The discovery of high-temperature superconductivity in bilayer nickelate La_(3)Ni_(2)O_(7)under high-pressure conditions has spurred extensive efforts to stabilize superconductivity at ambient pressure.Recently,the re...The discovery of high-temperature superconductivity in bilayer nickelate La_(3)Ni_(2)O_(7)under high-pressure conditions has spurred extensive efforts to stabilize superconductivity at ambient pressure.Recently,the realization of superconductivity in compressively strained La_(3)Ni_(2)O_(7)thin films grown on the SrLaAlO_(4)substrates,with a T_(c)exceeding 40 K,represents a significant step toward this goal.Here,we investigate the influence of film thickness and carrier doping on the electronic structure of La_(3)Ni_(2)O_(7)thin films,ranging from 0.5 to 3 unit cells,using first-principles calculations.For a 2 unit-cell film with an optimal doping concentration of 0.3 hole per formula unit(0.15 hole/Ni),the Ni-d_(z^(2))interlayer bonding state crosses the Fermi level,resulting in the formation ofγpockets at the Fermi surface.These findings align with angle-resolved photoemission spectroscopy experimental data.Our results provide theoretical validation for the recent experimental discovery of ambient-pressure superconductivity in La_(3)Ni_(2)O_(7)thin films and underscore the significant impact of film thickness and carrier doping on electronic property modulation.展开更多
Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the e...Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.展开更多
Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Her...Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.展开更多
Thework presents the electronic structure computations and optical spectroscopy studies of half-Heusler ScNiBi and YNiBi compounds.Our first-principles computations of the electronic structures were based on density f...Thework presents the electronic structure computations and optical spectroscopy studies of half-Heusler ScNiBi and YNiBi compounds.Our first-principles computations of the electronic structures were based on density functional theory accounting for spin-orbit coupling.These compounds are computed to be semiconductors.The calculated gap values make ScNiBi and YNiBi valid for thermoelectric and optoelectronic applications and as selective filters.In ScNiBi and YNiBi,an intense peak at the energy of−2 eV is composed of theNi 3d states in the conduction band,and the valence band mostly contains these states with some contributions from the Bi 6p and Sc 3d or Y 4d electronic states.These states participate in the formation of the indirect gap of 0.16 eV(ScNiBi)and 0.18 eV(YNiBi).Within the spectral ellipsometry technique in the interval 0.22–15μm of wavelength,the optical functions of materials are studied,and their dispersion features are revealed.A good matching of the experimental and modeled optical conductivity spectra allowed us to analyze orbital contributions.The abnormally low optical absorption observed in the low-energy region of the spectrum is referred to as the results of band calculations indicating a small density of electronic states near the Fermi energy of these complex materials.展开更多
Diradicaloid polycyclic hydrocarbons(PHs)own unique open-shell electronic structures and exhibit potential utility in the fields of organic electronics and spintronics.Herein,we disclose precise fusion of B/O-heterocy...Diradicaloid polycyclic hydrocarbons(PHs)own unique open-shell electronic structures and exhibit potential utility in the fields of organic electronics and spintronics.Herein,we disclose precise fusion of B/O-heterocycles onto PHs for control over their electronic structures and diradical properties.We designed and synthesized four B/O-containing diradicaloid isomers that feature the fluoreno[3,2-b]fluorene and fluoreno[2,1-a]fluoreneπ-skeletons,respectively.The precise B/O-heterocycle fusion modes along with the changed conjugation patterns lead to their modulated electronic structures and properties,such as diradical and aromatic structures,energy levels and band gaps,as well as magnetic,electrochemical and photophysical properties.Notably,the mode A may decrease the open-shell extent,whereas the mode B can enhance the diradical nature,leading to their well-tuned diradical characters in the range of0.46-0.70.Moreover,the mode A stabilizes the LUMOs and the mode B obviously increases the HOMO levels,which are remarkably contributed by the B and O atoms,respectively,further giving rise to the decreased band gaps and redshifted absorptions.This study clearly illustrates the electronic effects of B/O-heterocycle fusion on PHs and gains insight into B/O-type organic diradicaloids.These findings will provide an important guideline for the design of more fascinating heteroatom-containing diradicaloids.展开更多
As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)poss...As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.展开更多
Urea-assisted water electrolysis offers a promising route to reduce energy consumption for hydrogen production and meanwhile treat urea-rich wastewater.Herein,we devised a shear force-involved polyoxometalate-organic ...Urea-assisted water electrolysis offers a promising route to reduce energy consumption for hydrogen production and meanwhile treat urea-rich wastewater.Herein,we devised a shear force-involved polyoxometalate-organic supramolecular self-assembly strategy to fabricate 3D hierarchical porous nanoribbon assembly Mn-VN cardoons.A bimetallic polyoxovanadate(POV)with the inherent structural feature of Mn surrounded by[VO_(6)]octahedrons was introduced to trigger precise Mn incorporation in VN lattice,thereby achieving simultaneous morphology engineering and electronic structure modulation.The lattice contraction of VN caused by Mn incorporation drives electron redistribution.The unique hierarchical architecture with modulated electronic structure that provides more exposed active sites,facilitates mass and charge transfer,and optimizes the associated adsorption behavior.Mn-VN exhibits excellent activity with low overpotentials of 86 m V and 1.346 V at 10 m A/cm^(2)for hydrogen evolution reaction(HER)and urea oxidation reaction(UOR),respectively.Accordingly,in the two-electrode urea-assisted water electrolyzer utilizing Mn-VN as a bifunctional catalyst,hydrogen production can occur at low voltage(1.456 V@10 m A/cm^(2)),which has the advantages of energy saving and competitive durability over traditional water electrolysis.This work provides a simple and mild route to construct nanostructures and modulate electronic structure for designing high-efficiency electrocatalysts.展开更多
