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Tuning electronic structure of RuO_(2)by single atom Zn and oxygen vacancies to boost oxygen evolution reaction in acidic medium 被引量:1
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作者 Qing Qin Tiantian Wang +7 位作者 Zijian Li Guolin Zhang Haeseong Jang Liqiang Hou Yu Wang Min Gyu Kim Shangguo Liu Xien Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期94-102,I0003,共10页
The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct ... The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER. 展开更多
关键词 ELECTROCATALYST Acidic oxygen evolution reaction Electronic structure engineering DURABILITY Reaction barrier
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Tuning the surface electronic structure of noble metal aerogels to promote the electrocatalytic oxygen reduction
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作者 Hongxing Yuan Wei Gao +2 位作者 Xinhao Wan Jianqi Ye Dan Wen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期557-564,I0013,共9页
The sluggish kinetics of the oxygen reduction reaction(ORR)is the bottleneck for various electrochemical energy conversion devices.Regulating the electronic structure of electrocatalysts by ligands has received partic... The sluggish kinetics of the oxygen reduction reaction(ORR)is the bottleneck for various electrochemical energy conversion devices.Regulating the electronic structure of electrocatalysts by ligands has received particular attention in deriving valid ORR electrocatalysts.Here,the surface electronic structure of Ptbased noble metal aerogels(NMAs)was modulated by various organic ligands,among which the electron-withdrawing ligand of 4-methylphenylene effectively boosted the ORR electrocatalysis.Theoretical calculations suggested the smaller energy barrier for the transformation of O^(*) to OH^(*) and downshift the d-band center of Pt due to the interaction between 4-methylphenylene and the surface metals,thus enhancing the ORR intrinsic activity.Both Pt3Ni and Pt Pd aerogels with 4-methylphenylene decoration performed significant enhancement in ORR activity and durability in different media.Remarkably,the 4-methylphenylene modified Pt Pd aerogel exhibited the higher halfwave potential of 0.952 V and the mass activity of 10.2 times of commercial Pt/C.This work explained the effect of electronic structure on ORR electrocatalytic properties and would promote functionalized NMAs as efficient ORR electrocatalysts. 展开更多
关键词 Noble metal aerogels Surface electronic structure ORR ELECTROCATALYST Organic ligands
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Electronic structure and spin state regulation of vanadium nitride via a sulfur doping strategy toward flexible zinc-air batteries
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作者 Daijie Deng Honghui Zhang +6 位作者 Jianchun Wu Xing Tang Min Ling Sihua Dong Li Xu Henan Li Huaming Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期239-249,I0007,共12页
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
关键词 S-doped VN Electronic structures Spin state regulation Oxygen reduction reaction Zinc-air batteries
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Mechanical Properties and Electronic Structures of M(M=Ti,V,Cr,Mn and Fe)Dopedβ-Si_(3)N_(4) from First-Principle
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作者 龙敏 黄福祥 +4 位作者 XU Liangyu LI Xuemei YANG Zhou LENG Yue MEI Shini 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期639-644,共6页
The structures,mechanical properties and electronic structures of M metals(M=Ti,V,Cr,Mn and Fe)dopedβ-Si_(3)N_(4) were investigated by First-principles calculations within CASTEP.The calculated lattice parameters of... The structures,mechanical properties and electronic structures of M metals(M=Ti,V,Cr,Mn and Fe)dopedβ-Si_(3)N_(4) were investigated by First-principles calculations within CASTEP.The calculated lattice parameters ofβ-Si_(3)N_(4) were consistent with previous date.The cohesive energy and formation enthalpy show that initialβ-Si_(3)N_(4) has the highest structural stability.The calculated elastic constant and the Voigt-Reuss-Hill approximation indicate that elastic moduli ofβ-Si_(3)N_(4) are slightly reduced by M doping.Based on Poisson’s and Pugh’s ratio,β-Si_(3)N_(4) is a ductile material and the toughness ofβ-Si_(3)N_(4) increases with M doping,and Fe doping exhibited the best toughness.The results of density of states,charge distributions and overlapping populations indicate thatβ-Si_(3)N_(4) has the strong covalent and ionic bond strength between N and Si. 展开更多
关键词 first-principles β-Si_(3)N_(4) mechanical properties electronic structure
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Geometries and electronic structures of Zr_(n)Cu(n=2–12) clusters: A joint machine-learning potential density functional theory investigation
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作者 王一志 崔秀花 +3 位作者 刘静 井群 段海明 曹海宾 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期595-602,共8页
