The interaction between metal and support is critical in oxygen catalysis as it governs the charge transfer between these two entities,influences the electronic structures of the supported metal,affects the adsorption...The interaction between metal and support is critical in oxygen catalysis as it governs the charge transfer between these two entities,influences the electronic structures of the supported metal,affects the adsorption energies of reaction intermediates,and ultimately impacts the catalytic performance.In this study,we discovered a unique charge transfer reversal phenomenon in a metal/carbon nanohybrid system.Specifically,electrons were transferred from the metal-based species to N-doped carbon,while the carbon support reciprocally donated electrons to the metal domain upon the introduction of nickel.This led to the exceptional electrocatalytic performances of the resulting Ni-Fe/Mo_(2)C@nitrogen-doped carbon catalyst,with a half-wave potential of 0.91 V towards oxygen reduction reaction(ORR)and a low overpotential of 290 m V at 10 mA cm^(-2)towards oxygen evolution reaction(OER)under alkaline conditions.Additionally,the Fe-Ni/Mo_(2)C@carbon heterojunction catalyst demonstrated high specific capacity(794 mA h g_(Zn)~(-1))and excellent cycling stability(200 h)in a Zn-air battery.Theoretical calculations revealed that Mo_(2)C effectively inhibited charge transfer from Fe to the support,while secondary doping of Ni induced a charge transfer reversal,resulting in electron accumulation in the Fe-Ni alloy region.This local electronic structure modulation significantly reduced energy barriers in the oxygen catalysis process,enhancing the catalytic efficiency of both ORR and OER.Consequently,our findings underscore the potential of manipulating charge transfer reversal between the metal and support as a promising strategy for developing highly-active and durable bi-functional oxygen electrodes.展开更多
In the development of Li-ion batteries(LIBs)with high energy/power density,long cycle-life,fast charging,and high safety,an insight into charge transfer reactions is required.Although electrochemical impedance spectro...In the development of Li-ion batteries(LIBs)with high energy/power density,long cycle-life,fast charging,and high safety,an insight into charge transfer reactions is required.Although electrochemical impedance spectroscopy(EIS)is regarded as a powerful diagnosis tool,it is not a direct but an indirect measurement.With respect to this,some critical questions need to be answered:(i)why EIS can reflect the kinetics of charge transfer reactions;(ii)what the inherent logical relationship between impedance models under different physical scenes is;(iii)how charge transfer reactions compete with each other at multiple scales.This work aims at answering these questions via developing a theory framework so as to mitigate the blindness and uncertainty in unveiling charge transfer reactions in LIBs.To systematically answer the above questions,this article is organized into a three-in-one(review,tutorial,and research)type and the following contributions are made:(i)a brief review is given for impedance model development of the LIBs over the past half century;(ii)an open source code toolbox is developed based on the unified impedance model;(iii)the competive mechanisms of charge transfer reactions are unveiled based on the developed EIS-Toolbox@LIB.This work not only clarifies theoretical fundamentals,but also provides an easy-to-use open source code for EIS-Toolbox@LIB to optimize fast charge/discharge,mitigate cycle aging,and improve energy/power density.展开更多
Inspired by the function of crucial components in photosystemⅡ(PSⅡ),electrochemical and dyesensitized photoelectrochemical(DSPEC)water oxidation devices were constructed by the selfassembly of well-designed amphipat...Inspired by the function of crucial components in photosystemⅡ(PSⅡ),electrochemical and dyesensitized photoelectrochemical(DSPEC)water oxidation devices were constructed by the selfassembly of well-designed amphipathic Ru(bda)-based catalysts(bda=2,2'-bipyrdine-6,6'-dicarbonoxyl acid)and aliphatic chain decorated electrode surfaces,forming lipid bilayer membrane(LBM)-like structures.The Ru(bda)catalysts on electrode-supported LBM films demonstrated remarkable water oxidation performance with different O-O formation mechanisms.However,compared to the slow charge transfer process,the O-O formation pathways did not determine the PEC water oxidation efficiency of the dyesensitized photoanodes,and the different reaction rates for similar catalysts with different catalytic paths did not determine the PEC performance of the DSPECs.Instead,charge transfer plays a decisive role in the PEC water oxidation rate.When an indolo[3,2-b]carbazole derivative was introduced between the Ru(bda)catalysts and aliphatic chain-modified photosensitizer in LBM films,serving as a charge transfer mediator for the tyrosine-histidine pair in PSⅡ,the PEC water oxidation performance of the corresponding photoanodes was dramatically enhanced.展开更多
Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical performance.Recently,considerable efforts have been devoted to t...Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical performance.Recently,considerable efforts have been devoted to this endeavor.This review systematically summarizes the impact of built-in electric fields on enhancing charge separation and transfer mechanisms,focusing on the modulation of built-in electric fields in terms of depth and orderliness.First,mechanisms and tuning strategies for built-in electric fields are explored.Then,the state-of-the-art works regarding built-in electric fields for modulating charge separation and transfer are summarized and categorized according to surface and interface depth.Finally,current strategies for constructing bulk built-in electric fields in photoelectrodes are explored,and insights into future developments for enhancing charge separation and transfer in high-performance photoelectrochemical applications are provided.展开更多
