Recently,non-centrosymmetric(NCS)Hg-based chalcogenides have garnered significant interest due to their strong second-harmonic-generation intensities(deff),making them attractive candidates for infrared nonlinear opti...Recently,non-centrosymmetric(NCS)Hg-based chalcogenides have garnered significant interest due to their strong second-harmonic-generation intensities(deff),making them attractive candidates for infrared nonlinear optical(IR-NLO)application.However,achieving both wide band gaps(Eg)and large phasematched deffsimultaneously in these materials remains a challenge due to their inherent constraints on each other.In this research,we have successfully obtained two quaternary NCS Hg-based chalcogenides,Rb2HgGe_(3)S_(8)and Cs_(2)HgGe_(3)S_(8),by implementing a bandgap engineering strategy that involves alkali metal introduction and Hg/Ge ratio regulation.Both compounds consist of 2D[Hg Ge_(3)S_(8)]_(2)–anionic layers made of 1D[HgGeS_(6)]^(6–)chains and dimeric[Ge_(2)S_(6)]_(4–)polyhedra arranged alternately,and the charge-balanced Rb+/Cs+cations located between these layers.Remarkably,Rb_(2)HgGe_(3)S_(8)and Cs_(2)HgGe_(3)S_(8)exhibit overall properties required for promising IR-NLO materials,including sufficient PM deff(0.55–0.70×AgGaS_(2)@20_(5)0 nm),large Eg(3.27–3.41 e V),giant laser-induced damage thresholds(17.4–19.7×AgGaS_(2)@1064 nm),broad optical transmission intervals(0.32–17.5μm),and suitable theoretical birefringence(0.069–0.086@2050 nm).Furthermore,in-depth theoretical analysis reveals that the exceptional IRNLO performance is attributed to the synergy effects of distorted[HgS_(4)]and[GeS_(4)]tetrahedra.Our study provides a useful strategy for enhancing the Eg and advancing Hg-based IR-NLO materials,which is expected to extended and implemented in other chalcogenide systems.展开更多
Non-layered two-dimensional(2D)materials have sparked much interest recently due to their atomic thickness,large surface area,thickness-and facet-dependent properties.Currently,these materials are mainly grown from we...Non-layered two-dimensional(2D)materials have sparked much interest recently due to their atomic thickness,large surface area,thickness-and facet-dependent properties.Currently,these materials are mainly grown from wet-chemistry methods but suffer from small size,low quality,and multi-facets,which is a major challenge hindering their facet-dependent property studies and applications.Here,we report the facet-engineered growth(FEG)of non-layered 2D manganese chalcogenides(MnX,X=S,Se,Te)based on the chemical vapor deposition method.The as-grown samples exhibit large-area surfaces of single facet,high-crystallinity,and ordered domain orientation.As a proof-of-concept,we show the facet-dependent electrocatalytic property of non-layered 2D MnSe,proving they are ideal candidates for fundamental research.Furthermore,we elucidate the underlying mechanism of FEG during the vapor growth process by the interfacial energy derived nucleation models.The method developed in this work provides new opportunities for regulating and designing the structure of 2D materials.展开更多
Lithium-ion batteries(LIBs)gradually occupied the energy storage market due to their long cycling life;high working voltage;as well as energy density.However;LIBs have high costs due to the limited lithium resource an...Lithium-ion batteries(LIBs)gradually occupied the energy storage market due to their long cycling life;high working voltage;as well as energy density.However;LIBs have high costs due to the limited lithium resource and difficulty to exploit.Potassium ion batteries(PIBs)have aroused extensive attention over the past few years since they possess considerable potassium salt resources while exhibiting similar electrochemical properties to LIBs.The electrode material takes on great significance in determining the properties exhibited by the batteries.Zinc-based chalcogenides have served as the most suitable anode materials for their numerous raw material resources;low prices;and environmental friendliness.Nevertheless;the application of Zinc-based chalcogenides has been continuously hindered by sluggish diffusion kinetics;low electrical conductivity;as well as huge volume vari-ation.Several effective strategies have been explored to settle the above matters(e.g.;designing nanostructures;constructing carbon composite structures;as well as doping anions or cations to construct heterojunction).In this review;the recent advance of zinc-based chalcogenides(e.g.;electrochemical mechanisms;challenges;and perspectives)are summarized.This review can provide novel insights into the development of transition metal chalcogenides for PIBs.展开更多