Zr-based amorphous alloys have attracted extensive attention because of their large glassy formation ability, wide supercooled liquid region, high elasticity, and unique mechanical strength induced by their icosahedra... Zr-based amorphous alloys have attracted extensive attention because of their large glassy formation ability, wide supercooled liquid region, high elasticity, and unique mechanical strength induced by their icosahedral local structures.To determine the microstructures of Zr–Cu clusters, the stable and metastable geometry of Zr_(n)Cu(n=2–12) clusters are screened out via the CALYPSO method using machine-learning potentials, and then the electronic structures are investigated using density functional theory. The results show that the Zr_(n)Cu(n ≥ 3) clusters possess three-dimensional geometries, Zr_(n)Cu(n≥9) possess cage-like geometries, and the Zr_(12)Cu cluster has icosahedral geometry. The binding energy per atom gradually gets enlarged with the increase in the size of the clusters, and Zr_(n)Cu(n=5,7,9,12) have relatively better stability than their neighbors. The magnetic moment of most Zr_(n)Cu clusters is just 1μB, and the main components of the highest occupied molecular orbitals(HOMOs) in the Zr_(12)Cu cluster come from the Zr-d state. There are hardly any localized two-center bonds, and there are about 20 σ-type delocalized three-center bonds. 展开更多
关键词 geometries and electronic structures magnetic and chemical bonds machine learning potentials Zr–Cu clusters
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Structure,electronic,and nonlinear optical properties of superalkaline M_(3)O(M=Li,Na)doped cyclo[18]carbon
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作者 刘晓东 卢其亮 罗其全 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期311-317,共7页
Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an ef... Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an effective method to improve the optical properties of the system because considerable electron transfer occurs.In this paper,the geometry,bonding properties,electronic structure,absorption spectrum,and nonlinear optical(NLO)properties of superalkaline M_(3)O(M=Li,Na)-doped cyclo[18]carbon were studied by using density functional theory.M_(3)O and the C_(18) rings are not coplanar.The C_(18) ring still exhibits alternating long and short bonds.The charge transfer between M_(3)O and C_(18) forms stable[M_(3)O]+[C_(18)]-ionic complexes.C_(18)M_(3)O(M=Li,Na)shows striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm and 1460 nm. 展开更多
关键词 superalkaline doped carbon structure and electronic properties nonlinear optical properties density functional theory(DFT)
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Tuning the electronic structure of a metal-organic framework for an efficient oxygen evolution reaction by introducing minor atomically dispersed ruthenium 被引量:1
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作者 Yuwen Li Yuhang Wu +5 位作者 Tongtong Li Mengting Lu Yi Chen Yuanjing Cui Junkuo Gao Guodong Qian 《Carbon Energy》 SCIE CSCD 2023年第2期61-71,共11页
The establishment of efficient oxygen evolution electrocatalysts is of great value but also challenging.Herein,a durable metal–organic framework(MOF)with minor atomically dispersed ruthenium and an optimized electron... The establishment of efficient oxygen evolution electrocatalysts is of great value but also challenging.Herein,a durable metal–organic framework(MOF)with minor atomically dispersed ruthenium and an optimized electronic structure is constructed as an efficient electrocatalyst.Significantly,the obtained NiRu_(0.08)-MOF with doping Ru only needs an overpotential of 187 mV at 10 mA cm^(-2) with a Tafel slop of 40 mV dec^(-1) in 0.1M KOH for the oxygen evolution reaction,and can work continuously for more than 300 h.Ultrahigh Ru mass activity is achieved,reaching 56.7 Ag^(-1)_(Ru) at an overpotential of 200 mV,which is 36 times higher than that of commercial RuO_(2).X-ray adsorption spectroscopy and density function theory calculations reveal that atomically dispersed ruthenium on metal sites in MOFs is expected to optimize the electronic structure of nickel sites,thus improving the conductivity of the catalyst and optimizing the adsorption energy of intermediates,resulting in significant optimization of electrocatalytic performance.This study could provide a new avenue for the design of efficient and stable MOF electrocatalysts. 展开更多
关键词 ELECTROCATALYSIS electronic structure metal-organic framework oxygen evolution reaction
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Rapid Expansion of China's Electronics Industry Towards a Rational Structure
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《China's Foreign Trade》 1999年第4期23-23,共1页
关键词 RATIONAL Rapid Expansion of China’s electronics Industry Towards a Rational structure
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Electronic structure study of the charge-density-wave Kondo lattice CeTe_(3)
