Constructing heterojunction photocatalysts is a highly effective strategy for achieving overall water splitting,particularly by overcoming the challenge of sluggish electron-hole transport.This study employed a defect...Constructing heterojunction photocatalysts is a highly effective strategy for achieving overall water splitting,particularly by overcoming the challenge of sluggish electron-hole transport.This study employed a defect-induced in situ growth approach to anchor NiSe onto carbon-vacancy-rich C_(3)N_(5)(C_(v)-C_(3)N_(5)),forming interfacial Ni-N bonds.The resulting NiSe/C_(v)-C_(3)N_(5)heterojunction exhibited stoichiometric H_(2)and O_(2)evolution rates of 1956.1 and 989.1μmol g^(-1)h^(-1),respectively,8.4 times higher than a counterpart lacking interfacial bonding.Both theoretical calculations and experimental data confirmed that the Ni–N bonds were instrumental in enhancing photocatalytic performance by inducing and reinforcing S-scheme charge transfer.Illumination X-ray photoelectron spectroscopy analysis revealed that a synergistic charge transfer pathway:photoexcited electrons from the NiSe conduction band migrated sequentially to Ni atoms,then to N atoms,and ultimately recombined with holes in the C_(v)-C_(3)N_(5)valence band.Moreover,these interfacial bonds significantly lowered the energy barrier and shortened the transport distance for electron transfer,amplifying the built-in interfacial electric field and accelerating charge dynamics.This study provides critical insights into the rational design of heterojunction photocatalysts for efficient water splitting.展开更多
采用沉淀法制备铁掺杂镍碳酸盐纳米球前驱体,并对其进行硒化处理,得到性能优异的铁掺杂的氧化镍和硒化镍的混合物(Fe-NiO/NiSe2)电催化剂。利用XRD、XPS、TEM、FESEM等手段对材料的结构和组成进行表征,并对其进行了电化学性能测试。结...采用沉淀法制备铁掺杂镍碳酸盐纳米球前驱体,并对其进行硒化处理,得到性能优异的铁掺杂的氧化镍和硒化镍的混合物(Fe-NiO/NiSe2)电催化剂。利用XRD、XPS、TEM、FESEM等手段对材料的结构和组成进行表征,并对其进行了电化学性能测试。结果表明,Fe-NiO/NiSe2电催化剂材料具有优异的析氧性能,在1. 0 mol/L KOH电解液中,在10 m A/cm^2电流密度下所需过电势仅为323 m V,并具有显著的长期稳定性,作为析氧反应催化剂具有很好的应用前景。展开更多
Neuromorphic computing vision is the most promising technological solution to overcome the arithmetic bottleneck in machine vision applications.All-in-one neuromorphic sensors have been attracting increased attention ...Neuromorphic computing vision is the most promising technological solution to overcome the arithmetic bottleneck in machine vision applications.All-in-one neuromorphic sensors have been attracting increased attention because they can integrate visual perception,processing,and memory functionalities into one single device.However,the limited responsivity and data retention time of all-in-one neuromorphic sensors usually hinder their potential in multispectral machine vision,especially in the near-infrared(NIR)band which contains critical information for pattern recognition.Here,we demonstrate physisorption-assistant optoelectronic synaptic transistors based on Ta_(2)NiSe_(5)/SnS_(2) heterojunction,which present tunable synaptic functionality in broadband(375–1310 nm).We propose a strategy about the physisorption-assistant persistent photoconductivity(PAPPC)effect to effectively solve the problem in detecting and storing the NIR light information.Under this strategy,the responsivity and data retention time of our devices were significantly enhanced and prolonged in broadband from 375 to 1310 nm.Further,the devices realize multilevel non-volatile optoelectronic memory through the modulation of several optical and back-gate signals to simulate emotion-controlled learning and memory processes,optical writing-electric erasing,and associative learning.Moreover,we developed a simplified human visual system to simulate color-cognitive perception and memory functions.Our approach offers a route for creating advanced all-in-one neuromorphic sensors and developing neuromorphic computing vision.展开更多
A prerequisite for widespread applications of atomically thin transition metal dichalcogenides in future electronics is to achieve reliable electrical contacts,which is of considerable challenge due to the difficultie...A prerequisite for widespread applications of atomically thin transition metal dichalcogenides in future electronics is to achieve reliable electrical contacts,which is of considerable challenge due to the difficulties in selectively doping and inevitable physical damages of these atomically thin materials during typical metal integration process.Here,we report the in situ growth of ultrathin metallic NiSe single crystals on WSe2 in which the metallic NiSe nanosheets function as the contact electrodes to WSe2,creating an interface that is essentially free from chemical disorder.The NiSe/WSe2 heterostructures also exhibit well-aligned lattice orientation between the two layers,forming a periodic Moire pattern.Electrical transport studies demonstrate that the NiSe nanosheets exhibit an excellent metallic feature,as evidenced by the extra-high electrical conductivity of up to 1.6×10^6 S-nf1.The WSe2 transistors with the NiSe contact show field-effect mobilities (/vFe) more than double that with Cr/Au electrodes.This study demonstrates an effective pathway to achieve reliable electrical contacts to the atomically thin 2D materials,and maybe readily extended for fabricating 2D/2D low-resistance contacts for a variety of transition metal dichalcogenides.展开更多
文摘Constructing heterojunction photocatalysts is a highly effective strategy for achieving overall water splitting,particularly by overcoming the challenge of sluggish electron-hole transport.This study employed a defect-induced in situ growth approach to anchor NiSe onto carbon-vacancy-rich C_(3)N_(5)(C_(v)-C_(3)N_(5)),forming interfacial Ni-N bonds.The resulting NiSe/C_(v)-C_(3)N_(5)heterojunction exhibited stoichiometric H_(2)and O_(2)evolution rates of 1956.1 and 989.1μmol g^(-1)h^(-1),respectively,8.4 times higher than a counterpart lacking interfacial bonding.Both theoretical calculations and experimental data confirmed that the Ni–N bonds were instrumental in enhancing photocatalytic performance by inducing and reinforcing S-scheme charge transfer.Illumination X-ray photoelectron spectroscopy analysis revealed that a synergistic charge transfer pathway:photoexcited electrons from the NiSe conduction band migrated sequentially to Ni atoms,then to N atoms,and ultimately recombined with holes in the C_(v)-C_(3)N_(5)valence band.Moreover,these interfacial bonds significantly lowered the energy barrier and shortened the transport distance for electron transfer,amplifying the built-in interfacial electric field and accelerating charge dynamics.This study provides critical insights into the rational design of heterojunction photocatalysts for efficient water splitting.
