A new analytical potential energy function for diatomic molecular ion XY+ is proposed based on the energy consistent method (ECM). The Coulomb potential included in the new ionic potential contains multipole correctio...A new analytical potential energy function for diatomic molecular ion XY+ is proposed based on the energy consistent method (ECM). The Coulomb potential included in the new ionic potential contains multipole corrections, converges quickly and is variationally, changeable. The new potential and the ECM are applied to variationally studying the potential energies of eight electronic states of several diatomic molecular ions: the A2π state of CO+, the X2∑ g + state of Li 2 + , the X2∑ g + state of He 2 + , the 12∏u state of Na 2 + , the A2∏u state of N 2 + , the X1∑+ state of KrH+, the X2∑+ state of SiO+ and the A2π state of SO+ ion. The present results agree excellently with the experiment-based Rydberg-Klein-Rees (RKR) potentials, and are superior to the commonly used Huxley-Murrell-Sorbie (HMS) analytical potentials, and are better in some cases than some quantum mechanicalab initio potentials in the ionic asymptotic and dissociation regions.展开更多
The molecular dissociation energies of some electronic states of hydride and N2 molecules were studied using a parameter-free analytical formula suggested in this study and the algebraic method (AM) proposed recently....The molecular dissociation energies of some electronic states of hydride and N2 molecules were studied using a parameter-free analytical formula suggested in this study and the algebraic method (AM) proposed recently. The results show that the accurate AM dissociation energies DeAM agree excellently with experimental dissociation energies Deexpt, and that the dissociation energy of an electronic state such as the 23Δg state of 7Li2 whose experimental value is not available can be predicted using the new formula.展开更多
In this paper,the possibility of the monatomic chain (MC) formation for ZnO material was studied by molecular dynamics (MD) simulation.The process of MC formation and the effects of temperature,strain rate and size we...In this paper,the possibility of the monatomic chain (MC) formation for ZnO material was studied by molecular dynamics (MD) simulation.The process of MC formation and the effects of temperature,strain rate and size were studied extensively.The tensile process can be divided to be five stages and the ZnO diatomic chain (DC) can be found.The MD results show that most atoms in MC came from the original surface of ZnO nanowires (NWs).Temperature and strain rate are two important factors affecting the process,and both high temperature and low strain rate in a certain range would be beneficial to the formation of DC.Moreover,the effects of strain rate and temperature could attribute to the Arrhenius model and the energy release mechanism.Furthermore,multi-shell structure was found for the samples under tensile strain and the layer-layer distance was about 3.Our studies based on density functional theory showed that the most stable structure of ZnO DC was confirmed to be linear,and the I-V curve was also got using ATK.展开更多
The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the thr...The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the three-dimensional graphs of the potentials have been drawn. We have systematically investigated this kind of the potentials for a series of the diatomic molecules, such as HF, HCl, HBr, LiF, LiCl, and so on. The three-dimensional graph can clearly display the variation of the potential felt by an electron within a molecule and get a deeper understanding of the electronic motion and chemical bonding within a molecule.展开更多
In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active ...In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.展开更多
The design of diatomic catalysts with uniformly dispersed metal atoms is expected to improve catalytic performance,which is conducive to the intensive comprehending of the synergistic mechanism between dual-metal site...The design of diatomic catalysts with uniformly dispersed metal atoms is expected to improve catalytic performance,which is conducive to the intensive comprehending of the synergistic mechanism between dual-metal sites for the oxygen evolution reaction(OER)at the atomic level.Herein,we design a strategy to immobilize bimetallic Fe-Co atoms onto nitrogen-doped graphene to obtain a diatomic catalyst(DA-FC-NG)with FeN_(3)-CoN_(3) configuration.The DA-FC-NG shows excellent OER activity with a low overpotential(η_(10)=268 mV),which is superior to commercial iridium dioxide catalysts.Theoretical calculations uncover that the excellent activity of DA-FC-NG is due to the interaction between Fe and Co diatoms,which causes charge rearrangement and induces the adsorption of intermediates on the Fe-O-Co bridge structure,thus improving the catalytic OER performance.This work is of great significance for the design of highly active diatomic catalysts to replace noble metal catalysts for energy-related applications.展开更多