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作者 王博 周锐 +2 位作者 罗学兵 张云 陈秋云 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期414-421,共8页
The behaviors of f electrons are crucial for understanding the rich phase diagrams and ground-state properties of heavy fermion(HF)systems.The complicated interactions between f electrons and conduction electrons larg... The behaviors of f electrons are crucial for understanding the rich phase diagrams and ground-state properties of heavy fermion(HF)systems.The complicated interactions between f electrons and conduction electrons largely enrich the basic properties of HF compounds.Here the electronic structure,especially the f-electron character,of the charge-density-wave(CDW)Kondo lattice compound CeTe_(3)has been studied by high-resolution angle-resolved photoemission spectroscopy.A weakly dispersive quasiparticle band near the Fermi level has been observed directly,indicating hybridization between f electrons and conduction electrons.Temperature-dependent measurements confirm the localized to itinerant transition of f electrons as the temperature decreases.Furthermore,an energy gap formed by one conduction band at low temperature is gradually closed with increasing temperature,which probably originates from the CDW transition at extremely high temperature.Additionally,orbital information of different electrons has also been acquired with different photon energies and polarizations,which indicates the anisotropy and diverse symmetries of the orbitals.Our results may help understand the complicated f-electron behaviors when considering its interaction with other electrons/photons in CeTe_(3)and other related compounds. 展开更多
关键词 4f-electron CHARGE-DENSITY-WAVE electronic structure angle-resolved photoemission spectroscopy
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Intrinsic electronic structure and nodeless superconducting gap of YBa_(2)Cu_(3)O_(7)-σ observed by spatially-resolved laser-based angle resolved photoemission spectroscopy
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作者 李帅帅 苗泰民 +17 位作者 殷超辉 李颖昊 闫宏涛 陈逸雯 梁波 陈浩 朱文培 张申金 王志敏 张丰丰 杨峰 彭钦军 林成天 毛寒青 刘国东 许祖彦 赵林 周兴江 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期263-268,共6页
The spatially-resolved laser-based high-resolution angle resolved photoemission spectroscopy(ARPES) measurements have been performed on the optimally-doped YBa_(2)Cu_(3)O_(7)-σ(Y123) superconductor. For the first tim... The spatially-resolved laser-based high-resolution angle resolved photoemission spectroscopy(ARPES) measurements have been performed on the optimally-doped YBa_(2)Cu_(3)O_(7)-σ(Y123) superconductor. For the first time, we found the region from the cleaved surface that reveals clear bulk electronic properties. The intrinsic Fermi surface and band structures of Y123 were observed. The Fermi surface-dependent and momentum-dependent superconducting gap was determined which is nodeless and consistent with the d+is gap form. 展开更多
关键词 YBCO angle resolved photoemission spectroscopy electronic structure superconducting gap
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Pressure-induced phase transition and electronic structure evolution in layered semimetal HfTe_(2)
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作者 张美光 陈磊 +4 位作者 冯龙 拓换换 张云 魏群 李培芳 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第8期349-354,共6页
Motivated by the recent experimental work,the pressure-induced structural transition of well-known two-dimensional(2D)1T-Hf Te_(2)was investigated up to 50 GPa through the advanced CALYPSO structure search technique c... Motivated by the recent experimental work,the pressure-induced structural transition of well-known two-dimensional(2D)1T-Hf Te_(2)was investigated up to 50 GPa through the advanced CALYPSO structure search technique combined with the first-principles calculations.Our calculations suggested that the 1T-Hf Te_(2)will first transform to C2/m phase at 3.6 GPa with a volume reduction of 7.6%and then to P62m phase at 9.6 GPa with a volume collapse of 4.6%.The occurrences of 3D C2/m and P62m phases mainly originated from the enhanced Te-Te interlayer coupling and the drastic distortions of Hf-Te polyhedrons in P3m1 phase under compression.Concomitantly,the coordination number of Hf atoms increased from six in P3m1 to eight in C2/m and eventually to nine in P62m at elevated pressure.The metallic and semimetallic nature of C2/m and P62m phases were characterized,and the evidence of the reinforced covalent interactions of Te-Hf and Te-Te orbitals in these two novel high-pressure phases were manifested by the atom-projected electronic DOS and Bader charge. 展开更多
关键词 transition metal dichalcogenides pressure-induced phase transition crystal structure electronic structure
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Elucidating the promotion mechanism of the ternary cooperative heterostructure toward industrial-level urea oxidation catalysis