The electro-physical properties of thin layers of rhenium chalcogenides＇ alloys, their dynamical and static ampere-voltaic characteristics were investigated. During the investigation of static and dynamical ampere-vo...The electro-physical properties of thin layers of rhenium chalcogenides＇ alloys, their dynamical and static ampere-voltaic characteristics were investigated. During the investigation of static and dynamical ampere-voltaic characteristics of rectifying contact of aluminium and rhenium chalcogenides＇ alloys the switching effects were found.展开更多
Lead chalcohalides(PbYX,X=Cl,Br,I;Y=S,Se)is an extension of the classic Pb chalcogenides(PbY).Constructing the heterogeneous integration with PbYX and PbY material systems makes it possible to achieve significantly im...Lead chalcohalides(PbYX,X=Cl,Br,I;Y=S,Se)is an extension of the classic Pb chalcogenides(PbY).Constructing the heterogeneous integration with PbYX and PbY material systems makes it possible to achieve significantly improved optoelectronic performance.In this work,we studied the effect of introducing halogen precursors on the structure of classical PbS nanocrystals(NCs)during the synthesis process and realized the preparation of PbS/Pb_(3)S_(2)X_(2) core/shell structure for the first time.The core/shell structure can effectively improve their optical properties.Furthermore,our approach enables the synthesis of Pb_(3)S_(2)Br_(2) that had not yet been reported.Our results not only provide valuable insights into the heterogeneous integration of PbYX and PbY materials to elevate material properties but also provide an effective method for further expanding the preparation of PbYX material systems.展开更多
硫系玻璃因其宽红外透过范围、高声光品质因数等特点,成了低功耗高性能声光调制器的理想工作介质,有望突破传统介质声光调制器在效率与功耗方面的局限。以宽红外透过范围、高折射率的Ge_(21)Sb_(18)S_(61)硫系玻璃为研究对象,系统分析...硫系玻璃因其宽红外透过范围、高声光品质因数等特点,成了低功耗高性能声光调制器的理想工作介质,有望突破传统介质声光调制器在效率与功耗方面的局限。以宽红外透过范围、高折射率的Ge_(21)Sb_(18)S_(61)硫系玻璃为研究对象,系统分析了其热学、物理、光学及声学性能,并基于此成功研制出高性能光纤声光调制器。实验结果表明,在0.52 W射频驱动功率下,该调制器衍射效率达84%,上升时间为41 ns,消光比高达61 d B,展现出低功耗、高效率的优异性能。该声光调制器的研制为新型声光器件的设计与开发提供了重要技术支撑,对推动高速光通信、光纤传感等领域的应用具有重要意义。展开更多
Due to the weak interlayer interactions,the binary Ⅲ-Ⅵ chalcogenides Ga Se can exist in several distinct polymorphs.Among them,the so-called β-and ε-phases simultaneously exhibit favorable total energies and moder...Due to the weak interlayer interactions,the binary Ⅲ-Ⅵ chalcogenides Ga Se can exist in several distinct polymorphs.Among them,the so-called β-and ε-phases simultaneously exhibit favorable total energies and moderate band gaps,which offer a good platform to explore their thermoelectric properties.Here,we demonstrate by first-principles calculations that the two systems have very similar band structures and phonon dispersions,despite different stacking sequences between adjacent layers.Interestingly,the lattice thermal conductivity of ε-GaSe is obviously lower than that of β-GaSe,which is inherently tied to stronger lattice anharmonicity caused by bonding heterogeneity.Besides,both systems exhibit higher p-type power factors due to doubly degenerate bands with weaker dispersions around the valence band maximum.As a consequence,a significantly enhanced p-type figure-of-merit of 2.1 can be realized at 700 K along the out-of-plane direction of theε-phase.展开更多
Quaternary chalcogenides are viewed as a class of potential thermoelectric materials due to their good thermoelectric performance in the medium temperature region.In this work,carbon nanotubes(CNTs)with varying weight...Quaternary chalcogenides are viewed as a class of potential thermoelectric materials due to their good thermoelectric performance in the medium temperature region.In this work,carbon nanotubes(CNTs)with varying weight percentages are composited into the quaternary chalcogenide Cu_(2.1)Mn_(0.9)SnSe_(4)(CMTS)using a technique that combines ball-milling and hot-pressing,and the effect of CNTs on the thermoelectric performance of CMTS is investigated.The compositing of CNTs results in an increase in the intrinsic defects of CMTS,thereby enhancing the electrical conductivities of the composited samples.Besides,the addition of CNTs introduces various phonon scattering mechanisms,effectively restraining the lattice thermal conductivities of the composited samples,particularly in the low to medium temperature range.Ultimately,owing to the concurrent optimization of the power factor and thermal conductivity,the x=0.25 sample achieves a zT value of 0.37 at 673 K.The compositing of highly conductive secondary phase is recognized as a viable approach for the simultaneous enhancement of the thermoelectric properties of materials.展开更多