Diatomic catalysts(DACs)with two adjacent metal atoms supported on graphene can offer diverse functionalities,overcoming the inherent limitations of single atom catalysts(SACs).In this study,density functional theory ...Diatomic catalysts(DACs)with two adjacent metal atoms supported on graphene can offer diverse functionalities,overcoming the inherent limitations of single atom catalysts(SACs).In this study,density functional theory calculations were conducted to investigate the reactivity of the carbon dioxide(CO_(2))reduction reaction(CO_(2)RR)on metal sites of both DACs and SACs,as well as their synergistic effects on activity and selectivity.Calculation of the Gibbs free energies of CO_(2)RR and associated values of the limiting potentials to generate C_(1) products showed that Cu acts as a promoter rather than an active catalytic centre in the catalytic CO_(2)conversion on heteronuclear DACs(CuN_(4)-MN_(4)),improving the catalytic activity on the other metal compared to the related SAC MN_(4).Cu enhances the initial reduction of CO_(2)by promoting orbital hybridization between the key intermediate*COOH 2p-orbitals and the metals 3d-orbitals around the Fermi level.This degree of hybridization in the DACs CuN_(4)-MN_(4) decreases from Fe to Co,Ni,and Zn.Our work demonstrates how Cu regulates the CO_(2)RR performance of heteronuclear DACs,offering an effective approach to designing practical,stable,and high-performing diatomic catalysts for CO_(2)electroreduction.展开更多
Information about electronic excited states of molecular anions plays an important role in investigating electron attachment and detachment processes.Here we present a high-level theoretical study of the electronic st...Information about electronic excited states of molecular anions plays an important role in investigating electron attachment and detachment processes.Here we present a high-level theoretical study of the electronic structures of 12 alkali-metal-containing diatomic anions MX-(MX = LiH,LiF,LiCl,NaF,NaCl,NaBr,RbCl,KCl,KBr,RbI,KI and CsI).The equation-of-motion electron-attachment coupled-cluster singles and doubles(EOM-EA-CCSD) method is used to calculate the electron binding energies(EBEs) of 10 electronic excited states of each of the 12 molecule anions.With addition of different s-/p-/d-type diffusion functions in the basis set,we have identified possible excited dipole bound states(DBSs) of each anion.With the investigation of EBEs on the 12 MXs with dipole moment(DM) up to 12.1 D,we evaluate the dependence of the number of anionic excited DBSs on molecular DM.The results indicate that there are at least two or three DBSs of anions with a molecular DM larger than 7 D and a molecule with DM > 10 D can sustain a π-DBS of the anion.Our study has some implications for the excited DBS electronic states of alkali-metal-containing diatomic molecules.展开更多
The coexistence of multi-component active sites like single-atom sites,diatomic sites(DAS)and nanoclusters is shown to result in superior performances in the hydrogen evolution reaction(HER).Metal diatomic sites are m...The coexistence of multi-component active sites like single-atom sites,diatomic sites(DAS)and nanoclusters is shown to result in superior performances in the hydrogen evolution reaction(HER).Metal diatomic sites are more complex than single-atom sites but their unique electronic structures can lead to significant enhancement of the HER kinetics.Although the synthesis and identification of DAS is usually challenging,we report a simple access to a diatomic catalyst by anchoring Co-Ru DAS on nitrogen-doped carbon supports along with Ru nanoparticles(NPs).Experimental and theoretical results revealed the atomic-level characteristics of Co-Ru sites,their strong electronic coupling and their synergy with Ru NPs within the catalyst.The unique electronic structure of the catalyst resulted in an excellent HER activity and stability in alkaline media.This work provides a valuable insight into a widely applicable design of diatomic catalysts with multi-component active sites for highly efficient HER electrocatalysis.展开更多
New analytical expression and numerical approach are suggested to calculate dissociation energiesD e of diatomic molecular states using an extreme value method (EVM). Studies on some electronic states of OH, BH, N2, B...New analytical expression and numerical approach are suggested to calculate dissociation energiesD e of diatomic molecular states using an extreme value method (EVM). Studies on some electronic states of OH, BH, N2, Br2, CIF and CO molecules show that the accuracy of the EVM dissociation energies depends on the number of correct vibrational constants used in the calculations. The convergence qualities ofD e are suggested to be an alternative physical criterion to measure the qualities of the various sets of vibrational constants from different literature for the same diatomic state.展开更多
