The polarization switching plays a crucial role in controlling the final products in the catalytic pro-cess.The effect of polarization orientation on nitrogen reduction was investigated by anchoring transition metal a...The polarization switching plays a crucial role in controlling the final products in the catalytic pro-cess.The effect of polarization orientation on nitrogen reduction was investigated by anchoring transition metal atoms to form active centers on ferroelectric material In_(2)Se_(3).During the polariza-tion switching process,the difference in surface electrostatic potential leads to a redistribution of electronic states.This affects the interaction strength between the adsorbed small molecules and the catalyst substrate,thereby altering the reaction barrier.In addition,the surface states must be considered to prevent the adsorption of other small molecules(such as *O,*OH,and *H).Further-more,the V@↓-In_(2)Se_(3) possesses excellent catalytic properties,high electrochemical and thermody-namic stability,which facilitates the catalytic process.Machine learning also helps us further ex-plore the underlying mechanisms.The systematic investigation provides novel insights into the design and application of two-dimensional switchable ferroelectric catalysts for various chemical processes.展开更多
It is a challenging issue to further drive charge separation through the oriented design of Z-scheme het-erojunction in the exploitation of cost-effective photocatalytic materials.In this contribution,the unique Z-sch...It is a challenging issue to further drive charge separation through the oriented design of Z-scheme het-erojunction in the exploitation of cost-effective photocatalytic materials.In this contribution,the unique Z-scheme 3D/2D In_(2)Se_(3)/PCN heterojunction is developed through implanting In_(2)Se_(3) microspheres on PCN nanosheets using an in situ growth technique,which acquires the effective CO generation activity from photocatalytic CO_(2) reduction(CO_(2)R).The CO yield of 4 h in the CO_(2)R reaction over the optimal In_(2)Se_(3)/PCN-15 sample reaches up to 11.40 and 2.41 times higher than that of individual PCN and In_(2)Se_(3),respectively.Such greatly enhanced photocatalytic performance is primarily the improvement of photo-generated carrier separation efficiency.To be more specific,the formed built-in electric field is signifi-cantly intensified by producing the temperature difference potential between In_(2)Se_(3) and PCN owing to the photothermoelectric effect of In_(2)Se_(3),which actuates the high-efficiency separation of photogenerated charge carriers along the Z-scheme transfer path in the In_(2)Se_(3)/PCN heterojunction.The effective strat-egy of enhancing the built-in electric field to drive photogenerated charge separation proposed in this work opens up an innovative avenue to design Z-scheme heterojunction applied to high-efficiency pho-tocatalytic reactions,such as hydrogen generation from water splitting,CO_(2)R,and degradation of organic pollutants.展开更多
Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals hete...Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals heterostructures by a two-step chemical vapor deposition(CVD)method.After the growth of In_(2)Se_(3) at elevated temperatures,high densities of In_(2)Se_(3)/WS_(2) heterostructure bubbles with monolayer to multilayerβ-In_(2)Se_(3) crystals atop are observed.Fluorescence of the resultantβ-In_(2)Se_(3)/WS_(2) heterostructure is greatly enhanced in intensity upon the formation of bubbles,which are evidenced by the Newton’s rings in optical image owing to constructive and destructive interference.In photoluminescence(PL)mapping images of monolayerβ-In_(2)Se_(3)/monolayer WS2 heterobilayer bubble,significant oscillatory behavior of emission intensity is demonstrated due to constructive and destructive interference.However,oscillatory behaviors of peak position are also observed and come from a local heating effect induced by an excitation laser beam.The oscillatory mechanism of PL is further verified by changing the exterior pressure of bubbles placed in a home-made vacuum chamber.In addition,redshifted in peak position and broadening in peak width are observed due to strain effect during decreasing the exterior pressure of bubbles.展开更多