High-mobility semiconductor nanotubes have demonstrated great potential for applications in high-speed transistors,single-charge detection,and memory devices.Here we systematically investigated the electronic properti...High-mobility semiconductor nanotubes have demonstrated great potential for applications in high-speed transistors,single-charge detection,and memory devices.Here we systematically investigated the electronic properties of single-walled boron antimonide(BSb)nanotubes using first-principles calculations.We observed that rolling the hexagonal boron antimonide monolayer into armchair(ANT)and zigzag(ZNT)nanotubes induces compression and wrinkling effects,significantly modifying the band structures and carrier mobilities through band folding andπ^(*)-σ^(*)hybridization.As the chiral index increases,the band gap and carrier mobility of ANTs decrease monotonically,where electron mobility consistently exceeds hole mobility.In contrast,ZNTs exhibit a more complex trend:the band gap first increases and then decreases,and the carrier mobility displays oscillatory behavior.In particular,both ANTs and ZNTs could exhibit significantly higher carrier mobilities compared to hexagonal monolayer and zinc-blende BSb,reaching 10^(-3)-10^(-7) cm^(-2)·V^(-1)·s^(-1).Our findings highlight strong curvature-induced modifications in the electronic properties of single-walled BSb nanotubes,demonstrating the latter as a promising candidate for high-performance electronic devices.展开更多
Triggering structural asymmetry can induce charge redistribution and modify electronic structures,which is of great significance for the design of high-performance hydrogen oxidation reaction(HOR)electrocatalysts.Here...Triggering structural asymmetry can induce charge redistribution and modify electronic structures,which is of great significance for the design of high-performance hydrogen oxidation reaction(HOR)electrocatalysts.Herein,we propose a dual anion-induced strategy to create an innovative RuS_(2)-RuO_(2)heterostructure featuring abundant S-Ru-O interfaces(RuS_(2)-RuO_(2)@C).This RuS_(2)-RuO_(2)@C demonstrates an impressive mass activity of 2.61 mAμg_(RU)^(-1)and an exchange current density of 2.96 mA cm^(-2),surpassing Pt/C and other comparative samples by over 20 times.Durability assessments confirm the superior stability of RuS_(2)-RuO_(2)@C,with only minimal performance loss during operation.Density functional theory(DFT)calculations indicate that the asymmetric S-Ru-O configuration optimizes the interfacial electronic structure and shifts the d-band center closer to the Fermi level,effectively reducing the energy barrier of the rate-determining step(RDS)in the alkaline HOR process.Moreover,in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)characteristics disclose the formation of a substantial hydrogen bond network at the S-Ru-o interface,which aids in the desorption of H_(2)O_(ad)and facilitates the vital Volmer step in the HOR pathway.展开更多
Photocatalytic synthesis of hydrogen peroxide(H_(2)O_(2))has emerged as a promising approach because of its simplicity and environmental benefits.However,significant challenges remain obstacles to their advancement,su...Photocatalytic synthesis of hydrogen peroxide(H_(2)O_(2))has emerged as a promising approach because of its simplicity and environmental benefits.However,significant challenges remain obstacles to their advancement,such as the rapid recombination of photogenerated charge carriers and sluggish surface redox reactions on nonmetallic organic catalysts.Metal-based organic catalysts with tunable electronic structures are considered ideal for exploring the mechanisms and structure-performance relationships in H_(2)O_(2) synthesis.This review summarizes the fundamental principles of photocatalytic H_(2)O_(2) synthesis via oxygen reduction and water oxidation reactions.Recent advancements in electronic structure tuning strategies for metal-based organic catalysts are critically examined,focusing on their impact on light absorption range,photogenerated carrier separation,O_(2) activation,and the selective generation of H_(2)O_(2).In addition,this review comprehensively evaluates the applications of sacrificial agents in photocatalytic reaction systems and offers insights into the future development of metal-based organic catalysts for H_(2)O_(2) photosynthesis.展开更多
Determining the electronic structure of La_(3)Ni_(2)O_(7)is an essential step towards uncovering its superconducting mechanism.It is widely believed that the bilayer apical oxygens play an important role in the bilaye...Determining the electronic structure of La_(3)Ni_(2)O_(7)is an essential step towards uncovering its superconducting mechanism.It is widely believed that the bilayer apical oxygens play an important role in the bilayer La_(3)Ni_(2)O_(7)electronic structure.Applying the hybrid exchange–correlation functionals,we obtain a more accurate electronic structure of La_(3)Ni_(2)O_(7)at its high-pressure phase,where the bonding dz2 band is below the Fermi level owing to the apical oxygen.The symmetry properties of this electronic structure and its corresponding tight-binding model are further analyzed.We find that the antisymmetric part is highly entangled,leading to a minimal nearly degenerate two-orbital model.Then,the apical oxygen vacancies effect is studied using the dynamical cluster approximation.This disorder effect strongly destroys the antisymmetric b Fermi surface,leading to the possible disappearance of superconductivity.展开更多
We theoretically investigate the electronic structure of cylindrical magnetic topological insulator quantum wires in MnBi_(2)Te_(4).Our study reveals the emergence of topological surface states in the ferromagnetic ph...We theoretically investigate the electronic structure of cylindrical magnetic topological insulator quantum wires in MnBi_(2)Te_(4).Our study reveals the emergence of topological surface states in the ferromagnetic phase,characterized by spin-polarized subbands resulting from intrinsic magnetization.In the antiferromagnetic phase,we identify the coexistence of three distinct types of topological states,encompassing both surface states and central states.展开更多
