Nanotube-based mixed-dimensional or one-dimensional heterostructures have attracted great attention recently because of their unique physical properties and therefore potential for novel devices. Their chemical proper...Nanotube-based mixed-dimensional or one-dimensional heterostructures have attracted great attention recently because of their unique physical properties and therefore potential for novel devices. Their chemical properties, however, were less explored but can be utilized for energy storage and conversion.In this review, we summarize the recent progress of nanotube-based low dimensional materials for electrochemistry, in particular, lithium storage and hydrogen evolution. First, we describe the atomic structure of low-dimensional heterostructures and briefly touch previous work on planar van der Waals heterostructures(2D+2D) in electrochemistry applications. Then we focus this review on the more recently developed nanotube-based, i.e., 1D+2D and 1D + 1D heterostructures, and discuss their various preparation approaches and electrochemical performances. Finally, we outline the challenges and opportunities in this direction and particularly emphasize the possibility of building high-performance electrodes using a single-walled carbon nanotube-based ultra-thin 1D heterostructure, and the importance of understanding the fundamental mechanism at atomic precision.展开更多
Lithium metal batteries(LMBs)possess outstanding theoretical energy density and have attracted widespread attention as the next generation of energy storage devices for various crucial applications.However,the commerc...Lithium metal batteries(LMBs)possess outstanding theoretical energy density and have attracted widespread attention as the next generation of energy storage devices for various crucial applications.However,the commercialization of LMBs has to simultaneously overcome numerous challenges,such as inferior Coulombic efficiency and cycling performance,high self-discharge,and complicated interfacial reactions.It has traditionally been an enormous challenge about the uniform deposition of lithium on the surface of current collector to relieve the formation of lithium dendrites.In this study,a novel efficient strategy of plating uniform lithiophilic polythiophene derivatives substrates on Cu foils was developed and the nucleation mechanism of Li ions on polythiophene derivatives substrates was further explored.We first explored the interaction between polythiophene derivatives substrates and Li ions by firstprinciples calculations,and found shorter side chains of polythiophene derivatives can enhance the adsorption energy and promote the diffusion rate of Li ions.Polythiophene derivatives substrates have a large number of dispersive lipophilic sites and Li ions diffusion channels in the main chain,which can effectively regulate the nucleation and growth stages of Li ions deposition.We further found polythiophene derivatives with different side chains can induce the electrodeposition of Li ions with different morphology,while the polythiophene derivatives with the shortest side chains can contribute to the most excellent cycle efficiency,resulting in a uniform lithium deposition with less lithium dendritic growth experimentally.展开更多
Single-walled carbon nanotubes(SWCNTs)present excellent electronic and mechanical properties desired in wearable and flexible devices.The preparation of SWCNT films is the first step for fabricating various devices.Th...Single-walled carbon nanotubes(SWCNTs)present excellent electronic and mechanical properties desired in wearable and flexible devices.The preparation of SWCNT films is the first step for fabricating various devices.This work developed a scalable and feasible method to assemble SWCNT thin films on water surfaces based on Marangoni flow induced by surface tension gradient.The films possess a large area of 40 cm×30 cm(extensible),a tunable thickness of 15∼150 nm,a high transparency of up to 96%,and a decent conductivity.They are ready to be directly transferred to various substrates,including flexible ones.Flexible strain sensors were fabricated with the films on flexible substrates.These sensors worked with high sensitivity and repeatability.By realizing multi-functional human motion sensing,including responding to voices,monitoring artery pulses,and detecting knuckle and muscle actions,the assembled SWCNT films demonstrated the potential for application in smart devices.展开更多
