By simplifying catalyst-product separation and reducing phosphorus waste,heterogeneous hydroformylation offers a more sustainable alternative to homogeneous processes.However,heterogeneous hydroformylation catalysts d...By simplifying catalyst-product separation and reducing phosphorus waste,heterogeneous hydroformylation offers a more sustainable alternative to homogeneous processes.However,heterogeneous hydroformylation catalysts developed thus far still suffer from the issues of much lower activity and metal leaching,which severely hinder their practical application.Here,we demonstrate that incorporating phosphorus(P)atoms into graphitic carbon nitride(PCN)supports facilitates charge transfer from Rh to the PCN support,thus largely enhancing electronic metal-support interactions(EMSIs).In the styrene hydroformylation reaction,the activity of Rh_(1)/PCN single-atom catalysts(SACs)with varying P contents exhibited a volcano-shaped relationship with P doping,where the Rh_(1)/PCN SAC with optimal P doping showed exceptional activity,approximately 5.8-and 3.3-fold greater than that of the Rh_(1)/g-C_(3)N_(4)SAC without P doping and the industrial homogeneous catalyst HRh(CO)(PPh_(3))_(3),respectively.In addition,the optimal Rh_(1)/PCN SAC catalyst also demonstrated largely enhanced multicycle stability without any visible metal aggregation owing to the increased EMSIs,which sharply differed from the severe metal aggregation of large nanoparticles on the Rh_(1)/g-C_(3)N_(4)SAC.Mechan-istic studies revealed that the enhanced catalytic performance could be attributed to electron-deficient Rh species,which reduced CO adsorption while simultaneously promoting alkene adsorption through increased EMSIs.These findings suggest that tuning EMSIs is an effective way to achieve SACs with high activity and durability.展开更多
The notorious shuttle effect of polyiodides in aqueous Zinc-iodine(Zn-I2)batteries impedes their practical application,which renders it imperative to address this issue.Here,we report natural gelatin as an advanced aq...The notorious shuttle effect of polyiodides in aqueous Zinc-iodine(Zn-I2)batteries impedes their practical application,which renders it imperative to address this issue.Here,we report natural gelatin as an advanced aqueous binder for iodine-loading cathode to enable stable and efficient Zn-I_(2) batteries.The positively charged region in gelatin presents electrostatic attraction to the iodine species,while the electron-rich regions could donate electrons to form physical or even covalent bonds with iodine species,thus inhibiting polyiodides shuttle effect and boosting redox reaction.A high reversible capacity of 138 mAh g^(-1) after 3000 cycles at 2C and an ultra-long cycling stability of 30000 cycles at 25C with 107 mAh g^(-1) capacity was achieved.Gelatin binder also can accommodate high iodine-loading(~10 mg)cathode,punch cells,and severe temperature conditions(-10℃ and 60℃).In-situ UV-vis absorption spectroscopy,in-situ Raman spectra and theoretical calculation revealed the critical role of gelatin binder in suppressing polyiodide shuttling and accelerating reaction kinetics.This work uncovers the potential of natural low-cost binder material in advanced Zn-I_(2) batteries and drives future study of designing functional binders.展开更多
We explored a distinct mechanism for matter creation via electron-positron pair production during bound-bound transitions in the deexcitation of muonic atoms.For ions with nuclear charges Z≥24,transitions from low-ly...We explored a distinct mechanism for matter creation via electron-positron pair production during bound-bound transitions in the deexcitation of muonic atoms.For ions with nuclear charges Z≥24,transitions from low-lying excited states to the 1s-muon state can lead to the production of electron-positron pairs.We show that the Breit interaction determines the transition probabilities for states with nonzero orbital momentum.We show that the pair production arises mainly from the decay of the 2p states.Thus,the Breit interaction governs electron-positron pair production in bound-bound muon transitions.This process offers a unique opportunity to explore quantum electrodynamics in strong fields,as well as a class of nonradiative transitions involving electron-positron pair production.展开更多
A series of“half-sandwich”bis(imino)pyridyl iron complexes with a substituted 8-(p-Xphenyl)naphthylamine(X=OMe,Me,CF3)was designed and synthesized by combining weakπ-πinteraction with steric and electronic tunings...A series of“half-sandwich”bis(imino)pyridyl iron complexes with a substituted 8-(p-Xphenyl)naphthylamine(X=OMe,Me,CF3)was designed and synthesized by combining weakπ-πinteraction with steric and electronic tunings.The weak noncovalentπ-πinteraction as well as the steric and electronic effects of bis(imino)pyridyl iron complexes were identified by experimental analyses and calculations.The roles of weakπ-πinteraction,steric bulk,and electronic tuning on the ethylene polymerization performance of bis(imino)pyridyl iron catalysts were studied in detail.The combination ofπ-πinteraction with steric and electronic tunings can access to thermally stable bis(imino)pyridyl iron at 130°C.展开更多
A novel Cu-t-ZrO_(2)catalyst with enhanced electronic metal-support interaction(EMSI)is designed for efficient electrocatalytic conversion of nitrate(NO_(3^(-)))to ammonia(NH_(3)),achieving a remarkable Faradaic effic...A novel Cu-t-ZrO_(2)catalyst with enhanced electronic metal-support interaction(EMSI)is designed for efficient electrocatalytic conversion of nitrate(NO_(3^(-)))to ammonia(NH_(3)),achieving a remarkable Faradaic efficiency and yield rate of 97.54%and 33.64 mg h^(-1)mg_(cat)^(-1),respectively.Electrons are more likely to be transferred from Cu to t-ZrO_(2)at the electron-rich interface due to the lower work function,which promotes the formation of highly active Cu species and facilitates NO_(3^(-))adsorption,ensuring selective conversion into NH_(3).展开更多