We present a comprehensive electron momentum spectroscopy study on the electronic structure of trifluorobromomethane.The binding energy spectrum and electron momentum profiles of the entire outer-valence orbitals and ...We present a comprehensive electron momentum spectroscopy study on the electronic structure of trifluorobromomethane.The binding energy spectrum and electron momentum profiles of the entire outer-valence orbitals and the first inner-valence orbital along with several shake-up states were measured by using a high-sensitivity(e,2e)apparatus at an electron impact energy of 1213 eV.Theoretical calculations employing the density functional theory with B3LYP hybrid functional and the symmetry-adapted cluster configuration-interaction method were performed to interpret the experimental results.Important effects of electron correlations in the initial neutral and final ionic states on the electron momentum profiles have been observed.展开更多
The rapidly growing electric cars and energy storage systems have extremely promoted the development of advanced lithium and sodium ion batteries and stimulated evolution of high-capacity cathodes.Li/Na-rich layered c...The rapidly growing electric cars and energy storage systems have extremely promoted the development of advanced lithium and sodium ion batteries and stimulated evolution of high-capacity cathodes.Li/Na-rich layered cathodes consisting cationic and anionic reactions as the most typical representative of high-capacity cathodes have shown its tremendous potential.However,there is a long way to go before commercialization because of unsatisfactory performances including large voltage hysteresis,voltage fade and poor cycle performance.Numerous investigations on redox mechanisms and engineering strategies have been performed from the point view of structure and made significant progress,which has been well reviewed.Meanwhile,the unacceptable issues are essentially correlated to the electronic configuration of anionic redox and its interaction with adjacent transition metal cations,which can be well depicted from electronic structure.However,the investigations on anionic reaction process in the viewpoint of electronic structure have been much less summarized.This review aims to compile the current knowledge of anionic redox from the point view of electronic structure,including configuration,origination,evolution,detection and coupling relationship with cationic redox.This work is attempted to inspire new perspectives and design approaches for the development of high-capacity cathodes.展开更多
Single-atom catalysts are promising for H_(2)O_(2) photosynthesis from O_(2) and H_(2)O,but their efficiency is still limited by the ill-defined electronic structure.In this study,Co single-atoms with unique four plan...Single-atom catalysts are promising for H_(2)O_(2) photosynthesis from O_(2) and H_(2)O,but their efficiency is still limited by the ill-defined electronic structure.In this study,Co single-atoms with unique four planar N-coordination and one axial P-coordination(Co-N_(4)P_(1))are decorated on the lateral edges of nanorod-like crystalline g-C_(3)N_(4)(CCN)photocatalysts.Significantly,the electronic structures of central Co as active sites for O_(2) reduction reaction(ORR)and planar N-coordinator as active sites for H_(2)O oxidation reaction(WOR)in Co-N_(4)P_(1) can be well regulated by the synergetic effects of introducing axial P-coordinator,in contrast to the decorated Co single-atoms with only four planar N-coordination(Co-N_(4)).Specifically,directional photoelectron accumulation at central Co active sites,induced by an introduced midgap level in Co-N_(4)P_(1),mediates the ORR active sites from 4e–-ORR-selective terminal–NH_(2) sites to 2e–-ORR-selective Co sites,moreover,an elevated d-band center of Co 3d orbital strengthens ORR intermediate*OOH adsorption,thus jointly facilitating a highly selective and active 2e^(–)-ORR pathway to H_(2)O_(2) photosynthesis.Simultaneously,a downshifted p-band center of N_(2)p orbital in Co-N_(4)P_(1) weakens WOR intermediate*OH adsorption,thus enabling a preferable 2e^(–)-WOR pathway toward H_(2)O_(2) photosynthesis.Subsequently,Co-N_(4)P_(1) exhibits exceptional H_(2)O_(2) photosynthesis efficiency,reaching 295.6μmol g^(-1) h^(-1) with a remarkable solar-to-chemical conversion efficiency of 0.32%,which is 15 times that of Co-N_(4)(19.2μmol g^(-1) h^(-1))and 10 times higher than CCN(27.6μmol g^(-1) h^(-1)).This electronic structure modulation on single-atom catalysts offers a promising strategy for boosting the activity and selectivity of H_(2)O_(2) photosynthesis.展开更多
The electronic structure,elasticity,and magnetic properties of the Mn_(2)XIn(X=Fe,Co)full-Heusler compounds are comprehensively investigated via first-principles calculations.The calculated elastic constants indicate ...The electronic structure,elasticity,and magnetic properties of the Mn_(2)XIn(X=Fe,Co)full-Heusler compounds are comprehensively investigated via first-principles calculations.The calculated elastic constants indicate that both Mn_(2)FeIn and Mn_(2)Co In possess ductility.At the optimal lattice constants,the magnetic moments are found to be 1.40μB/f.u.for Mn_(2)FeIn and 1.69μB/f.u.for Mn_(2)CoIn.Under the biaxial strain ranging from-2%to 5%,Mn_(2)FeIn demonstrates a remarkable variation in the spin polarization,spanning from-2%to 74%,positioning it as a promising candidate for applications in spintronic devices.Analysis of the electronic structure reveals that the change in spin polarization under strain is due to the shift of the spin-down states at the Fermi surface.Additionally,under biaxial strain,the magnetic anisotropy of Mn_(2)FeIn undergoes a transition of easy-axis direction.Utilizing second-order perturbation theory and electronic structure analysis,the variation in magnetic anisotropy with strain can be attributed to changes of d-orbital states near the Fermi surface.展开更多
The electronic structure,magnetic,and optical properties of two-dimensional(2D)GaSe doped with rare earth elements X(X=Sc,Y,La,Ce,Eu)were calculated using the first-principles plane wave method based on den-sity funct...The electronic structure,magnetic,and optical properties of two-dimensional(2D)GaSe doped with rare earth elements X(X=Sc,Y,La,Ce,Eu)were calculated using the first-principles plane wave method based on den-sity functional theory.The results show that intrinsic 2D GaSe is a p-type nonmagnetic semiconductor with an indi-rect bandgap of 2.6611 eV.The spin-up and spin-down channels of Sc-,Y-,and La-doped 2D GaSe are symmetric,they are non-magnetic semiconductors.The magnetic moments of Ce-and Eu-doped 2D GaSe are 0.908μ_(B)and 7.163μ_(B),which are magnetic semiconductors.Impurity energy levels appear in both spin-up and spin-down chan-nels of Eu-doped 2D GaSe,which enhances the probability of electron transition.Compared with intrinsic 2D GaSe,the static dielectric constant of the doped 2D GaSe increases,and the polarization ability is strengthened.The ab-sorption spectrum of the doped 2D GaSe shifts in the low-energy direction,and the red-shift phenomenon occurs,which extends the absorption spectral range.The optical reflection coefficient of the doped 2D GaSe is improved in the low energy region,and the improvement of Eu-doped 2D GaSe is the most obvious.展开更多