基于像差校正扫描透射电子显微学和第一性原理计算,研究了van der Waals(范德瓦尔斯)层状β-In_(2)Se_(3)中堆垛缺陷的原子构型。结果表明,在2Hβ-In_(2)Se_(3)中存在大量的置换型层错(RSF)和滑移型层错(SSF),发现了一种在热力学上易自...基于像差校正扫描透射电子显微学和第一性原理计算,研究了van der Waals(范德瓦尔斯)层状β-In_(2)Se_(3)中堆垛缺陷的原子构型。结果表明,在2Hβ-In_(2)Se_(3)中存在大量的置换型层错(RSF)和滑移型层错(SSF),发现了一种在热力学上易自发形成的T相滑移型堆垛层错(tSSF);在3Rβ-In_(2)Se_(3)中只观察到一种能量较高的滑移型层错;2H和3Rβ-In_(2)Se_(3)以界面连续过渡的方式发生相分离。本文还构建9种β-In_(2)Se_(3)潜在的堆垛层错构型,并计算了相应的堆垛层错能并从能量角度分析了堆垛层错的成因。最后,指出建立分类术语描述类van der Waals层状材料堆垛层错的必要性。展开更多
Transition metal dichalcogenides(TMDCs)are promising candidates for future optoelectronic devices accounting for their high carrier mobility and excellent quantum efficiency.However,the limited light absorption effici...Transition metal dichalcogenides(TMDCs)are promising candidates for future optoelectronic devices accounting for their high carrier mobility and excellent quantum efficiency.However,the limited light absorption efficiency in atomically thin layers significantly hinders photocarrier generation,thereby impairing the optoelectronic performance and hindering practical applications.Herein,we successfully synthesized In_(2)Se_(3)/WSe_(2) heterostructures through a typical two-step chemical vapor deposition(CVD)method.The In_(2)Se_(3) nanosheet with strong light absorption capability,serving as the light absorption layer,was integrated with the monolayer WSe_(2),enhancing the photosensitivity of WSe_(2) significantly.Upon laser irradiation with a wavelength of 520 nm,the In_(2)Se_(3)/WSe_(2) heterostructure device shows an ultrahigh photoresponsivity with a value as high as 2333.5 A/W and a remarkable detectivity reaching up to 6.7×10^(12) Jones,which is the highest among almost the reported TMDCs-based heterostructures grown via CVD even some fabricated by mechanical exfoliation(ME).Combing the advantages of CVD method such as large scale,high yield,and clean interface,the In_(2)Se_(3)/WSe_(2) heterostructures would provide a novel path for future high-performance optoelectronic device.展开更多
硒化锑(Sb_(2)Se_(3))属于窄带隙半导体材料,具有良好的光吸收特性,已逐渐应用于光电催化领域.独特的一维(Sb_(4)Se_(6))_(n)带状结构单元连接方式,使其载流子传输具有高度各向异性.本文通过气相输运沉积法和原位水热法成功构建了还原...硒化锑(Sb_(2)Se_(3))属于窄带隙半导体材料,具有良好的光吸收特性,已逐渐应用于光电催化领域.独特的一维(Sb_(4)Se_(6))_(n)带状结构单元连接方式,使其载流子传输具有高度各向异性.本文通过气相输运沉积法和原位水热法成功构建了还原氧化石墨烯(rGO)修饰的准一维Sb_(2)Se_(3)@In_(2)S_(3)光陷阱异质结.研究结果表明,在rGO空间限域效应下,原位生长的非层状In_(2)S_(3)纳米片厚度从30 nm减小到10 nm,显著增加了光电极的电化学活性比表面积,进一步增强了光陷阱纳米结构对光的捕获能力.rGO和超薄In_(2)S_(3)纳米片共同修饰的准一维毛刷状Sb_(2)Se_(3)@In_(2)S_(3)-rGO纳米棒光电极在0 V(相对于可逆氢电极)的外加偏压下,光电流密度可达1.169 m A cm^(-2),约是Sb_(2)Se_(3)@In_(2)S_(3)和单体Sb_(2)Se_(3)的2倍和16倍,且稳定性良好,在中性条件下平均产氢速率为16.59μmol cm^(-2)h^(-1).实验结果和理论计算均表明,Ⅱ型异质结电荷传输方式是其光电化学增强的物理机制.以上工作为设计基于rGO修饰的复合光电极用于光电化学领域的研究提供了崭新的思路.展开更多
Indium selenide has garnered significant attention for high volumetric capacities,but is currently plagued by the sluggish charge transfer kinetics,severe volume effect,and rapid capacity degradation that hinder their...Indium selenide has garnered significant attention for high volumetric capacities,but is currently plagued by the sluggish charge transfer kinetics,severe volume effect,and rapid capacity degradation that hinder their practical applications.Herein,we design,synthesize,and characterize a multi-kernel-shell structure comprised of indium selenide encapsulated within carbon nanospheres(referred to as m-K-S In_(2)Se_(3)@C)through an integrated approach involving a hydrothermal method followed by a gaseous selenization process.Importantly,experimental measurements and density functional theory calculations confirm that the m-K-S In_(2)Se_(3)@C not only improve the adsorption capability for Li-ions but also lower the energy barrier for Li-ions diffusion.Profiting from numerous contact points,shorter diffusion distances and an improved volume buffering effect,the m-K-S In_(2)Se_(3)@C achieves an 800 mA h g^(−1)capacity over 1000 loops at 1000 mA g^(−1),a 520 mA h g^(−1)capacity at 5000 mA g^(−1)and an energy density of 270 Wh kg^(−1)when coupled with LiFePO4,surpassing most related anodes reported before.Broadly,the m-K-S structure with unique nano-micro structure offers a new approach to the design of advanced anodes for LIBs.展开更多