The electron localization is considered as a promising approach to optimize electromagnetic waves(EMW)dissipation.However,it is still difficult to realize well-controlled electron localization and elucidate the relate...The electron localization is considered as a promising approach to optimize electromagnetic waves(EMW)dissipation.However,it is still difficult to realize well-controlled electron localization and elucidate the related EMW loss mechanisms for current researches.In this study,a novel two-dimensional MXene(Ti_(3)C_(2)T_(x))nanosheet decorated with Ni nanoclusters(Ni-NC)system to construct an effective electron localization model based on electronic orbital structure is explored.Theoretical simulations and experimental results reveal that the metal-support interaction between Ni-NC and MXene disrupts symmetric electronic environments,leading to enhanced electron localization and dipole polarization.Additionally,Ni-NC generate a strong interfacial electric field,strengthening heterointerface interactions and promoting interfacial polarization.As a result,the optimized material achieves an exceptional reflection loss(RLmin)of-54 dB and a broad effective absorption bandwidth of 6.8 GHz.This study offers critical insights into the in-depth relationship between electron localization and EMW dissipation,providing a pathway for electron localization engineering in functional materials such as semiconductors,spintronics,and catalysis.展开更多
The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric ...The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric geometry at impact energy of 2.5 keV plus binding energy. The ionization bands have been assigned in detail via the high accuracy SACCI general-R method calculation and the experimental momentum profiles are compared with the theoretical ones calculated by Hartree-Fock and B3LYP/aug-cc-pVTZ（C,H）6-311G？？（I）. The spin-orbit coupling effect and intramolecular orbital interaction have been analyzed for the outermost two bands, which are assigned to the iodine 5p lone pairs, using NBO method and non-relativistic as well as relativistic calculations. It is found that both of the interactions will lead to the observed differences in electron momentum distributions. The experimental results agree with the relativistic theoretical momentum profiles, indicating that the spin-orbit coupling effect dominates in n-propyl iodide molecule.展开更多
The efficiency of electrochemical water splitting is extremely hampered by the sluggish oxygen evolution reaction(OER)occurred at the anode.Therefore,developing high-performance OER electrocatalysts is crucial for rea...The efficiency of electrochemical water splitting is extremely hampered by the sluggish oxygen evolution reaction(OER)occurred at the anode.Therefore,developing high-performance OER electrocatalysts is crucial for realizing the industrialized application of water splitting.Herein,a high-efficiency electrocatalyst of ruthenium-decorated nickel-iron hydroxide(10 Ru-NiFe LDH)supported on Ni foam is successfully synthesized for OER.Modifying NiFe LDH with ruthenium can optimize the electronic density to form high valences of metal sites,which is beneficial to promote its OER performance.Consequently,the 10 Ru-NiFe LDH only needs a low overpotential of 222 mV to achieve a current density of50 mA,cm^(-2),which exhibits fast OER kinetics with a small Tafel slope of 58 mV.dec^(-1).Moreover,this electrocatalyst shows high stability over 20 h at a high current density of 100 mA·cm^(-2)without obvious decay.The decent OER performances can be ascribed to the increased active sites and the synergistic electronic interactions among Ni,Fe and Ru.This work provides an effective approach for designing desirable electrocatalysts for OER.展开更多
We investigated the properties of polarons in a wurtzite ZnO/MgxZn1-xO quantum well by adopting a modified Lee–Low–Pines variational method, giving the ground state energy, transition energy, and phonon contribution...We investigated the properties of polarons in a wurtzite ZnO/MgxZn1-xO quantum well by adopting a modified Lee–Low–Pines variational method, giving the ground state energy, transition energy, and phonon contributions from various optical-phonon modes to the ground state energy as functions of the well width and Mg composition. In our calculations, we considered the effects of confined optical phonon modes, interface-optical phonon modes, and half-space phonon modes, as well as the anisotropy of the electron effective band mass, phonon frequency, and dielectric constant. Our numerical results indicate that the electron–optical phonon interactions importantly affect the polaronic energies in the ZnO/MgxZn1-xO quantum well. The electron–optical phonon interactions decrease the polaron energies. For quantum wells with narrower wells, the interface optical phonon and half-space phonon modes contribute more to the polaronic energies than the confined phonon modes. However, for wider quantum wells, the total contribution to the polaronic energy mainly comes from the confined modes. The contributions of the various phonon modes to the transition energy change differently with increasing well width. The contribution of the half-space phonons decreases slowly as the QW width increases, whereas the contributions of the confined and interface phonons reach a maximum at d ≈ 5.0 nm and then decrease slowly. However,the total contribution of phonon modes to the transition energy is negative and increases gradually with the QW width of d.As the composition x increases, the total contribution of phonons to the ground state energies increases slowly, but the total contributions of phonons to the transition energies decrease gradually. We analyze the physical reasons for these behaviors in detail.展开更多
Multifunctional supramolecular ultra-tough bionic e-skin with unique durability for human–machine interaction in complex scenarios still remains challenging.Herein,we develop a skininspired ultra-tough e-skin with tu...Multifunctional supramolecular ultra-tough bionic e-skin with unique durability for human–machine interaction in complex scenarios still remains challenging.Herein,we develop a skininspired ultra-tough e-skin with tunable mechanical properties by a physical cross-linking salting-freezing-thawing method.The gelling agent(β-Glycerophosphate sodium:Gp)induces the aggregation and binding of PVA molecular chains and thereby toughens them(stress up to 5.79 MPa,toughness up to 13.96 MJ m^(−3)).Notably,due to molecular self-assembly,hydrogels can be fully recycled and reprocessed by direct heating(100°C for a few seconds),and the tensile strength can still be maintained at about 100%after six recoveries.The hydrogel integrates transparency(>60%),super toughness(up to 13.96 MJ m^(−3),bearing 1500 times of its own tensile weight),good antibacterial properties(E.coli and S.aureus),UV protection(Filtration:80%–90%),high electrical conductivity(4.72 S m^(−1)),anti-swelling and recyclability.The hydrogel can not only monitor daily physiological activities,but also be used for complex activities underwater and message encryption/decryption.We also used it to create a complete finger joint rehabilitation system with an interactive interface that dynamically presents the user’s health status.Our multifunctional electronic skin will have a profound impact on the future of new rehabilitation medical,human–machine interaction,VR/AR and the metaverse fields.展开更多
