In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more...In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more Li+during charge and discharge processes due to the increased Ni content in their crystal structure,thereby providing higher energy density.However,a significant challenge associated with Ni-rich layered oxide cathodes is the crossover effect,which arises from the dissolution of Ni^(2+)from the cathode,leading to a rapid decline in battery capacity.Through the delocalization-induced effect of solvent molecules,Ni^(2+)is transformed into a fluorinated transition metal inorganic phase layer,thereby forming a corrosion-resistant Li metal interface.This prevents solvent molecules from being reduced and degraded by Li metal anode.The surface of the Li metal anode exhibits a smooth and flat deposition morphology after long-term cycling.Furthermore,the introduction of Ni^(2+)can enhance the concentration gradient of transition metal ions near the cathode,thereby suppressing the dissolution process of transition metal ions.Even the NCM955 cathode with a mass load of 22 mg cm^(−2)also has great capacity retention after cycling.The Ni^(2+)induced by high electronegative functional groups of solvent under the electron delocalization effect,preventing the Ni ions dissolution of cathode and constructing a corrosion-resistant Li metal interface layer.This work provides new insights into suppressing crossover effects in Li metal batteries with high nickel cathodes.展开更多
Transition metal-nitrogen-carbon materials(M-N-Cs),particularly Fe-N-Cs,have been found to be electroactive for accelerating oxygen reduction reaction(ORR)kinetics.Although substantial efforts have been devoted to des...Transition metal-nitrogen-carbon materials(M-N-Cs),particularly Fe-N-Cs,have been found to be electroactive for accelerating oxygen reduction reaction(ORR)kinetics.Although substantial efforts have been devoted to design Fe-N-Cs with increased active species content,surface area,and electronic conductivity,their performance is still far from satisfactory.Hitherto,there is limited research about regulation on the electronic spin states of Fe centers for Fe-N-Cs electrocatalysts to improve their catalytic performance.Here,we introduce Ti_(3)C_(2) MXene with sulfur terminals to regulate the electronic configuration of FeN_(4) species and dramatically enhance catalytic activity toward ORR.The MXene with sulfur terminals induce the spin-state transition of FeN_(4) species and Fe 3d electron delocalization with d band center upshift,enabling the Fe(II)ions to bind oxygen in the end-on adsorption mode favorable to initiate the reduction of oxygen and boosting oxygen-containing groups adsorption on FeN_(4) species and ORR kinetics.The resulting FeN_(4)-Ti_(3)C_(2)Sx exhibits comparable catalytic performance to those of commercial Pt-C.The developed wearable ZABs using FeN_(4)-Ti_(3)C_(2)Sx also exhibit fast kinetics and excellent stability.This study confirms that regulation of the electronic structure of active species via coupling with their support can be a major contributor to enhance their catalytic activity.展开更多
The misfit layer compound(SnS)_(1.2)(TiS_(2))_(2)is a promising low-cost thermoelectric material because of its low thermal conductivity derived from the superlattice-like structure.However,the strong covalent bonds w...The misfit layer compound(SnS)_(1.2)(TiS_(2))_(2)is a promising low-cost thermoelectric material because of its low thermal conductivity derived from the superlattice-like structure.However,the strong covalent bonds within each constituent layer highly localize the electrons thereby it is highly challenging to optimize the power factor by doping or alloying.Here,we show that Bi doping at the Sn site markedly breaks the covalent bonds networks and highly delocalizes the electrons.This results in a high charge carrier concentration and enhanced power factor throughout the whole temperature range.It is highly remarkable that Bi doping also significantly reduces the thermal conductivity by suppressing the heat conduction carried by phonons,indicating that it independently modulates phonon and charge transport properties.These effects collectively give rise to a maximum ZT of 0.3 at 720 K.In addition,we apply the single Kane band model and the Debye–Callaway model to clarify the electron and phonon transport mechanisms in the misfit layer compound(SnS)_(1.2)(TiS_(2))_(2).展开更多
Investigating the activation of the persulfate process through heterogeneous carbonaceous catalysts to expedite the reduction of uranyl ions(U(Ⅵ))is imperative.The primary hurdle involves understanding the transfer a...Investigating the activation of the persulfate process through heterogeneous carbonaceous catalysts to expedite the reduction of uranyl ions(U(Ⅵ))is imperative.The primary hurdle involves understanding the transfer and distribution of photogenerated carriers during the reduction process in this intricate system and deciphering the role of activated groups in promoting reduction efficiency.In this study,we strategically regulate the structure of polymeric carbon nitride to promote the N-doped state,thereby facilitating delocalization electron enrichment.The resulting active sites effectively activate peroxyl disulfate(PDS),generating radicals that expedite the selective reduction of U(VI).This strategic approach mitigates the inherent disadvantage of the short half-life of free radicals in persulfate-based advanced oxidation processes.As a consequence of our endeavors and with the simultaneous presence of PDS and hydrogen peroxide,we achieve an exceptional photoreduction efficiency of 100%within a remarkably short period of 20 min.This breakthrough presents a high-efficiency application with significant potential for addressing the pollution associated with uranylcontaining wastewater.Our findings not only contribute to the fundamental understanding of AOPs but also offer a practical solution with implications for environmental remediation.展开更多
Polymeric carbon nitride(PCN)is identified as a promising photocatalyst for H_(2)O_(2) production due to its visible^(-)light response,low cost,and high selectivity of 2e^(-) oxygen reduction reaction(ORR).However,the...Polymeric carbon nitride(PCN)is identified as a promising photocatalyst for H_(2)O_(2) production due to its visible^(-)light response,low cost,and high selectivity of 2e^(-) oxygen reduction reaction(ORR).However,the H_(2)O_(2) yield of carbon nitride is still restricted by narrow light absorption,low charge separation efficiency,and insufficient active sites.Herein,crystalline poly(heptazine imide)(PHI)-based carbon nitride with highly dispersed In sites and N defects was prepared through the ionothermal method using LiCl/KCl as molten salts.The largeπ-conjugated system and the existence of N defects greatly enhance the visible-light harvesting ability.The remaining K^(+) ions in the nitrogen cavities of PHI serve as interlayer electron channels,and the incorporation of N defects triggers asymmetric distribution of charges on the heptazine network,promoting interlayer and in-plane charge separation and transfer,respectively.The In sites accelerate charge transfer dynamics and act as active sites for ORR.The synergistic effect of metal modification and defect engineering boosts the electron delocalization within the photocatalyst and thus significantly improves the photocatalytic activity.The H_(2)O_(2) production rate of 10InPHI reaches 15.3 mmol g^(-1)h^(-1)through a two-step single-electron ORR pathway,underscoring the great potential of modified carbon nitride materials in efficient H_(2)O_(2) photosynthesis.展开更多