At present,industrial synthetic ammonia was still obtained through the Hubble-Bosch process,with large energy consumption.It is a research hotspot to realize green synthetic ammonia by using solar energy.The difficult...At present,industrial synthetic ammonia was still obtained through the Hubble-Bosch process,with large energy consumption.It is a research hotspot to realize green synthetic ammonia by using solar energy.The difficulty of photocatalytic ammonia synthesis was that the photo-excited electrons have not enough energy to active N≡N.In this study,Ti was doped into BiOBr by one-step hydrothermal method,which was oxidized into TiO_(2)when the doping amount reaches the maximum,in situ forming Ti_(0.31)B_(0.69)OB/TiO_(2)composites.Benefiting from the synergistic effect of Ti doping and S-scheme heterojunction,the synthetic ammonia efficiency of Ti_(0.31)B_(0.69)OB/TiO_(2)-11.96 reached 1.643 mmol·g_(cat)^(-1)at mild conditions and without hole scavenger for up to 7 h,the efficiency of synthetic ammonia is 115 times,10.5 times and 3.3 times of that of BiOBr,Ti_(0.31)B_(0.69)OB and TiO_(2),respectively.Specifically,DFT calculation confirms that Ti doping accurately refine the electronic structure of BiOBr,facilitate nitrogen adsorption activation and reduce hydrogenation reaction energy barrier,thus accelerating the reaction kinetics of photocatalytic nitrogen reduction(NRR),Meanwhile,constructing S-scheme heterojunction boosts the separation and transfer of photogenerated electron-hole pairs,improving the reduction ability of electrons in the conduction band of TiO_(2)and the oxidation ability of holes in the valence band of Ti_(0.31)B_(0.69)OB.展开更多
Mo_(2)C is an excellent electrocatalyst for hydrogen evolution reaction(HER).However,Mo_(2)C is a poor electrocatalyst for oxygen evolution reaction(OER).Herein,two different elements,namely Co and Fe,are incorporated...Mo_(2)C is an excellent electrocatalyst for hydrogen evolution reaction(HER).However,Mo_(2)C is a poor electrocatalyst for oxygen evolution reaction(OER).Herein,two different elements,namely Co and Fe,are incorporated in Mo_(2)C that,therefore,has a finely tuned electronic structure,which is not achievable by incorporation of any one of the metals.Consequently,the resulting electrocatalyst Co_(0.8)Fe_(0.2)-Mo_(2)C-80 displayed excellent OER catalytic performance,which is evidenced by a low overpotential of 214.0(and 246.5)mV to attain a current density of 10(and 50)mA cm^(-2),an ultralow Tafel slope of 38.4 mV dec^(-1),and longterm stability in alkaline medium.Theoretical data demonstrates that Co_(0.8)Fe_(0.2)-Mo_(2)C-80 requires the lowest overpotential(1.00 V)for OER and Co centers to be the active sites.The ultrahigh catalytic performance of the electrocatalyst is attributed to the excellent intrinsic catalytic activity due to high Brunauer-Emmett-Teller specific surface area,large electrochemically active surface area,small Tafel slope,and low chargetransfer resistance.展开更多
The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on...The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on photocatalysts present notable challenges.In this study,we have devised a straightforward hydrothermal method to synthesize Bi_(2)O_(3)(BO)derived from metal‐organic frameworks(MOFs),loaded with flower-like ZnIn_(2)S_(4)(ZIS).This approach substantially enhances water adsorption and surface catalytic reactions,resulting in a remarkable enhancement of photocatalytic activity.By employing triethanolamine(TEOA)as a sacrificial agent,the hydrogen evolution rate achieved with 15%(mass fraction)ZIS loading on BO reached an impressive value of 1610μmol∙h^(−1)∙g^(−1),marking a 6.34-fold increase compared to that observed for bare BO.Furthermore,through density functional theory(DFT)and ab initio molecular dynamics(AIMD)calculations,we have identified the reactions occurring at the ZIS/BO S-scheme heterojunction interface,including the identification of active sites for water adsorption and catalytic reactions.This study provides valuable insights into the development of high-performance composite photocatalytic materials with tailored electronic properties and wettability.展开更多
基金supported by the National Key R&D Program of China(Gran Nos.2022YFA1402304 and 2022YFA1402802)the National Natural Science Foundation of China(Grant Nos.12494591,12122405,12274169,and 92165204)+4 种基金Program for Science and Technology Innovation Team in Zhejiang(Grant No.2021R01004)Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)Guangdong Fundamental Research Center for Magnetoelectric Physics(2024B0303390001)Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2401010)the Fundamental Research Funds for the Central Universities。
文摘The discovery of high-temperature superconductivity in bilayer nickelate La_(3)Ni_(2)O_(7)under high-pressure conditions has spurred extensive efforts to stabilize superconductivity at ambient pressure.Recently,the realization of superconductivity in compressively strained La_(3)Ni_(2)O_(7)thin films grown on the SrLaAlO_(4)substrates,with a T_(c)exceeding 40 K,represents a significant step toward this goal.Here,we investigate the influence of film thickness and carrier doping on the electronic structure of La_(3)Ni_(2)O_(7)thin films,ranging from 0.5 to 3 unit cells,using first-principles calculations.For a 2 unit-cell film with an optimal doping concentration of 0.3 hole per formula unit(0.15 hole/Ni),the Ni-d_(z^(2))interlayer bonding state crosses the Fermi level,resulting in the formation ofγpockets at the Fermi surface.These findings align with angle-resolved photoemission spectroscopy experimental data.Our results provide theoretical validation for the recent experimental discovery of ambient-pressure superconductivity in La_(3)Ni_(2)O_(7)thin films and underscore the significant impact of film thickness and carrier doping on electronic property modulation.
