in the low spin state, revealing the strong ligand field character of 1-amino-2-indanol. This work provides an effective approach to coordination complexes possessing low spin state metal centers.展开更多
The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we develope...The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we developed a spin-state and delocalized electron regulation method to optimize oxygen evolution reaction(OER)performance by in-situ growth of NiCo_(2)(OH)_(x) using Oswald ripening and coordinating etching process on MXene and plasma treatment.X-ray absorption spectroscopy,magnetic tests and electron paramagnetic resonance reveal that the coupling of NiCo_(2)(OH)_(x) and MXene can induce remarkable spin-state transition of Co^(3+)and transition metal ions electron delocalization,plasma treatment further optimizes the 3 d orbital structure and delocalized electron density.The unique Jahn-Teller phenomenon can be brought by the intermediate spin state(t2 _(g)^(5) e_(g)^(1))of Co^(3+),which benefits from the partial electron occupied egorbitals.This distinct electron configuration(t2_(g)^(5) e_(g)^(1))with unpaired electrons leads to orbital degeneracy,that the adsorption free energy of intermediate species and conductivity were further optimized.The optimized electrocatalyst exhibits excellent OER activity with an overpotential of 268 m V at 10 m A cm^(-2).DFT calculations show that plasma treatment can effectively regulate the d-band center of TMs to optimize the adsorption and improve the OER activity.This approach could guide the rational design and discovery of electrocatalysts with ideal electron configurations in the future.展开更多
基金financially supported by the Sichuan Science and Technology Program (Grant No. 2025NSFSC0139)the China Postdoctoral Science Foundation (Grant No.2023MD734228)+10 种基金funding from Generalitat de Catalunya 2021SGR00457supported by MCIN with funding from European Union NextGenerationEU(PRTR-C17.I1)by Generalitat de Catalunya (In-CAEM Project)the support from the project AMaDE(PID2023-149158OB-C43)funded by MCIN/AEI/10.13039/501100011033/by “ERDF A way of making Europe”by the “European Union”supported by the Severo Ochoa program from Spanish MCIN/AEI (Grant No.:CEX2021-001214-S)funded by the CERCA Programme/Generalitat de Catalunyaperformed in the framework of Universitat Autònoma de Barcelona Materials Science PhD programfunding from the CSC-UAB PhD scholarship program. ICN2 is founding member of e-DREAM[87]
文摘The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.
基金the National Natural Science Foundation of China(Grant No.U2002217,52102342,52103024 and 12404116)Key Research Program of the Chinese Academy of Sciences(Grant No.ZDRW-CN2021-3-1-18)+5 种基金Chenguang Program of Shanghai Education Development Foundation,Shanghai Municipal Education Commission(Grant No.21CGA40)9th Young Elite Scientists Sponsorship Program by CAST(Grant No.2023QNRC001)10th Young Elite Scientists Sponsorship Program by CAST(Grant No.YESS20240270)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232832)Donghua University 2024 Cultivation Project of Discipline Innovation(Grant No.xkcx-202413)Student Training Program for Innovation and Entrepreneurship of Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences(Grant No.CXCY20230305).
文摘Ferroelectric materials are gaining increasing attention for the development of advanced catalytic technologies due to their field-responsive polarization states.However,achieving dynamic optimization of catalytic activity using ferroelectrics remains a fundamental challenge.Inspired by the force-adaptive mechanisms of fish scales,we introduce an intracrystalline force regulation strategy to dynamically control cobalt spin states and enhance peroxymonosulfate(PMS)activation in Fenton-like processes.This approach utilizes BaTi_(0.92)Co_(0.08)O_(3-δ)(BTC-8)nano-ferroelectrics,where ultrasound irradiation generates a built-in electric field that drives electrons towards cobalt sites.This electron transfer is further facilitated by electronegativity differences between cobalt and barium/titanium ions.The resulting piezo-driven electron flow promotes continuous regeneration of high-spin Co^(2+),enhancing PMS adsorption and SO_(4)^(-)-OH bond cleavage,leading to increased production of⋅SO_(4)^(-)and singlet oxygen(^(1)O_(2))for organic pollutant degradation.Consequently,BTC-8 achieves a reaction rate(k=1.7960 min^(-1))28.93 times higher than that of pure barium titanate,surpassing previously reported PMS activation and piezocatalytic systems.This work represents a shift from static electronic structure design to dynamic electronic engineering in the development of advanced catalytic strategies for water remediation.