文摘采用沉淀法制备铁掺杂镍碳酸盐纳米球前驱体,并对其进行硒化处理,得到性能优异的铁掺杂的氧化镍和硒化镍的混合物(Fe-NiO/NiSe2)电催化剂。利用XRD、XPS、TEM、FESEM等手段对材料的结构和组成进行表征,并对其进行了电化学性能测试。结果表明,Fe-NiO/NiSe2电催化剂材料具有优异的析氧性能,在1. 0 mol/L KOH电解液中,在10 m A/cm^2电流密度下所需过电势仅为323 m V,并具有显著的长期稳定性,作为析氧反应催化剂具有很好的应用前景。
基金support from the National Natural Science Foundation of China(grant Nos.62334010,62121005,62022081,and 62304221)the National Key Research and Development Program(grant number 2021YFA0717600)+1 种基金the Natural Science Foundation of Jilin Province(20240101377JC)the International Fund Program of Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences.
文摘Neuromorphic computing vision is the most promising technological solution to overcome the arithmetic bottleneck in machine vision applications.All-in-one neuromorphic sensors have been attracting increased attention because they can integrate visual perception,processing,and memory functionalities into one single device.However,the limited responsivity and data retention time of all-in-one neuromorphic sensors usually hinder their potential in multispectral machine vision,especially in the near-infrared(NIR)band which contains critical information for pattern recognition.Here,we demonstrate physisorption-assistant optoelectronic synaptic transistors based on Ta_(2)NiSe_(5)/SnS_(2) heterojunction,which present tunable synaptic functionality in broadband(375–1310 nm).We propose a strategy about the physisorption-assistant persistent photoconductivity(PAPPC)effect to effectively solve the problem in detecting and storing the NIR light information.Under this strategy,the responsivity and data retention time of our devices were significantly enhanced and prolonged in broadband from 375 to 1310 nm.Further,the devices realize multilevel non-volatile optoelectronic memory through the modulation of several optical and back-gate signals to simulate emotion-controlled learning and memory processes,optical writing-electric erasing,and associative learning.Moreover,we developed a simplified human visual system to simulate color-cognitive perception and memory functions.Our approach offers a route for creating advanced all-in-one neuromorphic sensors and developing neuromorphic computing vision.
基金the financial support from the Fundamental Research Funds of the Central Universities (No.531107051078)the Double First-Class University In让iative of Hunan University (No.531109100004)+2 种基金the 111 Project of China (No.D17003)the support from the National Natural Science Foundation of China (No.751214296,51802090,61874041,and 61804050)Hunan Key Laboratory of Two-Dimensional Materials (No.801200005).
文摘A prerequisite for widespread applications of atomically thin transition metal dichalcogenides in future electronics is to achieve reliable electrical contacts,which is of considerable challenge due to the difficulties in selectively doping and inevitable physical damages of these atomically thin materials during typical metal integration process.Here,we report the in situ growth of ultrathin metallic NiSe single crystals on WSe2 in which the metallic NiSe nanosheets function as the contact electrodes to WSe2,creating an interface that is essentially free from chemical disorder.The NiSe/WSe2 heterostructures also exhibit well-aligned lattice orientation between the two layers,forming a periodic Moire pattern.Electrical transport studies demonstrate that the NiSe nanosheets exhibit an excellent metallic feature,as evidenced by the extra-high electrical conductivity of up to 1.6×10^6 S-nf1.The WSe2 transistors with the NiSe contact show field-effect mobilities (/vFe) more than double that with Cr/Au electrodes.This study demonstrates an effective pathway to achieve reliable electrical contacts to the atomically thin 2D materials,and maybe readily extended for fabricating 2D/2D low-resistance contacts for a variety of transition metal dichalcogenides.