基金supported by the National Natural Science Foundation of China(U21A20281)the Special Fund for Young Teachers from Zhengzhou University(JC23557030,JC23257011)+1 种基金the Key Research Projects of Higher Education Institutions of Henan Province(24A530009)the Project of Zhongyuan Critical Metals Laboratory(GJJSGFYQ202336).
文摘Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.
基金supported by National Natural Science Foundation of China(No.523B2070,No.52225606).
文摘Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.
文摘Thework presents the electronic structure computations and optical spectroscopy studies of half-Heusler ScNiBi and YNiBi compounds.Our first-principles computations of the electronic structures were based on density functional theory accounting for spin-orbit coupling.These compounds are computed to be semiconductors.The calculated gap values make ScNiBi and YNiBi valid for thermoelectric and optoelectronic applications and as selective filters.In ScNiBi and YNiBi,an intense peak at the energy of−2 eV is composed of theNi 3d states in the conduction band,and the valence band mostly contains these states with some contributions from the Bi 6p and Sc 3d or Y 4d electronic states.These states participate in the formation of the indirect gap of 0.16 eV(ScNiBi)and 0.18 eV(YNiBi).Within the spectral ellipsometry technique in the interval 0.22–15μm of wavelength,the optical functions of materials are studied,and their dispersion features are revealed.A good matching of the experimental and modeled optical conductivity spectra allowed us to analyze orbital contributions.The abnormally low optical absorption observed in the low-energy region of the spectrum is referred to as the results of band calculations indicating a small density of electronic states near the Fermi energy of these complex materials.
基金supported by National Natural Science Foundation of China(Nos.52373182 and 22175074)Jilin Scientific and Technological Development Program(No.20220101054JC)Department of Education of Jilin Province(No.JJKH20221046KJ)。
文摘Diradicaloid polycyclic hydrocarbons(PHs)own unique open-shell electronic structures and exhibit potential utility in the fields of organic electronics and spintronics.Herein,we disclose precise fusion of B/O-heterocycles onto PHs for control over their electronic structures and diradical properties.We designed and synthesized four B/O-containing diradicaloid isomers that feature the fluoreno[3,2-b]fluorene and fluoreno[2,1-a]fluoreneπ-skeletons,respectively.The precise B/O-heterocycle fusion modes along with the changed conjugation patterns lead to their modulated electronic structures and properties,such as diradical and aromatic structures,energy levels and band gaps,as well as magnetic,electrochemical and photophysical properties.Notably,the mode A may decrease the open-shell extent,whereas the mode B can enhance the diradical nature,leading to their well-tuned diradical characters in the range of0.46-0.70.Moreover,the mode A stabilizes the LUMOs and the mode B obviously increases the HOMO levels,which are remarkably contributed by the B and O atoms,respectively,further giving rise to the decreased band gaps and redshifted absorptions.This study clearly illustrates the electronic effects of B/O-heterocycle fusion on PHs and gains insight into B/O-type organic diradicaloids.These findings will provide an important guideline for the design of more fascinating heteroatom-containing diradicaloids.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22178148 and 22278193)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.
基金supported by the National Natural Science Foundation of China(Nos.22322104,22171074)the Natural Science Foundation of Heilongjiang Province(No.YQ2021B009)+3 种基金the Reform and Development Fund Project of Local University supported by the Central Government(Outstanding Youth Program)Heilongjiang Province Young Scientific and Technological Talent Lifting Project(No.2023QNTJ019)the Basic Research Support Project for Outstanding Young Teachers in Heilongjiang Provincial University(No.YQJH2023129)the Outstanding Youth Science Foundation of Heilongjiang University(No.JCL202301)。
文摘Urea-assisted water electrolysis offers a promising route to reduce energy consumption for hydrogen production and meanwhile treat urea-rich wastewater.Herein,we devised a shear force-involved polyoxometalate-organic supramolecular self-assembly strategy to fabricate 3D hierarchical porous nanoribbon assembly Mn-VN cardoons.A bimetallic polyoxovanadate(POV)with the inherent structural feature of Mn surrounded by[VO_(6)]octahedrons was introduced to trigger precise Mn incorporation in VN lattice,thereby achieving simultaneous morphology engineering and electronic structure modulation.The lattice contraction of VN caused by Mn incorporation drives electron redistribution.The unique hierarchical architecture with modulated electronic structure that provides more exposed active sites,facilitates mass and charge transfer,and optimizes the associated adsorption behavior.Mn-VN exhibits excellent activity with low overpotentials of 86 m V and 1.346 V at 10 m A/cm^(2)for hydrogen evolution reaction(HER)and urea oxidation reaction(UOR),respectively.Accordingly,in the two-electrode urea-assisted water electrolyzer utilizing Mn-VN as a bifunctional catalyst,hydrogen production can occur at low voltage(1.456 V@10 m A/cm^(2)),which has the advantages of energy saving and competitive durability over traditional water electrolysis.This work provides a simple and mild route to construct nanostructures and modulate electronic structure for designing high-efficiency electrocatalysts.
