Considering the intrinsic advantages of natural copiousness and cost-effectiveness of potassium resource,potassium-ion batteries(KIBs) are booming as prospective alternatives to lithium-ion batteries(LIBs) in large-sc...Considering the intrinsic advantages of natural copiousness and cost-effectiveness of potassium resource,potassium-ion batteries(KIBs) are booming as prospective alternatives to lithium-ion batteries(LIBs) in large-scale energy storage scenarios. Nevertheless, lacking desirable electrodes for reversibly hosting the bulky K+hinders the widespread application of KIBs, and it needs to be urgently solved. Hereon, the porous S-doped Sb_(2)O_(3)-graphene-carbon(SAGC) nanofibers are manufactured through an adjustable and facile approach, which involves electrospinning, in situ etching and sulfuration. The synthesized SAGC is featured by the ultra-small amorphous Sb_(2)O_(3) homogeneously wrapped inside the carbon matrix, as well as the co-incorporation of graphene and sulfur. Tentatively,the SAGC nanofiber sheets are applied as binder-free anodes for KIBs, exhibiting a prominent cycling life(256.72 m Ah·g^(-1) over 150 cycles at 100 m A·g^(-1)) and rate·g^(-1) over 100 cycles at 1 A·g^(-1)). The positive synergy among all the active components accounts for the distinguished performances of the SAGC. By reinforcing the tolerability to the swelling stress, producing the valid electrochemical active sites, and promoting the charge transferring for reversible K+uptake, the SAGC finally renders the excellent cyclability, capacity, and rate capability. Moreover, the extrinsic electrochemical pseudocapacitance characteristics induced by the porous carbon substrate elevate the K-storage capacity of the SAGC as well. It is hoped that the conclusions drawn may offer new insights into a direction for the high-performance binderfree KIB anodes.展开更多
Reducing thermal conductivity while avoiding adverse interfacial reactions during sintering is crucial for improving the thermoelectric performance of Bi_(2)Te_(3)based composites.Inert ceramic nanoparticles are good ...Reducing thermal conductivity while avoiding adverse interfacial reactions during sintering is crucial for improving the thermoelectric performance of Bi_(2)Te_(3)based composites.Inert ceramic nanoparticles are good candidates for achieving this goal.In this study,we designed and prepared a series of p-type Bi_(0.5)Sb_(1.5)Te_(3)nanocomposites decorated with Y_(2)O_(3)ceramic nanoparticles via ball-milling dispersion and spark-plasma sintering.Owing to the chemical stability of the ceramics,no traces of atomic doping or interfacial reactions were observed.Transport measurements revealed that the Y_(2)O_(3)nanoparticles distributed along the grain boundaries acted as energy-dependent carrier-filtering centers to improve the scattering parameter and Seebeck coefficient,contributing to the elevated power factor even with a decreased electrical conductivity.Moreover,the incorporated Y_(2)O_(3)nanoparticles and various defect structures they induced effectively strengthened the phonon scattering and suppressed the lattice thermal conductivity.Consequently,a peak figure of merit(ZT)of 1.23 at 313 K was achieved for 0.4%Y_(2)O_(3)/Bi_(0.5)Sb_(1.5)Te_(3),which is 13%higher than that of the matrix.In addition,the Vickers hardness of the composite material was 35%higher than that of the matrix.This study demonstrates the effectiveness of ceramic nanoparticles in synergistic ally improving the thermoelectric and mechanical properties,which may be further extended to other thermoelectric systems.展开更多
Tailoring a rational structure to control the huge volume variation is practical in regulating alkali-ion battery performance on the basis of the anisotropic properties of crystallized anode materials.Here,a double-se...Tailoring a rational structure to control the huge volume variation is practical in regulating alkali-ion battery performance on the basis of the anisotropic properties of crystallized anode materials.Here,a double-serrated orthorhombic antimony oxide(Sb_(2)O_(3))microbelt was prepared by a thermally induced recrystallization/sublimation process.In situ transmission electron microscopy(TEM),in situ X-ray powder diffraction(XRD),and ex situ scanning electron microscopy(SEM)measurements demonstrate that Sb_(2)O_(3)microbelts exhibit a quasi-one-dimensional expansion perpendicular to the belt(along the[100]direction)during sodiation.The unconstrained microbelt surface space can appropriately accommodate the oriented volume variation.Thus,Sb_(2)O_(3)microbelts exhibit enhanced cycling and rate performance in half-cell sodium-ion batteries samples.Via support of reduced graphene oxide(RGO),Sb_(2)O_(3)@RGOcomposites deliver good rate capability(312.3 mAh g−1 at 3 A g−1)for sodium-ion full-cell batteries and good cycling performance(473.9 mAh g−1 at 100 mA g−1 after 100 cycles)for half-cell potassium-ion batteries.In situ Raman measurements reveal that the conversion/alloying-type Sb_(2)O_(3)anode undergoes a fully reversible alloying reaction and partially reversible conversion mechanism,which explains its irreversible capacity during the first cycle.The delicate structural design and clarification of the alkali-ion storage mechanisms facilitate the development of Sb_(2)O_(3)anodes for energy storage applications.展开更多
Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2....Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.展开更多