基金supported by the Research Fund for International Scientists(RFIS-Grant numbers:52150410410)National Natural Science Foundation of Chinathe Deanship of Scientific Research and Graduate Studies at King Khalid University for funding this research work through Large Research Project under the grant number RGP2/121/1445.
文摘Inspired by molecular catalysts,researchers developed atomically precise nitrogen-coordinated single or dual metal sites imbedded in graphitized carbon(M-N-C)to fully utilize metallic sites for 02activation.These catalysts performed remarkably well in the electrocatalytic oxygen reduction reaction(ORR)due to their distinct coordination and electrical structures,Nonetheless,their maximum efficacy in practical applications has yet to be achieved.This agenda identifies tailoring the coordination environment,spin states,intersite distance,and metal-metal interaction as innovative approaches to regulate the ORR performance of these catalysts.However,it is necessary to undertake a precise assessment of these methodologies and the knowledge obtained to be implemented in the design of future M-N-C catalysts for ORR.Therefore,this review aims to analyze recent progress in M-N-C ORR catalysts,emphasizing their innovative engineering with aspects such as alteration in intersite distance,metal-metal interaction,coordination environment,and spin states.Additionally,we critically discuss how to logically monitor the atomic structure,local coordination,spin,and electronic states of M-N-C catalysts to modulate their ORR activity.We have also highlighted the challenges associated with M-N-C catalysts and proposed suggestions for their future design and fabrication.
文摘Dual-atom catalysts(DACs),a natural extension of single-atom catalysts(SACs),have emerged as a prominent focal point in the field of heterogeneous catalysis,particularly in the context of chemical and energy conversion processes.Despite the fact that the catalytic activity of DACs is significantly modulated by the electronic structure of the catalyst,understanding how electron spin states are affected by variations in topology and geometric structure remains challenging and relatively unexplored.Herein,we propose the rational design of stable DACs composed of two iron atoms anchored on pristine graphdiyne(GDY),Fe_(2)-GDYn.A comprehensive and systematic investigation was carried out to elucidate the electronic configuration and spin states involved in the deliberate convergence towards the magnetic ground state,with the aim of uncovering the structure-spin relationship.Through an in-depth analysis of spin populations,electronic localization/delocalization,and the chemical bonding characteristics of the central metal atoms and the GDY skeleton,it was revealed that the spin coupling between the two iron atoms is preponderantly dictated by adjacent short-range Fe-Fe interactions.Conversely,spin decoupling can be attributed to the long-rangeπ-bond component within the linkage.Moreover,geometric and chemical bonding asymmetries were found to induce orbital and spin splitting in iron atoms possessing an electronic configuration of d8.These findings provide important insights into the relationship between topology and spin,thereby presenting novel strategies for the rational design of spin-manipulated DACs.
基金supported by the National Natural Science Foundation of China(No.52172214,52472220)。
文摘Modulating the electronic structure has emerged as an effective strategy for optimizing the adsorption and catalytic capabilities of electrocatalysts in lithium-sulfur(Li-S)batteries.However,the regulation of electronic structure involving spin-related charge transfer and orbital interactions has been largely underexplored in sulfur electrocatalysts.Herein,selenium-deficient bimetallic selenides embedded in a coaxial carbon layer(CoSe_(2-x)/ZnSe)were meticulously fabricated as electrocatalysts,aiming to modulate the electron spin state of Co catalytic sites to enhance the bidirectional lithium polysulfides(LiPSs)conversion kinetics and suppress the LiPSs shuttling effect.Density functional theory(DFT)calculations and experimental results indicate that the selenium vacancies at the CoSe_(2-x)/ZnSe heterointerfaces weaken the ligand fields and drive the Co 3d orbital electronic structure transition from low-spin to high-spin states.Such tailored spin state configuration generates more unpaired electrons and upshifts the dband center,thus accelerating the charge transfer and strengthening the orbital interactions between LiPSs and Co catalytic sites.As a consequence,the assembled Li-S batteries with CoSe_(2-x)/ZnSe electrocatalysts exhibit an ultralow average decay rate of 0.028%per cycle at 1 C over 1000 cycles.This work presents a novel strategy for manipulating ligand fields to realize electron spin state modulation in sulfur electrocatalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.52422314,U23A20687,and 52231008)the International Science&Technology Cooperation Program of Hainan Province(No.GHYF2023007).