基金Project supported by the National Key R&D Program of China(Grant Nos.2022YFA1402503,2023YFA1406200,2023YFB3003001)the National Natural Science Foundation of China(Grant Nos.12074138 and 12047530)+2 种基金the Interdisciplinary Integration and Innovation Project of JLUFundamental Research Funds for the Central Universitiesthe Program for JLU Science and Technology Innovative Research Team(JLUSTIRT)。
文摘High-mobility semiconductor nanotubes have demonstrated great potential for applications in high-speed transistors,single-charge detection,and memory devices.Here we systematically investigated the electronic properties of single-walled boron antimonide(BSb)nanotubes using first-principles calculations.We observed that rolling the hexagonal boron antimonide monolayer into armchair(ANT)and zigzag(ZNT)nanotubes induces compression and wrinkling effects,significantly modifying the band structures and carrier mobilities through band folding andπ^(*)-σ^(*)hybridization.As the chiral index increases,the band gap and carrier mobility of ANTs decrease monotonically,where electron mobility consistently exceeds hole mobility.In contrast,ZNTs exhibit a more complex trend:the band gap first increases and then decreases,and the carrier mobility displays oscillatory behavior.In particular,both ANTs and ZNTs could exhibit significantly higher carrier mobilities compared to hexagonal monolayer and zinc-blende BSb,reaching 10^(-3)-10^(-7) cm^(-2)·V^(-1)·s^(-1).Our findings highlight strong curvature-induced modifications in the electronic properties of single-walled BSb nanotubes,demonstrating the latter as a promising candidate for high-performance electronic devices.
基金supported by the National Natural Science Foundation of China(no.52363028,21965005)the Natural Science Foundation of Guangxi Province(2021GXNSFAA076001,2018GXNSFAA294077)the Guangxi Technology Base and Talent Subject(GUIKE AD23023004,GUIKE AD20297039).
文摘Triggering structural asymmetry can induce charge redistribution and modify electronic structures,which is of great significance for the design of high-performance hydrogen oxidation reaction(HOR)electrocatalysts.Herein,we propose a dual anion-induced strategy to create an innovative RuS_(2)-RuO_(2)heterostructure featuring abundant S-Ru-O interfaces(RuS_(2)-RuO_(2)@C).This RuS_(2)-RuO_(2)@C demonstrates an impressive mass activity of 2.61 mAμg_(RU)^(-1)and an exchange current density of 2.96 mA cm^(-2),surpassing Pt/C and other comparative samples by over 20 times.Durability assessments confirm the superior stability of RuS_(2)-RuO_(2)@C,with only minimal performance loss during operation.Density functional theory(DFT)calculations indicate that the asymmetric S-Ru-O configuration optimizes the interfacial electronic structure and shifts the d-band center closer to the Fermi level,effectively reducing the energy barrier of the rate-determining step(RDS)in the alkaline HOR process.Moreover,in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)characteristics disclose the formation of a substantial hydrogen bond network at the S-Ru-o interface,which aids in the desorption of H_(2)O_(ad)and facilitates the vital Volmer step in the HOR pathway.
文摘Photocatalytic synthesis of hydrogen peroxide(H_(2)O_(2))has emerged as a promising approach because of its simplicity and environmental benefits.However,significant challenges remain obstacles to their advancement,such as the rapid recombination of photogenerated charge carriers and sluggish surface redox reactions on nonmetallic organic catalysts.Metal-based organic catalysts with tunable electronic structures are considered ideal for exploring the mechanisms and structure-performance relationships in H_(2)O_(2) synthesis.This review summarizes the fundamental principles of photocatalytic H_(2)O_(2) synthesis via oxygen reduction and water oxidation reactions.Recent advancements in electronic structure tuning strategies for metal-based organic catalysts are critically examined,focusing on their impact on light absorption range,photogenerated carrier separation,O_(2) activation,and the selective generation of H_(2)O_(2).In addition,this review comprehensively evaluates the applications of sacrificial agents in photocatalytic reaction systems and offers insights into the future development of metal-based organic catalysts for H_(2)O_(2) photosynthesis.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.NSFC-12494590,NSFC-12174428,and NSFC-12274279)the New Cornerstone Investigator Programthe Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.2022YSBR-048).
文摘Determining the electronic structure of La_(3)Ni_(2)O_(7)is an essential step towards uncovering its superconducting mechanism.It is widely believed that the bilayer apical oxygens play an important role in the bilayer La_(3)Ni_(2)O_(7)electronic structure.Applying the hybrid exchange–correlation functionals,we obtain a more accurate electronic structure of La_(3)Ni_(2)O_(7)at its high-pressure phase,where the bonding dz2 band is below the Fermi level owing to the apical oxygen.The symmetry properties of this electronic structure and its corresponding tight-binding model are further analyzed.We find that the antisymmetric part is highly entangled,leading to a minimal nearly degenerate two-orbital model.Then,the apical oxygen vacancies effect is studied using the dynamical cluster approximation.This disorder effect strongly destroys the antisymmetric b Fermi surface,leading to the possible disappearance of superconductivity.