The electronic metal-support interaction(EMSI)is one of most intriguing phenomena in heterogeneous catalysis.In this work,this subtle effect is clearly demonstrated by density functional theory(DFT)calculations of sin...The electronic metal-support interaction(EMSI)is one of most intriguing phenomena in heterogeneous catalysis.In this work,this subtle effect is clearly demonstrated by density functional theory(DFT)calculations of single Pt atom supported on vacancies in a boron nitride nanosheet.Moreover,the relation between the EMSI and the performance of Pt in propane direct dehydrogenation(PDH)is investigated in detail.The charge state and partial density of states of single Pt atom show distinct features at different anchoring positions,such as boron and nitrogen vacancies(Bvac and Nvac,respectively).Single Pt atom become positively and negatively charged on Bvac and Nvac,respectively.Therefore,the electronic structure of Pt can be adjusted by rational deposition on the support.Moreover,Pt atoms in different charge states have been shown to have different catalytic abilities in PDH.The DFT calculations reveal that Pt atoms on Bvac(Pt-Bvac)have much higher reactivity towards reactant/product adsorption and C–H bond activation than Pt supported on Nvac(Pt-Nvac),with larger adsorption energy and lower barrier along the reaction pathway.However,the high reactivity of Pt-Bvac also hinders propene desorption,which could lead to unwanted deep dehydrogenation.Therefore,the results obtained herein suggest that a balanced reactivity for C–H activation in propane and propene desorption is required to achieve optimum yields.Based on this descriptor,a single Pt atom on a nitrogen vacancy is considered an effective catalyst for PDH.Furthermore,the deep dehydrogenation of the formed propene is significantly suppressed,owing to the large barrier on Pt-Nvac.The current work demonstrates that the catalytic properties of supported single Pt atoms can be tuned by rationally depositing them on a boron nitride nanosheet and highlights the great potential of single-atom catalysis in the PDH reaction.展开更多
Lithium-sulfur battery is strongly considered as the most promising next-generation energy storage system because of the high theoretical specific capacity.The serious"shuttle effect"and sluggish reaction ki...Lithium-sulfur battery is strongly considered as the most promising next-generation energy storage system because of the high theoretical specific capacity.The serious"shuttle effect"and sluggish reaction kinetic limited the commercial application of lithium-sulfur battery.Many hetero structure s were applied to accelerate polysulfides conversion and suppress their migration in lithium-sulfur batteries.Nevertheless,the effect of the interface in heterostructure was not clear.Here,the Co_(2)B@MXene heterostructure is synthesized through chemical reactions at room temperature and employed as the interlayer material for Li-S batteries.The theoretical calculations and experimental results indicate that the interfacial electronic interaction of Co_(2)B@MXene induce the transfer of electrons from Co_(2)B to MXene,enhancing the catalytic ability and favoring fast redox kinetics of the polysulfides,and the theoretical calculations also reveal the underlying mechanisms for the electron transfer is that the two materials have different Fermi energy levels.The cell with Co_(2)B@MXene exhibits a high initial capacity of1577 mAh/g at 0.1 C and an ultralow capacity decay of 0.0088%per cycle over 2000 cycles at 2 C.Even at5.1 mg/cm^(2) of sulfur loading,the cell with Co_(2)B@MXene delivers 5.2 mAh/cm^(2) at 0.2 C.展开更多
The quasi-pure pitch-angle scattering of energetic electrons driven by field-aligned propagating whistler mode waves during the 9～15 October 1990 magnetic storm at L≈ 3 ～ 4 is studied, and numerical calculations fo...The quasi-pure pitch-angle scattering of energetic electrons driven by field-aligned propagating whistler mode waves during the 9～15 October 1990 magnetic storm at L≈ 3 ～ 4 is studied, and numerical calculations for energetic electrons in gyroresonance with a band of frequency of whistler mode waves distributed over a standard Gaussian spectrum is performed. It is found that the whistler mode waves can efficiently drive energetic electrons from the larger pitchangles into the loss cone, and lead to a flat-top distribution during the main phase of geomagnetic storms. This result perhaps presents a feasible interpretation for observation of time evolution of the quasi-isotropic pitch-angle distribution by Combined Release and Radiation Effects Satellite （CRRES） spacecraft at L ≈ 3 ～ 4.展开更多
Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and ...Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and starch were firstly mixed with distilled water containing ammonium hydroxide to form graphite/starch slurry under an ultrasonic assistant. The cation-π interaction could improve delamination degree and dispersion of graphite in starch matrix. The slurry was first used as a coating material on the surface of wood and paper to develop shielding packages. The effect of coating thickness and coating layers on EM shielding property of the materials was investigated. Second, the composites with a high orientation of graphite were fabricated by compression at high pressures. The electrical conductivity and EM shielding effectiveness(SET) of the materials were greatly enhanced by construction of cation-πinteraction and orientation of graphite. Specifically, the EM SETvalues increased from 56.9 to 66.8 d B for the composites with 50 wt.% graphite and 2.0 mm in thickness by constructing cation-π interaction. The EM SETvalues raised from 17.4 to 66.8 d B via the graphite orientation in the materials with the same components and thickness. The shielding mechanism of the compressed composites with orientation dispersion of graphite was also discussed in comparison to the coating layer with random dispersion of graphite.展开更多