Nowadays,memristors are extremely similar to biological synapses and can achieve many basic functions of biological synapses,making them become a new generation of research hotspots for brain-like neurocomputing.In th...Nowadays,memristors are extremely similar to biological synapses and can achieve many basic functions of biological synapses,making them become a new generation of research hotspots for brain-like neurocomputing.In this work,we prepare a memristor based on two-dimensionalα-In_(2)Se_(3)nanosheets,which exhibits excellent electrical properties,faster switching speeds,and continuous tunability of device conduction.Meanwhile,most basic bio-synapse functions can be implemented faithfully,such as short-term memory(STM),long-term memory(LTM),four different types of spike-timing-dependent plasticity(STDP),and paired-pulse facilitation(PPF).More importantly,we systematically study three effective methods to achieve LTM,in which the reinforcement learning can be faithfully simulated according to the Ebbinghaus forgetting curve.Therefore,we believe this work will promote the development of learning functions for brain-like computing and artificial intelligence.展开更多
Emulation of advanced synaptic functions of the human brain with electronic devices contributes an important step toward constructing high‐efficiency neuromorphic systems.Ferroelectric materials are promising candida...Emulation of advanced synaptic functions of the human brain with electronic devices contributes an important step toward constructing high‐efficiency neuromorphic systems.Ferroelectric materials are promising candidates as synaptic weight elements in neural network hardware due to their controllable polarization states.However,the increased depolarization field at the na-noscale and the complex fabrication process of the traditional ferroelectric materials hamper the development of high‐density,low‐power,and highly sensitive synaptic devices.Here,we report the implementation of two‐dimensional(2D)ferroelectricα‐In_(2)Se_(3)as an active channel material to emulate typical synaptic functions.Theα‐In_(2)Se_(3)‐based synaptic device fea-tures multimode operations,enabled by the coupled ferroelectric polarization under various voltage pulses applied at both drain and gate terminals.Moreover,the energy consumption can be reduced to~1 pJ by using high‐κdielectric(Al2O3).The successful control of ferroelectric polarizations inα‐In_(2)Se_(3)and its application in artificial synapses are expected to inspire the implementation of 2D ferroelectric materials for future neuromorphic systems.展开更多
文摘The polarization switching plays a crucial role in controlling the final products in the catalytic pro-cess.The effect of polarization orientation on nitrogen reduction was investigated by anchoring transition metal atoms to form active centers on ferroelectric material In_(2)Se_(3).During the polariza-tion switching process,the difference in surface electrostatic potential leads to a redistribution of electronic states.This affects the interaction strength between the adsorbed small molecules and the catalyst substrate,thereby altering the reaction barrier.In addition,the surface states must be considered to prevent the adsorption of other small molecules(such as *O,*OH,and *H).Further-more,the V@↓-In_(2)Se_(3) possesses excellent catalytic properties,high electrochemical and thermody-namic stability,which facilitates the catalytic process.Machine learning also helps us further ex-plore the underlying mechanisms.The systematic investigation provides novel insights into the design and application of two-dimensional switchable ferroelectric catalysts for various chemical processes.