Co_(3)O_(4) is a promising catalyst for the chlorine evolution reaction(CER)in seawater;however,its CER selectivity is compromised by the adsorption of the competitive oxygen evolution reaction intermediate(OH^(-))at ...Co_(3)O_(4) is a promising catalyst for the chlorine evolution reaction(CER)in seawater;however,its CER selectivity is compromised by the adsorption of the competitive oxygen evolution reaction intermediate(OH^(-))at Co sites.Inspired by the hard-soft acid-base(HSAB)theory,this study proposes incorporating early transition metal sites(V)with a low degree of electron delocalization into Co_(3)O_(4) to modulate the selective adsorption of reactants on catalytic sites.Experimental and theoretical calculations reveal that V incorporation facilitates the electron accumulation at the Co site,significantly strengthening the interaction between Co and Cl^(-).Meanwhile,the loss of electrons from V sites generates a more localized electronic state that preferentially adsorbs OH^(-),thus reducing the Co-OH interaction and releasing more Co sites for Cl^(-)adsorption.Therefore,Co_(2)VO_(4) exhibits a high CER selectivity of 92.3%and maintains one of the highest stabilities over 300 h in natural seawater.The resulting half-flow cell achieves~100%disinfection efficiency in seawater,validating the HSAB theory-based design strategy and offering new guidance for developing highly selective seawater CER catalysts.展开更多
The chlorine evolution reaction(CER)serves as the cornerstone and crucial step in the conversion of chloride ions to chlorine gas,while accompanied by the occurrence of the oxygen evolution reaction(OER)in practical p...The chlorine evolution reaction(CER)serves as the cornerstone and crucial step in the conversion of chloride ions to chlorine gas,while accompanied by the occurrence of the oxygen evolution reaction(OER)in practical processes that lead to difficulty in achieving the purity requirements of the product Cl_(2)for industrial applications.Pd-doped Co_(3)O_(4) nanoneedles(Pd-Co_(3)O_(4)NNs)were synthesized via hydrothermal-calcination methods.Pd sites induce electron delocalization,creating asymmetric active Co sites in Co_(3)O_(4),enhancing CER performance.The unique nanoneedle arrays of the designed catalysts increase the number of exposed active sites,facilitating electron transfer and endowing the Pd-Co_(3)O_(4)NNs with a tip catalytic effect,further optimizing the catalytic reaction kinetics of CER with an overpotential of 118 mV at 100 mA cm^(-2)and a Tafel slope of 53.93 mV dec^(-1).The density functional theory(DFT)calculations reveal that Pd incorporation at octahedral sites triggers charge redistribution and d-band center downshift,weakening intermediate adsorption and sustaining catalytic activity.This work offers new insights into noble-metal-doped spinel oxides,highlighting their potential for industrial applications.展开更多
Wide-temperature applications of sodium-ion batteries(SIBs)are severely limited by the sluggish ion insertion/diffusion kinetics of conversion-type anodes.Quantum-sized transition metal dichalcogenides possess unique ...Wide-temperature applications of sodium-ion batteries(SIBs)are severely limited by the sluggish ion insertion/diffusion kinetics of conversion-type anodes.Quantum-sized transition metal dichalcogenides possess unique advantages of charge delocalization and enrich uncoordinated electrons and short-range transfer kinetics,which are crucial to achieve rapid low-temperature charge transfer and high-temperature interface stability.Herein,a quantum-scale FeS_(2) loaded on three-dimensional Ti_(3)C_(2) MXene skeletons(FeS_(2) QD/MXene)fabricated as SIBs anode,demonstrating impressive performance under wide-temperature conditions(−35 to 65).The theoretical calculations combined with experimental characterization interprets that the unsaturated coordination edges of FeS_(2) QD can induce delocalized electronic regions,which reduces electrostatic potential and significantly facilitates efficient Na+diffusion across a broad temperature range.Moreover,the Ti_(3)C_(2) skeleton reinforces structural integrity via Fe-O-Ti bonding,while enabling excellent dispersion of FeS_(2) QD.As expected,FeS_(2) QD/MXene anode harvests capacities of 255.2 and 424.9 mAh g^(−1) at 0.1 A g^(−1) under−35 and 65,and the energy density of FeS_(2) QD/MXene//NVP full cell can reach to 162.4 Wh kg^(−1) at−35,highlighting its practical potential for wide-temperatures conditions.This work extends the uncoordinated regions induced by quantum-size effects for exceptional Na^(+)ion storage and diffusion performance at wide-temperatures environment.展开更多
Lithium-sulfur(Li-S)batteries mainly rely on the reversible electrochemical reaction of between lithium ions(Li^(+))and sulfur species to achieve energy storage and conversion,therefore,increasing the number of free L...Lithium-sulfur(Li-S)batteries mainly rely on the reversible electrochemical reaction of between lithium ions(Li^(+))and sulfur species to achieve energy storage and conversion,therefore,increasing the number of free Li^(+)and improving the Li^(+)diffusion kinetics will effectively enhance the cell performance.Here,Mo-based MXene heterostructure(MoS_(2)@Mo_(2)C)was developed by partial vulcanization of Mo_(2)C MXene,in which the introduction of similar valence S into Mo-based MXene(Mo_(2)C)can create an electron delocalization effect.Through theoretical simulations and electrochemical characterisation,it is demonstrated that the MoS_(2)@Mo_(2)C heterojunction can effectively promote ion desolvation,increase the amount of free Li^(+),and accelerate Li^(+)transport for more efficient polysulfide conversion.In addition,the MoS_(2)@Mo_(2)C material is also capable of accelerating the oxidation and reduction of polysulfides through its sufficient defects and vacancies to further enhance the catalytic efficiency.Consequently,the Li-S battery with the designed MoS_(2)@Mo_(2)C electrocatalyst performed for 500 cycles at 1 C and still maintained the ideal capacity(664.7 mAh·g^(−1)),and excellent rate performance(567.6 mAh·g^(−1)at 5 C).Under the extreme conditions of high loading,the cell maintained an excellent capacity of 775.6 mAh·g^(−1)after 100 cycles.It also retained 838.4 mAh·g^(−1)for 70 cycles at a low temperature of 0℃,and demonstrated a low decay rate(0.063%).These results indicate that the delocalized electrons effectively accelerate the catalytic conversion of lithium polysulfide,which is more practical for enhancing the behaviour of Li-S batteries.展开更多