The dynamics of a relativistic electron submitted to an intense, plane wave, linearly polarized laser field is reviewed. Based on the dynamics, the temperature of the electron in the laser field is delined and calcula...The dynamics of a relativistic electron submitted to an intense, plane wave, linearly polarized laser field is reviewed. Based on the dynamics, the temperature of the electron in the laser field is delined and calculated. It is found that the calculated temperature fits the first temperature observed in the experiment by Malka et al. A model to evaluate the electron temperature by taking the electron-ion scattering into account is proposed. It is found that when I ≥ 4.0 × 101s W/cm2 the electron temperature by considering the scattering, T hs, is evidently larger than the electron temperature without considering the scattering, Th. This result is in favor of explaining the two-temperature distribution of the electron energy observed in the experiment by Malka et al.展开更多
Catalyst design relies heavily on electronic metal‐support interactions,but the metal‐support interface with an uncontrollable electronic or coordination environment makes it challenging.Herein,we outline a promisin...Catalyst design relies heavily on electronic metal‐support interactions,but the metal‐support interface with an uncontrollable electronic or coordination environment makes it challenging.Herein,we outline a promising approach for the rational design of catalysts involving heteroatoms as anchors for Pd nanoparticles for ethanol oxidation reaction(EOR)catalysis.The doped B and N atoms from dimethylamine borane(DB)occupy the position of the Ti_(3)C_(2) lattice to anchor the supported Pd nanoparticles.The electrons transfer from the support to B atoms,and then to the metal Pd to form a stable electronic center.A strong electronic interaction can be produced and the d‐band center can be shifted down,driving Pd into the dominant metallic state and making Pd nanoparticles deposit uniformly on the support.As‐obtained Pd/DB–Ti_(3)C_(2) exhibits superior durability to its counterpart(∼14.6% retention)with 91.1% retention after 2000 cycles,placing it among the top single metal anodic catalysts.Further,in situ Raman and density functional theory computations confirm that Pd/DB–Ti_(3)C_(2) is capable of dehydrogenating ethanol at low reaction energies.展开更多
For CO catalytic oxidation,Cu and Ce species are of great importance,between which the synergistic effect is worth investigating.In this work,CeO_(2)/Cu_(2)O with Cu_(2)O{111}and{100}planes were comparatively explored...For CO catalytic oxidation,Cu and Ce species are of great importance,between which the synergistic effect is worth investigating.In this work,CeO_(2)/Cu_(2)O with Cu_(2)O{111}and{100}planes were comparatively explored on CO catalytic oxidation to reveal the effects of interfacial electronic interactions and oxygen defects.The activity result demonstrates that CeO_(2)/o-Cu_(2)O{111}has superior performance compared with CeO_(2)/c-Cu_(2)O{100}.Credit to the coordination unsaturated copper atoms(Cu_(CUS))on oCu_(2)O{111}surface,the interfacial electronic interactions on CeO_(2)/o-Cu_(2)O{111}are more obvious than those on CeO_(2)/c-Cu_(2)O{100},leading to richer oxygen defect generation,better redox and activation abilities of CO and O_(2)reactants.Furthermore,the reaction mechanism of CeO_(2)/o-Cu_(2)O{111}on CO oxidation is revealed,i.e.,CO and O_(2)are adsorbed on the Cucus on Cu_(2)O{111}and oxygen defect of CeO_(2),respectively,and then synergistically promote the CO oxidation to CO_(2).The work sheds light on the designing optimized ceria and copper-based catalysts and the mechanism of CO oxidation.展开更多
Cyano substitution has been established as a viable approach to optimize the performance of all-small-molecule organic solar cells.However,the effect of cyano substitution on the dynamics of photo-charge generation re...Cyano substitution has been established as a viable approach to optimize the performance of all-small-molecule organic solar cells.However,the effect of cyano substitution on the dynamics of photo-charge generation remains largely unexplored.Here,we report an ultrafast spectroscopic study showing that electron transfer is markedly promoted by enhanced intermolecular charge-transfer interaction in all-small-molecule blends with cyanided donors.The delocalized excitations,arising from intermolecular interaction in the moiety of cyano-substituted donor,undergo ultrafast electron transfer with a lifetime of∼3 ps in the blend.In contrast,some locally excited states,surviving in the film of donor without cyano substitution,are not actively involved in the charge separation.These findings well explain the performance improvement of devices with cyanided donors,suggesting that manipulating intermolecular interaction is an efficient strategy for device optimization.展开更多
In this paper,a scheme of commonly-resonated extended interaction circuit system based on high order TMn,mode is proposed to lock the phases of two extended interaction oscillators(EIOs)for generating high power at G-...In this paper,a scheme of commonly-resonated extended interaction circuit system based on high order TMn,mode is proposed to lock the phases of two extended interaction oscillators(EIOs)for generating high power at G-band.Two separate EIOs are coupled through a specific single-gap coupling field supported by a designed gap waveguide with length Lg,which form the phase-locked EIOs based on the commonly-resonated system.As a whole system,the system has been focused on with mode analysis based on different single-gap coupling fields,mode hopping,which present the variation of phase difference between the two-beam-wave interactions when changing Lg.To demonstrate the effectiveness of the proposed circuit system in producing the phase locking,we conducted particle-in-cell(PIC)simulations to show that the interesting mode hopping occurs with the phase difference of O and r between the output signals from two output ports,corresponding to the excitation of the TMn mode with different n.Simulation results show that 1)the oscillator can deliver two times of the output power obtained from one single oscillator at 220 GHz,2)the two EIOs can still deliver output signals with phase difference of O and when the currents of the two beams are different or the fabrication errors of the two EIO cavities are taken into account.The proposed scheme is promising in extending to phase locking between multiple EIOs,and generating higher power at millimeter-wave and higher frequencies.展开更多
基金supported by the Petrochemical Research Institute Foundation(21-CB-09-01)the National Natural Science Foundation of China(22302186,22025205)+1 种基金the China Postdoctoral Science Foundation(2022M713030,2023T160618)the Fundamental Research Funds for the Central Universities(WK2060000058,WK2060000038).