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作者 Xiujuan Xu Xiaotong Wei +2 位作者 Liangliang Xu Minghua Huang Arafat Toghan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第10期116-125,I0005,共11页
From the perspective of electronic structure modulation,it is highly desirable to rationally design the active urea oxidation reaction(UOR)catalysts through interface engineering.The binary cooperative heterostructure... From the perspective of electronic structure modulation,it is highly desirable to rationally design the active urea oxidation reaction(UOR)catalysts through interface engineering.The binary cooperative heterostructure systems have been shown significant enhancement for catalyzing UOR,but their performance still remains unsatisfactory for industrialization because of the unfavorable intermediate adsorption/desorption and deficient electron transfer channels.In response,taking the ternary cooperative Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure as the proof-of-concept paradigm,a catalytic model is rationally put forward to elucidate the UOR promotion mechanism at the molecular level.The rod-like Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) nanoarrays with three-phase heterojunction are experimentally fabricated on Ni foam(named as Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF)via simple two-step processes.The density functional theory calculations disclose that construction of Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4) heterostructure model not only induce charge redistribution at the interfacial region for creating innumerable electron transfer channels,but also endow it with a moderate d-band center that could help to build a balance between adsorption and desorption of diverse UOR intermediates.Benefiting from the unique rod-like nanoarrays with large specific surface area and the optimized electronic structure,the well-designed Ni_5P_(4)/NiSe_(2)/Ni_(3)Se_(4)/NF could act as a robust catalyst for driving UOR at industrial-level current densities under tough environments,offering great potential for commercial applications. 展开更多
关键词 Urea oxidation reaction Ternary cooperative heterostructure Electronic structure Interface engineering
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Predicting novel atomic structure of the lowest-energy Fe_(n)P_(13-n)(n=0-13)clusters:A new parameter for characterizing chemical stability
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作者 蒋元祺 彭平 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期574-581,共8页
A series of novel atomic structure of lowest-energy Fe_(n)P_(13-n)(n=0-13)clusters via density functional theory(DFT)calculations and an unbiased structure search using Crystal structure AnaLYsis by Particle Swarm Opt... A series of novel atomic structure of lowest-energy Fe_(n)P_(13-n)(n=0-13)clusters via density functional theory(DFT)calculations and an unbiased structure search using Crystal structure AnaLYsis by Particle Swarm Optimization(CALYPSO)code.Our research results show that the global minimum geometry structure of neutral Fe_(13-n)P_(n)(n=0-6)clusters tend to form cage structures but the lowest-energy Fe_(13-n)P_(n)(n=7-13)clusters are gradually evolution from a cage structure to a chain shape geometric structure.Their geometric structure should responsible for the raise of binding energy from Fe_7P_(6)to P_(13)clusters rather than chemical components.This is completely different from a linear relation of the binding energy with chemical components in our previous research for Cu_(n)Zr_(13-n)(n=3-10)clusters(J.Mol.Liq.343117603(2021)).Hence,in order to characterize the global chemical stability of target cluster,we proposed a new parameter(jyq=η/χ)that the chemical hardness of isolated cluster is used to be divided by its electronegativity.One of the biggest advantages of this parameter is successful coupling the ability of a resistance to redistribution of electrons and the ability to attract electrons from other system(such as atom,molecular or metallic clusters).Moreover,it is found that the P_(13)cluster shows typical insulator characteristics but the Fe_(12)P_(1)shows typical conductor characteristics,which phenomena can be attributed to the remarkable delocalized and localized electrons in Fe_(12)P_(1)and P_(13),respectively.In terms of nearly-free-electron mode,we also found that the number of electrons on Femi level(N(E_F))are obviously tended to toward a lower value when Fe was replaced gradually with P from Fe_(13)to P_(13),and a non-magnetic can be observed in Fe_(13),Fe_(2)P_(11),Fe_(1)P_(12),and P_(13)that mainly because their perfect symmetrical between spin-up and spin-down of density of states of electrons. 展开更多
关键词 Fe-P cluster density functional theory(DFT) ground-state structure electronic structure
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Probing electronic structures of transition metal complexes using electron paramagnetic resonance spectroscopy