A semiconductor/dielectric interface is one of the dominant factors in device characteristics,and a variety of oxides with high dielectric constants and low interface trap densities have been used in carbon nanotube t...A semiconductor/dielectric interface is one of the dominant factors in device characteristics,and a variety of oxides with high dielectric constants and low interface trap densities have been used in carbon nanotube transistors.Given the crystal structure of nanotubes with no dangling bonds,there remains room to investigate unconventional dielectric materials.Here,we fabricate carbon nanotube transistors with boron nitride nanotubes as interfacial layers between channels and gate dielectrics,where a single semiconducting nanotube is used to focus on switching behaviors at the subthreshold regime.The subthreshold swing of 68 mV·dec^(−1)is obtained despite a 100-nm-thick Sio_(2)dielectric,corresponding to the effective interface trap density of 5.2×10^(11)cm^(−2)·eV^(−1),one order of magnitude lower than those of carbon nanotube devices without boron nitride passivation.The interfacial layers also result in the mild suppression of threshold voltage variation and hysteresis.We achieve Ohmic contacts through the selective etching of boron nitride nanotubes with XeF2 gas,overcoming the trade-off imposed by wrapping the inner nanotubes.Negligible impacts of fluorinating carbon nanotubes on device performances are also confirmed as long as the etching is applied exclusively at source/drain regions.Our results represent an important step toward nanoelectronics that exploit the advantage of one-dimensional van der Waals heterostructures.展开更多
We present a systematic study of the effects of surfactants in the separation of single-walled carbon nanotubes （SWNTs） by density gradient ultracentrifugation （DGU）. Through analysis of the buoyant densities, lay...We present a systematic study of the effects of surfactants in the separation of single-walled carbon nanotubes （SWNTs） by density gradient ultracentrifugation （DGU）. Through analysis of the buoyant densities, layer positions, and optical absorbance spectra of SWNT separations using the bile salt sodium deoxycholate （DOC） and the anionic salt sodium dodecyl sulfate （SDS）, we clarify the roles and interactions of these two surfactants in yielding different DGU outcomes. The separation mechanism described here can also help in designing new DGU experiments by qualitatively predicting outcomes of different starting recipes, improving the efficacy of DGU and simplifying post-DGU fractionation.展开更多
Field-effect transistors （FETs） have been fabricated using as-grown single-walled carbon nanotubes （SWNTs） for the channel as well as both source and drain electrodes. The underlying Si substrate was employed as t...Field-effect transistors （FETs） have been fabricated using as-grown single-walled carbon nanotubes （SWNTs） for the channel as well as both source and drain electrodes. The underlying Si substrate was employed as the back-gate electrode. Fabrication consisted of patterned catalyst deposition by surface modification followed by dip-coating and synthesis of SWNTs by alcohol chemical vapor deposition （CVD）. The electrodes and channel were grown simultaneously in one CVD process. The resulting FETs exhibited excellent performance, with an I ON/I OFF ratio of 10^6 and a maximum ON-state current （/ON） exceeding 13 uA. The large I ON is attributed to SWNT bundles connecting the SWNT channel with the SWNT electrodes. Bundling creates a large contact area, which results in a small contact resistance despite the presence of Schottky barriers at metallic-semiconducting interfaces. The approach described here demonstrates a significant step toward the realization of metal-free electronics.展开更多
The charge interaction and corresponding doping effect between single-walled carbonnanotubes (SWNTs) and various fullerene derivatives, namely, C60, phenyl-C61-butyricacid methyl ester (PC61BM), methano-indenefulleren...The charge interaction and corresponding doping effect between single-walled carbonnanotubes (SWNTs) and various fullerene derivatives, namely, C60, phenyl-C61-butyricacid methyl ester (PC61BM), methano-indenefullerene (MIF), 10,100,40,400-tetrahydrodi[1,4]methanonaphthaleno[5,6]fullerene (ICBA), 1,4-bis(dimethylphenylsilylmethyl)[60]fullerene (SIMEF-1), and dimethyl(orthoanisyl) silylmethyl(dimethylphenylsilylmethyl)[60]fullerene (SIMEF-2), are investigated. A variety of analytical techniques,including field-effect transistors (FETs) made of horizontally aligned arrays ofSWNTs, is used as a means of investigation. Data from different measurements haveto be used to obtain a concrete evaluation for the fullerene-applied SWNTs. The datacollectively points toward the conclusion that fullerenes with high molecular orbitalenergy levels, namely, MIF, SIMEF-1, SIMEF-2, and PC61BM, induce p-type doping,while fullerenes with low molecular orbital energy levels, namely, ICBA and C60,induce n-type doping on the carbon nanotubes. Nevertheless, the SWNTs retained ptypecharacteristics because n-doping induced by the fullerenes are weak compared tothe p-doping of the water and oxygen on carbon nanotubes. This means that fullerenederivatives have the ability to fine-tune the energy levels of carbon nanotubes, whichcan play a crucial role in carbon nanotube-based electronics, such as solar cells, lightemittingdevices, and FETs.展开更多