The non-spherical lowest-lying Lin(n=15–17)isomers were found with high symmetric compact structures,of which the stability was not rationalized in a previous report(J.Chem.Phys.1199444(2003)).Based on the newly prop...The non-spherical lowest-lying Lin(n=15–17)isomers were found with high symmetric compact structures,of which the stability was not rationalized in a previous report(J.Chem.Phys.1199444(2003)).Based on the newly proposed super-valence bond model,the three prolate lithium clusters can be viewed as magnetic superatomic molecules,which are composed by sharing valence electron pairs and nuclei between two superatom units,namely,Li10 or Li11,and thus their stability can be given a good understanding.Molecular orbital and chemical bonding analysis clearly reveal that the Lin(n=15–17)clusters with prolate shapes are magnetic superatomic molecules.Our work may aid in the developments of the cluster-assembled materials or superatom-bonds.展开更多
The localized molecular orbitals and energy levels for [Co_6 (μ_3-S)_8 (PH_3)_6]￣(n+)(n=0, 1) as model molecules of the electron-rich [Co_6 (μ_3-S)_8 (PPh_3)_6]￣(n+) (n=0,1) cluster compounds have been calculated ...The localized molecular orbitals and energy levels for [Co_6 (μ_3-S)_8 (PH_3)_6]￣(n+)(n=0, 1) as model molecules of the electron-rich [Co_6 (μ_3-S)_8 (PPh_3)_6]￣(n+) (n=0,1) cluster compounds have been calculated by using Edmiston-Ruedenberg energy localization scheme under the spin-unrestricted CNDO/2 approximation. It is shown that the cluster skeletons of these two isostructural molecules consist of the edge-localized two-centered two-electron (Co-S) bonds plus a pair of the skeleton electrons delocalized on the whole cluster core,leading an extra stability of the cluster core.The one-electron oxidation for the neutral molecule gives rise to a one-electron σ (Co-Co) bond.which further resonates among the three diagonal lines of the {Co_6} octahedron. The comparison between [Co_6 (μ_3-S)_8(PPh_3)_6] and [Co_6(μ_3-CO)_8(CO)_6]￣(4-) indicates that the latter possesses face-localized bridging-bonds which are further delocalized on the whole surface of the cluster octahedron by the back-donation bonds from the lone electron pairs on the Co atoms to the capping carbonyl CO ligands. The structural features of the series of the [Co6(μ_3-X)_8L_6]￣(n+)(X =S, Se; L=PPh_3,PEt_3, CO;n=0, 1) cluster compounds are briefly rationalized on the basis of the localization description as well.展开更多
The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we develope...The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we developed a spin-state and delocalized electron regulation method to optimize oxygen evolution reaction(OER)performance by in-situ growth of NiCo_(2)(OH)_(x) using Oswald ripening and coordinating etching process on MXene and plasma treatment.X-ray absorption spectroscopy,magnetic tests and electron paramagnetic resonance reveal that the coupling of NiCo_(2)(OH)_(x) and MXene can induce remarkable spin-state transition of Co^(3+)and transition metal ions electron delocalization,plasma treatment further optimizes the 3 d orbital structure and delocalized electron density.The unique Jahn-Teller phenomenon can be brought by the intermediate spin state(t2 _(g)^(5) e_(g)^(1))of Co^(3+),which benefits from the partial electron occupied egorbitals.This distinct electron configuration(t2_(g)^(5) e_(g)^(1))with unpaired electrons leads to orbital degeneracy,that the adsorption free energy of intermediate species and conductivity were further optimized.The optimized electrocatalyst exhibits excellent OER activity with an overpotential of 268 m V at 10 m A cm^(-2).DFT calculations show that plasma treatment can effectively regulate the d-band center of TMs to optimize the adsorption and improve the OER activity.This approach could guide the rational design and discovery of electrocatalysts with ideal electron configurations in the future.展开更多
The architectural design of redox-active organic molecules and the modulation of their electronic properties significantly influence their application in energy storage systems within aqueous environments.However,thes...The architectural design of redox-active organic molecules and the modulation of their electronic properties significantly influence their application in energy storage systems within aqueous environments.However,these organic molecules often exhibit sluggish reaction kinetics and unsatisfactory utilization of active sites,presenting significant challenges for their practical deployment as electrode materials in aqueous batteries.In this study,we have synthesized a novel organic compound(PTPZ),comprised of a centrally symmetric and fully ladder-type structure,tailored for aqueous proton storage.This unique configuration imparts the PTPZ molecule with high electron delocalization and enhanced structural stability.As an electrode material,PTPZ demonstrates a substantial proton-storage capacity of 311.9mAh g^(-1),with an active group utilization efficiency of up to 89% facilitated by an 8-electron transfer process,while maintaining a capacity retention of 92.89% after 8000 chargingdischarging cycles.Furthermore,in-situ monitoring technologies and various theoretical analyses have pinpointed the associated electrochemical processes of the PTPZ electrode,revealing exceptional redox activity,rapid proton diffusion,and efficient charge transfer.These attributes confer a significant competitive advantage to PTPZ as an anode material for high-performance proton storage devices.Consequently,this work contributes to the rational design of organic electrode materials for the advancement of rechargeable aqueous batteries.展开更多
Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,p...Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,poor cycling stability and safety concerns could be caused by uncontrolled dendrite and high reactivity of Li metal,which hinder the practical application of Li-metal anode in high-energy rechargeable Li metal batteries(LMBs).Here,a facile way is reported to stabilize Li metal anode by building high lithiophilic Mg-Li-Cu alloy.Due to the delocalization of electrons on the deposited lithium enhanced by Cu self-diffusion into Mg-Li alloy,the growth of lithium dendrites could be inhibited by Mg-Li-Cu alloy.Moreover,the parasitic reactions with electrolyte could be avoided by the Mg-Li-Cu alloy anode.It is noteworthy that the symmetric battery life of Mg-Li-Cu alloy electrodes exceeds 9000 h at 1 m A cm^(-2)and 1 m Ah cm^(-2).The full cell(LiFePO_(4)|Mg-Li-Cu)exhibits a specific capacity of 148.2 m Ah g^(-1),with a capacity retention of 96.4%,at 1 C after 500 cycles.This work not only pave the way for application of flexible alloy anode in highly stable LMBs,but also provides novel strategies for preparation and optimization of Mg alloy.展开更多
The sluggish interfacial kinetics at the Zn electrode-electrolyte interface is one of the reasons for the limited cycle stability of aqueous zinc ion batteries(AZIBs).Here,an electrolyte additive with an electron delo...The sluggish interfacial kinetics at the Zn electrode-electrolyte interface is one of the reasons for the limited cycle stability of aqueous zinc ion batteries(AZIBs).Here,an electrolyte additive with an electron delocalization effect is proposed to improve interfacial kinetics on the anode,achieving a stable and long lifespan of AZIBs.The conjugated maleimide(MI)anion presents an electron delocalization effect and adsorbs on the Zn,which improves the charge transfer process and the interfacial kinetics.Also,a double protective layer of H_(2)O-poor electrical double layer and solid electrolyte interphase with organic substance is formed by the absorption of MI anions.Benefit from the MI additive,a no-dendrite anode is obtained by suppressing the side reactions and guiding the homogeneous deposition of Zn^(2+).Finally,a stable Zn||Zn symmetric cell performance up to 5600 h is achieved,and an impressive average coulombic efficiency(~99.91%)is obtained in Zn||Cu cell after 2500 cycles.The Zn||MnO_(2)full cell also exhibits a lifespan of 2000 cycles at 2 A g^(-1).The method using the electron delocalization effect of MI provides a new idea for additive selection to stabilize the electrode-electrolyte interface and to facilitate interfacial kinetics.展开更多