基金National Natural Science Foundation of China(Nos.52072153 and 62004143)Key R&D Program of Hubei Province(No.2022BAA084)+2 种基金Postdoctoral Science Foundation of China(No.2021M690023)Graduate Research Innovation Program of Jiangsu Provincial(Nos.KYCX22_3694 and KYCX23_3649)Zhenjiang Key R&D Programmes(No.SH2021021).
文摘It is a challenging issue to further drive charge separation through the oriented design of Z-scheme het-erojunction in the exploitation of cost-effective photocatalytic materials.In this contribution,the unique Z-scheme 3D/2D In_(2)Se_(3)/PCN heterojunction is developed through implanting In_(2)Se_(3) microspheres on PCN nanosheets using an in situ growth technique,which acquires the effective CO generation activity from photocatalytic CO_(2) reduction(CO_(2)R).The CO yield of 4 h in the CO_(2)R reaction over the optimal In_(2)Se_(3)/PCN-15 sample reaches up to 11.40 and 2.41 times higher than that of individual PCN and In_(2)Se_(3),respectively.Such greatly enhanced photocatalytic performance is primarily the improvement of photo-generated carrier separation efficiency.To be more specific,the formed built-in electric field is signifi-cantly intensified by producing the temperature difference potential between In_(2)Se_(3) and PCN owing to the photothermoelectric effect of In_(2)Se_(3),which actuates the high-efficiency separation of photogenerated charge carriers along the Z-scheme transfer path in the In_(2)Se_(3)/PCN heterojunction.The effective strat-egy of enhancing the built-in electric field to drive photogenerated charge separation proposed in this work opens up an innovative avenue to design Z-scheme heterojunction applied to high-efficiency pho-tocatalytic reactions,such as hydrogen generation from water splitting,CO_(2)R,and degradation of organic pollutants.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51732010 and 51972280)the Natural Science Foundation of Hebei Province,China(Grant No.E2019203233)the Research Program of the College Science&Technology of Hebei Province,China(Grant No.ZD2020121).
文摘Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals heterostructures by a two-step chemical vapor deposition(CVD)method.After the growth of In_(2)Se_(3) at elevated temperatures,high densities of In_(2)Se_(3)/WS_(2) heterostructure bubbles with monolayer to multilayerβ-In_(2)Se_(3) crystals atop are observed.Fluorescence of the resultantβ-In_(2)Se_(3)/WS_(2) heterostructure is greatly enhanced in intensity upon the formation of bubbles,which are evidenced by the Newton’s rings in optical image owing to constructive and destructive interference.In photoluminescence(PL)mapping images of monolayerβ-In_(2)Se_(3)/monolayer WS2 heterobilayer bubble,significant oscillatory behavior of emission intensity is demonstrated due to constructive and destructive interference.However,oscillatory behaviors of peak position are also observed and come from a local heating effect induced by an excitation laser beam.The oscillatory mechanism of PL is further verified by changing the exterior pressure of bubbles placed in a home-made vacuum chamber.In addition,redshifted in peak position and broadening in peak width are observed due to strain effect during decreasing the exterior pressure of bubbles.