We recently demonstrated experimentally the synthesis of one-dimensional(1D)van der Waals(vdW)heterostructure,where single-crystal hexagonal boron nitride or molybdenum disulfide nanotubes seamlessly wrapped a singlew...We recently demonstrated experimentally the synthesis of one-dimensional(1D)van der Waals(vdW)heterostructure,where single-crystal hexagonal boron nitride or molybdenum disulfide nanotubes seamlessly wrapped a singlewalled carbon nanotube and formed a coaxial hetero-nanotube with the diameter typically being 1–5 nm.1D vdW heterostructures have created large room for fundamental research from synthesis to application,but most directions are still at their initial stages.The materials that can be employed to construct 1D vdW heterostructures are limited to only a few types.In this review,we provide an outlook to the question:what are the building blocks available now and could be available in the future for the fabrication of 1D vdW heterostructures?展开更多
基金supported by JSPS KAKENHI(JP18H05329,JP19H02543,JP20H00220,JP20KK0114)by JST,CREST(JPMJCR20B5),Japan+2 种基金conducted at the Advanced Characterization Nanotechnology Platform of the University of Tokyosupported by the “Nanotechnology Platform”of the MEXT,Japan(JPMXP09A20UT0063 and JPMXP09A21UT0050)。
文摘Nanotube-based mixed-dimensional or one-dimensional heterostructures have attracted great attention recently because of their unique physical properties and therefore potential for novel devices. Their chemical properties, however, were less explored but can be utilized for energy storage and conversion.In this review, we summarize the recent progress of nanotube-based low dimensional materials for electrochemistry, in particular, lithium storage and hydrogen evolution. First, we describe the atomic structure of low-dimensional heterostructures and briefly touch previous work on planar van der Waals heterostructures(2D+2D) in electrochemistry applications. Then we focus this review on the more recently developed nanotube-based, i.e., 1D+2D and 1D + 1D heterostructures, and discuss their various preparation approaches and electrochemical performances. Finally, we outline the challenges and opportunities in this direction and particularly emphasize the possibility of building high-performance electrodes using a single-walled carbon nanotube-based ultra-thin 1D heterostructure, and the importance of understanding the fundamental mechanism at atomic precision.
基金funded by the JSPS KAKENHI Grant Numbers JP19H02543,JP20H00220,JP15H05760,and JP18H05329the National Natural Science Foundation of China(Grant No.51872132)+9 种基金supported by the National Natural Science Foundation of China(21875284 and 22075320)the National Natural Science Foundation of China(11404017)the SUSTech Presidential Postdoctoral Fellowshipfunded by the China Postdoctoral Science Fundation(2020M670156)the Technology Innovation Commission of Shenzhen(Grant No.JCYJ20190809154007586)funded by the JSPS KAKENHI Grant Numbers JP15H05760,JP18H05329funded by the Fundamental Research Funds for the Central Universities(3102019QD0418)the National Key Research and Development Program of China(No.2017YFB0702100)the Technology Foundation for Selected Overseas Chinese Scholarthe Ministry of Human Resources and Social Security of China。
文摘Lithium metal batteries(LMBs)possess outstanding theoretical energy density and have attracted widespread attention as the next generation of energy storage devices for various crucial applications.However,the commercialization of LMBs has to simultaneously overcome numerous challenges,such as inferior Coulombic efficiency and cycling performance,high self-discharge,and complicated interfacial reactions.It has traditionally been an enormous challenge about the uniform deposition of lithium on the surface of current collector to relieve the formation of lithium dendrites.In this study,a novel efficient strategy of plating uniform lithiophilic polythiophene derivatives substrates on Cu foils was developed and the nucleation mechanism of Li ions on polythiophene derivatives substrates was further explored.We first explored the interaction between polythiophene derivatives substrates and Li ions by firstprinciples calculations,and found shorter side chains of polythiophene derivatives can enhance the adsorption energy and promote the diffusion rate of Li ions.Polythiophene derivatives substrates have a large number of dispersive lipophilic sites and Li ions diffusion channels in the main chain,which can effectively regulate the nucleation and growth stages of Li ions deposition.We further found polythiophene derivatives with different side chains can induce the electrodeposition of Li ions with different morphology,while the polythiophene derivatives with the shortest side chains can contribute to the most excellent cycle efficiency,resulting in a uniform lithium deposition with less lithium dendritic growth experimentally.