A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se dopin...A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se doping level,a hollow spherical catalyst structure composed of CoSSe was successfully synthesized,which exhibited exceptional activity for hydrogen evolution in acidic solutions.The influences of Se doping on the microstructure and catalytic mechanism of hydrogen evolution reaction(HER)of these composites were systematically investigated.The experimental results reveal that the hollow spherical sample displays an overpotential value of 143 mV along with a Tafel slope value of 69.8 mV·dec^(-1)at a current density of 10 mA·cm^(-2)in an acid aqueous solution.Furthermore,it demonstrates remarkable cycling stability after undergoing 3000 cycles.The comprehensive analysis indicates that Se doping optimizes the electronic structure and enhances conductivity,meanwhile the unique hollow spherical architecture increases active sites for HER and significantly improves overall electrocatalytic performance.展开更多
Birefringent crystals play an irreplaceable role in optical systems by adjusting the polarization state of light in optical devices.This work successfully synthesized a new thiophosphate phase ofβ-Pb_(3)P_(2)S_(8)thr...Birefringent crystals play an irreplaceable role in optical systems by adjusting the polarization state of light in optical devices.This work successfully synthesized a new thiophosphate phase ofβ-Pb_(3)P_(2)S_(8)through the high-temperature solid-state spontaneous crystallization method.Different from the cubicα-Pb_(3)P_(2)S_(8),theβ-Pb_(3)P_(2)S_(8)crystallizes in the orthorhombic Pbcn space group.Notably,β-Pb_(3)P_(2)S_(8)shows a large band gap of 2.37 e V in lead-based chalcogenides,wide infrared transparent window(2.5-15μm),and excellent thermal stability.Importantly,the experimental birefringence shows the largest value of0.26@550 nm in chalcogenides,even larger than the commercialized oxide materials.The Barder charge analysis result indicates that the exceptional birefringence effect is mainly from the Pb^(2+)and S^(2-)in the[Pb S_n]polyhedrons.Meanwhile,the parallelly arranged polyhedral layers could improve the structural anisotropic.Therefore,this work supports a new method for designing chalcogenides with exceptional birefringence effect in the infrared region.展开更多
Multifunctional semiconductors play an important role in developing advanced photoelectric technologies.In this work,based on an octahedral replacement strategy in chalcogenides,a new selenide semiconductor NaMn_(3)Ga...Multifunctional semiconductors play an important role in developing advanced photoelectric technologies.In this work,based on an octahedral replacement strategy in chalcogenides,a new selenide semiconductor NaMn_(3)Ga_(3)Se_(8)was rationally designed,and synthesized by the flux method.The compound crystallizes in the noncentrosymmetric(NCS)P_(6)space group,and is composed of unique prismatic[NaSe_(6)],octahedral[MnSe_(6)]and tetrahedral[GaSe_(4)]motifs,inheriting the stable three-dimensional framework built by the octahedral and tetrahedral units in the A^(Ⅰ)Mg_(3)^(Ⅱ)C_(3)^(Ⅲ)Q_(8)^(Ⅵ)family.NaMn_(3)Ga_(3)Se_(8)shows the largest known secondary nonlinear optical(NLO)response of~2.1×AgGaS_(2)(AGS)in the A^(Ⅰ)Mg_(3)^(Ⅱ)C_(3)^(Ⅲ)Q_(8)^(Ⅵ)family,and a high laser-induced damage threshold of~3.0×AGS.Meanwhile,the introduction of Mn2t with unpaired 3d electrons induces a strong red emission band(685–805 nm)under the excitation source of 496 nm,as well as a paramagnetic to antiferromagnetic(AFM)transition at 7.3 K.The results confirm that NaMn_(3)Ga_(3)Se_(8)possesses multifunctional features including significant NLO response,fluorescence emission and AFM properties,and illustrate that replacing octahedral units with approaching size and geometry(like[MgSe_(6)]and[MnSe_(6)])could be a feasible way to develop multifunctional chalcogenides.展开更多