Na_(3)V_(2)(PO_(4))_(3)is considered as one of the most promising cathodes for sodium ion batteries due to its excellent thermal stability,long cycle life and high energy density.However,the inferior intrinsic electro...Na_(3)V_(2)(PO_(4))_(3)is considered as one of the most promising cathodes for sodium ion batteries due to its excellent thermal stability,long cycle life and high energy density.However,the inferior intrinsic electronic conductivity which brings about the poor rate capability and cycling performance hinders its commercial application.Herein,the S-N co-doped carbon-coated Na_(3)V_(2)(PO_(4))_(3)(NVP@SNC)has been synthesized to resolve the problem.The prepared NVP@SNC forms a hierarchical structure assembled with nanosheets,which is in favor of the electrolyte infiltration and shortening the Na^(+)transmission distance.Numerous lattice defects can be induced in carbon layer by the co-doped elements(S-N),which reduce the Na^(+)diffusion energy barriers and provide adequate Na^(+)migration channels,thus jointly boosting the Na^(+)diffusion coefficient.Consequently,the NVP@SNC cathode shows a high reversible capacity with outstanding rate performance and super long-cycle stability.When discharged at 2.0C,it delivers the capacity near to the theoretical value with a capacity retention of 88.7%after 400cycles.Even if the current is as high as 50.0C,a high capacity of 58.6 mAh·g^(-1)has been released,and41.4 mAh·g^(-1)has been remained after the super long cycling of 4000 circles.This study is expected to supply a new thought of developing high-performance cathodes by diatomic doping for sodium ion battery.展开更多
Diatomic site catalysts(DACs)with two adjacent atomic metal species can provide synergistic interactions and more sophisticated functionalities to break the bottleneck of intrinsic drawbacks of single atom catalysts(S...Diatomic site catalysts(DACs)with two adjacent atomic metal species can provide synergistic interactions and more sophisticated functionalities to break the bottleneck of intrinsic drawbacks of single atom catalysts(SACs).Herein,we have designed a CuZn diatomic site(CuZn-DAS)electrocatalyst with unique coordination structure(CuN_(4)-ZnN_(4))by anchoring and ordering the spatial distance between the metal precursors on the carbon nitride(C_(3)N_(4))derived N-doped carbon(NC)substrate.The CuZn-DAS/NC shows high activity and selectivity for electroreduction CO_(2)into CO.The Faradaic efficiency for CO of CuZn-DAS/NC(98.4%)is higher than that of Cu single atomic site on NC(Cu-SAS/NC)(36.4%)and Zn single atomic site on NC(Zn-SAS/NC)(66.8%)at-0.6 V versus reversible hydrogen electrode(vs.RHE).In situ characterizations reveal that the CuZn-DAS is more favorable for the formation and adsorption of^(*)COOH than those of the electrocatalysts with single atomic site.Theorical calculations show that the charge redistribution of Zn site in CuZn-DAS/NC caused by the considerable electron transfers from Zn atoms to the adjacent Cu atoms can reduce the adsorption energy barriers for^(*)COOH and^(*)CO production,improving the activity and CO selectivity.展开更多
Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contam...Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contaminants(EOCs)by activating peroxymonosulfate(PMS).However,the construction of atomically dispersed catalysts with diatomic/multiatomic metal active sites by activating PMS to degrade pollutants is still seldom reported,despite the unique merits of atom-pair in synergistic electronic modulation and breaking stubborn restriction of scaling relations on catalytic activity.We have synthesized Fe1-N-C,Fe_(2)-N-C,and Fe_(3)-N-C catalysts with monoatomic iron,diatomic iron,and triatomic iron active center,respectively.The results show that the catalytic degradation activity of Fe_(2)-N-C is twice that of Fe1-N-C and Fe_(3)-N-C due to its unique Fe_(2)N6 coordination structure,which fulfilled the complete degradation of rhodamine B(RhB),bisphenol A(BPA),and 2,4-dichlorophenol(2,4-DP)within 2 min.Electron paramagnetic resonance(EPR)and radical quenching experiments confirmed that the reaction was a nonradical reaction on the catalyst surface.And singlet oxygen and Fe(IV)are the key active species.展开更多
The explicit expressions of energy eigenvalues and eigenfunctions of bound states for a three-dimensional diatomic molecule oscillator with a hyperbolic potential function are obtained approximately by means of the hy...The explicit expressions of energy eigenvalues and eigenfunctions of bound states for a three-dimensional diatomic molecule oscillator with a hyperbolic potential function are obtained approximately by means of the hypergeometric series method. Then for a one-dimensional system, the rigorous solutions of bound states are solved with a similar method. The eigenfunctions of a one-dimensional diatomic molecule oscillator, expressed in terms of the Jacobi polynomial, are employed as an orthonormal basis set, and the analytic expressions of matrix elements for position and momentum operators are given in a closed form.展开更多
Nonsequential double ionization （NSDI） processes of nonaligned diatomic molecules N2 and O2 are studied using the S-matrix theory. Our results show that the NSDI process significantly depends on the molecular symmet...Nonsequential double ionization （NSDI） processes of nonaligned diatomic molecules N2 and O2 are studied using the S-matrix theory. Our results show that the NSDI process significantly depends on the molecular symmetry and structure. The ratio of NSDI rate to single ionization rate as a function of the field intensity is obtained. It is found that N2 behaves closely with its companion atom Ar in the ratios over the entire intensity range, while O2 exhibits an obvious suppression effect, which is qualitatively consistent with the experiment.展开更多