BiScO_(3)-PbTiO_(3)binary ceramics own both high Curie temperature and prominent piezoelectric properties,while the high dielectric loss needs to be reduced substantially for practical application especially at high t...BiScO_(3)-PbTiO_(3)binary ceramics own both high Curie temperature and prominent piezoelectric properties,while the high dielectric loss needs to be reduced substantially for practical application especially at high temperatures.In this work,a ternary perovskite system of(1-x-y)BiScO3-yPbTiO3-xBi(Mn_(2/3)Sb_(1/3))O_(3)(BS-yPT-xBMS)with x=0.005,y=0.630-0.645 and x=0.015,y=0.625-0.640 was prepared by the traditional solid-state reaction method.The phase structure,microstructure,dielectric/piezoelectric/ferroelectric properties were studied.Among BS-yPT-xBMS ceramic series,the BS-0.630PT-0.015BMS at morphotropic phase boundary possesses the reduced dielectric loss factor(tanδ=1.20%)and increased mechanical quality factor(Qm=84),and maintains a high Curie temperature(TC=410°C)and excellent piezoelectric properties(d_(33)=330 pC/N)simultaneously.Of particular importance,at elevated temperature of 200°C,the value of tanδis only increased to 1.59%.All these properties indicate that the BS-0.630PT-0.015BMS ceramic has great potential for application in high-temperature piezoelectric devices.展开更多
Photonic and plasmonic hybrid nanostructures are the key solution for integratednanophotonic circuits with ultracompact size but relative low loss. However,the poor tunability and modulability of conventional waveguid...Photonic and plasmonic hybrid nanostructures are the key solution for integratednanophotonic circuits with ultracompact size but relative low loss. However,the poor tunability and modulability of conventional waveguides makesthem cumbersome for optical multiplexing. Here we make use of twodimensionalmolecular crystal, α-Sb_(2)O_(3) as a dielectric waveguide via totalinternal reflection, which shows polarization-sensitive modulation of the propagatingbeams due to its large polarization mode dispersion. Both experimentsand simulations are performed to verify such concept. These Sb_(2)O_(3) nanoflakescan be coupled with plasmonic nanowires to form nanophotonic beam splittersand routers which can be easily modulated by changing the polarization of theincidence. It thus provides a robust, exploitable and tunable platform for onchipnanophotonics.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.51404103,51574117 and 61376073)Hunan Provincial Education Department(No.20C0613)the College Student Innovation and Entrepreneurship Training Program of Hunan Province (No.S2022115350874)。
文摘Considering the intrinsic advantages of natural copiousness and cost-effectiveness of potassium resource,potassium-ion batteries(KIBs) are booming as prospective alternatives to lithium-ion batteries(LIBs) in large-scale energy storage scenarios. Nevertheless, lacking desirable electrodes for reversibly hosting the bulky K+hinders the widespread application of KIBs, and it needs to be urgently solved. Hereon, the porous S-doped Sb_(2)O_(3)-graphene-carbon(SAGC) nanofibers are manufactured through an adjustable and facile approach, which involves electrospinning, in situ etching and sulfuration. The synthesized SAGC is featured by the ultra-small amorphous Sb_(2)O_(3) homogeneously wrapped inside the carbon matrix, as well as the co-incorporation of graphene and sulfur. Tentatively,the SAGC nanofiber sheets are applied as binder-free anodes for KIBs, exhibiting a prominent cycling life(256.72 m Ah·g^(-1) over 150 cycles at 100 m A·g^(-1)) and rate·g^(-1) over 100 cycles at 1 A·g^(-1)). The positive synergy among all the active components accounts for the distinguished performances of the SAGC. By reinforcing the tolerability to the swelling stress, producing the valid electrochemical active sites, and promoting the charge transferring for reversible K+uptake, the SAGC finally renders the excellent cyclability, capacity, and rate capability. Moreover, the extrinsic electrochemical pseudocapacitance characteristics induced by the porous carbon substrate elevate the K-storage capacity of the SAGC as well. It is hoped that the conclusions drawn may offer new insights into a direction for the high-performance binderfree KIB anodes.
基金financially supported by the National Natural Science Foundation of China(Nos.11834012 and 52130203)。
文摘Reducing thermal conductivity while avoiding adverse interfacial reactions during sintering is crucial for improving the thermoelectric performance of Bi_(2)Te_(3)based composites.Inert ceramic nanoparticles are good candidates for achieving this goal.In this study,we designed and prepared a series of p-type Bi_(0.5)Sb_(1.5)Te_(3)nanocomposites decorated with Y_(2)O_(3)ceramic nanoparticles via ball-milling dispersion and spark-plasma sintering.Owing to the chemical stability of the ceramics,no traces of atomic doping or interfacial reactions were observed.Transport measurements revealed that the Y_(2)O_(3)nanoparticles distributed along the grain boundaries acted as energy-dependent carrier-filtering centers to improve the scattering parameter and Seebeck coefficient,contributing to the elevated power factor even with a decreased electrical conductivity.Moreover,the incorporated Y_(2)O_(3)nanoparticles and various defect structures they induced effectively strengthened the phonon scattering and suppressed the lattice thermal conductivity.Consequently,a peak figure of merit(ZT)of 1.23 at 313 K was achieved for 0.4%Y_(2)O_(3)/Bi_(0.5)Sb_(1.5)Te_(3),which is 13%higher than that of the matrix.In addition,the Vickers hardness of the composite material was 35%higher than that of the matrix.This study demonstrates the effectiveness of ceramic nanoparticles in synergistic ally improving the thermoelectric and mechanical properties,which may be further extended to other thermoelectric systems.