This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% im...This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% impurity concentration. Our comprehensive analysis encompasses structural properties, electronic band structures, and charge density distributions. The optimized lattice constant and band gap energy of 3C-SiC were found to be 4.373 Å and 1.36 eV respectively, which is in agreement with previous research (Bui, 2012;Muchiri et al., 2018). Our results show that B doping narrows the band gap, enhances electrical conductivity, and influences charge transfer interactions. The charge density analysis reveals substantial interactions between B dopants and surrounding carbon atoms. This work not only enhances our understanding of the material’s electronic properties, but also highlights the importance of charge density analysis for characterizing charge transfer mechanisms and their implications in the 3C-SiC semiconductors.展开更多
The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,wh...The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,while the challenge associated with N_(2) activation highlights the demand for efficient electrocatalysts.Herein,we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet(PdCu/B)behave as efficient NRR electrocatalysts toward NH_(3) synthesis.Theoretical and experimental results confirm that the highly efficient NH_(3) synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site,which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N_(2) and thus optimizes the reaction pathway of NRR over the separated Pd sites.Compared with monometallic Pd/B and Cu/B,the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH_(3) synthesis.This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.展开更多
The great challenges are remained in constructing graphite-based anode with well built-in structures to accelerate kinetics and enhance stability in the advanced K-ion batteries(KIBs).Here,we firstly report the design...The great challenges are remained in constructing graphite-based anode with well built-in structures to accelerate kinetics and enhance stability in the advanced K-ion batteries(KIBs).Here,we firstly report the design of expanded graphite cohered by N,B bridge-doping carbon patches(NBEG)for efficient K-ion adsorption/diffusion and long-term durability.It is the B co-doping that plays a crucial role in maximizing doping-site utilization of N atoms,balancing the adsorption-diffusion kinetics,and promoting the charge transfer between NBEG and K ions.Especially,the robust lamellar structure,suitable interlayer distance,and rich active sites of the designed NBEG favor the rapid ion/electron transfer pathways and high K-ion storage capacity.Consequently,even at a low N,B doping concentration(4.36 at%,2.07 at%),NBEG anode shows prominent electrochemical performance for KIBs,surpassing most of the advanced carbon-based anodes.Kinetic studies,density functional theory simulations,and in-situ Raman spectroscopy are further performed to reveal the K-ion storage mechanism and confirm the critical actions of co-doping B.This work offers the new methods for graphite-electrode design and the deeper insights into their energy storage mechanisms in KIBs.展开更多
Partial genetically encoded 4-hy-droxybenzylidene-imidazolinone(HBI)-type chromophores are new promising fluorescent probes,which are suitable for imaging and detection of living cells.How-ever,the lack of infrared ch...Partial genetically encoded 4-hy-droxybenzylidene-imidazolinone(HBI)-type chromophores are new promising fluorescent probes,which are suitable for imaging and detection of living cells.How-ever,the lack of infrared chro-mophores hinders the develop-ment seriously.Here more than 30 HBI-type chromophores with reg-ular structure modifications were employed and typical spectral redshift change laws and mechanisms were investigated by quantum methods.Results show that both one-photon spectrum(OPS,absorption/emission)and two-photon absorption(TPA)can achieve large redshift via either extending conjugated lengths of frag-3 or enlarging conjugated areas of frag-1 of HBI skeleton.Spectral redshifts of all chromophores are highly related to intramolecular charge transfer(ICT),but neutral ones are closely related to the total ICT or electron-accept-ing-numbers of frag-3,and the high correlative factor of anions is the aromaticity of frag-2 bridge.The frag-2 bridge with high aromaticity can open a reverse charge transfer channel in anion relative to neutral,obtaining significant redshift.Based on analysis,a new 6-hydroxyl-naphthalene-imidazolinone(HNI)series,which have larger conjugated area in frag-1,are pre-dicted.The OPS and TPA of anionic HNI ones acquire about 76−96 nm and 119−146 nm red-shift relative to traditional HBI series respectively as a whole.The longest emission of anionic HNI-4 realizes more 244 nm redshift relative to HBI-1.Our work clarifies worthy spectral reg-ularities and redshift mechanisms of HBI-type chromophores and provides valuable design strategy for infrared chromophores synthesis in experiment.展开更多
Type-Ⅱband alignment can realize the efficient charge transfer and separation at the semiconductor heterointerface,which results in photoluminescence(PL)quenching.Recently,several researches demonstrated great enhanc...Type-Ⅱband alignment can realize the efficient charge transfer and separation at the semiconductor heterointerface,which results in photoluminescence(PL)quenching.Recently,several researches demonstrated great enhancement of localized PL at the interface of type-Ⅱtwo-dimensional(2D)heterostructure.However,the dominant physical mechanism of this enhanced PL emission has not been well understood.In this work,we symmetrically study the exciton dynamics of type-Ⅱlateral heterostructures of monolayer MoS_(2) and WS_(2) at room temperatures.The strong PL enhancement along the one-dimensional(1D)heterointerface is associated with the trion emission of the WS_(2) shell,while a dramatic PL quenching of neutral exciton is observed on the MoS_(2) core.The enhanced quantum yield of WS2trion emission can be explained by charge-transfer-enhanced photoexcited carrier dynamics,which is facilitated by resonance hole transfer from MoS_(2) side to WS_(2) side.This work sheds light on the 1D exciton photophysics in lateral heterostructures,which has the potential to lead to new concepts and applications of optoelectronic device.展开更多