The development of potential theory heightens the understanding of fundamental interactions in quantum systems.In this paper,the bound state solution of the modified radial Klein–Gordon equation is presented for gene...The development of potential theory heightens the understanding of fundamental interactions in quantum systems.In this paper,the bound state solution of the modified radial Klein–Gordon equation is presented for generalised tanh-shaped hyperbolic potential from the Nikiforov–Uvarov method.The resulting energy eigenvalues and corresponding radial wave functions are expressed in terms of the Jacobi polynomials for arbitrary l states.It is also demonstrated that energy eigenvalues strongly correlate with potential parameters for quantum states.Considering particular cases,the generalised tanh-shaped hyperbolic potential and its derived energy eigenvalues exhibit good agreement with the reported findings.Furthermore,the rovibrational energies are calculated for three representative diatomic molecules,namely H2,HCl and O2.The lowest excitation energies are in perfect agreement with experimental results.Overall,the potential model is displayed to be a viable candidate for concurrently prescribing numerous quantum systems.展开更多
Fe/Co-based diatomic catalysts decorated on an N-doped graphene substrate are investigated by first-principles calculations to improve the electrochemical properties of Li–S batteries.Our results demonstrate that Fe ...Fe/Co-based diatomic catalysts decorated on an N-doped graphene substrate are investigated by first-principles calculations to improve the electrochemical properties of Li–S batteries.Our results demonstrate that Fe CoN8@Gra not only possesses moderate adsorption energies towards Li2Snspecies,but also exhibits superior catalytic activity for both reduction and oxidation reactions of the sulfur cathode.Moreover,the metallic property of the diatomic catalysts can be well maintained after Li2Snadsorption,which could help the sulfur cathode to maintain high conductivity during the whole charge–discharge process.Given these exceptional properties,it is expected that Fe CoN8@Gra could be a promising diatomic catalyst for Li–S batteries and afford insights for further development of advanced Li–S batteries.展开更多
Considering intracellular hydrogen peroxide(H_(2)O_(2))plays pivotal roles in the regulation of serial biological processes,the in-situ detection of intracellular H2O2 has attracted an extensive attention.In the prese...Considering intracellular hydrogen peroxide(H_(2)O_(2))plays pivotal roles in the regulation of serial biological processes,the in-situ detection of intracellular H2O2 has attracted an extensive attention.In the present work,an atomically dispersed diatomic active sites Nanozymes(FeN_(3)/PtN_(4)-single-atom nanozymes(SAzyme))was prepared exhibiting enhanced peroxidase-like activity.The obvious synergistic effect between Fe-Pt heteronuclear diatomic active sites was confirmed by series of characterization and density functional theory(DFT).The peroxidase-like activity of Fe-sites could be substantially enhanced by the bonded Pt-sites via the modulation effect.As a consequence,the gap between the d-band centre(εd)of Fe 3d orbitals and the Fermi energy level was narrowed and the electronic interaction could be strengthened,leading to a lower free energy barrier and a lower activation energy as well as fortified metal-O bonding in the kinetic pathway.Therefore,the constructed FeN3/PtN4-SAzyme exhibited higher peroxidase-like activity than that of FeN4-SAzyme.The FeN3/PtN4-SAzyme-assisted oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)facilitated the colorimetric detection of dopamine(DA),an important biomolecule.The linear detection range and limit of detection(LOD)of DA and H_(2)O_(2) were 1-10 μM,0.01-1.0 mM and 0.109 μM,7.97 μM,respectively.In addition,the constructed SAzymes were also applied for the in-situ detection of intracellular H2O2,expanding the application scope of the newborn SAzymes.展开更多
In this paper we study the existence and stability of two-dimensional discrete gap breathers in a two-dimensional diatomic face-centered square lattice consisting of alternating light and heavy atoms, with on-site pot...In this paper we study the existence and stability of two-dimensional discrete gap breathers in a two-dimensional diatomic face-centered square lattice consisting of alternating light and heavy atoms, with on-site potential and coupling potential. This study is focused on two-dimensional breathers with their frequency in the gap that separates the acoustic and optical bands of the phonon spectrum. We demonstrate the possibility of the existence of two-dimensional gap breathers by using a numerical method. Six types of two-dimensional gap breathers are obtained, i.e., symmetric, mirror-symmetric and asymmetric, whether the center of the breather is on a light or a heavy atom. The difference between one-dimensional discrete gap breathers and two-dimensional discrete gap breathers is also discussed. We use Aubry＇s theory to analyze the stability of discrete gap breathers in the two-dimensional diatomic face-centered square lattice.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.10074048)the Science Foundation of the Ministry of Education of China.