文摘By simplifying catalyst-product separation and reducing phosphorus waste,heterogeneous hydroformylation offers a more sustainable alternative to homogeneous processes.However,heterogeneous hydroformylation catalysts developed thus far still suffer from the issues of much lower activity and metal leaching,which severely hinder their practical application.Here,we demonstrate that incorporating phosphorus(P)atoms into graphitic carbon nitride(PCN)supports facilitates charge transfer from Rh to the PCN support,thus largely enhancing electronic metal-support interactions(EMSIs).In the styrene hydroformylation reaction,the activity of Rh_(1)/PCN single-atom catalysts(SACs)with varying P contents exhibited a volcano-shaped relationship with P doping,where the Rh_(1)/PCN SAC with optimal P doping showed exceptional activity,approximately 5.8-and 3.3-fold greater than that of the Rh_(1)/g-C_(3)N_(4)SAC without P doping and the industrial homogeneous catalyst HRh(CO)(PPh_(3))_(3),respectively.In addition,the optimal Rh_(1)/PCN SAC catalyst also demonstrated largely enhanced multicycle stability without any visible metal aggregation owing to the increased EMSIs,which sharply differed from the severe metal aggregation of large nanoparticles on the Rh_(1)/g-C_(3)N_(4)SAC.Mechan-istic studies revealed that the enhanced catalytic performance could be attributed to electron-deficient Rh species,which reduced CO adsorption while simultaneously promoting alkene adsorption through increased EMSIs.These findings suggest that tuning EMSIs is an effective way to achieve SACs with high activity and durability.
基金supported by National Natural Science Foundation of China(22309029,52404316)Guangdong Basic and Applied Basic Research Foundation(Nos.2024A1515140011,and 2024A1515110010)+2 种基金Dongguan Social Development Technology Foundation(Nos.20231800907933,and 20221800905122)Collaborative Innovation Center of Marine Science and Technology of Hainan University(No.XTCX2022HYC14)Start-up Research Foundation of Hainan University(No.KYQD(ZR)-23069).
文摘The notorious shuttle effect of polyiodides in aqueous Zinc-iodine(Zn-I2)batteries impedes their practical application,which renders it imperative to address this issue.Here,we report natural gelatin as an advanced aqueous binder for iodine-loading cathode to enable stable and efficient Zn-I_(2) batteries.The positively charged region in gelatin presents electrostatic attraction to the iodine species,while the electron-rich regions could donate electrons to form physical or even covalent bonds with iodine species,thus inhibiting polyiodides shuttle effect and boosting redox reaction.A high reversible capacity of 138 mAh g^(-1) after 3000 cycles at 2C and an ultra-long cycling stability of 30000 cycles at 25C with 107 mAh g^(-1) capacity was achieved.Gelatin binder also can accommodate high iodine-loading(~10 mg)cathode,punch cells,and severe temperature conditions(-10℃ and 60℃).In-situ UV-vis absorption spectroscopy,in-situ Raman spectra and theoretical calculation revealed the critical role of gelatin binder in suppressing polyiodide shuttling and accelerating reaction kinetics.This work uncovers the potential of natural low-cost binder material in advanced Zn-I_(2) batteries and drives future study of designing functional binders.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1602501)the National Natural Science Foundation of China(Grant No.12011530060)+1 种基金supported solely by the Russian Science Foundation(Grant No.22-12-00043)supported by the Chinese Academy of Sciences(CAS)Presidents International Fellowship Initiative(PIFI)(Grant Nos.2018VMB0016 and 2022VMC0002),respectively。
文摘We explored a distinct mechanism for matter creation via electron-positron pair production during bound-bound transitions in the deexcitation of muonic atoms.For ions with nuclear charges Z≥24,transitions from low-lying excited states to the 1s-muon state can lead to the production of electron-positron pairs.We show that the Breit interaction determines the transition probabilities for states with nonzero orbital momentum.We show that the pair production arises mainly from the decay of the 2p states.Thus,the Breit interaction governs electron-positron pair production in bound-bound muon transitions.This process offers a unique opportunity to explore quantum electrodynamics in strong fields,as well as a class of nonradiative transitions involving electron-positron pair production.
基金supported by the State Key Research Development Program of China(No.2021YFB3800701)National Natural Science Foundation of China(NSFC,No.52173016)+2 种基金Guangdong Basic and Applied Basic Research Foundation(Nos.2024A1515012784,2024A1515011102,and 2023A1515110549)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.24qnpy047)PetroChina Scientific and Technological Projects(No.2022DJ6308).
文摘A series of“half-sandwich”bis(imino)pyridyl iron complexes with a substituted 8-(p-Xphenyl)naphthylamine(X=OMe,Me,CF3)was designed and synthesized by combining weakπ-πinteraction with steric and electronic tunings.The weak noncovalentπ-πinteraction as well as the steric and electronic effects of bis(imino)pyridyl iron complexes were identified by experimental analyses and calculations.The roles of weakπ-πinteraction,steric bulk,and electronic tuning on the ethylene polymerization performance of bis(imino)pyridyl iron catalysts were studied in detail.The combination ofπ-πinteraction with steric and electronic tunings can access to thermally stable bis(imino)pyridyl iron at 130°C.
基金supported by the Natural Scientific Foundation of China(Nos.22127803,22174110,22203050)Natural Scientific Foundation of Shandong(No.ZR2022QB002)China Postdoctoral Science Foundation(No.2020T130331)。
文摘A novel Cu-t-ZrO_(2)catalyst with enhanced electronic metal-support interaction(EMSI)is designed for efficient electrocatalytic conversion of nitrate(NO_(3^(-)))to ammonia(NH_(3)),achieving a remarkable Faradaic efficiency and yield rate of 97.54%and 33.64 mg h^(-1)mg_(cat)^(-1),respectively.Electrons are more likely to be transferred from Cu to t-ZrO_(2)at the electron-rich interface due to the lower work function,which promotes the formation of highly active Cu species and facilitates NO_(3^(-))adsorption,ensuring selective conversion into NH_(3).