CMOS image sensors produced by the existing CMOS manufacturing process usually have difficulty achieving complete charge transfer owing to the introduction of potential barriers or Si/SiO_(2)interface state traps in t...CMOS image sensors produced by the existing CMOS manufacturing process usually have difficulty achieving complete charge transfer owing to the introduction of potential barriers or Si/SiO_(2)interface state traps in the charge transfer path,which reduces the charge transfer efficiency and image quality.Until now,scholars have only considered mechanisms that limit charge transfer from the perspectives of potential barriers and spill back effect under high illumination condition.However,the existing models have thus far ignored the charge transfer limitation due to Si/SiO_(2)interface state traps in the transfer gate channel,particularly under low illumination.Therefore,this paper proposes,for the first time,an analytical model for quantifying the incomplete charge transfer caused by Si/SiO_(2)interface state traps in the transfer gate channel under low illumination.This model can predict the variation rules of the number of untransferred charges and charge transfer efficiency when the trap energy level follows Gaussian distribution,exponential distribution and measured distribution.The model was verified with technology computer-aided design simulations,and the results showed that the simulation results exhibit the consistency with the proposed model.展开更多
This paper is aimed to investigate the effect of packing material on plasma characteristic from the viewpoint of charge transfer process.Both the charge accumulation and release processes in the dielectric barrier dis...This paper is aimed to investigate the effect of packing material on plasma characteristic from the viewpoint of charge transfer process.Both the charge accumulation and release processes in the dielectric barrier discharge reactor and packed-bed reactor were investigated by measuring voltage and current waveforms and taking ICCD images.The packing material was ZrO2 pellets and the reactors were driven by a parameterized nanosecond pulse source.The quantity of transferred charges in the dielectric barrier discharge reactor was enhanced when decreasing pulse rise time or increasing pulse width(within 150 ns),but reduced when the gas gap was packed with pellets.The quantity of accumulated charges in the primary discharge was larger than the quantity of released charges in the secondary discharges in the dielectric barrier discharge reactor,but they were almost equal in the packed-bed reactor.It indicates that the discharge behavior has been changed from the view of charge transfer process once the gas gap was packed with pellets,and the ICCD images confirmed it.展开更多
The variational method is applied to the study of charge transfer in dry DNA by using an extended Holstein small polaron model in two cases: the site-dependent flnite-chain discrete case and the site-independent cont...The variational method is applied to the study of charge transfer in dry DNA by using an extended Holstein small polaron model in two cases: the site-dependent flnite-chain discrete case and the site-independent continuous one. The treatments in the two cases are proven to be consistent in theory and calculation. Discrete and continuous treatments of Holstein model both can yield a nonlinear equation to describe the charge migration in an actual long-range DNA chain. Our theoretical results of binding energy Eb, probability amplitude of charge carrier Ф and the relation between energy and charge-lattice coupling strength are in accordance with the available experimental results and recent theoretical calculations.展开更多
1. The transient absorption spectra of the WS2 monolayer sample.In the measurement of the transient absorption spectra of the WS2 monolayer sample, A 400-nm (3.1eV) pump pulse with a peak fluence of about 10μJ/cm2exc...1. The transient absorption spectra of the WS2 monolayer sample.In the measurement of the transient absorption spectra of the WS2 monolayer sample, A 400-nm (3.1eV) pump pulse with a peak fluence of about 10μJ/cm2excites the electrons from the valence band into the conduction band,the展开更多
In this work,a novel NiP_(2)/g-C_(3)N_(4)heterojunction via homogeneous precipitation method assisted by thermal phosphorization reaction was designed and constructed,and the optimized sample showed the excellent phot...In this work,a novel NiP_(2)/g-C_(3)N_(4)heterojunction via homogeneous precipitation method assisted by thermal phosphorization reaction was designed and constructed,and the optimized sample showed the excellent photocatalytic H_(2)evolution activity under visible-light irradiation,which was nearly 112 times higher than that of pristine g-C_(3)N_(4)sample.Experimental characterizations and DFT calculations demonstrated that the NiP_(2)nanoparticles covered on the g-C_(3)N_(4)surface can form a built-in electric field at the interface to accelerate the transfer of photoexcited electrons from g-C_(3)N_(4)to NiP_(2),crucial for hindering the recombination of electron-hole pairs.Moreover,the energy barrier of hydrogen evolution reaction can also vastly reduce when combined NiP_(2)and g-C_(3)N_(4)to construct NiP_(2)/g-C_(3)N_(4)heterojunction.This work represents a method through combing experimental and theoretical tools to thoroughly investigate the mechanism of photocatalytic process.展开更多
A novel CMOS image sensor(CIS) pinned photodiode(PPD) pixel, named as O-T pixel, is proposed and investigated by TCAD simulations. Compared with the conventional PPD pixel, the proposed pixel features the overlapping ...A novel CMOS image sensor(CIS) pinned photodiode(PPD) pixel, named as O-T pixel, is proposed and investigated by TCAD simulations. Compared with the conventional PPD pixel, the proposed pixel features the overlapping gate(OG)and the temporary storage diffusing(TSD) region, based on which the several-nanosecond-level charge transfer could be achieved and the complete charge transfer from the PPD to the floating node(FD) could be realized. And systematic analyses of the influence of the doping conditions of the proposed processes, the OG length, and the photodiode length on the transfer performances of the proposed pixel are conducted. Optimized simulation results show that the total charge transfer time could reach about 5.862 ns from the photodiode to the sensed node and the corresponding charge transfer efficiency could reach as high as 99.995% in the proposed pixel with 10 μm long photodiode and 2.22 μm long OG. These results demonstrate a great potential of the proposed pixel in high-speed applications.展开更多