基金supported by National Natural Science Foundation of China(22120102004,21631002)Ministry of Science and Technology of China(2016YFA0201904)+3 种基金Shenzhen KQTD Project(KQTD20180411143400981)Beijing National Laboratory for Molecular Sciences(BNLMS-CXTD-202001)JSPS KAKENHI(JP20H00220)and by JST,CREST(JPMJCR20B5),Japan,。
文摘Single-walled carbon nanotubes(SWCNTs)present excellent electronic and mechanical properties desired in wearable and flexible devices.The preparation of SWCNT films is the first step for fabricating various devices.This work developed a scalable and feasible method to assemble SWCNT thin films on water surfaces based on Marangoni flow induced by surface tension gradient.The films possess a large area of 40 cm×30 cm(extensible),a tunable thickness of 15∼150 nm,a high transparency of up to 96%,and a decent conductivity.They are ready to be directly transferred to various substrates,including flexible ones.Flexible strain sensors were fabricated with the films on flexible substrates.These sensors worked with high sensitivity and repeatability.By realizing multi-functional human motion sensing,including responding to voices,monitoring artery pulses,and detecting knuckle and muscle actions,the assembled SWCNT films demonstrated the potential for application in smart devices.
基金supported by JSPS(Nos.KAKENHI JP22H01411,JP20H00220,JP23H05443,JP21H05233,and JP23H02052),JST(No.CREST JPMJCR20B5)World Premier International Research Center Initiative(WPI)and the Ministry of Education,Culture,Sports,Science and Technology(MEXT),Japan.A part of this work was conducted at Takeda Sentanchi Supercleanroom,The University of Tokyo,supported by“Advanced Research Infrastructure for Materials and Nanotechnology in Japan(ARIM)”of MEXT(Proposal Number JPMXP09F22UT1086).
文摘A semiconductor/dielectric interface is one of the dominant factors in device characteristics,and a variety of oxides with high dielectric constants and low interface trap densities have been used in carbon nanotube transistors.Given the crystal structure of nanotubes with no dangling bonds,there remains room to investigate unconventional dielectric materials.Here,we fabricate carbon nanotube transistors with boron nitride nanotubes as interfacial layers between channels and gate dielectrics,where a single semiconducting nanotube is used to focus on switching behaviors at the subthreshold regime.The subthreshold swing of 68 mV·dec^(−1)is obtained despite a 100-nm-thick Sio_(2)dielectric,corresponding to the effective interface trap density of 5.2×10^(11)cm^(−2)·eV^(−1),one order of magnitude lower than those of carbon nanotube devices without boron nitride passivation.The interfacial layers also result in the mild suppression of threshold voltage variation and hysteresis.We achieve Ohmic contacts through the selective etching of boron nitride nanotubes with XeF2 gas,overcoming the trade-off imposed by wrapping the inner nanotubes.Negligible impacts of fluorinating carbon nanotubes on device performances are also confirmed as long as the etching is applied exclusively at source/drain regions.Our results represent an important step toward nanoelectronics that exploit the advantage of one-dimensional van der Waals heterostructures.
基金Acknowledgements Part of this work was financially supported by Grant- in-Aid for Scientific Research （No. 22226006 and 19054003）, ＂Development of Nanoelectronic Device Technology＂ of New Energy and Industrial Technology Development Organization （NEDO）, and the Global Centers of Excellence （COE） Program ＂Global Center for Excellence for Mechanical Systems Innovation＂. P. Z. acknowledges a scholarship granted by the China Scholarship Council and G. L. acknowledges support from the NanoJapan program funded by the National Science Foundation.