基金supported by the National Key Research and Development Program of China (Grant No. 2024YFE0100600)the National Natural Science Foundation of China (No 52373303)+2 种基金the Shanghai Municipal Science and Technology Major Project (2021SHZDZX0100)the Fundamental Research Funds for the Central Universitiesthe Interdisciplinary Joint Research and Development Project of Tongji University (No 2024-4-ZD-03)
文摘The electron localization is considered as a promising approach to optimize electromagnetic waves(EMW)dissipation.However,it is still difficult to realize well-controlled electron localization and elucidate the related EMW loss mechanisms for current researches.In this study,a novel two-dimensional MXene(Ti_(3)C_(2)T_(x))nanosheet decorated with Ni nanoclusters(Ni-NC)system to construct an effective electron localization model based on electronic orbital structure is explored.Theoretical simulations and experimental results reveal that the metal-support interaction between Ni-NC and MXene disrupts symmetric electronic environments,leading to enhanced electron localization and dipole polarization.Additionally,Ni-NC generate a strong interfacial electric field,strengthening heterointerface interactions and promoting interfacial polarization.As a result,the optimized material achieves an exceptional reflection loss(RLmin)of-54 dB and a broad effective absorption bandwidth of 6.8 GHz.This study offers critical insights into the in-depth relationship between electron localization and EMW dissipation,providing a pathway for electron localization engineering in functional materials such as semiconductors,spintronics,and catalysis.
文摘The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric geometry at impact energy of 2.5 keV plus binding energy. The ionization bands have been assigned in detail via the high accuracy SACCI general-R method calculation and the experimental momentum profiles are compared with the theoretical ones calculated by Hartree-Fock and B3LYP/aug-cc-pVTZ（C,H）6-311G？？（I）. The spin-orbit coupling effect and intramolecular orbital interaction have been analyzed for the outermost two bands, which are assigned to the iodine 5p lone pairs, using NBO method and non-relativistic as well as relativistic calculations. It is found that both of the interactions will lead to the observed differences in electron momentum distributions. The experimental results agree with the relativistic theoretical momentum profiles, indicating that the spin-orbit coupling effect dominates in n-propyl iodide molecule.
基金financially supported by the National Natural Science Foundation of China (Nos.12074435, 51871250 and 52001335)the Science and Technology Innovation Program of Hunan Province (No.2021RC4001)the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metal (No.SKL-SPM-202005)
文摘The efficiency of electrochemical water splitting is extremely hampered by the sluggish oxygen evolution reaction(OER)occurred at the anode.Therefore,developing high-performance OER electrocatalysts is crucial for realizing the industrialized application of water splitting.Herein,a high-efficiency electrocatalyst of ruthenium-decorated nickel-iron hydroxide(10 Ru-NiFe LDH)supported on Ni foam is successfully synthesized for OER.Modifying NiFe LDH with ruthenium can optimize the electronic density to form high valences of metal sites,which is beneficial to promote its OER performance.Consequently,the 10 Ru-NiFe LDH only needs a low overpotential of 222 mV to achieve a current density of50 mA,cm^(-2),which exhibits fast OER kinetics with a small Tafel slope of 58 mV.dec^(-1).Moreover,this electrocatalyst shows high stability over 20 h at a high current density of 100 mA·cm^(-2)without obvious decay.The decent OER performances can be ascribed to the increased active sites and the synergistic electronic interactions among Ni,Fe and Ru.This work provides an effective approach for designing desirable electrocatalysts for OER.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11264027 and 11364030)the Project of Prairie Excellent Specialist of Inner Mongolia,Chinathe "Thousand,Hundred and Ten" Talent Training Project Foundation of Inner Mongolia Normal University,China(Grant No.RCPY-2-2012-K-039)
文摘We investigated the properties of polarons in a wurtzite ZnO/MgxZn1-xO quantum well by adopting a modified Lee–Low–Pines variational method, giving the ground state energy, transition energy, and phonon contributions from various optical-phonon modes to the ground state energy as functions of the well width and Mg composition. In our calculations, we considered the effects of confined optical phonon modes, interface-optical phonon modes, and half-space phonon modes, as well as the anisotropy of the electron effective band mass, phonon frequency, and dielectric constant. Our numerical results indicate that the electron–optical phonon interactions importantly affect the polaronic energies in the ZnO/MgxZn1-xO quantum well. The electron–optical phonon interactions decrease the polaron energies. For quantum wells with narrower wells, the interface optical phonon and half-space phonon modes contribute more to the polaronic energies than the confined phonon modes. However, for wider quantum wells, the total contribution to the polaronic energy mainly comes from the confined modes. The contributions of the various phonon modes to the transition energy change differently with increasing well width. The contribution of the half-space phonons decreases slowly as the QW width increases, whereas the contributions of the confined and interface phonons reach a maximum at d ≈ 5.0 nm and then decrease slowly. However,the total contribution of phonon modes to the transition energy is negative and increases gradually with the QW width of d.As the composition x increases, the total contribution of phonons to the ground state energies increases slowly, but the total contributions of phonons to the transition energies decrease gradually. We analyze the physical reasons for these behaviors in detail.
基金support from the National Natural Science Foundation of China(32201179)Guangdong Basic and Applied Basic Research Foundation(2020A1515110126 and 2021A1515010130)the Fundamental Research Funds for the Central Universities(N2119006 and N2224001-10)is gratefully acknowledged.