基金This study is supported by the National Natural Science Foundation of China(nos.21701163,21671181,and 21831006)the Anhui Provincial Natural Science Foundation(no.1808085QB25).
文摘Tailoring a rational structure to control the huge volume variation is practical in regulating alkali-ion battery performance on the basis of the anisotropic properties of crystallized anode materials.Here,a double-serrated orthorhombic antimony oxide(Sb_(2)O_(3))microbelt was prepared by a thermally induced recrystallization/sublimation process.In situ transmission electron microscopy(TEM),in situ X-ray powder diffraction(XRD),and ex situ scanning electron microscopy(SEM)measurements demonstrate that Sb_(2)O_(3)microbelts exhibit a quasi-one-dimensional expansion perpendicular to the belt(along the[100]direction)during sodiation.The unconstrained microbelt surface space can appropriately accommodate the oriented volume variation.Thus,Sb_(2)O_(3)microbelts exhibit enhanced cycling and rate performance in half-cell sodium-ion batteries samples.Via support of reduced graphene oxide(RGO),Sb_(2)O_(3)@RGOcomposites deliver good rate capability(312.3 mAh g−1 at 3 A g−1)for sodium-ion full-cell batteries and good cycling performance(473.9 mAh g−1 at 100 mA g−1 after 100 cycles)for half-cell potassium-ion batteries.In situ Raman measurements reveal that the conversion/alloying-type Sb_(2)O_(3)anode undergoes a fully reversible alloying reaction and partially reversible conversion mechanism,which explains its irreversible capacity during the first cycle.The delicate structural design and clarification of the alkali-ion storage mechanisms facilitate the development of Sb_(2)O_(3)anodes for energy storage applications.
基金This work is supported by the National Natural Science Foundation of China(Nos.51732010,5197228051801175),and Natural Science Foundation of Hebei Province(No.E2019203233).
文摘Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.51972144,U1806221 and U2006218)the Taishan Scholars Program,the Case-by-Case Project for Top Outstanding Talents of Jinan,the Shandong Provincial Natural Science Foundation(Grant No.ZR2020KA003)+2 种基金the Primary Research&Development Plan of Shandong Province(Grant No.2019JZZY010313)the Project of“20 Items of University”of Jinan(Grant Nos.T202009 and T201907)the Introduction Program of Senior Foreign Experts(G2021024003L).
文摘BiScO_(3)-PbTiO_(3)binary ceramics own both high Curie temperature and prominent piezoelectric properties,while the high dielectric loss needs to be reduced substantially for practical application especially at high temperatures.In this work,a ternary perovskite system of(1-x-y)BiScO3-yPbTiO3-xBi(Mn_(2/3)Sb_(1/3))O_(3)(BS-yPT-xBMS)with x=0.005,y=0.630-0.645 and x=0.015,y=0.625-0.640 was prepared by the traditional solid-state reaction method.The phase structure,microstructure,dielectric/piezoelectric/ferroelectric properties were studied.Among BS-yPT-xBMS ceramic series,the BS-0.630PT-0.015BMS at morphotropic phase boundary possesses the reduced dielectric loss factor(tanδ=1.20%)and increased mechanical quality factor(Qm=84),and maintains a high Curie temperature(TC=410°C)and excellent piezoelectric properties(d_(33)=330 pC/N)simultaneously.Of particular importance,at elevated temperature of 200°C,the value of tanδis only increased to 1.59%.All these properties indicate that the BS-0.630PT-0.015BMS ceramic has great potential for application in high-temperature piezoelectric devices.
基金National Key Research and DevelopmentProgram of China, Grant/Award Number:2020YFA0211300National NaturalScience Foundation of China,Grant/Award Numbers: 12374356,21825103Fundamental Research Fundsfor the Central Universities, Grant/AwardNumbers: 2042023kf0211, 2042023kf0233。
文摘Photonic and plasmonic hybrid nanostructures are the key solution for integratednanophotonic circuits with ultracompact size but relative low loss. However,the poor tunability and modulability of conventional waveguides makesthem cumbersome for optical multiplexing. Here we make use of twodimensionalmolecular crystal, α-Sb_(2)O_(3) as a dielectric waveguide via totalinternal reflection, which shows polarization-sensitive modulation of the propagatingbeams due to its large polarization mode dispersion. Both experimentsand simulations are performed to verify such concept. These Sb_(2)O_(3) nanoflakescan be coupled with plasmonic nanowires to form nanophotonic beam splittersand routers which can be easily modulated by changing the polarization of theincidence. It thus provides a robust, exploitable and tunable platform for onchipnanophotonics.