Due to the advantages of low energy consumption and high CO_(2) selectivity, the development of solid amine-based materials has been regarded as a hot research topic in the field of DAC for the past decades.The adsorp...Due to the advantages of low energy consumption and high CO_(2) selectivity, the development of solid amine-based materials has been regarded as a hot research topic in the field of DAC for the past decades.The adsorption capacity and stability over multiple cycles have been the top priorities for evaluation of practical application value. Herein, we synthesized a novel DAC material by loading TEPA onto defect-rich Mg_(0.55)Al-O MMOs with enhanced charge transfer effect. The optimal Mg_(0.55)Al-O-TEPA67% demonstrates the highest CO_(2)uptake of(3.0 mmol g^(-1)) and excellent regenerability, maintaining ~90% of the initial adsorption amount after 80 adsorption/desorption cycles. The in situ DRIFTS experiments suggested the formation of bicarbonate species under wet conditions. DFT calculations indicated that the stronger bonding between Mg_(0.55)Al-O support and solid amine was caused by the abundance of oxygen defects on MMOs confirmed by XPS and ESR, which favors the charge transfer between the support and amine,resulting in intense interaction and excellent regenerability. This work for the first time conducted comprehensive and systematic investigation on the stabilization mechanism for MMOs supported solid amine adsorbents with highest uptake and superior cyclic stability in depth, which is different from the most popular SiO_(2)-support, thus providing facile strategy and comprehensive theoretical mechanism support for future research about DAC materials.展开更多
The twisted intramolecular charge transfer and the excited state relaxation of 1-aminoanthraquinone (1-NH2-AQ) in different solvents are investigated using quantum chemical calculations in this paper. The geometries...The twisted intramolecular charge transfer and the excited state relaxation of 1-aminoanthraquinone (1-NH2-AQ) in different solvents are investigated using quantum chemical calculations in this paper. The geometries of the ground state are optimized both in gas and solvents based on the high-level ab initio calculations, the lowest excited singlet state geometry is optimized only in gas for simplicity. An intramolecular charge transfer property is substantiated by the large change of dipole moments between the So and S1 states. The mechanism of twisted intramolecular charge transfer is proposed by the conformational relaxation on the potential surface of the $1 state. Quantum chemical calculations present that internal conversion and intersystem crossing are important approaches to the ultrafast deactivation of the S~ state via the twisting of the amino group, The smaller energy difference between the So and S1 state shows that the internal conversion process is much faster in a polar solvent than in a nonpolar solvent. Energy intersections between the T2 and S1 state in cyclohexane and dioxane indicate a faster intersystem crossing process in them than in ethanol. These theoretical results agree well with the previous experimental results. Energy barriers are predicted on the potential surface of the S1 state, and they have a positive correlation to solvent viscosity, and the timescale of twisted intra-molecular charge transfer in dioxane is predicted to be longer than in cyclohexane and ethanol.展开更多
The spectophotometry of charge transfer (CT) complexes of tetrachloro-p-benzoquinone(TCB) with tertiary amine [triethylamine (TEA), triphylamine (TPA), N,N-dimethylphenylamine(DMPA), N-ethylcarbazole (ECZ)] have been ...The spectophotometry of charge transfer (CT) complexes of tetrachloro-p-benzoquinone(TCB) with tertiary amine [triethylamine (TEA), triphylamine (TPA), N,N-dimethylphenylamine(DMPA), N-ethylcarbazole (ECZ)] have been studied in dichloromethane in UV-visible region.The CT complexes parameter, molar ratio of reactAnts in complex, molar extinction coefficient equilibrium constant KCT, free energy G and dissociation energy of the CT complex excited stateE, have also been estimated and discussed.展开更多
Ce^4+-doped Ca2SnO4 with a one-dimensional structure, which emits bright blue light, is prepared by using a solid-state reaction method. The x-ray diffraction results show that the Ce^4+ ions doped in Ca2SnO4 occupy...Ce^4+-doped Ca2SnO4 with a one-dimensional structure, which emits bright blue light, is prepared by using a solid-state reaction method. The x-ray diffraction results show that the Ce^4+ ions doped in Ca2SnO4 occupy the Sn^4+ sites. The excitation and emission spectra of Ca2Sn1-xCexO4 appear to have broad bands with peaks at - 268nm and -442nm, respectively. A long excited-state lifetime (-83μs) for the emission from Ca2Sn1-xCexO4 suggests that the luminescence originates from a ligand-to-metal Ce^4+ charge transfer (CT). The luminescent properties of Ca2Snl_xCexO4 have been compared with those of Sr2CeO4, which is the only material reported so far to show Ce^4+ CT luminescence. More interestingly, it is observed that the emission intensity of Ca2Sn1-xCexO4 with a small doping concentration (x - 0.03) is comparable to that of Sr2CeO4 in which the concentration of active centre is 100%.展开更多
The nonradiative charge-transfer cross sections for protons colliding with Rb(5s) atoms are calculated by using the quantum-mechanical molecularorbital close-coupling method in an energy range of 10-a keV-10 keV. Th...The nonradiative charge-transfer cross sections for protons colliding with Rb(5s) atoms are calculated by using the quantum-mechanical molecularorbital close-coupling method in an energy range of 10-a keV-10 keV. The total and state-selective charge-transfer cross sections are in good agreement with the experimental data in the relatively low energy region. The importance of rotational coupling for chargetransfer process is stressed. Compared with the radiative charge-transfer process, nonradiative charge transfer is a dominant mechanism at energies above 15 eV. The resonance structures of state-selective charge-transfer cross sections arising from the competition among channels are analysed in detail. The radiative and nonradiative1 charge-transfer rate coefficients from low to high temperature are presented.展开更多