The evolution of energy storage technology has seen remarkable progress,with a shift from pure metals to sophisticated,tailor-made active materials.The synthesis of nanostructures with exceptional properties is crucia...The evolution of energy storage technology has seen remarkable progress,with a shift from pure metals to sophisticated,tailor-made active materials.The synthesis of nanostructures with exceptional properties is crucial in the advancement of electrode materials.In this regard,our study highlights the fabrication of a novel,oriented heterostructure comprised of Zn-Mn-Co-telluride grown on a pre-oxidized copper mesh using a hydrothermal method followed by a solvothermal process.This innovative approach leads to the formation of the Zn-Mn-Cotelluride@CuO@Cu heterostructure,which demonstrates the unique oriented morphology.It outperforms both Zn-Mn-Co-telluride@Cu and CuO@Cu by exhibiting lower electrical resistivity,increased redox activity,higher specific capacity,and improved ion diffusion characteristics.The conductivity enhancements of the heterostructure are corroborated by density functional theory(DFT)calculations.When utilized in a hybrid supercapacitor(HSC)alongside activated carbon(AC)electrodes,the Zn-Mn-Co-telluride@CuO@Cu heterostructurebased HSC achieves an energy density of 75.7 Wh kg^(-1).Such findings underscore the potential of these novel electrode materials to significantly impact the design of next-generation supercapacitor devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22175175 and 22193043)Natural Science Foundation of Fujian Province(Nos.2022L3092 and 2023H0041)+1 种基金Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR118)the Youth Innovation Promotion Association CAS(No.2022303)。
文摘Recently,non-centrosymmetric(NCS)Hg-based chalcogenides have garnered significant interest due to their strong second-harmonic-generation intensities(deff),making them attractive candidates for infrared nonlinear optical(IR-NLO)application.However,achieving both wide band gaps(Eg)and large phasematched deffsimultaneously in these materials remains a challenge due to their inherent constraints on each other.In this research,we have successfully obtained two quaternary NCS Hg-based chalcogenides,Rb2HgGe_(3)S_(8)and Cs_(2)HgGe_(3)S_(8),by implementing a bandgap engineering strategy that involves alkali metal introduction and Hg/Ge ratio regulation.Both compounds consist of 2D[Hg Ge_(3)S_(8)]_(2)–anionic layers made of 1D[HgGeS_(6)]^(6–)chains and dimeric[Ge_(2)S_(6)]_(4–)polyhedra arranged alternately,and the charge-balanced Rb+/Cs+cations located between these layers.Remarkably,Rb_(2)HgGe_(3)S_(8)and Cs_(2)HgGe_(3)S_(8)exhibit overall properties required for promising IR-NLO materials,including sufficient PM deff(0.55–0.70×AgGaS_(2)@20_(5)0 nm),large Eg(3.27–3.41 e V),giant laser-induced damage thresholds(17.4–19.7×AgGaS_(2)@1064 nm),broad optical transmission intervals(0.32–17.5μm),and suitable theoretical birefringence(0.069–0.086@2050 nm).Furthermore,in-depth theoretical analysis reveals that the exceptional IRNLO performance is attributed to the synergy effects of distorted[HgS_(4)]and[GeS_(4)]tetrahedra.Our study provides a useful strategy for enhancing the Eg and advancing Hg-based IR-NLO materials,which is expected to extended and implemented in other chalcogenide systems.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(52125309)the National Natural Science Foundation of China(51991343,51920105002,and 52102179)+4 种基金Guangdong Basic and Applied Basic Research Foundation(2023A1515011752)Guangdong Innovative and Entrepreneurial Research Team Program(2017ZT07C341)Shenzhen Basic Research Project(JCYJ20200109144616617,JCYJ20220818101014029)Shuimu Tsinghua Scholar Program(2022SM092)China Postdoctoral Science Foundation(2021M691715)。
文摘Non-layered two-dimensional(2D)materials have sparked much interest recently due to their atomic thickness,large surface area,thickness-and facet-dependent properties.Currently,these materials are mainly grown from wet-chemistry methods but suffer from small size,low quality,and multi-facets,which is a major challenge hindering their facet-dependent property studies and applications.Here,we report the facet-engineered growth(FEG)of non-layered 2D manganese chalcogenides(MnX,X=S,Se,Te)based on the chemical vapor deposition method.The as-grown samples exhibit large-area surfaces of single facet,high-crystallinity,and ordered domain orientation.As a proof-of-concept,we show the facet-dependent electrocatalytic property of non-layered 2D MnSe,proving they are ideal candidates for fundamental research.Furthermore,we elucidate the underlying mechanism of FEG during the vapor growth process by the interfacial energy derived nucleation models.The method developed in this work provides new opportunities for regulating and designing the structure of 2D materials.