基金Project sponsored by the Natural Science Foundation of Chongqing,China(Grant No.CSTB2024NSCQMSX0736)the Special Project of Chongqing Technology Innovation and Application Development(Major Project)(Grant No.CSTB2024TIAD-STX0035)the Research Foundation of Institute for Advanced Sciences of CQUPT(Grant No.E011A2022328)。
文摘We theoretically investigate the electronic structure of cylindrical magnetic topological insulator quantum wires in MnBi_(2)Te_(4).Our study reveals the emergence of topological surface states in the ferromagnetic phase,characterized by spin-polarized subbands resulting from intrinsic magnetization.In the antiferromagnetic phase,we identify the coexistence of three distinct types of topological states,encompassing both surface states and central states.
基金Project supported by the National Natural Science Foundation of China(Grant No.12127804).
文摘We present a comprehensive electron momentum spectroscopy study on the electronic structure of trifluorobromomethane.The binding energy spectrum and electron momentum profiles of the entire outer-valence orbitals and the first inner-valence orbital along with several shake-up states were measured by using a high-sensitivity(e,2e)apparatus at an electron impact energy of 1213 eV.Theoretical calculations employing the density functional theory with B3LYP hybrid functional and the symmetry-adapted cluster configuration-interaction method were performed to interpret the experimental results.Important effects of electron correlations in the initial neutral and final ionic states on the electron momentum profiles have been observed.
基金financially supported by the National Key Research and Development Program of China(No.2019YFA0405601)the National Natural Science Foundation of China(No.52130202)the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(No.2022yjrc105)。
文摘The rapidly growing electric cars and energy storage systems have extremely promoted the development of advanced lithium and sodium ion batteries and stimulated evolution of high-capacity cathodes.Li/Na-rich layered cathodes consisting cationic and anionic reactions as the most typical representative of high-capacity cathodes have shown its tremendous potential.However,there is a long way to go before commercialization because of unsatisfactory performances including large voltage hysteresis,voltage fade and poor cycle performance.Numerous investigations on redox mechanisms and engineering strategies have been performed from the point view of structure and made significant progress,which has been well reviewed.Meanwhile,the unacceptable issues are essentially correlated to the electronic configuration of anionic redox and its interaction with adjacent transition metal cations,which can be well depicted from electronic structure.However,the investigations on anionic reaction process in the viewpoint of electronic structure have been much less summarized.This review aims to compile the current knowledge of anionic redox from the point view of electronic structure,including configuration,origination,evolution,detection and coupling relationship with cationic redox.This work is attempted to inspire new perspectives and design approaches for the development of high-capacity cathodes.
文摘Single-atom catalysts are promising for H_(2)O_(2) photosynthesis from O_(2) and H_(2)O,but their efficiency is still limited by the ill-defined electronic structure.In this study,Co single-atoms with unique four planar N-coordination and one axial P-coordination(Co-N_(4)P_(1))are decorated on the lateral edges of nanorod-like crystalline g-C_(3)N_(4)(CCN)photocatalysts.Significantly,the electronic structures of central Co as active sites for O_(2) reduction reaction(ORR)and planar N-coordinator as active sites for H_(2)O oxidation reaction(WOR)in Co-N_(4)P_(1) can be well regulated by the synergetic effects of introducing axial P-coordinator,in contrast to the decorated Co single-atoms with only four planar N-coordination(Co-N_(4)).Specifically,directional photoelectron accumulation at central Co active sites,induced by an introduced midgap level in Co-N_(4)P_(1),mediates the ORR active sites from 4e–-ORR-selective terminal–NH_(2) sites to 2e–-ORR-selective Co sites,moreover,an elevated d-band center of Co 3d orbital strengthens ORR intermediate*OOH adsorption,thus jointly facilitating a highly selective and active 2e^(–)-ORR pathway to H_(2)O_(2) photosynthesis.Simultaneously,a downshifted p-band center of N_(2)p orbital in Co-N_(4)P_(1) weakens WOR intermediate*OH adsorption,thus enabling a preferable 2e^(–)-WOR pathway toward H_(2)O_(2) photosynthesis.Subsequently,Co-N_(4)P_(1) exhibits exceptional H_(2)O_(2) photosynthesis efficiency,reaching 295.6μmol g^(-1) h^(-1) with a remarkable solar-to-chemical conversion efficiency of 0.32%,which is 15 times that of Co-N_(4)(19.2μmol g^(-1) h^(-1))and 10 times higher than CCN(27.6μmol g^(-1) h^(-1)).This electronic structure modulation on single-atom catalysts offers a promising strategy for boosting the activity and selectivity of H_(2)O_(2) photosynthesis.
基金Project supported by the Fundamental Research Funds for the Provincial Universities of Zhejiang Province,China(Grant No.GK229909299001-05)Zhejiang Provincial Public Welfare Projects of China(Grant No.LGG22F030017)。
文摘The electronic structure,elasticity,and magnetic properties of the Mn_(2)XIn(X=Fe,Co)full-Heusler compounds are comprehensively investigated via first-principles calculations.The calculated elastic constants indicate that both Mn_(2)FeIn and Mn_(2)Co In possess ductility.At the optimal lattice constants,the magnetic moments are found to be 1.40μB/f.u.for Mn_(2)FeIn and 1.69μB/f.u.for Mn_(2)CoIn.Under the biaxial strain ranging from-2%to 5%,Mn_(2)FeIn demonstrates a remarkable variation in the spin polarization,spanning from-2%to 74%,positioning it as a promising candidate for applications in spintronic devices.Analysis of the electronic structure reveals that the change in spin polarization under strain is due to the shift of the spin-down states at the Fermi surface.Additionally,under biaxial strain,the magnetic anisotropy of Mn_(2)FeIn undergoes a transition of easy-axis direction.Utilizing second-order perturbation theory and electronic structure analysis,the variation in magnetic anisotropy with strain can be attributed to changes of d-orbital states near the Fermi surface.
