Molecular materials are playing a pivotal role in the advancement of prospective THz technologies.Herein,we have prepared nine isostructural coordination complexes of general formula[Ln^(Ⅲ)(H_(2)O)_(3)][AgI(CN)_(2)]_...Molecular materials are playing a pivotal role in the advancement of prospective THz technologies.Herein,we have prepared nine isostructural coordination complexes of general formula[Ln^(Ⅲ)(H_(2)O)_(3)][AgI(CN)_(2)]_(3)(LnAg,Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,and Dy).Vibrational spectroscopy has unveiled gradual changes in theν(CuN)stretching frequencies within both infrared(IR)and Raman spectra from LaAg to DyAg,stemming from incremental alterations in crystallographic unit cell parameters and volumes.Similarly,the THz spectra manifest pronounced absorption signals between 1.0 to 1.2 THz,which can be judiciously tuned by varying lanthanide(^(Ⅲ))ion and measurement temperature.Ab initio density-functional theory(DFT)calculations of THz spectra elucidate the primary contribution from opposite translational vibrations of Ag atoms and O atoms from H_(2)O around Ln(^(Ⅲ))atoms.Furthermore,thin films of LnAg can achieve a large return loss in a broad bandwidth in impedance-matching simulations.展开更多
The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a nov...The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a novel magnetically separable Au-loaded CaFe_(2)O_(4)/CoAl LDH heterostructure with strong coulombic interfacial interactions fabricated through a simple two-step process.XRD,XPS and TEM analysis of the synthesized samples were carried out for the structural and morphological characterization.The TEM study confirmed the existence of a firm attachment between the Au nanoparticles with the CaFe_(2)O_(4)/CoAl LDH heterostructures,which provides a unique support due to an exterior confinement effect.Formation of the heterojunction with a different electronic behaviour was also confirmed from an inverted V-shaped M-S plot,suggesting the presence of a large intimate contact interface between CoAl LDH and CaFe_(2)O_(4)to favour the efficient separation and transfer of photoinduced charge pairs.The CoAl LDH-CaFe_(2)O_(4)@Au ternary heterostructure showed a high hydrogen generation rate of 379.1μmol h^(−1),oxygen evolution rate of 205.5μmol h^(−1)and Cr(VI)reduction rate of 99%under visible light irradiation.The CoAl LDH-CaFe_(2)O_(4)@Au heterostructure demonstrated its long-term stability and durability during photocatalytic investigations.The efficient photocatalytic activity of the catalysts was due to the synergistic effect of hot electron transfer by Au nanoparticles and easy mass transport through the interface owing to formation of a p-n junction by increasing the contact area.The mechanism of the photocatalytic activity was also supported by PL,EIS and photocurrent measurements.This work provides a novel strategy to design junction-based nanostructures as a promising photocatalyst for solar energy conversion.展开更多
The oxygen evolution reaction(OER)plays a key role in sustainable energy technologies.Herein,we report a facile Ketjenblack carbon(KB)-templated in situ synthesis method to fabricate highly dispersed bimetallic NiFe p...The oxygen evolution reaction(OER)plays a key role in sustainable energy technologies.Herein,we report a facile Ketjenblack carbon(KB)-templated in situ synthesis method to fabricate highly dispersed bimetallic NiFe phosphides as highly efficient OER electrocatalysts.The Fe dopant can effectively modulate the electronic structure and increase the oxidation degree of Ni_(2)P species.Remarkably,benefitting from the large specific surface area,optimized electronic structure and faster charge transfer kinetics,the KB-templated NiFe phosphides exhibit dramatically enhanced OER activity in alkaline medium.By tailoring the Ni/Fe ratio,(Ni_(0.5)Fe_(0.5))_(2)P/C-KB-900 delivers a current density of 20 mA cm^(-2)at an ultra-low overpotential of 296 mV and a small Tafel slope of 77 mV dec^(-1),which is much more active than commercial RuO_(2).Post-electrolysis characterization further reveals that the bimetallic phosphides are in situ converted to NiFe oxides/hydroxides during the OER,serving as the OER active sites with high activity.This work offers a novel route to design and fabricate transition metal phosphide/carbon catalysts for water splitting by controlling the morphology and composition.展开更多
