It is a rapidly developed subject in expanding the fundamental properties and application of two-dimensional(2D)materials.The weak van der Waals interaction in 2D materials inspired researchers to explore 2D heterostr...It is a rapidly developed subject in expanding the fundamental properties and application of two-dimensional(2D)materials.The weak van der Waals interaction in 2D materials inspired researchers to explore 2D heterostructures(2DHs)based broadband photodetectors in the far-infrared(IR)and middle-IR regions with high response and high detectivity.This review focuses on the strategy and motivation of designing 2DHs based high-performance IR photodetectors,which provides a wide view of this field and new expectation for advanced photodetectors.First,the photocarriers'generation mechanism and frequently employed device structures are presented.Then,the 2DHs are divided into semimetal/semiconductor 2DHs,semiconductor/semiconductor 2DHs,and multidimensional semi-2DHs;the advantages,motivation,mechanism,recent progress,and outlook are discussed.Finally,the challenges for next-generation photodetectors are described for this rapidly developing field.展开更多
Solid electrolytes have gained attention recently for the development of next-generation Li-ion batteries since they can fun-damentally improve the battery stability and safety.Among various types of solid electrolyte...Solid electrolytes have gained attention recently for the development of next-generation Li-ion batteries since they can fun-damentally improve the battery stability and safety.Among various types of solid electrolytes,composite solid electrolytes(CSEs)exhibit both high ionic conductivity and excellent interfacial contact with the electrodes.Incorporating active nanofib-ers into the polymer matrix demonstrates an effective method to fabricate CSEs.However,current CSEs based on traditional poly(ethylene oxide)(PEO)polymer suffer from the poor ionic conductivity of PEO and agglomeration effect of inorganic fillers at high concentrations,which limit further improvements in Li+conductivity and electrochemical stability.Herein,we synthesize a novel PEO based cross-linked polymer(CLP)as the polymer matrix with naturally amorphous structure and high room-temperature ionic conductivity of 2.40×10^(−4)S cm^(−1).Li_(0.3)La_(0.557)TiO_(3)(LLTO)nanofibers are incorporated into the CLP matrix to form composite solid electrolytes,achieving enhanced ionic conductivity without showing filler agglomeration.The high content of Li-conductive nanofibers improves the mechanical strength,ensures the conductive network,and increases the total Li+conductivity to 3.31×10^(−4)S cm^(−1).The all-solid-state Li|LiFePO_(4)batteries with LLTO nanofiber-incorporated CSEs are able to deliver attractive specific capacity of 147 mAh g^(−1)at room temperature,and no evident dendrite is found at the anode/electrolyte interface after 100 cycles.展开更多
High-performance electrocatalysts for water splitting are desired due to the urgent requirement of clean and sustainable hydrogen production.To reduce the energy barrier,herein,we adopt a facile in-situ surface modifi...High-performance electrocatalysts for water splitting are desired due to the urgent requirement of clean and sustainable hydrogen production.To reduce the energy barrier,herein,we adopt a facile in-situ surface modification strategy to develop a low-cost and efficient electrocatalyst for water splitting.The synthesized mulberry-like NiS/Ni nanoparticles exhibit excellent catalytic performance for water splitting.Small overpotentials of 301 and 161 mV are needed to drive the current density of 10 mA cm^-2 accompanying with remarkably low Tafel slopes of 46 and 74 mV dec^-1 for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively.Meanwhile,a robust electrochemical stability is demonstrated.Further high-resolution X-ray photoelectron spectroscopy analyses reveal that the intrinsic HER activity improvement is attributed to the electron-enriched S on the strongly coupled NiS and Ni interface,which simultaneously facilitates the important electron transfer,consistent with the electrochemical impedance results.The post characterizations demonstrate that surface reconstructed oxyhydroxide contributes to the OER activity and NiS/Ni is an OER precatalyst.This structure construction with in-situ formation of active interface provides an effective way to design efficient electrocatalysts for energy conversion.展开更多
Two-dimensional(2D)ternary wide-bandgap semiconducting materials have great potential in power device,flexible electronic device,short-wavelength light emitting diodes(LEDs)and photodetectors due to the controllable b...Two-dimensional(2D)ternary wide-bandgap semiconducting materials have great potential in power device,flexible electronic device,short-wavelength light emitting diodes(LEDs)and photodetectors due to the controllable bandgap,strong light-material interaction,and controlled freedom degree of stoichiometry variation.However,it is still a great challenge to precisely control the growth of high-quality 2D ternary wide-bandgap semiconducting materials due to the variety of components,which hinders their development for practical applications.In this work,high-quality 2D ternary bismuth oxybromide single-crystal nanosheets with a high yield were prepared by space-confined chemical vapor deposition(CVD)method.The devices based on 2D ultrathin BiOBr single-crystal nanoflakes show a high UV detecting performance including low dark current(Idark)of 1.46pA and high re s ponsivity(R),external quantum efficiency(EQE)and detectivity(D*)of 14.96 A W-1,5460%,and 5.74 × 10^10 Jones,respectively,as well as fast response process(τrise=80 ms,τdecay=40 ms).The excellent UV performance can be ascribed to the photogating effect by trapped states,which endow it with great potential for high-performance UV detectors.展开更多