Electrocatalysis provides an optimal approach for the conversion of carbon dioxide(CO_(2))into high-value chemicals,thereby presenting a promising avenue toward achieve carbon neutrality.However,addressing the selecti...Electrocatalysis provides an optimal approach for the conversion of carbon dioxide(CO_(2))into high-value chemicals,thereby presenting a promising avenue toward achieve carbon neutrality.However,addressing the selectivity and stability challenges of metal catalysts in electrolytic reduction remains a daunting task.In this study,the electrospinning method is employed to fabricate porous carbon nanofibers loaded with bismuth nanoparticles with the help of in situ pyrolysis.The porous carbon nanofibers as conductive support would facilitate the dispersion of bismuth active sites while inhibiting their aggregation and promoting the mass transfer,thus enhancing their electrocatalytic activity and stability.Additionally,nitrogen doping induces electron delocalization in bismuth atoms through metal-support interactions,thus enabling efficient adsorption of intermediates for improving selectivity based on the theoretical calculation.Consequently,Bi@PCNF-500 exhibits the exceptional selectivity and stability across a wide range of potential windows.Notably,its faradaic efficiency(FE)of formate reaches 92.7%in H-cell and94.9%in flow cell,respectively,with good electrocatalytic stability.The in situ characterization and theoretical calculations elucidate the plausible reaction mechanism to obtain basic rules for designing efficient electrocatalyst.展开更多
The unique hot carrier-driven direct plasmonic photocatalysis of coinage metal nanomaterials(NMs)via energetic localized surface plasmon resonance(LSPR)in visible-light region has been explored in recent years.However...The unique hot carrier-driven direct plasmonic photocatalysis of coinage metal nanomaterials(NMs)via energetic localized surface plasmon resonance(LSPR)in visible-light region has been explored in recent years.However,the low photoinduced electron transfer efficiency and insufficient separation of electronhole pairs would severely preclude their widespread practical applications.Herein,we demonstrate an interesting plasmonic photocatalyst based on the construction of icosahedral(Ih)Au@C_(60) core-shell NMs,taking advantage of specific delocalizedπelectrons structure of a tight C_(60) shell and enhanced LSPR property of Ih Au core.Then,the pronounced interfacial interaction at junction region endows the obtained Au@C_(60) NMs with an outstanding photoinduced hot carrier-transmission during photocatalytic reaction,facilitating a remarkably higher(1.89 times)photocatalytic activity toward visible-light driven degradation of crystal violet(CV)dyes,as compared to bare Au NMs.Impressively,the photocatalytic activity of Ih Au@C_(60) NMs can be effectively optimized by changing the p H value of reaction solution,with the kinetic rate constant reaching the maximum value of 0.179 min^(-1) in pH011.4 solution,while 0.005 min^(-1) at pH03.0.Moreover,due to the protection of a tight C_(60) shell,the Ih Au@C_(60) NMs also possess excellent photocatalytic stability/reusability in recycling runs,holding great potential for the design of robust and high-performance plasmonic photocatalysts in repeated practical applications.展开更多
By use of the Keldysh non-equilibrium Green’s-function methods, the third harmonic susceptibilities of two polyaniline families, PANI-HCl and PANI-H 3PO 4, are calculated [ x (3) ( ω )≈10 -12 esu]. It was found tha...By use of the Keldysh non-equilibrium Green’s-function methods, the third harmonic susceptibilities of two polyaniline families, PANI-HCl and PANI-H 3PO 4, are calculated [ x (3) ( ω )≈10 -12 esu]. It was found that the third harmonic susceptibility of polyaniline strongly depends on the delocalization of the electrons. The refractive indices n ( λ =589 nm) of PANI-HCl and PANI-H 3PO 4 are calculated by use of three common methods (the Lorentz-Lorentz theoretical model, the Gladstone-Dale group contribution and the Vogel group correlation) based on group contributions to molar refraction. The calculated n values are varied from 1.31 to 1.42 for PANI-HCl and 1.36 to 1.45 for PANI-H 3PO 4.展开更多
Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–s...Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–shell structure through the bridge Br atom.Carbon shell wrapped copper bromide nanorods(CuBr@C)are constructed for the first time by chemical vapour deposition with hexabromobenzene(HBB).HBB pyrolysis provides both bridge Br atom and C shells.The C shell protects the stability of the internal halide structure,while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic activity.Impressively,the hydrogen evolution reaction(HER)activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes,surpassing commercial Pt/C at over 200 mA·cm^(−2).Density functional theory(DFT)calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces,leading to optimization of hydrogen adsorption energy.展开更多
基金the support from Yunnan Fundamental Research Projects(202301BE070001-029,202401CF070129,202501CF070181)National Natural Science Foundation of China(22209012,22479067)Kunming University of Science and Technology Analysis and Testing Fund Support Project(2023T20220172)。
文摘In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more Li+during charge and discharge processes due to the increased Ni content in their crystal structure,thereby providing higher energy density.However,a significant challenge associated with Ni-rich layered oxide cathodes is the crossover effect,which arises from the dissolution of Ni^(2+)from the cathode,leading to a rapid decline in battery capacity.Through the delocalization-induced effect of solvent molecules,Ni^(2+)is transformed into a fluorinated transition metal inorganic phase layer,thereby forming a corrosion-resistant Li metal interface.This prevents solvent molecules from being reduced and degraded by Li metal anode.The surface of the Li metal anode exhibits a smooth and flat deposition morphology after long-term cycling.Furthermore,the introduction of Ni^(2+)can enhance the concentration gradient of transition metal ions near the cathode,thereby suppressing the dissolution process of transition metal ions.Even the NCM955 cathode with a mass load of 22 mg cm^(−2)also has great capacity retention after cycling.The Ni^(2+)induced by high electronegative functional groups of solvent under the electron delocalization effect,preventing the Ni ions dissolution of cathode and constructing a corrosion-resistant Li metal interface layer.This work provides new insights into suppressing crossover effects in Li metal batteries with high nickel cathodes.