文摘基于像差校正扫描透射电子显微学和第一性原理计算,研究了van der Waals(范德瓦尔斯)层状β-In_(2)Se_(3)中堆垛缺陷的原子构型。结果表明,在2Hβ-In_(2)Se_(3)中存在大量的置换型层错(RSF)和滑移型层错(SSF),发现了一种在热力学上易自发形成的T相滑移型堆垛层错(tSSF);在3Rβ-In_(2)Se_(3)中只观察到一种能量较高的滑移型层错;2H和3Rβ-In_(2)Se_(3)以界面连续过渡的方式发生相分离。本文还构建9种β-In_(2)Se_(3)潜在的堆垛层错构型,并计算了相应的堆垛层错能并从能量角度分析了堆垛层错的成因。最后,指出建立分类术语描述类van der Waals层状材料堆垛层错的必要性。
基金support from the following funding:the National Key R&D Program of China(No.2022YFA1204300)the National Natural Science Foundation of China(Nos.62104066,52221001,62090035,U19A2090,U22A20138 and 51902098)+5 种基金the Natural Science Foundation of Hunan Province(No.2021JJ20016)the Science and Technology Innovation Program of Hunan Province(Nos.2021RC3061 and 2020RC2028)the Key Program of Science and Technology Department of Hunan Province(Nos.2019XK2001 and 2020XK2001)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF016)the National Postdoctoral Program for Innovative Talents(No.BX2021094)the Postdoctoral Science Foundation of China(No.2020M680112).
文摘Transition metal dichalcogenides(TMDCs)are promising candidates for future optoelectronic devices accounting for their high carrier mobility and excellent quantum efficiency.However,the limited light absorption efficiency in atomically thin layers significantly hinders photocarrier generation,thereby impairing the optoelectronic performance and hindering practical applications.Herein,we successfully synthesized In_(2)Se_(3)/WSe_(2) heterostructures through a typical two-step chemical vapor deposition(CVD)method.The In_(2)Se_(3) nanosheet with strong light absorption capability,serving as the light absorption layer,was integrated with the monolayer WSe_(2),enhancing the photosensitivity of WSe_(2) significantly.Upon laser irradiation with a wavelength of 520 nm,the In_(2)Se_(3)/WSe_(2) heterostructure device shows an ultrahigh photoresponsivity with a value as high as 2333.5 A/W and a remarkable detectivity reaching up to 6.7×10^(12) Jones,which is the highest among almost the reported TMDCs-based heterostructures grown via CVD even some fabricated by mechanical exfoliation(ME).Combing the advantages of CVD method such as large scale,high yield,and clean interface,the In_(2)Se_(3)/WSe_(2) heterostructures would provide a novel path for future high-performance optoelectronic device.
基金supported by the National Natural Science Foundation of China(11974276,11804274,and 22078261)。
文摘硒化锑(Sb_(2)Se_(3))属于窄带隙半导体材料,具有良好的光吸收特性,已逐渐应用于光电催化领域.独特的一维(Sb_(4)Se_(6))_(n)带状结构单元连接方式,使其载流子传输具有高度各向异性.本文通过气相输运沉积法和原位水热法成功构建了还原氧化石墨烯(rGO)修饰的准一维Sb_(2)Se_(3)@In_(2)S_(3)光陷阱异质结.研究结果表明,在rGO空间限域效应下,原位生长的非层状In_(2)S_(3)纳米片厚度从30 nm减小到10 nm,显著增加了光电极的电化学活性比表面积,进一步增强了光陷阱纳米结构对光的捕获能力.rGO和超薄In_(2)S_(3)纳米片共同修饰的准一维毛刷状Sb_(2)Se_(3)@In_(2)S_(3)-rGO纳米棒光电极在0 V(相对于可逆氢电极)的外加偏压下,光电流密度可达1.169 m A cm^(-2),约是Sb_(2)Se_(3)@In_(2)S_(3)和单体Sb_(2)Se_(3)的2倍和16倍,且稳定性良好,在中性条件下平均产氢速率为16.59μmol cm^(-2)h^(-1).实验结果和理论计算均表明,Ⅱ型异质结电荷传输方式是其光电化学增强的物理机制.以上工作为设计基于rGO修饰的复合光电极用于光电化学领域的研究提供了崭新的思路.
基金supported by the National Natural Science Foundation of China(22101065 and 51972075)the Heilongjiang Provincial Natural Science Foundation of China(YQ2021B001)+1 种基金the Project funded by China Postdoctoral Science Foundation(2023T160153 and 2020M681075)the Fundamental Research Funds for the Central Universities.