文摘Multifunctional supramolecular ultra-tough bionic e-skin with unique durability for human–machine interaction in complex scenarios still remains challenging.Herein,we develop a skininspired ultra-tough e-skin with tunable mechanical properties by a physical cross-linking salting-freezing-thawing method.The gelling agent(β-Glycerophosphate sodium:Gp)induces the aggregation and binding of PVA molecular chains and thereby toughens them(stress up to 5.79 MPa,toughness up to 13.96 MJ m^(−3)).Notably,due to molecular self-assembly,hydrogels can be fully recycled and reprocessed by direct heating(100°C for a few seconds),and the tensile strength can still be maintained at about 100%after six recoveries.The hydrogel integrates transparency(>60%),super toughness(up to 13.96 MJ m^(−3),bearing 1500 times of its own tensile weight),good antibacterial properties(E.coli and S.aureus),UV protection(Filtration:80%–90%),high electrical conductivity(4.72 S m^(−1)),anti-swelling and recyclability.The hydrogel can not only monitor daily physiological activities,but also be used for complex activities underwater and message encryption/decryption.We also used it to create a complete finger joint rehabilitation system with an interactive interface that dynamically presents the user’s health status.Our multifunctional electronic skin will have a profound impact on the future of new rehabilitation medical,human–machine interaction,VR/AR and the metaverse fields.
基金supported by the National Science Foundation of China(91545117)the Natural Science Foundation of Liaoning Province(201602676)+1 种基金the Fundamental Research Funds for Colleges and Universities in Liaoning Province(LQN201703)the Startup Foundation for Doctors of Shenyang Normal University(BS201620)~~
文摘The electronic metal-support interaction(EMSI)is one of most intriguing phenomena in heterogeneous catalysis.In this work,this subtle effect is clearly demonstrated by density functional theory(DFT)calculations of single Pt atom supported on vacancies in a boron nitride nanosheet.Moreover,the relation between the EMSI and the performance of Pt in propane direct dehydrogenation(PDH)is investigated in detail.The charge state and partial density of states of single Pt atom show distinct features at different anchoring positions,such as boron and nitrogen vacancies(Bvac and Nvac,respectively).Single Pt atom become positively and negatively charged on Bvac and Nvac,respectively.Therefore,the electronic structure of Pt can be adjusted by rational deposition on the support.Moreover,Pt atoms in different charge states have been shown to have different catalytic abilities in PDH.The DFT calculations reveal that Pt atoms on Bvac(Pt-Bvac)have much higher reactivity towards reactant/product adsorption and C–H bond activation than Pt supported on Nvac(Pt-Nvac),with larger adsorption energy and lower barrier along the reaction pathway.However,the high reactivity of Pt-Bvac also hinders propene desorption,which could lead to unwanted deep dehydrogenation.Therefore,the results obtained herein suggest that a balanced reactivity for C–H activation in propane and propene desorption is required to achieve optimum yields.Based on this descriptor,a single Pt atom on a nitrogen vacancy is considered an effective catalyst for PDH.Furthermore,the deep dehydrogenation of the formed propene is significantly suppressed,owing to the large barrier on Pt-Nvac.The current work demonstrates that the catalytic properties of supported single Pt atoms can be tuned by rationally depositing them on a boron nitride nanosheet and highlights the great potential of single-atom catalysis in the PDH reaction.
基金supported by the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.2019DX13)。
文摘Lithium-sulfur battery is strongly considered as the most promising next-generation energy storage system because of the high theoretical specific capacity.The serious"shuttle effect"and sluggish reaction kinetic limited the commercial application of lithium-sulfur battery.Many hetero structure s were applied to accelerate polysulfides conversion and suppress their migration in lithium-sulfur batteries.Nevertheless,the effect of the interface in heterostructure was not clear.Here,the Co_(2)B@MXene heterostructure is synthesized through chemical reactions at room temperature and employed as the interlayer material for Li-S batteries.The theoretical calculations and experimental results indicate that the interfacial electronic interaction of Co_(2)B@MXene induce the transfer of electrons from Co_(2)B to MXene,enhancing the catalytic ability and favoring fast redox kinetics of the polysulfides,and the theoretical calculations also reveal the underlying mechanisms for the electron transfer is that the two materials have different Fermi energy levels.The cell with Co_(2)B@MXene exhibits a high initial capacity of1577 mAh/g at 0.1 C and an ultralow capacity decay of 0.0088%per cycle over 2000 cycles at 2 C.Even at5.1 mg/cm^(2) of sulfur loading,the cell with Co_(2)B@MXene delivers 5.2 mAh/cm^(2) at 0.2 C.
基金National Natural Science Foundation of China(Nos.40774078,40404012,40674076,40474064)the Visiting Scholar Foundation of State Key Laboratory of Space Weather,Chinese Academy of Sciences
文摘The quasi-pure pitch-angle scattering of energetic electrons driven by field-aligned propagating whistler mode waves during the 9～15 October 1990 magnetic storm at L≈ 3 ～ 4 is studied, and numerical calculations for energetic electrons in gyroresonance with a band of frequency of whistler mode waves distributed over a standard Gaussian spectrum is performed. It is found that the whistler mode waves can efficiently drive energetic electrons from the larger pitchangles into the loss cone, and lead to a flat-top distribution during the main phase of geomagnetic storms. This result perhaps presents a feasible interpretation for observation of time evolution of the quasi-isotropic pitch-angle distribution by Combined Release and Radiation Effects Satellite （CRRES） spacecraft at L ≈ 3 ～ 4.
基金financially supported by the National Natural Science Foundation of China(No.52173264)the Natural Scienceof Chongqing(No.cstc2020jcyjmsxmX0401)。
文摘Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and starch were firstly mixed with distilled water containing ammonium hydroxide to form graphite/starch slurry under an ultrasonic assistant. The cation-π interaction could improve delamination degree and dispersion of graphite in starch matrix. The slurry was first used as a coating material on the surface of wood and paper to develop shielding packages. The effect of coating thickness and coating layers on EM shielding property of the materials was investigated. Second, the composites with a high orientation of graphite were fabricated by compression at high pressures. The electrical conductivity and EM shielding effectiveness(SET) of the materials were greatly enhanced by construction of cation-πinteraction and orientation of graphite. Specifically, the EM SETvalues increased from 56.9 to 66.8 d B for the composites with 50 wt.% graphite and 2.0 mm in thickness by constructing cation-π interaction. The EM SETvalues raised from 17.4 to 66.8 d B via the graphite orientation in the materials with the same components and thickness. The shielding mechanism of the compressed composites with orientation dispersion of graphite was also discussed in comparison to the coating layer with random dispersion of graphite.