基金supported by the National Key Research and Devel-opment Program of China(no.2022YFB2502000)the National Natural Science Foundation of China(no.U21A2033251771076)+1 种基金Guangdong Basic and Applied Basic Research Foundation(nos.2020B1515120049,2021A1515010332 and 2021A1515010153)R&D Program in Key Areas of Guangdong Province(no.2020B0101030005).
文摘Lithium-ion batteries(LIBs)gradually occupied the energy storage market due to their long cycling life;high working voltage;as well as energy density.However;LIBs have high costs due to the limited lithium resource and difficulty to exploit.Potassium ion batteries(PIBs)have aroused extensive attention over the past few years since they possess considerable potassium salt resources while exhibiting similar electrochemical properties to LIBs.The electrode material takes on great significance in determining the properties exhibited by the batteries.Zinc-based chalcogenides have served as the most suitable anode materials for their numerous raw material resources;low prices;and environmental friendliness.Nevertheless;the application of Zinc-based chalcogenides has been continuously hindered by sluggish diffusion kinetics;low electrical conductivity;as well as huge volume vari-ation.Several effective strategies have been explored to settle the above matters(e.g.;designing nanostructures;constructing carbon composite structures;as well as doping anions or cations to construct heterojunction).In this review;the recent advance of zinc-based chalcogenides(e.g.;electrochemical mechanisms;challenges;and perspectives)are summarized.This review can provide novel insights into the development of transition metal chalcogenides for PIBs.
文摘The electro-physical properties of thin layers of rhenium chalcogenides＇ alloys, their dynamical and static ampere-voltaic characteristics were investigated. During the investigation of static and dynamical ampere-voltaic characteristics of rectifying contact of aluminium and rhenium chalcogenides＇ alloys the switching effects were found.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFE0110300)the National Natural Science Foundation of China(Grant Nos.52372215,92163114,and 52202274)+5 种基金the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20230504)the Special Fund for the"Dual Carbon"Science and Technology Innovation of Jiangsu province(Industrial Prospect and Key Technology Research program)(Grant Nos.BE2022023 and BE2022021)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.21KJA430004)Gusu Innovation and Entre preneurship Leading Talent Program(Grant No.ZXL2022451)the China Postdoctoral Science Foundation(Grant No.2023M732523)supported by Suzhou Key Laboratory of Functional Nano&Soft Materials,Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project.
文摘Lead chalcohalides(PbYX,X=Cl,Br,I;Y=S,Se)is an extension of the classic Pb chalcogenides(PbY).Constructing the heterogeneous integration with PbYX and PbY material systems makes it possible to achieve significantly improved optoelectronic performance.In this work,we studied the effect of introducing halogen precursors on the structure of classical PbS nanocrystals(NCs)during the synthesis process and realized the preparation of PbS/Pb_(3)S_(2)X_(2) core/shell structure for the first time.The core/shell structure can effectively improve their optical properties.Furthermore,our approach enables the synthesis of Pb_(3)S_(2)Br_(2) that had not yet been reported.Our results not only provide valuable insights into the heterogeneous integration of PbYX and PbY materials to elevate material properties but also provide an effective method for further expanding the preparation of PbYX material systems.