文摘Indium selenide has garnered significant attention for high volumetric capacities,but is currently plagued by the sluggish charge transfer kinetics,severe volume effect,and rapid capacity degradation that hinder their practical applications.Herein,we design,synthesize,and characterize a multi-kernel-shell structure comprised of indium selenide encapsulated within carbon nanospheres(referred to as m-K-S In_(2)Se_(3)@C)through an integrated approach involving a hydrothermal method followed by a gaseous selenization process.Importantly,experimental measurements and density functional theory calculations confirm that the m-K-S In_(2)Se_(3)@C not only improve the adsorption capability for Li-ions but also lower the energy barrier for Li-ions diffusion.Profiting from numerous contact points,shorter diffusion distances and an improved volume buffering effect,the m-K-S In_(2)Se_(3)@C achieves an 800 mA h g^(−1)capacity over 1000 loops at 1000 mA g^(−1),a 520 mA h g^(−1)capacity at 5000 mA g^(−1)and an energy density of 270 Wh kg^(−1)when coupled with LiFePO4,surpassing most related anodes reported before.Broadly,the m-K-S structure with unique nano-micro structure offers a new approach to the design of advanced anodes for LIBs.
基金financially supported by the National Key R&D Plan“Nano Frontier”Key Special Project(2021YFA1200502)the Cultivation Projects of National Major R&D Project(92164109)+9 种基金the National Natural Science Foundation of China(61874158,62004056 and 62104058)the Special Project of Strategic Leading Science and Technology of Chinese Academy of Sciences(XDB44000000-7)Hebei Basic Research Special Key Project(F2021201045)the Support Program for the Top Young Talents of Hebei Province(70280011807)the Supporting Plan for 100 Excellent Innovative Talents in Colleges and Universities of Hebei Province(SLRC2019018)the Outstanding Young Scientific Research and Innovation Team of Hebei University(605020521001)the Special Support Funds for National High Level Talents(041500120001)the High-level Talent Research Startup Project of Hebei University(521000981426)the Science and Technology Project of Hebei Education Department(QN2020178 and QN2021026)the Post-graduate’s Innovation Fund Project of Hebei Province(CXZZBS2022020)。
文摘Nowadays,memristors are extremely similar to biological synapses and can achieve many basic functions of biological synapses,making them become a new generation of research hotspots for brain-like neurocomputing.In this work,we prepare a memristor based on two-dimensionalα-In_(2)Se_(3)nanosheets,which exhibits excellent electrical properties,faster switching speeds,and continuous tunability of device conduction.Meanwhile,most basic bio-synapse functions can be implemented faithfully,such as short-term memory(STM),long-term memory(LTM),four different types of spike-timing-dependent plasticity(STDP),and paired-pulse facilitation(PPF).More importantly,we systematically study three effective methods to achieve LTM,in which the reinforcement learning can be faithfully simulated according to the Ebbinghaus forgetting curve.Therefore,we believe this work will promote the development of learning functions for brain-like computing and artificial intelligence.
基金Ministry of Education—Singapore,Grant/Award Number:MOE‐2019‐T2‐1‐002National Natural Science Foundation of China,Grant/Award Numbers:21872100,U2032147Agency for Science,Technology and Research,Grant/Award Numbers:A1938c0035,A20G9b0135。
文摘Emulation of advanced synaptic functions of the human brain with electronic devices contributes an important step toward constructing high‐efficiency neuromorphic systems.Ferroelectric materials are promising candidates as synaptic weight elements in neural network hardware due to their controllable polarization states.However,the increased depolarization field at the na-noscale and the complex fabrication process of the traditional ferroelectric materials hamper the development of high‐density,low‐power,and highly sensitive synaptic devices.Here,we report the implementation of two‐dimensional(2D)ferroelectricα‐In_(2)Se_(3)as an active channel material to emulate typical synaptic functions.Theα‐In_(2)Se_(3)‐based synaptic device fea-tures multimode operations,enabled by the coupled ferroelectric polarization under various voltage pulses applied at both drain and gate terminals.Moreover,the energy consumption can be reduced to~1 pJ by using high‐κdielectric(Al2O3).The successful control of ferroelectric polarizations inα‐In_(2)Se_(3)and its application in artificial synapses are expected to inspire the implementation of 2D ferroelectric materials for future neuromorphic systems.