文摘The dynamics of a relativistic electron submitted to an intense, plane wave, linearly polarized laser field is reviewed. Based on the dynamics, the temperature of the electron in the laser field is delined and calculated. It is found that the calculated temperature fits the first temperature observed in the experiment by Malka et al. A model to evaluate the electron temperature by taking the electron-ion scattering into account is proposed. It is found that when I ≥ 4.0 × 101s W/cm2 the electron temperature by considering the scattering, T hs, is evidently larger than the electron temperature without considering the scattering, Th. This result is in favor of explaining the two-temperature distribution of the electron energy observed in the experiment by Malka et al.
基金Key Research and Development Program of Zhejiang,Grant/Award Number:2021C03022National Natural Science Foundation of China,Grant/Award Numbers:22002104,22272115,22202145,22202146,22102112,22202147。
文摘Catalyst design relies heavily on electronic metal‐support interactions,but the metal‐support interface with an uncontrollable electronic or coordination environment makes it challenging.Herein,we outline a promising approach for the rational design of catalysts involving heteroatoms as anchors for Pd nanoparticles for ethanol oxidation reaction(EOR)catalysis.The doped B and N atoms from dimethylamine borane(DB)occupy the position of the Ti_(3)C_(2) lattice to anchor the supported Pd nanoparticles.The electrons transfer from the support to B atoms,and then to the metal Pd to form a stable electronic center.A strong electronic interaction can be produced and the d‐band center can be shifted down,driving Pd into the dominant metallic state and making Pd nanoparticles deposit uniformly on the support.As‐obtained Pd/DB–Ti_(3)C_(2) exhibits superior durability to its counterpart(∼14.6% retention)with 91.1% retention after 2000 cycles,placing it among the top single metal anodic catalysts.Further,in situ Raman and density functional theory computations confirm that Pd/DB–Ti_(3)C_(2) is capable of dehydrogenating ethanol at low reaction energies.
基金Project supported by the National Natural Science Foundation of China(21707066,21677069)。
文摘For CO catalytic oxidation,Cu and Ce species are of great importance,between which the synergistic effect is worth investigating.In this work,CeO_(2)/Cu_(2)O with Cu_(2)O{111}and{100}planes were comparatively explored on CO catalytic oxidation to reveal the effects of interfacial electronic interactions and oxygen defects.The activity result demonstrates that CeO_(2)/o-Cu_(2)O{111}has superior performance compared with CeO_(2)/c-Cu_(2)O{100}.Credit to the coordination unsaturated copper atoms(Cu_(CUS))on oCu_(2)O{111}surface,the interfacial electronic interactions on CeO_(2)/o-Cu_(2)O{111}are more obvious than those on CeO_(2)/c-Cu_(2)O{100},leading to richer oxygen defect generation,better redox and activation abilities of CO and O_(2)reactants.Furthermore,the reaction mechanism of CeO_(2)/o-Cu_(2)O{111}on CO oxidation is revealed,i.e.,CO and O_(2)are adsorbed on the Cucus on Cu_(2)O{111}and oxygen defect of CeO_(2),respectively,and then synergistically promote the CO oxidation to CO_(2).The work sheds light on the designing optimized ceria and copper-based catalysts and the mechanism of CO oxidation.
基金supported by the National Key R&D Program of China(No.2018YFA0209100 and No.2017YFA0303703)the National Natural Science Foundation of China(No.21922302,No.21873047,No.91850105,and No.91833305)+1 种基金the Fundamental Research Funds for the Central Universities(No.020414380126)Chun-feng Zhang acknowledges financial support from the Tang Scholar Program。
文摘Cyano substitution has been established as a viable approach to optimize the performance of all-small-molecule organic solar cells.However,the effect of cyano substitution on the dynamics of photo-charge generation remains largely unexplored.Here,we report an ultrafast spectroscopic study showing that electron transfer is markedly promoted by enhanced intermolecular charge-transfer interaction in all-small-molecule blends with cyanided donors.The delocalized excitations,arising from intermolecular interaction in the moiety of cyano-substituted donor,undergo ultrafast electron transfer with a lifetime of∼3 ps in the blend.In contrast,some locally excited states,surviving in the film of donor without cyano substitution,are not actively involved in the charge separation.These findings well explain the performance improvement of devices with cyanided donors,suggesting that manipulating intermolecular interaction is an efficient strategy for device optimization.
基金Supported in part by the National Natural Science Foundation of China(62401125)the Natural Science Foundation of Sichuan Province(2023NSFSC1376)the Fundamental Research Funds for the Central Universities(ZYGX2024J008)。
文摘In this paper,a scheme of commonly-resonated extended interaction circuit system based on high order TMn,mode is proposed to lock the phases of two extended interaction oscillators(EIOs)for generating high power at G-band.Two separate EIOs are coupled through a specific single-gap coupling field supported by a designed gap waveguide with length Lg,which form the phase-locked EIOs based on the commonly-resonated system.As a whole system,the system has been focused on with mode analysis based on different single-gap coupling fields,mode hopping,which present the variation of phase difference between the two-beam-wave interactions when changing Lg.To demonstrate the effectiveness of the proposed circuit system in producing the phase locking,we conducted particle-in-cell(PIC)simulations to show that the interesting mode hopping occurs with the phase difference of O and r between the output signals from two output ports,corresponding to the excitation of the TMn mode with different n.Simulation results show that 1)the oscillator can deliver two times of the output power obtained from one single oscillator at 220 GHz,2)the two EIOs can still deliver output signals with phase difference of O and when the currents of the two beams are different or the fabrication errors of the two EIO cavities are taken into account.The proposed scheme is promising in extending to phase locking between multiple EIOs,and generating higher power at millimeter-wave and higher frequencies.