文摘Oxygen reduction reaction(ORR)in neutral electrolyte is urgently needed in various areas,such as metalair batteries.However,the N-coordinated transition-metal single-atom electrocatalysts confront sluggish catalytic kinetics due to the inappropriate electronic structure and the as-resulted unreasonable adsorption strength towards oxygen-containing intermediates.In this work,we develop a strategy to tune the Fe d-orbital spin state by introducing inert Si atom into the first coordination sphere of Fe-N_(4)moieties.The experimental and theoretical results suggest that Si atom generates the coordination field distortion of Fe and induces the Fe d-orbital spin state transforming from low to medium spin state.The optimized spin-electron filled state(t2g^(4)eg^(1))of Fe sites weakens the adsorption strength to intermediates and reduces the energy barrier of^(∗)OH desorption.Consequently,Fe-Si/NC catalyst exhibits superior ORR performance compared with that of Fe-NC and commercial Pt/C,showing a more positive half-wave potential of 0.753 V(vs.RHE)in 0.1 mol/L phosphate buffered saline.In addition,Fe-Si/NC-based neutral zinc-air batteries show a maximum power density of 108.9 mW cm^(−2)and long-term stability for 200 h.This work represents the possibility of constructing distorted coordination configurations of single-atom catalysts to modulate electronic structure and enhance ORR activity in neutral electrolyte.
基金This work was supported by the National Natural Science Foundation of China （No.U1232118, No.21203099）, the National Basic Research Program （No.2014CB932403）, the Program of Introducing Talents of Disciplines to China Universities （No.B06006）, Research Program for Advanced and Applied Technology of Tianjin （No.13JCYBJC36800）, Doctoral Fund of Ministry of Education of China （No.20120031120033）, Fok Ying Tung Education Foundation （No.151008）, and Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund （the second phase）. We appreciate the supports from the National Super-Computing Center at Tianjin and Guangzhou.
文摘By the first-principles calculations, most studies indicated that the （1102）-CoO2 termination of LaCoO3 cannot be stabilized, which disagrees with the experimental observation. Besides the crystal structure, we found that the spin states of Co3＋ ions could affect surface stability, which previously were not well considered. By examining the different states of Co3＋ ions in hexagonal-phase LaCoO3, including low spin, intermediate spin, and high spin states, the surface grand potentials of these facets are calculated and compared. The results show that the spin states of Co3＋ ions have an important influence on stability of the LaCoO3 facets. Different from the previous results, the stability diagrams demonstrate that the （1102）- CoO2 termination can stably exist under O-rich condition, which can get an agreement with the experimental ones. Furthermore, the surface oxygen vacancy formation energies （Eov） of stable facets are computed in different spin states. The Eov of these possible exposed terminations strongly depend on the spin state of Co3＋ ions： in particular, the Eov of the HS states is lower than that of other spin states. This indicates that one can tune the properties of LaCoO3 by directly tuning the spin states of Co3＋ ions.
基金This work was supported by the National Natural Science Foundation of People’s Republic of China(No.NSFC52174246)the Interdisciplinary Scientific Research Foundation of Guangxi University(No.2022JCC016).
文摘Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.
基金the National Natural Science Foundation of China(Nos.61774055,51871138,and U2102212)the Science and Technology Committee of Shanghai(No.19010500400)。
文摘Photocatalysis is considered as one of the most promising technologies to generate renewable energy and degrade environmental pollutants.Tremendous efforts have been made to improve photocatalytic efficiency.Among these,tuning spin polarization and introducing an external magnetic field are considered two promising strategies to boost photocatalytic performance.Herein this review highlights the recent breakthroughs through manipulating spin states and applying external magnetic fields for enhancing photocatalytic reactions.The relevant characterization techniques and fundamental mechanisms are summarized.Spin polarization states of photocatalysts have received considerable attention due to their unique roles,including inhibiting the recombination of photoexcited carriers owing to spin orientation constraint,enhancing the reaction product selectivity,and reducing the reaction barriers via optimizing the absorption energy and binding strength.As for the effects of external magnetic field on photocatalytic performance,we mainly discuss the separation enhancement of photoinduced carriers under static and time-varying magnetic fields and the magneto-hydrodynamic effect of charged particles.Lastly,the negative magnetoresistance effect is discussed due to the synergistic effects of the electron spin state and an external magnetic field.These discussions in this review may provide new insights into designing new semiconductors for boosting photocatalytic performance in internal and external magnetic fields.