Single-ion conducting polymer electrolytes(SIPEs)can be formed by anchoring charge delocalized anions on the side chains of a crosslinked polymer matrix,thereby eliminating the severe concentration polarization efect ...Single-ion conducting polymer electrolytes(SIPEs)can be formed by anchoring charge delocalized anions on the side chains of a crosslinked polymer matrix,thereby eliminating the severe concentration polarization efect in conventional dual-ion polymer electrolytes.Addition of a plasticizer into the polymer matrix confers advantages of both liquid and solid electrolytes.However,plasticized SIPEs usually face a trade-of between conductivity and mechanical strength.With insufcient strength,potentially there is short-circuiting failure during cycling.To address this challenge,a simple and mechanicallyrobust SIPE was developed by crosslinking monomer lithium(4-styrenesulfonyl)(trifuoromethylsulfonyl)imide(LiSTFSI)and crosslinker poly(ethylene glycol)diacrylate(PEGDA),with plasticizer propylene carbonate(PC),on electrospun polyacrylonitrile nanofbers(PAN-NFs).The well-fabricated polymer matrix provided fast and efective Li^(+) conductive pathways with a remarkable ionic conductivity of 8.09×10^(-4) S cm^(−1) and a superior lithium-ion transference number close to unity(t_(Li+)=0.92).The introduction of PAN-NFs not only improved the mechanical strength and fexibility but also endowed the plasticized SIPE with a wide electrochemical stability window(4.9 V vs.Li^(+)/Li)and better cycling stability.Superior longterm lithium cycling stability and dynamic interfacial compatibility were demonstrated by lithium symmetric cell testing.Most importantly,the assembled all-solid-state Li metal batteries showed stable cycling performance and remarkable rate capability both in low and high current densities.Therefore,this straightforward and mechanically reinforced SIPE exhibits great potential in the development of advanced all-solid-state Li-metal batteries.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51722204,91421110,51802145)the National Key Basic Research Program of China(Grant No.2014CB931702)+3 种基金the Sichuan Provincial Fund for Distinguished Young Academic and Technology Leaders(Grant No.2014JQ0011)the Science and Technology Support Program of Sichuan Province(Grant No.2018RZ0042,2016RZ0033,2018RZ0082)the Natural Science Foundation of Guangdong Province(2018A030310225)China Postdoctoral Science Foundation(Grant No.2018M643443).
文摘It is a rapidly developed subject in expanding the fundamental properties and application of two-dimensional(2D)materials.The weak van der Waals interaction in 2D materials inspired researchers to explore 2D heterostructures(2DHs)based broadband photodetectors in the far-infrared(IR)and middle-IR regions with high response and high detectivity.This review focuses on the strategy and motivation of designing 2DHs based high-performance IR photodetectors,which provides a wide view of this field and new expectation for advanced photodetectors.First,the photocarriers'generation mechanism and frequently employed device structures are presented.Then,the 2DHs are divided into semimetal/semiconductor 2DHs,semiconductor/semiconductor 2DHs,and multidimensional semi-2DHs;the advantages,motivation,mechanism,recent progress,and outlook are discussed.Finally,the challenges for next-generation photodetectors are described for this rapidly developing field.
基金the Department of Energy,Office of Energy Efficiency and Renewable Energy(EERE),under Award Number DE-EE0007806.
文摘Solid electrolytes have gained attention recently for the development of next-generation Li-ion batteries since they can fun-damentally improve the battery stability and safety.Among various types of solid electrolytes,composite solid electrolytes(CSEs)exhibit both high ionic conductivity and excellent interfacial contact with the electrodes.Incorporating active nanofib-ers into the polymer matrix demonstrates an effective method to fabricate CSEs.However,current CSEs based on traditional poly(ethylene oxide)(PEO)polymer suffer from the poor ionic conductivity of PEO and agglomeration effect of inorganic fillers at high concentrations,which limit further improvements in Li+conductivity and electrochemical stability.Herein,we synthesize a novel PEO based cross-linked polymer(CLP)as the polymer matrix with naturally amorphous structure and high room-temperature ionic conductivity of 2.40×10^(−4)S cm^(−1).Li_(0.3)La_(0.557)TiO_(3)(LLTO)nanofibers are incorporated into the CLP matrix to form composite solid electrolytes,achieving enhanced ionic conductivity without showing filler agglomeration.The high content of Li-conductive nanofibers improves the mechanical strength,ensures the conductive network,and increases the total Li+conductivity to 3.31×10^(−4)S cm^(−1).The all-solid-state Li|LiFePO_(4)batteries with LLTO nanofiber-incorporated CSEs are able to deliver attractive specific capacity of 147 mAh g^(−1)at room temperature,and no evident dendrite is found at the anode/electrolyte interface after 100 cycles.