Two-dimensional(2D)intrinsic multiferroics have attracted considerable attention for the next generation of advanced information technologies.Herein,we report that bilayer Janus FeSCl,a novel 2D system designed by sub...Two-dimensional(2D)intrinsic multiferroics have attracted considerable attention for the next generation of advanced information technologies.Herein,we report that bilayer Janus FeSCl,a novel 2D system designed by substituting sulfur in monolayer 1T-FeCl_(2),exhibits a giant spontaneous valley polarization and intrinsic magnetoelectric coupling.This Janus structure exhibits a ground-state bilayer structure that breaks space-inversion symmetry,enabling sliding ferroelectricity.Each monolayer displays robust intralayer ferromagnetic ordering,while the bilayer hosts interlayer antiferromagnetic alignment with opposing magnetic moments.Crucially,ferrovalley-mediated coupling links ferroelectric polarization and antiferromagnetic order,allowing electric-field-driven magnetic reversal.Notably,the direction of the net magnetic moment can be reversed through ferroelectric polarization switching,enabling nonvolatile control of the magnetism.The elucidated mechanisms are generalizable to diverse 2D material families,offering a universal framework for designing atomic-scale multiferroics.This work not only establishes foundational insights into 2D multiferroics but also advances the understanding of coupled charge-spin-valley physics in low-dimensional systems.展开更多
基金financed in part by a JSPS Grant-in-Aid for Scientific Research(A)(Grant Number 20H00369),IRL DYNACOM(CNRS),the CNRS-University of Tokyo“Excellence Science”Joint Research Program,and the Second CNRS-University of Tokyo PhD Joint ProgramThe authors acknowledge the Cryogenic Research Center,The University of Tokyo,the Center for Nano Lithography&Analysis,The University of Tokyo supported by MEXT,and the MEXT Quantum Leap Flagship Program(Grant Number JPMXS0118068681)for the support.G.L.is grateful to JSPS KAKENHI(Grant Number 23KJ0736)+4 种基金O.S.is thankful to JSPS KAKENHI(Grant Number 21K14582)K.K.acknowledges a Grant-in-Aid for JSPS fellows(Grant Number 23K19238)Y.M.and L.W.thank the JST SPRING(Grant Number JPMJSP2108)K.N.recognizes the Iketani Science and Technology Foundation(Grant Number 0351111-A)M.Y.is grateful to JSPS Grant-in-Aid for Young Scientists(Grant Number JP24K17606)。
文摘Molecular materials are playing a pivotal role in the advancement of prospective THz technologies.Herein,we have prepared nine isostructural coordination complexes of general formula[Ln^(Ⅲ)(H_(2)O)_(3)][AgI(CN)_(2)]_(3)(LnAg,Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,and Dy).Vibrational spectroscopy has unveiled gradual changes in theν(CuN)stretching frequencies within both infrared(IR)and Raman spectra from LaAg to DyAg,stemming from incremental alterations in crystallographic unit cell parameters and volumes.Similarly,the THz spectra manifest pronounced absorption signals between 1.0 to 1.2 THz,which can be judiciously tuned by varying lanthanide(^(Ⅲ))ion and measurement temperature.Ab initio density-functional theory(DFT)calculations of THz spectra elucidate the primary contribution from opposite translational vibrations of Ag atoms and O atoms from H_(2)O around Ln(^(Ⅲ))atoms.Furthermore,thin films of LnAg can achieve a large return loss in a broad bandwidth in impedance-matching simulations.