基金partly supported by projects from JSPS KAKENHI (Grant No. 18340167)MEXT KAKENHI (Grant No. 20103002)+2 种基金NSFC (Grand No.90914002)China Geological Survey (Grant No. 1212011220926)the Ministry of Education of China (Grant No. 20130022110003)
文摘Silicate perovskites（（Mg, Fe）SiO 3 and CaS iO 3） are believed to be the major constituent minerals in the lower mantle. The phase relation, solid solution, spin state of iron and water solubility related to the lower mantle perovskite are of great effect on the geodynamics of the Earth＇s interior and on ore mineralization. Previous studies indicate that a large amount of iron coupled with aluminum can incorporate into magnesium perovskite, but this is discordant with the disproportionation of（Mg,Fe）SiO 3 perovskite into iron-free MgS i O3 perovskite and hexagonal phase（Mg0.6Fe0.4）SiO 3 in the Earth＇s lower mantle. MnS iO 3 is the first chemical component confirmed to form wide range solid solution with Ca SiO 3 perovskite and complete solid solution with MgS i O3 perovskite at the P-T conditions in the lower mantle, and addition of Mn Si O3 will strongly affects the mutual solubility between Mg Si O3 and CaS iO 3. The spin state of iron is deeply depends on the site occupation of the Fe3＋or Fe2＋, the synthesis and the annealing conditions of the sample. It seems that the spin state of Fe2＋ in the lower mantle perovskite can be settled as high spin, however, the existence of intermediate spin or low spin state of Fe2＋ in perovskite has not been clarified. Moreover, different results have also been reported for the spin state of Fe3＋ in perovskite. The water solubility of the lower mantle perovskite is related with its composition. In pure Mg SiO 3 perovskite, only less than 500 ppm water was reported. Al–Mg Si O3 perovskite or Al–Fe–MgS iO 3 perovskite in the lower mantle accommodates water of 1100 to 1800 ppm. Further experiments are necessary to clarify the detailed conditions for perovskite solid solution, to reliably analyze the valence and spin states of iron in the coexisting iron-bearing phases, and to compare the water solubility of different phases at different layers for deeply understanding the geodynamics of the Earth＇s interior and ore mineralization.
基金supported by the National Natural Science Foundation of China (Grant No. 10804007)the Special Research Foundation and Development Program (Grant No. 200800041003)Research Funds of Beijing Jiaotong University (Grant No. 2007XM049)
文摘We investigate phase diffusion of a two-component Bose--Einstein condensates prepared initially in arbitrary coherent spin state ｜θ0,φ0｜. Analytical expression of the phase-diffusion time is presented for θ0～π/2 case. In comparison with the symmetrical case （i.e., θ0=π/2）, we find that the diffusion process becomes slow due to the reduced atom number variance.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.22178148,22278193,22075113)the Jiangsu Province and Education Ministry Co-Sponsored Synergistic Innovation Center of Modern Agricultural Equipment(Grant No.XTCX2029)+1 种基金a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX22_3691)。
文摘Owing to the distinctive structural characteristics,vanadium nitride(VN)is highly regarded as a catalyst for oxygen reduction reaction(ORR)in zinc-air batteries(ZABs).However,VN exhibits limited intrinsic ORR activity due to the weak adsorption ability to O-containing species.Here,the S-doped VN anchored on N,S-doped multi-dimensional carbon(S-VN/Co/NS-MC)was constructed using the solvothermal and in-situ doping methods.Incorporating sulfur atoms into VN species alters the electron spin state of vanadium in the S-VN/Co/NS-MC for regulating the adsorption energy of vanadium sites to oxygen molecules.The introduced sulfur atoms polarize the V 3d_(z)^(2) electrons,shifting spin-down electrons closer to the Fermi level in the S-VN/Co/NS-MC.Consequently,the introduction of sulfur atoms into VN species enhances the adsorption energy of vanadium sites for oxygen molecules.The*OOH dissociation transitions from being unspontaneous on the VN surface to a spontaneous state on the S-doped VN surface.Then,the ORR barrier on the S-VN/Co/NS-MC surface is reduced.The S-VN/Co/NS-MC demonstrates a higher half-wave potential and limiting current density compared to the VN/Co/N-MC.The S-VN/Co/NS-MC-based liquid ZABs display a power density of 195.7 m W cm^(-2),a specific capacity of 815.7 m A h g^(-1),and a cycling stability exceeding 250 h.The S-VN/Co/NS-MC-based flexible ZABs are successfully employed to charge both a smart watch and a mobile phone.This approach holds promise for advancing the commercial utilization of VN-based catalysts in ZABs.