基金This work was financailly supported by the National Natural Science Foundation of China(Nos.51722204 and 51802145)the National Key Basic Research Program of China(No.2014CB931702)+2 种基金the Sichuan Science and Technology Program(Nos.2018RZ0082 and 2019JDRC0070)the Fundamental Research Fund for the Central Universities(No.A03018023801053)the Open Project of Jiangsu Key Laboratory for Carbon-Based Functional Materials Devices at Soochow University(No.KJS1807).
文摘High-performance electrocatalysts for water splitting are desired due to the urgent requirement of clean and sustainable hydrogen production.To reduce the energy barrier,herein,we adopt a facile in-situ surface modification strategy to develop a low-cost and efficient electrocatalyst for water splitting.The synthesized mulberry-like NiS/Ni nanoparticles exhibit excellent catalytic performance for water splitting.Small overpotentials of 301 and 161 mV are needed to drive the current density of 10 mA cm^-2 accompanying with remarkably low Tafel slopes of 46 and 74 mV dec^-1 for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively.Meanwhile,a robust electrochemical stability is demonstrated.Further high-resolution X-ray photoelectron spectroscopy analyses reveal that the intrinsic HER activity improvement is attributed to the electron-enriched S on the strongly coupled NiS and Ni interface,which simultaneously facilitates the important electron transfer,consistent with the electrochemical impedance results.The post characterizations demonstrate that surface reconstructed oxyhydroxide contributes to the OER activity and NiS/Ni is an OER precatalyst.This structure construction with in-situ formation of active interface provides an effective way to design efficient electrocatalysts for energy conversion.
基金financially supported by the National Natural Science Foundation of China(No.U0634002)the National Basic Research Program of China(No.2003CB314701)。
文摘Two-dimensional(2D)ternary wide-bandgap semiconducting materials have great potential in power device,flexible electronic device,short-wavelength light emitting diodes(LEDs)and photodetectors due to the controllable bandgap,strong light-material interaction,and controlled freedom degree of stoichiometry variation.However,it is still a great challenge to precisely control the growth of high-quality 2D ternary wide-bandgap semiconducting materials due to the variety of components,which hinders their development for practical applications.In this work,high-quality 2D ternary bismuth oxybromide single-crystal nanosheets with a high yield were prepared by space-confined chemical vapor deposition(CVD)method.The devices based on 2D ultrathin BiOBr single-crystal nanoflakes show a high UV detecting performance including low dark current(Idark)of 1.46pA and high re s ponsivity(R),external quantum efficiency(EQE)and detectivity(D*)of 14.96 A W-1,5460%,and 5.74 × 10^10 Jones,respectively,as well as fast response process(τrise=80 ms,τdecay=40 ms).The excellent UV performance can be ascribed to the photogating effect by trapped states,which endow it with great potential for high-performance UV detectors.
基金This work was supported by the Samuel S.Walker Distinguished Professorship in the Wilson College of Textiles at North Carolina State University。
文摘Single-ion conducting polymer electrolytes(SIPEs)can be formed by anchoring charge delocalized anions on the side chains of a crosslinked polymer matrix,thereby eliminating the severe concentration polarization efect in conventional dual-ion polymer electrolytes.Addition of a plasticizer into the polymer matrix confers advantages of both liquid and solid electrolytes.However,plasticized SIPEs usually face a trade-of between conductivity and mechanical strength.With insufcient strength,potentially there is short-circuiting failure during cycling.To address this challenge,a simple and mechanicallyrobust SIPE was developed by crosslinking monomer lithium(4-styrenesulfonyl)(trifuoromethylsulfonyl)imide(LiSTFSI)and crosslinker poly(ethylene glycol)diacrylate(PEGDA),with plasticizer propylene carbonate(PC),on electrospun polyacrylonitrile nanofbers(PAN-NFs).The well-fabricated polymer matrix provided fast and efective Li^(+) conductive pathways with a remarkable ionic conductivity of 8.09×10^(-4) S cm^(−1) and a superior lithium-ion transference number close to unity(t_(Li+)=0.92).The introduction of PAN-NFs not only improved the mechanical strength and fexibility but also endowed the plasticized SIPE with a wide electrochemical stability window(4.9 V vs.Li^(+)/Li)and better cycling stability.Superior longterm lithium cycling stability and dynamic interfacial compatibility were demonstrated by lithium symmetric cell testing.Most importantly,the assembled all-solid-state Li metal batteries showed stable cycling performance and remarkable rate capability both in low and high current densities.Therefore,this straightforward and mechanically reinforced SIPE exhibits great potential in the development of advanced all-solid-state Li-metal batteries.