文摘A new analytical potential energy function for diatomic molecular ion XY+ is proposed based on the energy consistent method (ECM). The Coulomb potential included in the new ionic potential contains multipole corrections, converges quickly and is variationally, changeable. The new potential and the ECM are applied to variationally studying the potential energies of eight electronic states of several diatomic molecular ions: the A2π state of CO+, the X2∑ g + state of Li 2 + , the X2∑ g + state of He 2 + , the 12∏u state of Na 2 + , the A2∏u state of N 2 + , the X1∑+ state of KrH+, the X2∑+ state of SiO+ and the A2π state of SO+ ion. The present results agree excellently with the experiment-based Rydberg-Klein-Rees (RKR) potentials, and are superior to the commonly used Huxley-Murrell-Sorbie (HMS) analytical potentials, and are better in some cases than some quantum mechanicalab initio potentials in the ionic asymptotic and dissociation regions.
基金Supported by the National Natural Science Foundation of China (Grant No. 10474068)the Science Foundation of Ministry of Education of China
文摘The molecular dissociation energies of some electronic states of hydride and N2 molecules were studied using a parameter-free analytical formula suggested in this study and the algebraic method (AM) proposed recently. The results show that the accurate AM dissociation energies DeAM agree excellently with experimental dissociation energies Deexpt, and that the dissociation energy of an electronic state such as the 23Δg state of 7Li2 whose experimental value is not available can be predicted using the new formula.
基金supported by the National Natural Science Foundation of China (Grant No.60936001)
文摘In this paper,the possibility of the monatomic chain (MC) formation for ZnO material was studied by molecular dynamics (MD) simulation.The process of MC formation and the effects of temperature,strain rate and size were studied extensively.The tensile process can be divided to be five stages and the ZnO diatomic chain (DC) can be found.The MD results show that most atoms in MC came from the original surface of ZnO nanowires (NWs).Temperature and strain rate are two important factors affecting the process,and both high temperature and low strain rate in a certain range would be beneficial to the formation of DC.Moreover,the effects of strain rate and temperature could attribute to the Arrhenius model and the energy release mechanism.Furthermore,multi-shell structure was found for the samples under tensile strain and the layer-layer distance was about 3.Our studies based on density functional theory showed that the most stable structure of ZnO DC was confirmed to be linear,and the I-V curve was also got using ATK.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 20073018).
文摘The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the three-dimensional graphs of the potentials have been drawn. We have systematically investigated this kind of the potentials for a series of the diatomic molecules, such as HF, HCl, HBr, LiF, LiCl, and so on. The three-dimensional graph can clearly display the variation of the potential felt by an electron within a molecule and get a deeper understanding of the electronic motion and chemical bonding within a molecule.
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)
文摘In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.
基金supported by the National Natural Science Foundation of China(No.22075099)the Natural Science Foundation of Jilin Province(No.20220101051JC)+1 种基金the Education Department of Jilin Province(No.JJKH20220968CY)the Graduate Innovation Fund of Jilin University(No.2023CX036).
文摘The design of diatomic catalysts with uniformly dispersed metal atoms is expected to improve catalytic performance,which is conducive to the intensive comprehending of the synergistic mechanism between dual-metal sites for the oxygen evolution reaction(OER)at the atomic level.Herein,we design a strategy to immobilize bimetallic Fe-Co atoms onto nitrogen-doped graphene to obtain a diatomic catalyst(DA-FC-NG)with FeN_(3)-CoN_(3) configuration.The DA-FC-NG shows excellent OER activity with a low overpotential(η_(10)=268 mV),which is superior to commercial iridium dioxide catalysts.Theoretical calculations uncover that the excellent activity of DA-FC-NG is due to the interaction between Fe and Co diatoms,which causes charge rearrangement and induces the adsorption of intermediates on the Fe-O-Co bridge structure,thus improving the catalytic OER performance.This work is of great significance for the design of highly active diatomic catalysts to replace noble metal catalysts for energy-related applications.