文摘The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a novel magnetically separable Au-loaded CaFe_(2)O_(4)/CoAl LDH heterostructure with strong coulombic interfacial interactions fabricated through a simple two-step process.XRD,XPS and TEM analysis of the synthesized samples were carried out for the structural and morphological characterization.The TEM study confirmed the existence of a firm attachment between the Au nanoparticles with the CaFe_(2)O_(4)/CoAl LDH heterostructures,which provides a unique support due to an exterior confinement effect.Formation of the heterojunction with a different electronic behaviour was also confirmed from an inverted V-shaped M-S plot,suggesting the presence of a large intimate contact interface between CoAl LDH and CaFe_(2)O_(4)to favour the efficient separation and transfer of photoinduced charge pairs.The CoAl LDH-CaFe_(2)O_(4)@Au ternary heterostructure showed a high hydrogen generation rate of 379.1μmol h^(−1),oxygen evolution rate of 205.5μmol h^(−1)and Cr(VI)reduction rate of 99%under visible light irradiation.The CoAl LDH-CaFe_(2)O_(4)@Au heterostructure demonstrated its long-term stability and durability during photocatalytic investigations.The efficient photocatalytic activity of the catalysts was due to the synergistic effect of hot electron transfer by Au nanoparticles and easy mass transport through the interface owing to formation of a p-n junction by increasing the contact area.The mechanism of the photocatalytic activity was also supported by PL,EIS and photocurrent measurements.This work provides a novel strategy to design junction-based nanostructures as a promising photocatalyst for solar energy conversion.
基金National Natural Science Foundation of China(51672083)Program of Shanghai Academic/Technology Research Leader(18XD1401400)+4 种基金Basic Research Program of Shanghai(17JC1404702)Leading talents in Shanghai in 2018111 project(B14018)Research Foundation of China Postdoctoral Science(2017M621384)Fundamental Research Funds for the Central Universities(222201718002)。
文摘The oxygen evolution reaction(OER)plays a key role in sustainable energy technologies.Herein,we report a facile Ketjenblack carbon(KB)-templated in situ synthesis method to fabricate highly dispersed bimetallic NiFe phosphides as highly efficient OER electrocatalysts.The Fe dopant can effectively modulate the electronic structure and increase the oxidation degree of Ni_(2)P species.Remarkably,benefitting from the large specific surface area,optimized electronic structure and faster charge transfer kinetics,the KB-templated NiFe phosphides exhibit dramatically enhanced OER activity in alkaline medium.By tailoring the Ni/Fe ratio,(Ni_(0.5)Fe_(0.5))_(2)P/C-KB-900 delivers a current density of 20 mA cm^(-2)at an ultra-low overpotential of 296 mV and a small Tafel slope of 77 mV dec^(-1),which is much more active than commercial RuO_(2).Post-electrolysis characterization further reveals that the bimetallic phosphides are in situ converted to NiFe oxides/hydroxides during the OER,serving as the OER active sites with high activity.This work offers a novel route to design and fabricate transition metal phosphide/carbon catalysts for water splitting by controlling the morphology and composition.
基金support fromthe National Natural Science Foundation of China(Grants No.12404267,No.12404048,No.12404104).
文摘Two-dimensional(2D)intrinsic multiferroics have attracted considerable attention for the next generation of advanced information technologies.Herein,we report that bilayer Janus FeSCl,a novel 2D system designed by substituting sulfur in monolayer 1T-FeCl_(2),exhibits a giant spontaneous valley polarization and intrinsic magnetoelectric coupling.This Janus structure exhibits a ground-state bilayer structure that breaks space-inversion symmetry,enabling sliding ferroelectricity.Each monolayer displays robust intralayer ferromagnetic ordering,while the bilayer hosts interlayer antiferromagnetic alignment with opposing magnetic moments.Crucially,ferrovalley-mediated coupling links ferroelectric polarization and antiferromagnetic order,allowing electric-field-driven magnetic reversal.Notably,the direction of the net magnetic moment can be reversed through ferroelectric polarization switching,enabling nonvolatile control of the magnetism.The elucidated mechanisms are generalizable to diverse 2D material families,offering a universal framework for designing atomic-scale multiferroics.This work not only establishes foundational insights into 2D multiferroics but also advances the understanding of coupled charge-spin-valley physics in low-dimensional systems.