文摘The electronic structure,magnetic,and optical properties of two-dimensional(2D)GaSe doped with rare earth elements X(X=Sc,Y,La,Ce,Eu)were calculated using the first-principles plane wave method based on den-sity functional theory.The results show that intrinsic 2D GaSe is a p-type nonmagnetic semiconductor with an indi-rect bandgap of 2.6611 eV.The spin-up and spin-down channels of Sc-,Y-,and La-doped 2D GaSe are symmetric,they are non-magnetic semiconductors.The magnetic moments of Ce-and Eu-doped 2D GaSe are 0.908μ_(B)and 7.163μ_(B),which are magnetic semiconductors.Impurity energy levels appear in both spin-up and spin-down chan-nels of Eu-doped 2D GaSe,which enhances the probability of electron transition.Compared with intrinsic 2D GaSe,the static dielectric constant of the doped 2D GaSe increases,and the polarization ability is strengthened.The ab-sorption spectrum of the doped 2D GaSe shifts in the low-energy direction,and the red-shift phenomenon occurs,which extends the absorption spectral range.The optical reflection coefficient of the doped 2D GaSe is improved in the low energy region,and the improvement of Eu-doped 2D GaSe is the most obvious.
基金financially supported by the National Natural Science Foundation of China(Nos.22168040 and 22162025)the Project of Science&Technology Office of Shannxi Province(No.2022JM-062)。
文摘At present,industrial synthetic ammonia was still obtained through the Hubble-Bosch process,with large energy consumption.It is a research hotspot to realize green synthetic ammonia by using solar energy.The difficulty of photocatalytic ammonia synthesis was that the photo-excited electrons have not enough energy to active N≡N.In this study,Ti was doped into BiOBr by one-step hydrothermal method,which was oxidized into TiO_(2)when the doping amount reaches the maximum,in situ forming Ti_(0.31)B_(0.69)OB/TiO_(2)composites.Benefiting from the synergistic effect of Ti doping and S-scheme heterojunction,the synthetic ammonia efficiency of Ti_(0.31)B_(0.69)OB/TiO_(2)-11.96 reached 1.643 mmol·g_(cat)^(-1)at mild conditions and without hole scavenger for up to 7 h,the efficiency of synthetic ammonia is 115 times,10.5 times and 3.3 times of that of BiOBr,Ti_(0.31)B_(0.69)OB and TiO_(2),respectively.Specifically,DFT calculation confirms that Ti doping accurately refine the electronic structure of BiOBr,facilitate nitrogen adsorption activation and reduce hydrogenation reaction energy barrier,thus accelerating the reaction kinetics of photocatalytic nitrogen reduction(NRR),Meanwhile,constructing S-scheme heterojunction boosts the separation and transfer of photogenerated electron-hole pairs,improving the reduction ability of electrons in the conduction band of TiO_(2)and the oxidation ability of holes in the valence band of Ti_(0.31)B_(0.69)OB.
基金financial support from the SERB-SURE under file number of SUR/2022/003129Jong Hyeok Park acknowledges the support of the National Research Foundation of Korea (NRF)funded by the Ministry of Science and ICT (RS-2023-00302697,RS-2023-00268523).
文摘Mo_(2)C is an excellent electrocatalyst for hydrogen evolution reaction(HER).However,Mo_(2)C is a poor electrocatalyst for oxygen evolution reaction(OER).Herein,two different elements,namely Co and Fe,are incorporated in Mo_(2)C that,therefore,has a finely tuned electronic structure,which is not achievable by incorporation of any one of the metals.Consequently,the resulting electrocatalyst Co_(0.8)Fe_(0.2)-Mo_(2)C-80 displayed excellent OER catalytic performance,which is evidenced by a low overpotential of 214.0(and 246.5)mV to attain a current density of 10(and 50)mA cm^(-2),an ultralow Tafel slope of 38.4 mV dec^(-1),and longterm stability in alkaline medium.Theoretical data demonstrates that Co_(0.8)Fe_(0.2)-Mo_(2)C-80 requires the lowest overpotential(1.00 V)for OER and Co centers to be the active sites.The ultrahigh catalytic performance of the electrocatalyst is attributed to the excellent intrinsic catalytic activity due to high Brunauer-Emmett-Teller specific surface area,large electrochemically active surface area,small Tafel slope,and low chargetransfer resistance.
文摘The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on photocatalysts present notable challenges.In this study,we have devised a straightforward hydrothermal method to synthesize Bi_(2)O_(3)(BO)derived from metal‐organic frameworks(MOFs),loaded with flower-like ZnIn_(2)S_(4)(ZIS).This approach substantially enhances water adsorption and surface catalytic reactions,resulting in a remarkable enhancement of photocatalytic activity.By employing triethanolamine(TEOA)as a sacrificial agent,the hydrogen evolution rate achieved with 15%(mass fraction)ZIS loading on BO reached an impressive value of 1610μmol∙h^(−1)∙g^(−1),marking a 6.34-fold increase compared to that observed for bare BO.Furthermore,through density functional theory(DFT)and ab initio molecular dynamics(AIMD)calculations,we have identified the reactions occurring at the ZIS/BO S-scheme heterojunction interface,including the identification of active sites for water adsorption and catalytic reactions.This study provides valuable insights into the development of high-performance composite photocatalytic materials with tailored electronic properties and wettability.