基金financially supported by the Outstanding Youth Scientific Research Project for Colleges and Universities of Anhui Province of China (2022AH020054)the Anhui Provincial Natural Science Foundation (2208085Y06)+2 种基金the National Natural Science Foundation of China (Nos.21975001 and U2002213)the Support Program of Excellent Young Talents in Anhui Provincial Colleges and Universities (gxyq ZD2022034)the Double Tops Joint Fund of the Yunnan Science and Technology Bureau and Yunnan University (2019FY003025)。
文摘The interaction between metal and support is critical in oxygen catalysis as it governs the charge transfer between these two entities,influences the electronic structures of the supported metal,affects the adsorption energies of reaction intermediates,and ultimately impacts the catalytic performance.In this study,we discovered a unique charge transfer reversal phenomenon in a metal/carbon nanohybrid system.Specifically,electrons were transferred from the metal-based species to N-doped carbon,while the carbon support reciprocally donated electrons to the metal domain upon the introduction of nickel.This led to the exceptional electrocatalytic performances of the resulting Ni-Fe/Mo_(2)C@nitrogen-doped carbon catalyst,with a half-wave potential of 0.91 V towards oxygen reduction reaction(ORR)and a low overpotential of 290 m V at 10 mA cm^(-2)towards oxygen evolution reaction(OER)under alkaline conditions.Additionally,the Fe-Ni/Mo_(2)C@carbon heterojunction catalyst demonstrated high specific capacity(794 mA h g_(Zn)~(-1))and excellent cycling stability(200 h)in a Zn-air battery.Theoretical calculations revealed that Mo_(2)C effectively inhibited charge transfer from Fe to the support,while secondary doping of Ni induced a charge transfer reversal,resulting in electron accumulation in the Fe-Ni alloy region.This local electronic structure modulation significantly reduced energy barriers in the oxygen catalysis process,enhancing the catalytic efficiency of both ORR and OER.Consequently,our findings underscore the potential of manipulating charge transfer reversal between the metal and support as a promising strategy for developing highly-active and durable bi-functional oxygen electrodes.
基金the financial support from the National Science Foundation of China(22078190)the National Key R&D Plan of China(2020YFB1505802)。
文摘In the development of Li-ion batteries(LIBs)with high energy/power density,long cycle-life,fast charging,and high safety,an insight into charge transfer reactions is required.Although electrochemical impedance spectroscopy(EIS)is regarded as a powerful diagnosis tool,it is not a direct but an indirect measurement.With respect to this,some critical questions need to be answered:(i)why EIS can reflect the kinetics of charge transfer reactions;(ii)what the inherent logical relationship between impedance models under different physical scenes is;(iii)how charge transfer reactions compete with each other at multiple scales.This work aims at answering these questions via developing a theory framework so as to mitigate the blindness and uncertainty in unveiling charge transfer reactions in LIBs.To systematically answer the above questions,this article is organized into a three-in-one(review,tutorial,and research)type and the following contributions are made:(i)a brief review is given for impedance model development of the LIBs over the past half century;(ii)an open source code toolbox is developed based on the unified impedance model;(iii)the competive mechanisms of charge transfer reactions are unveiled based on the developed EIS-Toolbox@LIB.This work not only clarifies theoretical fundamentals,but also provides an easy-to-use open source code for EIS-Toolbox@LIB to optimize fast charge/discharge,mitigate cycle aging,and improve energy/power density.
基金conducted by the Fundamental Research Center of Artificial Photosynthesis(FReCAP)financially supported by the National Natural Science Foundation of China(22172011 and 22088102)+1 种基金the National Key R&D Program of China(2022YFA0911904)the Fundamental Research Funds for the Central Universities(DUT22LK06,DUT22QN213 and DUT23LAB611)。
文摘Inspired by the function of crucial components in photosystemⅡ(PSⅡ),electrochemical and dyesensitized photoelectrochemical(DSPEC)water oxidation devices were constructed by the selfassembly of well-designed amphipathic Ru(bda)-based catalysts(bda=2,2'-bipyrdine-6,6'-dicarbonoxyl acid)and aliphatic chain decorated electrode surfaces,forming lipid bilayer membrane(LBM)-like structures.The Ru(bda)catalysts on electrode-supported LBM films demonstrated remarkable water oxidation performance with different O-O formation mechanisms.However,compared to the slow charge transfer process,the O-O formation pathways did not determine the PEC water oxidation efficiency of the dyesensitized photoanodes,and the different reaction rates for similar catalysts with different catalytic paths did not determine the PEC performance of the DSPECs.Instead,charge transfer plays a decisive role in the PEC water oxidation rate.When an indolo[3,2-b]carbazole derivative was introduced between the Ru(bda)catalysts and aliphatic chain-modified photosensitizer in LBM films,serving as a charge transfer mediator for the tyrosine-histidine pair in PSⅡ,the PEC water oxidation performance of the corresponding photoanodes was dramatically enhanced.
基金financially supported by the Industrial Technology Innovation Program of IMAST(No.2023JSYD 01003)the National Natural Science Foundation of China(Nos.52104292 and U2341209)。
文摘Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical performance.Recently,considerable efforts have been devoted to this endeavor.This review systematically summarizes the impact of built-in electric fields on enhancing charge separation and transfer mechanisms,focusing on the modulation of built-in electric fields in terms of depth and orderliness.First,mechanisms and tuning strategies for built-in electric fields are explored.Then,the state-of-the-art works regarding built-in electric fields for modulating charge separation and transfer are summarized and categorized according to surface and interface depth.Finally,current strategies for constructing bulk built-in electric fields in photoelectrodes are explored,and insights into future developments for enhancing charge separation and transfer in high-performance photoelectrochemical applications are provided.