基金Supported by the National Natural Science Foundation of China under No.61702427the Doctoral Program of Higher Education under Grant No.SWU115091+5 种基金the Fundamental Research Funds for the Central Universities(XDJK2018C048)the financial support in part by the 1000-Plan of Chongqing by Southwest University under No.SWU116007the National Natural Science Foundation of China under Grant No.61772437Sichuan Youth Science and Technique Foundation under No.2017JQ0048the National Natural Science Foundation of China under Grant No.61401371Josef Pieprzyk has been supported by National Science Centre,Poland,Project Registration Number UMO-2014/15/B/ST6/05130
文摘Since the use of a quantum channel is very expensive for transmitting large messages, it is vital to develop an effective quantum compression encoding scheme that is easy to implement. Given that, with the single-photon spin-orbit entanglement, we propose a quantum secret sharing scheme using orbital angular momentum onto multiple spin states based on Fibonacci compression encoding. In our proposed scheme, we can represent the frequency of any secret message which is typically collection of bits encodings of text or integers as a bitstring using the base Fibonacci sequence, which is encoded multiple spin states for secret shares transmitted to participants. We demonstrate that Fibonacci compression encoding carries excellent properties that enable us to achieve more robust quantum secret sharing schemes with fewer number of photons.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10974020 and 11174039)the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-11-0031)the Fundamental Research Funds for the Central Universities, China
文摘We propose a different entanglement concentration protocol （ECP） for nonlocal N-electron systems in a partially entangled Bell-type pure state using the CNOT gates and the projection measurements on an additional electron. For each nonlocal N-electron system, Alice first entangles it with the additional electron, and then she projects the additional electron onto an orthogonal basis for dividing the N-electron systems into two groups. In the first group, the N parties obtain a subset of N-electron systems in a maximally entangled state directly. In the second group, they obtain some less-entangled N-electron systems, which are the resource for the entanglement concentration in the next round. By iterating the entanglement concentration process several times, the present ECP has the maximal success probability, which is the theoretical limit of an ECP, equal to the entanglement of the partially entangled state, and higher than the others. This ECP may be useful in quantum computers based on electron-spin systems in the future.
基金supported by Russian Scientific Foundation (Grant No. 14-13-00139)
文摘Atomic and electronic structures of adsorbed nickel and vanadium atoms and nanoclusters （Nin and Vn, n = 1-10） on hexagonal h-BN and BC3 lattices were studied using DFT PBE/PBC/PW （Perdew-Burke- Ernzerhof potential of density functional theory/periodic boundary conditions/plane wave basis set） technique. For the sake of comparison the structure and properties of the same nanoclusters deposited on pristine graphene were calculated as well. It was found that for all types of supports an increase of n from 1 to 10 leaded to decrease of coordination types from 776 to r/2 and 771. The h-BN- and BC3-based nanocomposites were characterized by high （up to 18 μ for Ni10/BC3） magnetic moments of the nanoclusters and featured by positive binding energies. The graphene-based nanocomposites revealed energetic stability and, in general, lower magnetic moments per unit cell. The direct potential energy barriers for migration of Ni η2/η21 and η6/η6 types of dimers on graphene were low （10.9-28.9 kJ/mol） with high reverse barriers for η6/η6 dimers, which favored dynamically equilibrated Ni clusterization on graphene.
基金supported by the National Natural Science Foundation of China (10575092)the Natural Science Foundation of Zhejiang Province (R104265)
文摘Perovskite oxide La1-xSrxCoO3（0≤x≤0.5） series were prepared and effect of oxygen annealing on crystal structure and magnetic susceptibility were studied.High-temperature susceptibility could be well fitted by Curie-Weiss law for all Sr-doped samples.Weiss constant and effective magnetic moment were determined, and their variations with Sr doping and oxygen annealing condition were obtained.The result suggested that by assuming that the Co3＋ ions were in the intermediate-spin（IS） state, most of the Co4＋ ions in the as-prepared samples might be in the high-spin（HS） state, but both the Co3＋ and Co4＋ ions might be in the IS state after oxygen annealing, which indicated that annealing in flowing oxygen could cause transition of the spin state of Co4＋ ions from the HS state to IS state.