基金the China Scholarship Council for financial supportthe funding by the Leverhulme Trust(RPG2019-122)+4 种基金the ACT program(Accelerating CCS Technologies,Horizon2020 Project No.294766),which funded the FUNMIN projectFinancial contributions were made from Department for Business,Energy&Industrial Strategy(BEIS)together with extra funding from NERC and EPSRC research councils,United Kingdom,ADEME(FR),MINECO-AEI(ES)partially funded by EPSRC(EP/P020194/1)funded by EPSRC(EP/L000202)supported by QMUL Research-IT。
文摘Diatomic catalysts(DACs)with two adjacent metal atoms supported on graphene can offer diverse functionalities,overcoming the inherent limitations of single atom catalysts(SACs).In this study,density functional theory calculations were conducted to investigate the reactivity of the carbon dioxide(CO_(2))reduction reaction(CO_(2)RR)on metal sites of both DACs and SACs,as well as their synergistic effects on activity and selectivity.Calculation of the Gibbs free energies of CO_(2)RR and associated values of the limiting potentials to generate C_(1) products showed that Cu acts as a promoter rather than an active catalytic centre in the catalytic CO_(2)conversion on heteronuclear DACs(CuN_(4)-MN_(4)),improving the catalytic activity on the other metal compared to the related SAC MN_(4).Cu enhances the initial reduction of CO_(2)by promoting orbital hybridization between the key intermediate*COOH 2p-orbitals and the metals 3d-orbitals around the Fermi level.This degree of hybridization in the DACs CuN_(4)-MN_(4) decreases from Fe to Co,Ni,and Zn.Our work demonstrates how Cu regulates the CO_(2)RR performance of heteronuclear DACs,offering an effective approach to designing practical,stable,and high-performing diatomic catalysts for CO_(2)electroreduction.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12274178 and 12174148)Support of High Performance Computing Center of Jilin Universitythe high-performance computing cluster Tiger@IAMP。
文摘Information about electronic excited states of molecular anions plays an important role in investigating electron attachment and detachment processes.Here we present a high-level theoretical study of the electronic structures of 12 alkali-metal-containing diatomic anions MX-(MX = LiH,LiF,LiCl,NaF,NaCl,NaBr,RbCl,KCl,KBr,RbI,KI and CsI).The equation-of-motion electron-attachment coupled-cluster singles and doubles(EOM-EA-CCSD) method is used to calculate the electron binding energies(EBEs) of 10 electronic excited states of each of the 12 molecule anions.With addition of different s-/p-/d-type diffusion functions in the basis set,we have identified possible excited dipole bound states(DBSs) of each anion.With the investigation of EBEs on the 12 MXs with dipole moment(DM) up to 12.1 D,we evaluate the dependence of the number of anionic excited DBSs on molecular DM.The results indicate that there are at least two or three DBSs of anions with a molecular DM larger than 7 D and a molecule with DM > 10 D can sustain a π-DBS of the anion.Our study has some implications for the excited DBS electronic states of alkali-metal-containing diatomic molecules.
基金the National Natural Science Foundation of China(No.22271203)the State Key Laboratory of Organometallic Chemistry of Shanghai Institute of Organic Chemistry(No.KF2021005)the Collaborative Innovation Center of Suzhou Nano Science and Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions,and the Project of Scientific and Technologic Infrastructure of Suzhou(No.SZS201905).
文摘The coexistence of multi-component active sites like single-atom sites,diatomic sites(DAS)and nanoclusters is shown to result in superior performances in the hydrogen evolution reaction(HER).Metal diatomic sites are more complex than single-atom sites but their unique electronic structures can lead to significant enhancement of the HER kinetics.Although the synthesis and identification of DAS is usually challenging,we report a simple access to a diatomic catalyst by anchoring Co-Ru DAS on nitrogen-doped carbon supports along with Ru nanoparticles(NPs).Experimental and theoretical results revealed the atomic-level characteristics of Co-Ru sites,their strong electronic coupling and their synergy with Ru NPs within the catalyst.The unique electronic structure of the catalyst resulted in an excellent HER activity and stability in alkaline media.This work provides a valuable insight into a widely applicable design of diatomic catalysts with multi-component active sites for highly efficient HER electrocatalysis.
基金the Chinese National Natural Seienee Foundation of China(Grant No.10074048)the Seience Foundation of the Chinese Ministry of Edueation
文摘New analytical expression and numerical approach are suggested to calculate dissociation energiesD e of diatomic molecular states using an extreme value method (EVM). Studies on some electronic states of OH, BH, N2, Br2, CIF and CO molecules show that the accuracy of the EVM dissociation energies depends on the number of correct vibrational constants used in the calculations. The convergence qualities ofD e are suggested to be an alternative physical criterion to measure the qualities of the various sets of vibrational constants from different literature for the same diatomic state.