文摘This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% impurity concentration. Our comprehensive analysis encompasses structural properties, electronic band structures, and charge density distributions. The optimized lattice constant and band gap energy of 3C-SiC were found to be 4.373 Å and 1.36 eV respectively, which is in agreement with previous research (Bui, 2012;Muchiri et al., 2018). Our results show that B doping narrows the band gap, enhances electrical conductivity, and influences charge transfer interactions. The charge density analysis reveals substantial interactions between B dopants and surrounding carbon atoms. This work not only enhances our understanding of the material’s electronic properties, but also highlights the importance of charge density analysis for characterizing charge transfer mechanisms and their implications in the 3C-SiC semiconductors.
基金National Key R&D Program of China,Grant/Award Number:2020YFA0710000National Natural Science Foundation of China,Grant/Award Numbers:22008170,21978200,22161142002,22121004。
文摘The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,while the challenge associated with N_(2) activation highlights the demand for efficient electrocatalysts.Herein,we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet(PdCu/B)behave as efficient NRR electrocatalysts toward NH_(3) synthesis.Theoretical and experimental results confirm that the highly efficient NH_(3) synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site,which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N_(2) and thus optimizes the reaction pathway of NRR over the separated Pd sites.Compared with monometallic Pd/B and Cu/B,the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH_(3) synthesis.This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.
基金supported by the National Natural Science Foundation of China(21573059 and U1704251)the Overseas Expertise Introduction Project for Discipline Innovation(D17007)the Natural Science Foundation of Henan Province(212300410178)。
文摘The great challenges are remained in constructing graphite-based anode with well built-in structures to accelerate kinetics and enhance stability in the advanced K-ion batteries(KIBs).Here,we firstly report the design of expanded graphite cohered by N,B bridge-doping carbon patches(NBEG)for efficient K-ion adsorption/diffusion and long-term durability.It is the B co-doping that plays a crucial role in maximizing doping-site utilization of N atoms,balancing the adsorption-diffusion kinetics,and promoting the charge transfer between NBEG and K ions.Especially,the robust lamellar structure,suitable interlayer distance,and rich active sites of the designed NBEG favor the rapid ion/electron transfer pathways and high K-ion storage capacity.Consequently,even at a low N,B doping concentration(4.36 at%,2.07 at%),NBEG anode shows prominent electrochemical performance for KIBs,surpassing most of the advanced carbon-based anodes.Kinetic studies,density functional theory simulations,and in-situ Raman spectroscopy are further performed to reveal the K-ion storage mechanism and confirm the critical actions of co-doping B.This work offers the new methods for graphite-electrode design and the deeper insights into their energy storage mechanisms in KIBs.
基金supported by the National Natural Sci-ence Foundation of China(No.U1904196,No.82073699)the Natural Science Foundation of Henan(No.222300420055).
文摘Partial genetically encoded 4-hy-droxybenzylidene-imidazolinone(HBI)-type chromophores are new promising fluorescent probes,which are suitable for imaging and detection of living cells.How-ever,the lack of infrared chro-mophores hinders the develop-ment seriously.Here more than 30 HBI-type chromophores with reg-ular structure modifications were employed and typical spectral redshift change laws and mechanisms were investigated by quantum methods.Results show that both one-photon spectrum(OPS,absorption/emission)and two-photon absorption(TPA)can achieve large redshift via either extending conjugated lengths of frag-3 or enlarging conjugated areas of frag-1 of HBI skeleton.Spectral redshifts of all chromophores are highly related to intramolecular charge transfer(ICT),but neutral ones are closely related to the total ICT or electron-accept-ing-numbers of frag-3,and the high correlative factor of anions is the aromaticity of frag-2 bridge.The frag-2 bridge with high aromaticity can open a reverse charge transfer channel in anion relative to neutral,obtaining significant redshift.Based on analysis,a new 6-hydroxyl-naphthalene-imidazolinone(HNI)series,which have larger conjugated area in frag-1,are pre-dicted.The OPS and TPA of anionic HNI ones acquire about 76−96 nm and 119−146 nm red-shift relative to traditional HBI series respectively as a whole.The longest emission of anionic HNI-4 realizes more 244 nm redshift relative to HBI-1.Our work clarifies worthy spectral reg-ularities and redshift mechanisms of HBI-type chromophores and provides valuable design strategy for infrared chromophores synthesis in experiment.
基金Project supported by the National Natural Science Foundation of China(Grant No.61804047)the Training Program for the Natural Science Foundation of Henan Normal University,China(Grant No.2017PL02)+2 种基金the Scientific Research Start-up Foundation for Ph D of Chaohu University,China(Grant No.KYQD-2023012)the Natural Science Foundation Henan Province of China(Grant No.232300421236)the High Performance Computing Center(HPCC)of Henan Normal University,China。
文摘Type-Ⅱband alignment can realize the efficient charge transfer and separation at the semiconductor heterointerface,which results in photoluminescence(PL)quenching.Recently,several researches demonstrated great enhancement of localized PL at the interface of type-Ⅱtwo-dimensional(2D)heterostructure.However,the dominant physical mechanism of this enhanced PL emission has not been well understood.In this work,we symmetrically study the exciton dynamics of type-Ⅱlateral heterostructures of monolayer MoS_(2) and WS_(2) at room temperatures.The strong PL enhancement along the one-dimensional(1D)heterointerface is associated with the trion emission of the WS_(2) shell,while a dramatic PL quenching of neutral exciton is observed on the MoS_(2) core.The enhanced quantum yield of WS2trion emission can be explained by charge-transfer-enhanced photoexcited carrier dynamics,which is facilitated by resonance hole transfer from MoS_(2) side to WS_(2) side.This work sheds light on the 1D exciton photophysics in lateral heterostructures,which has the potential to lead to new concepts and applications of optoelectronic device.