文摘We present a systematic study of the effects of surfactants in the separation of single-walled carbon nanotubes （SWNTs） by density gradient ultracentrifugation （DGU）. Through analysis of the buoyant densities, layer positions, and optical absorbance spectra of SWNT separations using the bile salt sodium deoxycholate （DOC） and the anionic salt sodium dodecyl sulfate （SDS）, we clarify the roles and interactions of these two surfactants in yielding different DGU outcomes. The separation mechanism described here can also help in designing new DGU experiments by qualitatively predicting outcomes of different starting recipes, improving the efficacy of DGU and simplifying post-DGU fractionation.
文摘Field-effect transistors （FETs） have been fabricated using as-grown single-walled carbon nanotubes （SWNTs） for the channel as well as both source and drain electrodes. The underlying Si substrate was employed as the back-gate electrode. Fabrication consisted of patterned catalyst deposition by surface modification followed by dip-coating and synthesis of SWNTs by alcohol chemical vapor deposition （CVD）. The electrodes and channel were grown simultaneously in one CVD process. The resulting FETs exhibited excellent performance, with an I ON/I OFF ratio of 10^6 and a maximum ON-state current （/ON） exceeding 13 uA. The large I ON is attributed to SWNT bundles connecting the SWNT channel with the SWNT electrodes. Bundling creates a large contact area, which results in a small contact resistance despite the presence of Schottky barriers at metallic-semiconducting interfaces. The approach described here demonstrates a significant step toward the realization of metal-free electronics.
基金Japan Science and Technology Agency,Grant/Award Number:CIAiSJapan Society for the Promotion of Science,Grant/Award Numbers:JP15H05760,JP16H02285,JP17K04970,JP 18H05329,JP19K15669Yashima Foundation。
文摘The charge interaction and corresponding doping effect between single-walled carbonnanotubes (SWNTs) and various fullerene derivatives, namely, C60, phenyl-C61-butyricacid methyl ester (PC61BM), methano-indenefullerene (MIF), 10,100,40,400-tetrahydrodi[1,4]methanonaphthaleno[5,6]fullerene (ICBA), 1,4-bis(dimethylphenylsilylmethyl)[60]fullerene (SIMEF-1), and dimethyl(orthoanisyl) silylmethyl(dimethylphenylsilylmethyl)[60]fullerene (SIMEF-2), are investigated. A variety of analytical techniques,including field-effect transistors (FETs) made of horizontally aligned arrays ofSWNTs, is used as a means of investigation. Data from different measurements haveto be used to obtain a concrete evaluation for the fullerene-applied SWNTs. The datacollectively points toward the conclusion that fullerenes with high molecular orbitalenergy levels, namely, MIF, SIMEF-1, SIMEF-2, and PC61BM, induce p-type doping,while fullerenes with low molecular orbital energy levels, namely, ICBA and C60,induce n-type doping on the carbon nanotubes. Nevertheless, the SWNTs retained ptypecharacteristics because n-doping induced by the fullerenes are weak compared tothe p-doping of the water and oxygen on carbon nanotubes. This means that fullerenederivatives have the ability to fine-tune the energy levels of carbon nanotubes, whichcan play a crucial role in carbon nanotube-based electronics, such as solar cells, lightemittingdevices, and FETs.
基金supported by the National Natural Science Foundation of China(22120102004 and 21631002)Ministry of Science and Technology of China(2016YFA0201904)+3 种基金Shenzhen KQTD Project(KQTD20180411143400981)Beijing National Laboratory for Molecular Sciences(BNLMS-CXTD-202001)JSPS KAKENHI(JP18H05329,JP19H02543,JP20H00220 and JP20KK0114)JST,CREST,Japan(JPMJCR20B5)。
文摘We recently demonstrated experimentally the synthesis of one-dimensional(1D)van der Waals(vdW)heterostructure,where single-crystal hexagonal boron nitride or molybdenum disulfide nanotubes seamlessly wrapped a singlewalled carbon nanotube and formed a coaxial hetero-nanotube with the diameter typically being 1–5 nm.1D vdW heterostructures have created large room for fundamental research from synthesis to application,but most directions are still at their initial stages.The materials that can be employed to construct 1D vdW heterostructures are limited to only a few types.In this review,we provide an outlook to the question:what are the building blocks available now and could be available in the future for the fabrication of 1D vdW heterostructures?