文摘硫系玻璃因其宽红外透过范围、高声光品质因数等特点,成了低功耗高性能声光调制器的理想工作介质,有望突破传统介质声光调制器在效率与功耗方面的局限。以宽红外透过范围、高折射率的Ge_(21)Sb_(18)S_(61)硫系玻璃为研究对象,系统分析了其热学、物理、光学及声学性能,并基于此成功研制出高性能光纤声光调制器。实验结果表明,在0.52 W射频驱动功率下,该调制器衍射效率达84%,上升时间为41 ns,消光比高达61 d B,展现出低功耗、高效率的优异性能。该声光调制器的研制为新型声光器件的设计与开发提供了重要技术支撑,对推动高速光通信、光纤传感等领域的应用具有重要意义。
基金supported by the National Natural Science Foundation of China(Grant Nos.62074114 and 12474019)。
文摘Due to the weak interlayer interactions,the binary Ⅲ-Ⅵ chalcogenides Ga Se can exist in several distinct polymorphs.Among them,the so-called β-and ε-phases simultaneously exhibit favorable total energies and moderate band gaps,which offer a good platform to explore their thermoelectric properties.Here,we demonstrate by first-principles calculations that the two systems have very similar band structures and phonon dispersions,despite different stacking sequences between adjacent layers.Interestingly,the lattice thermal conductivity of ε-GaSe is obviously lower than that of β-GaSe,which is inherently tied to stronger lattice anharmonicity caused by bonding heterogeneity.Besides,both systems exhibit higher p-type power factors due to doubly degenerate bands with weaker dispersions around the valence band maximum.As a consequence,a significantly enhanced p-type figure-of-merit of 2.1 can be realized at 700 K along the out-of-plane direction of theε-phase.
基金supported by the National Natural Science Foundation of China(Nos.52171216 and 52472221)the Qilu Young Scholar Program of Shandong University and Core Facility Sharing Platform of Shandong University.
文摘Quaternary chalcogenides are viewed as a class of potential thermoelectric materials due to their good thermoelectric performance in the medium temperature region.In this work,carbon nanotubes(CNTs)with varying weight percentages are composited into the quaternary chalcogenide Cu_(2.1)Mn_(0.9)SnSe_(4)(CMTS)using a technique that combines ball-milling and hot-pressing,and the effect of CNTs on the thermoelectric performance of CMTS is investigated.The compositing of CNTs results in an increase in the intrinsic defects of CMTS,thereby enhancing the electrical conductivities of the composited samples.Besides,the addition of CNTs introduces various phonon scattering mechanisms,effectively restraining the lattice thermal conductivities of the composited samples,particularly in the low to medium temperature range.Ultimately,owing to the concurrent optimization of the power factor and thermal conductivity,the x=0.25 sample achieves a zT value of 0.37 at 673 K.The compositing of highly conductive secondary phase is recognized as a viable approach for the simultaneous enhancement of the thermoelectric properties of materials.
基金Funded by the Breeding Project of Anhui Polytechnic University(No.2019YQQ027)the Scientific Research Foundation of Anhui Polytechnic University(No.xjky2022016)+1 种基金the Open Research Found of Anhui Key Laboratory of High-performance Non-ferrous Metal Materials(No.YSJS-2023-07)the Innovative Entrepreneurship Training Program for College Students in Anhui Province(No.S202210363391)。
文摘A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se doping level,a hollow spherical catalyst structure composed of CoSSe was successfully synthesized,which exhibited exceptional activity for hydrogen evolution in acidic solutions.The influences of Se doping on the microstructure and catalytic mechanism of hydrogen evolution reaction(HER)of these composites were systematically investigated.The experimental results reveal that the hollow spherical sample displays an overpotential value of 143 mV along with a Tafel slope value of 69.8 mV·dec^(-1)at a current density of 10 mA·cm^(-2)in an acid aqueous solution.Furthermore,it demonstrates remarkable cycling stability after undergoing 3000 cycles.The comprehensive analysis indicates that Se doping optimizes the electronic structure and enhances conductivity,meanwhile the unique hollow spherical architecture increases active sites for HER and significantly improves overall electrocatalytic performance.