基金supported by the National Natural Science Foundation of China(62171172).
文摘CMOS image sensors produced by the existing CMOS manufacturing process usually have difficulty achieving complete charge transfer owing to the introduction of potential barriers or Si/SiO_(2)interface state traps in the charge transfer path,which reduces the charge transfer efficiency and image quality.Until now,scholars have only considered mechanisms that limit charge transfer from the perspectives of potential barriers and spill back effect under high illumination condition.However,the existing models have thus far ignored the charge transfer limitation due to Si/SiO_(2)interface state traps in the transfer gate channel,particularly under low illumination.Therefore,this paper proposes,for the first time,an analytical model for quantifying the incomplete charge transfer caused by Si/SiO_(2)interface state traps in the transfer gate channel under low illumination.This model can predict the variation rules of the number of untransferred charges and charge transfer efficiency when the trap energy level follows Gaussian distribution,exponential distribution and measured distribution.The model was verified with technology computer-aided design simulations,and the results showed that the simulation results exhibit the consistency with the proposed model.
基金supported by the National Science Fund for Distinguished Young Scholars(No.51925703)National Natural Science Foundation of China(Nos.51637010,51707186 and 51807190)。
文摘This paper is aimed to investigate the effect of packing material on plasma characteristic from the viewpoint of charge transfer process.Both the charge accumulation and release processes in the dielectric barrier discharge reactor and packed-bed reactor were investigated by measuring voltage and current waveforms and taking ICCD images.The packing material was ZrO2 pellets and the reactors were driven by a parameterized nanosecond pulse source.The quantity of transferred charges in the dielectric barrier discharge reactor was enhanced when decreasing pulse rise time or increasing pulse width(within 150 ns),but reduced when the gas gap was packed with pellets.The quantity of accumulated charges in the primary discharge was larger than the quantity of released charges in the secondary discharges in the dielectric barrier discharge reactor,but they were almost equal in the packed-bed reactor.It indicates that the discharge behavior has been changed from the view of charge transfer process once the gas gap was packed with pellets,and the ICCD images confirmed it.
基金Project supported by the National Nature Science Foundation of China (Grant No 50272063) and the Foundation for Excellent Talents of Anhui Province, China (Grant No 2001Z016).
文摘The variational method is applied to the study of charge transfer in dry DNA by using an extended Holstein small polaron model in two cases: the site-dependent flnite-chain discrete case and the site-independent continuous one. The treatments in the two cases are proven to be consistent in theory and calculation. Discrete and continuous treatments of Holstein model both can yield a nonlinear equation to describe the charge migration in an actual long-range DNA chain. Our theoretical results of binding energy Eb, probability amplitude of charge carrier Ф and the relation between energy and charge-lattice coupling strength are in accordance with the available experimental results and recent theoretical calculations.
文摘1. The transient absorption spectra of the WS2 monolayer sample.In the measurement of the transient absorption spectra of the WS2 monolayer sample, A 400-nm (3.1eV) pump pulse with a peak fluence of about 10μJ/cm2excites the electrons from the valence band into the conduction band,the
基金supported by the National Natural Science Foundation of China(Grant Nos.U1862105,22108214,22050410267)Natural Science Basic Research Plan in Shaanxi Province of China(Grant Nos.2017JZ001,2018KJXX-008)+3 种基金Fundamental Research Funds for the Central Universities(Grant No.cxtd2017004)China Postdoctoral Science Foundation(Grant No.2021TQ0262)the Promotion Plan for Young People of Shaanxi Association for Science and Technology(20210605)K.C.Wong Education Foundation,Hong Kong,China。
文摘In this work,a novel NiP_(2)/g-C_(3)N_(4)heterojunction via homogeneous precipitation method assisted by thermal phosphorization reaction was designed and constructed,and the optimized sample showed the excellent photocatalytic H_(2)evolution activity under visible-light irradiation,which was nearly 112 times higher than that of pristine g-C_(3)N_(4)sample.Experimental characterizations and DFT calculations demonstrated that the NiP_(2)nanoparticles covered on the g-C_(3)N_(4)surface can form a built-in electric field at the interface to accelerate the transfer of photoexcited electrons from g-C_(3)N_(4)to NiP_(2),crucial for hindering the recombination of electron-hole pairs.Moreover,the energy barrier of hydrogen evolution reaction can also vastly reduce when combined NiP_(2)and g-C_(3)N_(4)to construct NiP_(2)/g-C_(3)N_(4)heterojunction.This work represents a method through combing experimental and theoretical tools to thoroughly investigate the mechanism of photocatalytic process.
基金Project supported by the National Natural Science Foundation of China(Grant No.61574112)。
文摘A novel CMOS image sensor(CIS) pinned photodiode(PPD) pixel, named as O-T pixel, is proposed and investigated by TCAD simulations. Compared with the conventional PPD pixel, the proposed pixel features the overlapping gate(OG)and the temporary storage diffusing(TSD) region, based on which the several-nanosecond-level charge transfer could be achieved and the complete charge transfer from the PPD to the floating node(FD) could be realized. And systematic analyses of the influence of the doping conditions of the proposed processes, the OG length, and the photodiode length on the transfer performances of the proposed pixel are conducted. Optimized simulation results show that the total charge transfer time could reach about 5.862 ns from the photodiode to the sensed node and the corresponding charge transfer efficiency could reach as high as 99.995% in the proposed pixel with 10 μm long photodiode and 2.22 μm long OG. These results demonstrate a great potential of the proposed pixel in high-speed applications.