基金financially supported by the National Natural Science Foundation of China(Nos.11964010,11464014,51862008,52064014,52064013)the Natural Science Foundation of Hunan Province(No.2020JJ4495)the Youth Program of Hunan Provincial Education Department(No.21B0522)。
文摘Na_(3)V_(2)(PO_(4))_(3)is considered as one of the most promising cathodes for sodium ion batteries due to its excellent thermal stability,long cycle life and high energy density.However,the inferior intrinsic electronic conductivity which brings about the poor rate capability and cycling performance hinders its commercial application.Herein,the S-N co-doped carbon-coated Na_(3)V_(2)(PO_(4))_(3)(NVP@SNC)has been synthesized to resolve the problem.The prepared NVP@SNC forms a hierarchical structure assembled with nanosheets,which is in favor of the electrolyte infiltration and shortening the Na^(+)transmission distance.Numerous lattice defects can be induced in carbon layer by the co-doped elements(S-N),which reduce the Na^(+)diffusion energy barriers and provide adequate Na^(+)migration channels,thus jointly boosting the Na^(+)diffusion coefficient.Consequently,the NVP@SNC cathode shows a high reversible capacity with outstanding rate performance and super long-cycle stability.When discharged at 2.0C,it delivers the capacity near to the theoretical value with a capacity retention of 88.7%after 400cycles.Even if the current is as high as 50.0C,a high capacity of 58.6 mAh·g^(-1)has been released,and41.4 mAh·g^(-1)has been remained after the super long cycling of 4000 circles.This study is expected to supply a new thought of developing high-performance cathodes by diatomic doping for sodium ion battery.
基金This study was supported by the National Natural Science Foundation of China(Nos.52073124 and 52273058)the Natural Science Foundation of Jiangsu Province(No.SBK2022030167)+1 种基金the MOE&SAFEA,111 Project(No.B13025)the Fundamental Research Funds for the Central Universities.
文摘Diatomic site catalysts(DACs)with two adjacent atomic metal species can provide synergistic interactions and more sophisticated functionalities to break the bottleneck of intrinsic drawbacks of single atom catalysts(SACs).Herein,we have designed a CuZn diatomic site(CuZn-DAS)electrocatalyst with unique coordination structure(CuN_(4)-ZnN_(4))by anchoring and ordering the spatial distance between the metal precursors on the carbon nitride(C_(3)N_(4))derived N-doped carbon(NC)substrate.The CuZn-DAS/NC shows high activity and selectivity for electroreduction CO_(2)into CO.The Faradaic efficiency for CO of CuZn-DAS/NC(98.4%)is higher than that of Cu single atomic site on NC(Cu-SAS/NC)(36.4%)and Zn single atomic site on NC(Zn-SAS/NC)(66.8%)at-0.6 V versus reversible hydrogen electrode(vs.RHE).In situ characterizations reveal that the CuZn-DAS is more favorable for the formation and adsorption of^(*)COOH than those of the electrocatalysts with single atomic site.Theorical calculations show that the charge redistribution of Zn site in CuZn-DAS/NC caused by the considerable electron transfers from Zn atoms to the adjacent Cu atoms can reduce the adsorption energy barriers for^(*)COOH and^(*)CO production,improving the activity and CO selectivity.
基金supported by the National Natural Science Foundation of China(Nos.22074137 and 21721003)the Ministry of Science and Technology of China(No.2016YFA0203203).
文摘Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contaminants(EOCs)by activating peroxymonosulfate(PMS).However,the construction of atomically dispersed catalysts with diatomic/multiatomic metal active sites by activating PMS to degrade pollutants is still seldom reported,despite the unique merits of atom-pair in synergistic electronic modulation and breaking stubborn restriction of scaling relations on catalytic activity.We have synthesized Fe1-N-C,Fe_(2)-N-C,and Fe_(3)-N-C catalysts with monoatomic iron,diatomic iron,and triatomic iron active center,respectively.The results show that the catalytic degradation activity of Fe_(2)-N-C is twice that of Fe1-N-C and Fe_(3)-N-C due to its unique Fe_(2)N6 coordination structure,which fulfilled the complete degradation of rhodamine B(RhB),bisphenol A(BPA),and 2,4-dichlorophenol(2,4-DP)within 2 min.Electron paramagnetic resonance(EPR)and radical quenching experiments confirmed that the reaction was a nonradical reaction on the catalyst surface.And singlet oxygen and Fe(IV)are the key active species.
基金Project supported by the National Natural Science Foundation of China （Grant No 90403028）.
文摘The explicit expressions of energy eigenvalues and eigenfunctions of bound states for a three-dimensional diatomic molecule oscillator with a hyperbolic potential function are obtained approximately by means of the hypergeometric series method. Then for a one-dimensional system, the rigorous solutions of bound states are solved with a similar method. The eigenfunctions of a one-dimensional diatomic molecule oscillator, expressed in terms of the Jacobi polynomial, are employed as an orthonormal basis set, and the analytic expressions of matrix elements for position and momentum operators are given in a closed form.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11074026, 11074155, and 11104225)the Program for New Century Excellent Talents in University of the Ministry of Education of China (Grant No. NCET-08-0883)the National Basic Research Program of China (Grant No. 2011CB808100)
文摘Nonsequential double ionization （NSDI） processes of nonaligned diatomic molecules N2 and O2 are studied using the S-matrix theory. Our results show that the NSDI process significantly depends on the molecular symmetry and structure. The ratio of NSDI rate to single ionization rate as a function of the field intensity is obtained. It is found that N2 behaves closely with its companion atom Ar in the ratios over the entire intensity range, while O2 exhibits an obvious suppression effect, which is qualitatively consistent with the experiment.