基金supported by a Grant of the Innovation and Technology Commission of Hong Kong(Project number:ITS/461/18)City University of Hong Kong(Project number:9678179).
文摘Transition metal-nitrogen-carbon materials(M-N-Cs),particularly Fe-N-Cs,have been found to be electroactive for accelerating oxygen reduction reaction(ORR)kinetics.Although substantial efforts have been devoted to design Fe-N-Cs with increased active species content,surface area,and electronic conductivity,their performance is still far from satisfactory.Hitherto,there is limited research about regulation on the electronic spin states of Fe centers for Fe-N-Cs electrocatalysts to improve their catalytic performance.Here,we introduce Ti_(3)C_(2) MXene with sulfur terminals to regulate the electronic configuration of FeN_(4) species and dramatically enhance catalytic activity toward ORR.The MXene with sulfur terminals induce the spin-state transition of FeN_(4) species and Fe 3d electron delocalization with d band center upshift,enabling the Fe(II)ions to bind oxygen in the end-on adsorption mode favorable to initiate the reduction of oxygen and boosting oxygen-containing groups adsorption on FeN_(4) species and ORR kinetics.The resulting FeN_(4)-Ti_(3)C_(2)Sx exhibits comparable catalytic performance to those of commercial Pt-C.The developed wearable ZABs using FeN_(4)-Ti_(3)C_(2)Sx also exhibit fast kinetics and excellent stability.This study confirms that regulation of the electronic structure of active species via coupling with their support can be a major contributor to enhance their catalytic activity.
基金financially supported by the National Key Research and Development Program of China(Grant No.2018YFA0702100)the Joint Funds of the National Natural Science Foundation of China+1 种基金the Chinese Academy of Sciences’Large-Scale Scientific Facility(Grant No.U1932106)the Sichuan University Innovation Research Program of China(Grant No.2020SCUNL112)。
文摘The misfit layer compound(SnS)_(1.2)(TiS_(2))_(2)is a promising low-cost thermoelectric material because of its low thermal conductivity derived from the superlattice-like structure.However,the strong covalent bonds within each constituent layer highly localize the electrons thereby it is highly challenging to optimize the power factor by doping or alloying.Here,we show that Bi doping at the Sn site markedly breaks the covalent bonds networks and highly delocalizes the electrons.This results in a high charge carrier concentration and enhanced power factor throughout the whole temperature range.It is highly remarkable that Bi doping also significantly reduces the thermal conductivity by suppressing the heat conduction carried by phonons,indicating that it independently modulates phonon and charge transport properties.These effects collectively give rise to a maximum ZT of 0.3 at 720 K.In addition,we apply the single Kane band model and the Debye–Callaway model to clarify the electron and phonon transport mechanisms in the misfit layer compound(SnS)_(1.2)(TiS_(2))_(2).
基金National Natural Science Foundation of China,Grant/Award Numbers:22162009,32360236。
文摘Investigating the activation of the persulfate process through heterogeneous carbonaceous catalysts to expedite the reduction of uranyl ions(U(Ⅵ))is imperative.The primary hurdle involves understanding the transfer and distribution of photogenerated carriers during the reduction process in this intricate system and deciphering the role of activated groups in promoting reduction efficiency.In this study,we strategically regulate the structure of polymeric carbon nitride to promote the N-doped state,thereby facilitating delocalization electron enrichment.The resulting active sites effectively activate peroxyl disulfate(PDS),generating radicals that expedite the selective reduction of U(VI).This strategic approach mitigates the inherent disadvantage of the short half-life of free radicals in persulfate-based advanced oxidation processes.As a consequence of our endeavors and with the simultaneous presence of PDS and hydrogen peroxide,we achieve an exceptional photoreduction efficiency of 100%within a remarkably short period of 20 min.This breakthrough presents a high-efficiency application with significant potential for addressing the pollution associated with uranylcontaining wastewater.Our findings not only contribute to the fundamental understanding of AOPs but also offer a practical solution with implications for environmental remediation.
基金supported by the National Natural Science Foundation of China (22278056, 22478058)the Fundamental Research Funds for the Central Universities (DUT22LAB602)the National Key Research and Development Program of China (2022YFA1504402)。
文摘Polymeric carbon nitride(PCN)is identified as a promising photocatalyst for H_(2)O_(2) production due to its visible^(-)light response,low cost,and high selectivity of 2e^(-) oxygen reduction reaction(ORR).However,the H_(2)O_(2) yield of carbon nitride is still restricted by narrow light absorption,low charge separation efficiency,and insufficient active sites.Herein,crystalline poly(heptazine imide)(PHI)-based carbon nitride with highly dispersed In sites and N defects was prepared through the ionothermal method using LiCl/KCl as molten salts.The largeπ-conjugated system and the existence of N defects greatly enhance the visible-light harvesting ability.The remaining K^(+) ions in the nitrogen cavities of PHI serve as interlayer electron channels,and the incorporation of N defects triggers asymmetric distribution of charges on the heptazine network,promoting interlayer and in-plane charge separation and transfer,respectively.The In sites accelerate charge transfer dynamics and act as active sites for ORR.The synergistic effect of metal modification and defect engineering boosts the electron delocalization within the photocatalyst and thus significantly improves the photocatalytic activity.The H_(2)O_(2) production rate of 10InPHI reaches 15.3 mmol g^(-1)h^(-1)through a two-step single-electron ORR pathway,underscoring the great potential of modified carbon nitride materials in efficient H_(2)O_(2) photosynthesis.