基金supported by the Fundamental Research Funds for the Central Universities (2019JQ03015)the National Natural Science Foundation of China (42075169, U1810209)the Beijing Municipal Education Commission through the Innovative Transdisciplinary Program “Ecological Restoration Engineering”。
文摘Due to the advantages of low energy consumption and high CO_(2) selectivity, the development of solid amine-based materials has been regarded as a hot research topic in the field of DAC for the past decades.The adsorption capacity and stability over multiple cycles have been the top priorities for evaluation of practical application value. Herein, we synthesized a novel DAC material by loading TEPA onto defect-rich Mg_(0.55)Al-O MMOs with enhanced charge transfer effect. The optimal Mg_(0.55)Al-O-TEPA67% demonstrates the highest CO_(2)uptake of(3.0 mmol g^(-1)) and excellent regenerability, maintaining ~90% of the initial adsorption amount after 80 adsorption/desorption cycles. The in situ DRIFTS experiments suggested the formation of bicarbonate species under wet conditions. DFT calculations indicated that the stronger bonding between Mg_(0.55)Al-O support and solid amine was caused by the abundance of oxygen defects on MMOs confirmed by XPS and ESR, which favors the charge transfer between the support and amine,resulting in intense interaction and excellent regenerability. This work for the first time conducted comprehensive and systematic investigation on the stabilization mechanism for MMOs supported solid amine adsorbents with highest uptake and superior cyclic stability in depth, which is different from the most popular SiO_(2)-support, thus providing facile strategy and comprehensive theoretical mechanism support for future research about DAC materials.
基金Project supported by the Program of Outstanding Innovation Team of Hubei Normal University,China(Grant No.T201502)the Natural Science Foundation of Hubei Province,China(Grant Nos.2014CFB349 and 2016CFC742)the National Natural Science Foundation of China(Grant No.11674355)
文摘The twisted intramolecular charge transfer and the excited state relaxation of 1-aminoanthraquinone (1-NH2-AQ) in different solvents are investigated using quantum chemical calculations in this paper. The geometries of the ground state are optimized both in gas and solvents based on the high-level ab initio calculations, the lowest excited singlet state geometry is optimized only in gas for simplicity. An intramolecular charge transfer property is substantiated by the large change of dipole moments between the So and S1 states. The mechanism of twisted intramolecular charge transfer is proposed by the conformational relaxation on the potential surface of the $1 state. Quantum chemical calculations present that internal conversion and intersystem crossing are important approaches to the ultrafast deactivation of the S~ state via the twisting of the amino group, The smaller energy difference between the So and S1 state shows that the internal conversion process is much faster in a polar solvent than in a nonpolar solvent. Energy intersections between the T2 and S1 state in cyclohexane and dioxane indicate a faster intersystem crossing process in them than in ethanol. These theoretical results agree well with the previous experimental results. Energy barriers are predicted on the potential surface of the S1 state, and they have a positive correlation to solvent viscosity, and the timescale of twisted intra-molecular charge transfer in dioxane is predicted to be longer than in cyclohexane and ethanol.
文摘The spectophotometry of charge transfer (CT) complexes of tetrachloro-p-benzoquinone(TCB) with tertiary amine [triethylamine (TEA), triphylamine (TPA), N,N-dimethylphenylamine(DMPA), N-ethylcarbazole (ECZ)] have been studied in dichloromethane in UV-visible region.The CT complexes parameter, molar ratio of reactAnts in complex, molar extinction coefficient equilibrium constant KCT, free energy G and dissociation energy of the CT complex excited stateE, have also been estimated and discussed.
文摘Ce^4+-doped Ca2SnO4 with a one-dimensional structure, which emits bright blue light, is prepared by using a solid-state reaction method. The x-ray diffraction results show that the Ce^4+ ions doped in Ca2SnO4 occupy the Sn^4+ sites. The excitation and emission spectra of Ca2Sn1-xCexO4 appear to have broad bands with peaks at - 268nm and -442nm, respectively. A long excited-state lifetime (-83μs) for the emission from Ca2Sn1-xCexO4 suggests that the luminescence originates from a ligand-to-metal Ce^4+ charge transfer (CT). The luminescent properties of Ca2Snl_xCexO4 have been compared with those of Sr2CeO4, which is the only material reported so far to show Ce^4+ CT luminescence. More interestingly, it is observed that the emission intensity of Ca2Sn1-xCexO4 with a small doping concentration (x - 0.03) is comparable to that of Sr2CeO4 in which the concentration of active centre is 100%.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10979007,11025417,11179041,and 11004014)the NSAF (Grant No. 10876043)
文摘The nonradiative charge-transfer cross sections for protons colliding with Rb(5s) atoms are calculated by using the quantum-mechanical molecularorbital close-coupling method in an energy range of 10-a keV-10 keV. The total and state-selective charge-transfer cross sections are in good agreement with the experimental data in the relatively low energy region. The importance of rotational coupling for chargetransfer process is stressed. Compared with the radiative charge-transfer process, nonradiative charge transfer is a dominant mechanism at energies above 15 eV. The resonance structures of state-selective charge-transfer cross sections arising from the competition among channels are analysed in detail. The radiative and nonradiative1 charge-transfer rate coefficients from low to high temperature are presented.