文摘The development of potential theory heightens the understanding of fundamental interactions in quantum systems.In this paper,the bound state solution of the modified radial Klein–Gordon equation is presented for generalised tanh-shaped hyperbolic potential from the Nikiforov–Uvarov method.The resulting energy eigenvalues and corresponding radial wave functions are expressed in terms of the Jacobi polynomials for arbitrary l states.It is also demonstrated that energy eigenvalues strongly correlate with potential parameters for quantum states.Considering particular cases,the generalised tanh-shaped hyperbolic potential and its derived energy eigenvalues exhibit good agreement with the reported findings.Furthermore,the rovibrational energies are calculated for three representative diatomic molecules,namely H2,HCl and O2.The lowest excitation energies are in perfect agreement with experimental results.Overall,the potential model is displayed to be a viable candidate for concurrently prescribing numerous quantum systems.
基金the National Natural Science Foundation of China(Grant Nos.51972140 and 51903164)the Fund from Science and Technology Department of Jilin Province,China(Grant No.20200201069JC).
文摘Fe/Co-based diatomic catalysts decorated on an N-doped graphene substrate are investigated by first-principles calculations to improve the electrochemical properties of Li–S batteries.Our results demonstrate that Fe CoN8@Gra not only possesses moderate adsorption energies towards Li2Snspecies,but also exhibits superior catalytic activity for both reduction and oxidation reactions of the sulfur cathode.Moreover,the metallic property of the diatomic catalysts can be well maintained after Li2Snadsorption,which could help the sulfur cathode to maintain high conductivity during the whole charge–discharge process.Given these exceptional properties,it is expected that Fe CoN8@Gra could be a promising diatomic catalyst for Li–S batteries and afford insights for further development of advanced Li–S batteries.
基金This work was supported by the National Natural Science Foundation of China(Nos.22075122,21971152,and 21804067)the Primary Research and Development Plan of Shandong Province(No.2019GSF108093)Shandong Province Natural Science Foundation(Nos.ZR2020QB170,ZR2020MB003,and ZR2019BB038)。
文摘Considering intracellular hydrogen peroxide(H_(2)O_(2))plays pivotal roles in the regulation of serial biological processes,the in-situ detection of intracellular H2O2 has attracted an extensive attention.In the present work,an atomically dispersed diatomic active sites Nanozymes(FeN_(3)/PtN_(4)-single-atom nanozymes(SAzyme))was prepared exhibiting enhanced peroxidase-like activity.The obvious synergistic effect between Fe-Pt heteronuclear diatomic active sites was confirmed by series of characterization and density functional theory(DFT).The peroxidase-like activity of Fe-sites could be substantially enhanced by the bonded Pt-sites via the modulation effect.As a consequence,the gap between the d-band centre(εd)of Fe 3d orbitals and the Fermi energy level was narrowed and the electronic interaction could be strengthened,leading to a lower free energy barrier and a lower activation energy as well as fortified metal-O bonding in the kinetic pathway.Therefore,the constructed FeN3/PtN4-SAzyme exhibited higher peroxidase-like activity than that of FeN4-SAzyme.The FeN3/PtN4-SAzyme-assisted oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)facilitated the colorimetric detection of dopamine(DA),an important biomolecule.The linear detection range and limit of detection(LOD)of DA and H_(2)O_(2) were 1-10 μM,0.01-1.0 mM and 0.109 μM,7.97 μM,respectively.In addition,the constructed SAzymes were also applied for the in-situ detection of intracellular H2O2,expanding the application scope of the newborn SAzymes.
基金Project supported by the National Natural Science Foundation of China (Grant No 10574011)the Foundation for Researching Group by Beijing Normal University
文摘In this paper we study the existence and stability of two-dimensional discrete gap breathers in a two-dimensional diatomic face-centered square lattice consisting of alternating light and heavy atoms, with on-site potential and coupling potential. This study is focused on two-dimensional breathers with their frequency in the gap that separates the acoustic and optical bands of the phonon spectrum. We demonstrate the possibility of the existence of two-dimensional gap breathers by using a numerical method. Six types of two-dimensional gap breathers are obtained, i.e., symmetric, mirror-symmetric and asymmetric, whether the center of the breather is on a light or a heavy atom. The difference between one-dimensional discrete gap breathers and two-dimensional discrete gap breathers is also discussed. We use Aubry＇s theory to analyze the stability of discrete gap breathers in the two-dimensional diatomic face-centered square lattice.