基金supported by the Guangxi Science and Technology Program(2023AB38061)the National Natural Science Foundation of China(22162004,22479031)the High-performance Computing Platform of Guangxi University。
文摘Co_(3)O_(4) is a promising catalyst for the chlorine evolution reaction(CER)in seawater;however,its CER selectivity is compromised by the adsorption of the competitive oxygen evolution reaction intermediate(OH^(-))at Co sites.Inspired by the hard-soft acid-base(HSAB)theory,this study proposes incorporating early transition metal sites(V)with a low degree of electron delocalization into Co_(3)O_(4) to modulate the selective adsorption of reactants on catalytic sites.Experimental and theoretical calculations reveal that V incorporation facilitates the electron accumulation at the Co site,significantly strengthening the interaction between Co and Cl^(-).Meanwhile,the loss of electrons from V sites generates a more localized electronic state that preferentially adsorbs OH^(-),thus reducing the Co-OH interaction and releasing more Co sites for Cl^(-)adsorption.Therefore,Co_(2)VO_(4) exhibits a high CER selectivity of 92.3%and maintains one of the highest stabilities over 300 h in natural seawater.The resulting half-flow cell achieves~100%disinfection efficiency in seawater,validating the HSAB theory-based design strategy and offering new guidance for developing highly selective seawater CER catalysts.
基金supported by the National Natural Science Foundation of China(Grant Nos.52402273,52272222,52072197)Youth Innovation Team Development Program of Shandong Higher Education Institutions(Grant No.2022KJ155)Taishan Scholar Young Talent Program(Grant No.tsqn201909114)。
文摘The chlorine evolution reaction(CER)serves as the cornerstone and crucial step in the conversion of chloride ions to chlorine gas,while accompanied by the occurrence of the oxygen evolution reaction(OER)in practical processes that lead to difficulty in achieving the purity requirements of the product Cl_(2)for industrial applications.Pd-doped Co_(3)O_(4) nanoneedles(Pd-Co_(3)O_(4)NNs)were synthesized via hydrothermal-calcination methods.Pd sites induce electron delocalization,creating asymmetric active Co sites in Co_(3)O_(4),enhancing CER performance.The unique nanoneedle arrays of the designed catalysts increase the number of exposed active sites,facilitating electron transfer and endowing the Pd-Co_(3)O_(4)NNs with a tip catalytic effect,further optimizing the catalytic reaction kinetics of CER with an overpotential of 118 mV at 100 mA cm^(-2)and a Tafel slope of 53.93 mV dec^(-1).The density functional theory(DFT)calculations reveal that Pd incorporation at octahedral sites triggers charge redistribution and d-band center downshift,weakening intermediate adsorption and sustaining catalytic activity.This work offers new insights into noble-metal-doped spinel oxides,highlighting their potential for industrial applications.
基金supported by the National Nature Science Foundation of China(Nos.52202335 and 52171227)Natural Science Foundation of Jiangsu Province(No.BK20221137)National Key R&D Program of China(2024YFE0108500).
文摘Wide-temperature applications of sodium-ion batteries(SIBs)are severely limited by the sluggish ion insertion/diffusion kinetics of conversion-type anodes.Quantum-sized transition metal dichalcogenides possess unique advantages of charge delocalization and enrich uncoordinated electrons and short-range transfer kinetics,which are crucial to achieve rapid low-temperature charge transfer and high-temperature interface stability.Herein,a quantum-scale FeS_(2) loaded on three-dimensional Ti_(3)C_(2) MXene skeletons(FeS_(2) QD/MXene)fabricated as SIBs anode,demonstrating impressive performance under wide-temperature conditions(−35 to 65).The theoretical calculations combined with experimental characterization interprets that the unsaturated coordination edges of FeS_(2) QD can induce delocalized electronic regions,which reduces electrostatic potential and significantly facilitates efficient Na+diffusion across a broad temperature range.Moreover,the Ti_(3)C_(2) skeleton reinforces structural integrity via Fe-O-Ti bonding,while enabling excellent dispersion of FeS_(2) QD.As expected,FeS_(2) QD/MXene anode harvests capacities of 255.2 and 424.9 mAh g^(−1) at 0.1 A g^(−1) under−35 and 65,and the energy density of FeS_(2) QD/MXene//NVP full cell can reach to 162.4 Wh kg^(−1) at−35,highlighting its practical potential for wide-temperatures conditions.This work extends the uncoordinated regions induced by quantum-size effects for exceptional Na^(+)ion storage and diffusion performance at wide-temperatures environment.
基金supported by the National Natural Science Foundation of China(No.U1710252)the Natural Science Foundation of Jiangsu Province(BK.20210130)+3 种基金Innovative and Entrepreneurial Doctor in Jiangsu Province(No.JSSCBS20211428)China Postdoctoral Science Foundation(No.2023M731084)Shanghai Sailing Program of China(No.23YF1408900)the Fundamental Research Funds for the Central Universities(No.JKD01231701).
文摘Lithium-sulfur(Li-S)batteries mainly rely on the reversible electrochemical reaction of between lithium ions(Li^(+))and sulfur species to achieve energy storage and conversion,therefore,increasing the number of free Li^(+)and improving the Li^(+)diffusion kinetics will effectively enhance the cell performance.Here,Mo-based MXene heterostructure(MoS_(2)@Mo_(2)C)was developed by partial vulcanization of Mo_(2)C MXene,in which the introduction of similar valence S into Mo-based MXene(Mo_(2)C)can create an electron delocalization effect.Through theoretical simulations and electrochemical characterisation,it is demonstrated that the MoS_(2)@Mo_(2)C heterojunction can effectively promote ion desolvation,increase the amount of free Li^(+),and accelerate Li^(+)transport for more efficient polysulfide conversion.In addition,the MoS_(2)@Mo_(2)C material is also capable of accelerating the oxidation and reduction of polysulfides through its sufficient defects and vacancies to further enhance the catalytic efficiency.Consequently,the Li-S battery with the designed MoS_(2)@Mo_(2)C electrocatalyst performed for 500 cycles at 1 C and still maintained the ideal capacity(664.7 mAh·g^(−1)),and excellent rate performance(567.6 mAh·g^(−1)at 5 C).Under the extreme conditions of high loading,the cell maintained an excellent capacity of 775.6 mAh·g^(−1)after 100 cycles.It also retained 838.4 mAh·g^(−1)for 70 cycles at a low temperature of 0℃,and demonstrated a low decay rate(0.063%).These results indicate that the delocalized electrons effectively accelerate the catalytic conversion of lithium polysulfide,which is more practical for enhancing the behaviour of Li-S batteries.