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作者 Shengfa Ye 《Magnetic Resonance Letters》 2023年第1期43-60,I0003,共19页
Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,h... Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,how to extract the underlying electronicstructure information inevitably poses a major challenge to beginners,in particular for systems with S>1/2.In fact,the physical principles of transition metal EPR have long been well-established and since 1970s a series of dedicated voluminous monographs have been published already.Not surprisingly,they are not appropriate stating points for novices to grasp a panorama of the profound theory prior to scrutinizing in-depth references.The present review aims to fill this gap to provide a perspective of transition metal EPR and unveil some peculiar subtleties thereof on the basis of our recent work. 展开更多
关键词 EPR Electronic structures Transition metal complexes Spin Hamiltonian
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An Electron Model Based on the Fine Structure Constant
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作者 Arlen Young 《Journal of Modern Physics》 CAS 2023年第5期553-561,共9页
In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed ... In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed to resolve the electron’s charge and mass inconsistencies. That model is modified in this document by assuming the electron’s radius is exactly equal to the classical electron radius. The attributes of the internal components of the electron’s structure have been recalculated accordingly. The shape of the electron is also predicted, and found to be slightly aspherical on the order of an oblate ellipsoid. This shape is attributed to centrifugal force and compliant outer shell material. It is interesting to note that all of the electron’s attributes, both external and internal, with the exception of mass and angular moment, are functions of the fine structure constant a, and can be calculated from just three additional constants: electron mass, Planck’s constant, and speed of light. In particular, the ratios of the outer shell charge and mass to the electron charge and mass, respectively, are 3/2a. The ratios of the central core charge and mass to the electron charge and mass, respectively, are 1-(3/2a). Attributes of the electron are compared with those of the muon. Charge and spin angular momentum are the same, while mass, magnetic moment, and radius appear to be related by the fine structure constant. The mass of the electron outer shell is nearly equal to the mass of the muon. The muon internal structure can be modeled exactly the same as for the electron, with exactly the same attribute relationships. 展开更多
关键词 Fine structure Constant Negative Mass Electron Shape Electron structure Electron Mass Inconsistency Electron Charge Inconsistency MUON
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Study of the Electronic Structure and Optical Properties of Rare Earth Luminescent Materials
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作者 Chengxi Zhang 《Journal of Materials Science and Chemical Engineering》 2023年第10期8-18,共11页
Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properti... Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging. 展开更多
关键词 Rare Earth Luminescent Materials Electronic structure Optical Properties Luminescence Mechanism Prospects for Applications
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Understanding Bridging Sites and Accelerating Quantum Efficiency for Photocatalytic CO_(2) Reduction
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作者 Kangwang Wang Zhuofeng Hu +8 位作者 Peifeng Yu Alina M.Balu Kuan Li Longfu Li Lingyong Zeng Chao Zhang Rafael Luque Kai Yan Huixia Luo 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期68-84,共17页
We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in... We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR. 展开更多
关键词 Quantum efficiency Electronic structure Steric interaction Bridging sites CO_(2)reduction
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Strongly Coupled Ag/Sn-SnO_(2)Nanosheets Toward CO_(2)Electroreduction to Pure HCOOH Solutions at Ampere‑Level Current
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作者 Min Zhang Aihui Cao +5 位作者 Yucui Xiang Chaogang Ban Guang Han Junjie Ding Li‑Yong Gan Xiaoyuan Zhou 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期212-226,共15页
Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance... Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance electrocatalysts.Herein,we elaborately design and develop strongly coupled nanosheets composed of Ag nanoparticles and Sn-SnO_(2) grains,designated as Ag/Sn-SnO_(2) nanosheets(NSs),which possess optimized electronic structure,high electrical conductivity,and more accessible sites.As a result,such a catalyst exhibits unprecedented catalytic performance toward CO_(2)-to-formate conversion with near-unity faradaic efficiency(≥90%),ultrahigh partial current density(2,000 mA cm^(−2)),and superior long-term stability(200 mA cm^(−2),200 h),surpassing the reported catalysts of CO_(2) electroreduction to formate.Additionally,in situ attenuated total reflection-infrared spectra combined with theoretical calculations revealed that electron-enriched Sn sites on Ag/Sn-SnO_(2)NSs not only promote the formation of*OCHO and alleviate the energy barriers of*OCHO to*HCOOH,but also impede the desorption of H*.Notably,the Ag/Sn-SnO_(2)NSs as the cathode in a membrane electrode assembly with porous solid electrolyte layer reactor can continuously produce~0.12 M pure HCOOH solution at 100 mA cm^(−2)over 200 h.This work may inspire further development of advanced electrocatalysts and innovative device systems for promoting practical application of producing liquid fuels from CO_(2). 展开更多
关键词 Electrochemical CO_(2)reduction Coupled Ag/Sn-SnO_(2)nanosheets Electronic structure Porous solid electrolyte PURE
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Optical manipulation of the topological phase in ZrTe_(5) revealed by time-and angle-resolved photoemission
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作者 黄超之 徐骋洋 +8 位作者 朱锋锋 段绍峰 刘见喆 顾凌霄 王石崇 刘浩然 钱冬 罗卫东 张文涛 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期170-175,共6页
High-resolution time-and angle-resolved photoemission measurements were conducted on the topological insulator ZrTe_(5).With strong femtosecond photoexcitation,a possible ultrafast phase transition from a weak to a st... High-resolution time-and angle-resolved photoemission measurements were conducted on the topological insulator ZrTe_(5).With strong femtosecond photoexcitation,a possible ultrafast phase transition from a weak to a strong topological insulating phase was experimentally realized by recovering the energy gap inversion in a time scale that was shorter than 0.15 ps.This photoinduced transient strong topological phase can last longer than 2 ps at the highest excitation fluence studied,and it cannot be attributed to the photoinduced heating of electrons or modification of the conduction band filling.Additionally,the measured unoccupied electronic states are consistent with the first-principles calculation based on experimental crystal lattice constants,which favor a strong topological insulating phase.These findings provide new insights into the longstanding controversy about the strong and weak topological properties in ZrTe_(5),and they suggest that many-body effects including electron–electron interactions must be taken into account to understand the equilibrium weak topological insulating phase in ZrTe_(5). 展开更多
关键词 time-and angle-resolved photoemission spectroscopy electronic structure topological insulator
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Decade Milestone Advancement of Defect-Engineered g-C_(3)N_(4) for Solar Catalytic Applications
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作者 Shaoqi Hou Xiaochun Gao +8 位作者 Xingyue Lv Yilin Zhao Xitao Yin Ying Liu Juan Fang Xingxing Yu Xiaoguang Ma Tianyi Ma Dawei Su 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第4期153-218,共66页
Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is stil... Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is still confronted with a general fatal issue of insufficient supply of thermodynamically active photocarriers due to its inferior solar harvesting ability and sluggish charge transfer dynamics. Fortunately, this could be significantly alleviated by the “all-in-one” defect engineering strategy, which enables a simultaneous amelioration of both textural uniqueness and intrinsic electronic band structures. To this end, we have summarized an unprecedently comprehensive discussion on defect controls including the vacancy/non-metallic dopant creation with optimized electronic band structure and electronic density, metallic doping with ultraactive coordinated environment(M–N_(x), M–C_(2)N_(2), M–O bonding), functional group grafting with optimized band structure, and promoted crystallinity with extended conjugation π system with weakened interlayered van der Waals interaction. Among them, the defect states induced by various defect types such as N vacancy, P/S/halogen dopants, and cyano group in boosting solar harvesting and accelerating photocarrier transfer have also been emphasized. More importantly, the shallow defect traps identified by femtosecond transient absorption spectra(fs-TAS) have also been highlighted. It is believed that this review would pave the way for future readers with a unique insight into a more precise defective g-C_(3)N_(4) “customization”, motivating more profound thinking and flourishing research outputs on g-C_(3)N_(4)-based photocatalysis. 展开更多
关键词 Defect engineering g-C_(3)N_(4) Electronic band structures Photocarrier transfer kinetics Defect states
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