基金supported by National Natural Science Foundation of China (Nos. 10975082, 10775078)the Major State Basic Research Development Program of China (No. 2007CB815005)the Special Program of Higher Education Science Foundation of China (No. 20070003149)
文摘The high-spin states of 141pro nucleus have been studied by using in-beam v-ray spectroscopy technology through the126Te（19F, 4n） reaction at a beam energy of 90 MeV. The previous level scheme has been extended with spin up to 49/2 h. Many new levels and transitions are identified. Five collective band structures are observed. Based on systematic comparison with the neighboring nuclei, two bands with strong AI = 1 M1 transitions inside the bands are proposed as the oblate bands with γ--60°, and three bands with large signature splitting have been suggested as the oblate-triaxial deformation with γ--90°. The characteristics for these bands have been discussed.
基金the National Natural Science Foundation of China(Nos.52271011,52102291).
文摘Carbon nanofibers(CNFs)have received extensive and in-depth studied as anodes for sodium-ion batteries(SIBs),and yet their initial Coulombic efficiency and rate capability remain enormous challenge at practical level.Herein,CNFs anchored with cobalt nanocluster(CNFs-Co)were prepared using chemical vapor deposition and thermal reduction methods.The as-prepared CNFs-Co shows a high initial Coulombic efficiency of 91%and a high specific discharge capacity of 246 mAh/g at 0.1 A/g after 200 cycles as anode for SIBs.Meanwhile,the CNFs-Co anode still delivers a high cycling stability with 108 mAh/g after 1000 cycles at 10 A/g.These excellent electrochemical properties could be attributed to the involved spin state Co,which endows CNFs with large interplanar spacing(0.39 nm)and abundant vacancy defects.Importantly,the spin state Co downshifts the p-band center of carbon and strengthens the Na+adsorption energy from-2.33 eV to-2.64 eV based on density functional theory calculation.This novel strategy of modulating the carbon electronic structure by the spin state of magnetic metals provides a reference for the development of high-performance carbon-based anode materials.
基金Supported by the National Natural Science Foundation of China(21272167)Natural Science Foundation of Jiangsu Province(BK20171213)+1 种基金the Innovation of Graduate Student Training Project of Jiangsu Province(KYLX16_0109)the Priority Academic Program Development of Jiangsu Higher Education Institution
文摘Four complexes of compositions [Fe2（L^1）2]（1）, [Ni2（L^1）2]（2）, [Ni2（L^2）2]（3） and [Cu2（L^2）2]（4）（H2L^1 = 1-（（（2-hydroxy-2,3-dihydro-1 H-inden-1-yl）imino）methyl）naphthalen-2-ol, H2L^2 = 4-（（2-hydroxy-2,3-dihydro-1 H-inden-1-yl）imino）pentan-2-one） were synthesized under solvothermal conditions. The structures of 1~4 were characterized by X-ray single-crystal diffraction analysis. The magnetic properties of these four complexes are investigated. The dc magnetic measurements indicate that the metal ions of 1, 2 and 3 are in the low spin state, revealing the strong ligand field character of 1-amino-2-indanol. This work provides an effective approach to coordination complexes possessing low spin state metal centers.
基金supported by the National Natural Science Foundation of China(21801090,21831003 and 21621001)the Jilin Scientific and Technological Development Program(20200802003GH)+2 种基金the Scientific Research Project in the Education Department of Jilin Province(JJKH20211044KJ)the Project on Experimental Technique of Jilin University(409020720202)supported by Users with the Excellence Program of Hefei Science Center CAS(2020HSC-UE002)。
文摘The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we developed a spin-state and delocalized electron regulation method to optimize oxygen evolution reaction(OER)performance by in-situ growth of NiCo_(2)(OH)_(x) using Oswald ripening and coordinating etching process on MXene and plasma treatment.X-ray absorption spectroscopy,magnetic tests and electron paramagnetic resonance reveal that the coupling of NiCo_(2)(OH)_(x) and MXene can induce remarkable spin-state transition of Co^(3+)and transition metal ions electron delocalization,plasma treatment further optimizes the 3 d orbital structure and delocalized electron density.The unique Jahn-Teller phenomenon can be brought by the intermediate spin state(t2 _(g)^(5) e_(g)^(1))of Co^(3+),which benefits from the partial electron occupied egorbitals.This distinct electron configuration(t2_(g)^(5) e_(g)^(1))with unpaired electrons leads to orbital degeneracy,that the adsorption free energy of intermediate species and conductivity were further optimized.The optimized electrocatalyst exhibits excellent OER activity with an overpotential of 268 m V at 10 m A cm^(-2).DFT calculations show that plasma treatment can effectively regulate the d-band center of TMs to optimize the adsorption and improve the OER activity.This approach could guide the rational design and discovery of electrocatalysts with ideal electron configurations in the future.