基金Project supported by the PhD Starting Fund of Guangdong Ocean University(Grant No.120702/R17077)the National Natural Science Foundation of China(Grant No.11704080).
文摘The non-spherical lowest-lying Lin(n=15–17)isomers were found with high symmetric compact structures,of which the stability was not rationalized in a previous report(J.Chem.Phys.1199444(2003)).Based on the newly proposed super-valence bond model,the three prolate lithium clusters can be viewed as magnetic superatomic molecules,which are composed by sharing valence electron pairs and nuclei between two superatom units,namely,Li10 or Li11,and thus their stability can be given a good understanding.Molecular orbital and chemical bonding analysis clearly reveal that the Lin(n=15–17)clusters with prolate shapes are magnetic superatomic molecules.Our work may aid in the developments of the cluster-assembled materials or superatom-bonds.
文摘The localized molecular orbitals and energy levels for [Co_6 (μ_3-S)_8 (PH_3)_6]￣(n+)(n=0, 1) as model molecules of the electron-rich [Co_6 (μ_3-S)_8 (PPh_3)_6]￣(n+) (n=0,1) cluster compounds have been calculated by using Edmiston-Ruedenberg energy localization scheme under the spin-unrestricted CNDO/2 approximation. It is shown that the cluster skeletons of these two isostructural molecules consist of the edge-localized two-centered two-electron (Co-S) bonds plus a pair of the skeleton electrons delocalized on the whole cluster core,leading an extra stability of the cluster core.The one-electron oxidation for the neutral molecule gives rise to a one-electron σ (Co-Co) bond.which further resonates among the three diagonal lines of the {Co_6} octahedron. The comparison between [Co_6 (μ_3-S)_8(PPh_3)_6] and [Co_6(μ_3-CO)_8(CO)_6]￣(4-) indicates that the latter possesses face-localized bridging-bonds which are further delocalized on the whole surface of the cluster octahedron by the back-donation bonds from the lone electron pairs on the Co atoms to the capping carbonyl CO ligands. The structural features of the series of the [Co6(μ_3-X)_8L_6]￣(n+)(X =S, Se; L=PPh_3,PEt_3, CO;n=0, 1) cluster compounds are briefly rationalized on the basis of the localization description as well.
基金supported by the National Natural Science Foundation of China(21801090,21831003 and 21621001)the Jilin Scientific and Technological Development Program(20200802003GH)+2 种基金the Scientific Research Project in the Education Department of Jilin Province(JJKH20211044KJ)the Project on Experimental Technique of Jilin University(409020720202)supported by Users with the Excellence Program of Hefei Science Center CAS(2020HSC-UE002)。
文摘The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we developed a spin-state and delocalized electron regulation method to optimize oxygen evolution reaction(OER)performance by in-situ growth of NiCo_(2)(OH)_(x) using Oswald ripening and coordinating etching process on MXene and plasma treatment.X-ray absorption spectroscopy,magnetic tests and electron paramagnetic resonance reveal that the coupling of NiCo_(2)(OH)_(x) and MXene can induce remarkable spin-state transition of Co^(3+)and transition metal ions electron delocalization,plasma treatment further optimizes the 3 d orbital structure and delocalized electron density.The unique Jahn-Teller phenomenon can be brought by the intermediate spin state(t2 _(g)^(5) e_(g)^(1))of Co^(3+),which benefits from the partial electron occupied egorbitals.This distinct electron configuration(t2_(g)^(5) e_(g)^(1))with unpaired electrons leads to orbital degeneracy,that the adsorption free energy of intermediate species and conductivity were further optimized.The optimized electrocatalyst exhibits excellent OER activity with an overpotential of 268 m V at 10 m A cm^(-2).DFT calculations show that plasma treatment can effectively regulate the d-band center of TMs to optimize the adsorption and improve the OER activity.This approach could guide the rational design and discovery of electrocatalysts with ideal electron configurations in the future.
基金National Natural Science Foundation of China,Grant/Award Numbers:22279166,52002157National Institute of Education,Singapore,under its Academic Research Fund,Grant/Award Numbers:RI 1/21 EAH,RI 3/23 EAH+1 种基金China Postdoctoral Science Foundation,Grant/Award Numbers:2022M711686,2023M741471Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:SJCX24_2512。
文摘The architectural design of redox-active organic molecules and the modulation of their electronic properties significantly influence their application in energy storage systems within aqueous environments.However,these organic molecules often exhibit sluggish reaction kinetics and unsatisfactory utilization of active sites,presenting significant challenges for their practical deployment as electrode materials in aqueous batteries.In this study,we have synthesized a novel organic compound(PTPZ),comprised of a centrally symmetric and fully ladder-type structure,tailored for aqueous proton storage.This unique configuration imparts the PTPZ molecule with high electron delocalization and enhanced structural stability.As an electrode material,PTPZ demonstrates a substantial proton-storage capacity of 311.9mAh g^(-1),with an active group utilization efficiency of up to 89% facilitated by an 8-electron transfer process,while maintaining a capacity retention of 92.89% after 8000 chargingdischarging cycles.Furthermore,in-situ monitoring technologies and various theoretical analyses have pinpointed the associated electrochemical processes of the PTPZ electrode,revealing exceptional redox activity,rapid proton diffusion,and efficient charge transfer.These attributes confer a significant competitive advantage to PTPZ as an anode material for high-performance proton storage devices.Consequently,this work contributes to the rational design of organic electrode materials for the advancement of rechargeable aqueous batteries.
基金supported by Shandong Provincial Natural Science Foundation,China(ZR2022QE014)Basic Scientific Research Fund for Central Universities(202112018)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)。
文摘Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,poor cycling stability and safety concerns could be caused by uncontrolled dendrite and high reactivity of Li metal,which hinder the practical application of Li-metal anode in high-energy rechargeable Li metal batteries(LMBs).Here,a facile way is reported to stabilize Li metal anode by building high lithiophilic Mg-Li-Cu alloy.Due to the delocalization of electrons on the deposited lithium enhanced by Cu self-diffusion into Mg-Li alloy,the growth of lithium dendrites could be inhibited by Mg-Li-Cu alloy.Moreover,the parasitic reactions with electrolyte could be avoided by the Mg-Li-Cu alloy anode.It is noteworthy that the symmetric battery life of Mg-Li-Cu alloy electrodes exceeds 9000 h at 1 m A cm^(-2)and 1 m Ah cm^(-2).The full cell(LiFePO_(4)|Mg-Li-Cu)exhibits a specific capacity of 148.2 m Ah g^(-1),with a capacity retention of 96.4%,at 1 C after 500 cycles.This work not only pave the way for application of flexible alloy anode in highly stable LMBs,but also provides novel strategies for preparation and optimization of Mg alloy.