基金supported in part by the National Natural Science Foundation of China(No.52102218)the National Key Research and Development Program of China(No.2020YFA0710303)+2 种基金the Fujian Science&Technology Innovation Laboratory for Op-toelectronic Information of China(No.2021ZZ127)the Minjiang Scholar Professorship(No.GXRC-21004)the Natural Science Foundation of Fujian Province of China(No.2021J01594)。
文摘Birefringent crystals play an irreplaceable role in optical systems by adjusting the polarization state of light in optical devices.This work successfully synthesized a new thiophosphate phase ofβ-Pb_(3)P_(2)S_(8)through the high-temperature solid-state spontaneous crystallization method.Different from the cubicα-Pb_(3)P_(2)S_(8),theβ-Pb_(3)P_(2)S_(8)crystallizes in the orthorhombic Pbcn space group.Notably,β-Pb_(3)P_(2)S_(8)shows a large band gap of 2.37 e V in lead-based chalcogenides,wide infrared transparent window(2.5-15μm),and excellent thermal stability.Importantly,the experimental birefringence shows the largest value of0.26@550 nm in chalcogenides,even larger than the commercialized oxide materials.The Barder charge analysis result indicates that the exceptional birefringence effect is mainly from the Pb^(2+)and S^(2-)in the[Pb S_n]polyhedrons.Meanwhile,the parallelly arranged polyhedral layers could improve the structural anisotropic.Therefore,this work supports a new method for designing chalcogenides with exceptional birefringence effect in the infrared region.
基金supported by the Natural Science Foundation of the Xinjiang Uygur Autonomous Region(2024D01E30)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0880000)+1 种基金the Open Fund of the Anhui Key Laboratory of Photonic Materials and Devices(AHKL2024KF02)the National Natural Science Foundation of China(22475234,22335007,22193044 and 22361132544).
文摘Multifunctional semiconductors play an important role in developing advanced photoelectric technologies.In this work,based on an octahedral replacement strategy in chalcogenides,a new selenide semiconductor NaMn_(3)Ga_(3)Se_(8)was rationally designed,and synthesized by the flux method.The compound crystallizes in the noncentrosymmetric(NCS)P_(6)space group,and is composed of unique prismatic[NaSe_(6)],octahedral[MnSe_(6)]and tetrahedral[GaSe_(4)]motifs,inheriting the stable three-dimensional framework built by the octahedral and tetrahedral units in the A^(Ⅰ)Mg_(3)^(Ⅱ)C_(3)^(Ⅲ)Q_(8)^(Ⅵ)family.NaMn_(3)Ga_(3)Se_(8)shows the largest known secondary nonlinear optical(NLO)response of~2.1×AgGaS_(2)(AGS)in the A^(Ⅰ)Mg_(3)^(Ⅱ)C_(3)^(Ⅲ)Q_(8)^(Ⅵ)family,and a high laser-induced damage threshold of~3.0×AGS.Meanwhile,the introduction of Mn2t with unpaired 3d electrons induces a strong red emission band(685–805 nm)under the excitation source of 496 nm,as well as a paramagnetic to antiferromagnetic(AFM)transition at 7.3 K.The results confirm that NaMn_(3)Ga_(3)Se_(8)possesses multifunctional features including significant NLO response,fluorescence emission and AFM properties,and illustrate that replacing octahedral units with approaching size and geometry(like[MgSe_(6)]and[MnSe_(6)])could be a feasible way to develop multifunctional chalcogenides.
基金supported by the Hong Kong Research Grants Council(No.CityU 11201522).
文摘The evolution of energy storage technology has seen remarkable progress,with a shift from pure metals to sophisticated,tailor-made active materials.The synthesis of nanostructures with exceptional properties is crucial in the advancement of electrode materials.In this regard,our study highlights the fabrication of a novel,oriented heterostructure comprised of Zn-Mn-Co-telluride grown on a pre-oxidized copper mesh using a hydrothermal method followed by a solvothermal process.This innovative approach leads to the formation of the Zn-Mn-Cotelluride@CuO@Cu heterostructure,which demonstrates the unique oriented morphology.It outperforms both Zn-Mn-Co-telluride@Cu and CuO@Cu by exhibiting lower electrical resistivity,increased redox activity,higher specific capacity,and improved ion diffusion characteristics.The conductivity enhancements of the heterostructure are corroborated by density functional theory(DFT)calculations.When utilized in a hybrid supercapacitor(HSC)alongside activated carbon(AC)electrodes,the Zn-Mn-Co-telluride@CuO@Cu heterostructurebased HSC achieves an energy density of 75.7 Wh kg^(-1).Such findings underscore the potential of these novel electrode materials to significantly impact the design of next-generation supercapacitor devices.