基金supported by the National Natural Science Foundation of China(92372118,52072224)the Shandong Provincial Natural Science Foundation(ZR2023ZD52)。
文摘The sluggish interfacial kinetics at the Zn electrode-electrolyte interface is one of the reasons for the limited cycle stability of aqueous zinc ion batteries(AZIBs).Here,an electrolyte additive with an electron delocalization effect is proposed to improve interfacial kinetics on the anode,achieving a stable and long lifespan of AZIBs.The conjugated maleimide(MI)anion presents an electron delocalization effect and adsorbs on the Zn,which improves the charge transfer process and the interfacial kinetics.Also,a double protective layer of H_(2)O-poor electrical double layer and solid electrolyte interphase with organic substance is formed by the absorption of MI anions.Benefit from the MI additive,a no-dendrite anode is obtained by suppressing the side reactions and guiding the homogeneous deposition of Zn^(2+).Finally,a stable Zn||Zn symmetric cell performance up to 5600 h is achieved,and an impressive average coulombic efficiency(~99.91%)is obtained in Zn||Cu cell after 2500 cycles.The Zn||MnO_(2)full cell also exhibits a lifespan of 2000 cycles at 2 A g^(-1).The method using the electron delocalization effect of MI provides a new idea for additive selection to stabilize the electrode-electrolyte interface and to facilitate interfacial kinetics.
基金supported by the National Natural Science Foundation of China(Nos.22175108 and 22379086)the Natural Science Foundation of Shandong Province(Nos.ZR2020JQ09 and ZR2022ZD27)Taishan Scholars Program of Shandong Province(tstp20221105)。
文摘Electrocatalysis provides an optimal approach for the conversion of carbon dioxide(CO_(2))into high-value chemicals,thereby presenting a promising avenue toward achieve carbon neutrality.However,addressing the selectivity and stability challenges of metal catalysts in electrolytic reduction remains a daunting task.In this study,the electrospinning method is employed to fabricate porous carbon nanofibers loaded with bismuth nanoparticles with the help of in situ pyrolysis.The porous carbon nanofibers as conductive support would facilitate the dispersion of bismuth active sites while inhibiting their aggregation and promoting the mass transfer,thus enhancing their electrocatalytic activity and stability.Additionally,nitrogen doping induces electron delocalization in bismuth atoms through metal-support interactions,thus enabling efficient adsorption of intermediates for improving selectivity based on the theoretical calculation.Consequently,Bi@PCNF-500 exhibits the exceptional selectivity and stability across a wide range of potential windows.Notably,its faradaic efficiency(FE)of formate reaches 92.7%in H-cell and94.9%in flow cell,respectively,with good electrocatalytic stability.The in situ characterization and theoretical calculations elucidate the plausible reaction mechanism to obtain basic rules for designing efficient electrocatalyst.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Nos.11905115,11575102)the Shandong Jianzhu University XNBS Foundation(No.1608)the Fundamental Research Fund of Shandong University(No.2018JC022)。
文摘The unique hot carrier-driven direct plasmonic photocatalysis of coinage metal nanomaterials(NMs)via energetic localized surface plasmon resonance(LSPR)in visible-light region has been explored in recent years.However,the low photoinduced electron transfer efficiency and insufficient separation of electronhole pairs would severely preclude their widespread practical applications.Herein,we demonstrate an interesting plasmonic photocatalyst based on the construction of icosahedral(Ih)Au@C_(60) core-shell NMs,taking advantage of specific delocalizedπelectrons structure of a tight C_(60) shell and enhanced LSPR property of Ih Au core.Then,the pronounced interfacial interaction at junction region endows the obtained Au@C_(60) NMs with an outstanding photoinduced hot carrier-transmission during photocatalytic reaction,facilitating a remarkably higher(1.89 times)photocatalytic activity toward visible-light driven degradation of crystal violet(CV)dyes,as compared to bare Au NMs.Impressively,the photocatalytic activity of Ih Au@C_(60) NMs can be effectively optimized by changing the p H value of reaction solution,with the kinetic rate constant reaching the maximum value of 0.179 min^(-1) in pH011.4 solution,while 0.005 min^(-1) at pH03.0.Moreover,due to the protection of a tight C_(60) shell,the Ih Au@C_(60) NMs also possess excellent photocatalytic stability/reusability in recycling runs,holding great potential for the design of robust and high-performance plasmonic photocatalysts in repeated practical applications.
文摘By use of the Keldysh non-equilibrium Green’s-function methods, the third harmonic susceptibilities of two polyaniline families, PANI-HCl and PANI-H 3PO 4, are calculated [ x (3) ( ω )≈10 -12 esu]. It was found that the third harmonic susceptibility of polyaniline strongly depends on the delocalization of the electrons. The refractive indices n ( λ =589 nm) of PANI-HCl and PANI-H 3PO 4 are calculated by use of three common methods (the Lorentz-Lorentz theoretical model, the Gladstone-Dale group contribution and the Vogel group correlation) based on group contributions to molar refraction. The calculated n values are varied from 1.31 to 1.42 for PANI-HCl and 1.36 to 1.45 for PANI-H 3PO 4.
基金the National Natural Science Foundation of China(Nos.51872116 and 12034002)Jilin Province Science and Technology Development Program(No.20210301009GX)+3 种基金Project for Self-innovation Capability Construction of Jilin Province Development and Reform Commission(No.2021C026)the Program for JLU Science and Technology Innovative Research Team(JLUSTIRT,No.2017TD-09)Jilin Province Science and Technology Development Program(No.20190201233JC)the Fundamental Research Funds for the Central Universities.
文摘Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–shell structure through the bridge Br atom.Carbon shell wrapped copper bromide nanorods(CuBr@C)are constructed for the first time by chemical vapour deposition with hexabromobenzene(HBB).HBB pyrolysis provides both bridge Br atom and C shells.The C shell protects the stability of the internal halide structure,while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic activity.Impressively,the hydrogen evolution reaction(HER)activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes,surpassing commercial Pt/C at over 200 mA·cm^(−2).Density functional theory(DFT)calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces,leading to optimization of hydrogen adsorption energy.
