Flexible quasi-solid zinc-ion batteries(ZIBs)have large potential in power applications due to the low price,wearable nature,safety,and high capacity.However,the use of transition metal sulfide cathodes in ZIBs has no...Flexible quasi-solid zinc-ion batteries(ZIBs)have large potential in power applications due to the low price,wearable nature,safety,and high capacity.However,the use of transition metal sulfide cathodes in ZIBs has not been studied extensively and the underlying mechanism and theoretical basis of this type of batteries are not well understood.Herein,a highly active cobalt-doped Ni_(3)S_(2) porous nanocone framework(C12NS)is designed and demonstrated as a zinc-ion battery electrode.First-principles calculation and experiments reveal that the cobalt dopant improves the battery properties greatly.The assembled flexible zinc-ion battery exhibits a high specific capacity of 453.3 mAh g^(−1)at a current density of 0.4 A g^(−1)in as well as excellent cycling stability as manifested by a capacity retention ratio of 89.5%at a current density of 4 A g^(−1)after 5000 cycles.The peak energy density of 553.9 Wh kg^(−1)is also superior to those of most recently reported NiCo-based zinc-ion batteries.More importantly,the flexible battery can be operated under severe mechanical bending and even continues to work after physical puncturing without showing leakage.These exciting results not only reveal a novel design of cathode materials for zinc-based batteries,but also suggest their immense commercial potential in portable and wearable electronics.展开更多
This paper reports that a simple chemical vapour deposition method has been adopted to fabricate large scale, high density boron nanocones with thermal evaporation of B/B2O3 powders precursors in an Ar/H2 gas mixture ...This paper reports that a simple chemical vapour deposition method has been adopted to fabricate large scale, high density boron nanocones with thermal evaporation of B/B2O3 powders precursors in an Ar/H2 gas mixture at the synthesis temperature of 1000-1200℃. The lengths of boron nanocones are several micrometres, and the diameters of nanocone tops are in a range of 50-100 nm. transmission electron microscopy and selected area electron diffraction indicate that the nanocones are single crystalline α-tetragonal boron. The vapour liquid solid mechanism is the main formation mechanism of boron nanocones. One broad photolumineseence emission peak at the central wavelength of about 650 nm is observed under the 532 nm light excitation. Boron nanocones with good photoluminescence properties are promising candidates for applications in optical emitting devices.展开更多
Carbon nanocones have quite fascinating elec- tronic and structural properties, whose axial vibration is sel- dom investigated in previous studies. In this paper, based on a nonlocal elasticity theory, a nonuniform ro...Carbon nanocones have quite fascinating elec- tronic and structural properties, whose axial vibration is sel- dom investigated in previous studies. In this paper, based on a nonlocal elasticity theory, a nonuniform rod model is ap- plied to investigate the small-scale effect and the nonuniform effect on axial vibration of nanocones. Using the modified Wentzel-Brillouin-Kramers (WBK) method, an asymptotic solution is obtained for the axial vibration of general nonuni- form nanorods. Then, using similar procedure, the axial vi- bration of nanocones is analyzed for nonuniform parameters, mode number and nonlocal parameters. Explicit expressions are derived for mode frequencies of clamped-clamped and clamped-free boundary conditions. It is found that axial vi- bration frequencies are highly overestimated by the classical rod model because of ignorance of the effect of small length scale.展开更多
A systematic computational study of surface reactivity for pure and mono-hydrogenated carbon nanocoes (CNCs) formed from graphene sheets as functions of disclination angle, cone size and hydrogenation sites has been i...A systematic computational study of surface reactivity for pure and mono-hydrogenated carbon nanocoes (CNCs) formed from graphene sheets as functions of disclination angle, cone size and hydrogenation sites has been investigated through density functional (DFT) calculations and at the B3LYP/3-21G level of theory. Five disclination angles (60°, 120°, 180°, 240° and 300°) are applied and at any disclination angle four structures with different sizes are studied. For comparison, pure and mono-hydrogenated boron nitride nanocones (BNNCs) with disclination angles 60°, 120°, 180°, 240° and 300° are also investigated. The hydrogenation is done on three different sites, HS1 (above the first neighbor atom of the apex atoms), HS2 (above one atom of the apex atoms) and HS3 (above one atom far from the apex atoms). Our calculations show that the highest surface reactivity for pure CNCs and BNNCs at disclination angles 60°, 180° and 300° is 23.50 Debye for B41N49H10 cone and at disclination angles 120° and 240° is 15.30 Debye for C94H14 cone. For mono-hydrogenated CNCs, the highest surface reactivity is 22.17 Debye for C90H10-HS3 cone at angle 300° and for mono-hydrogenated BNNCs the highest surface reactivity is 28.97 Debye for B41N49H10-HS1 cone when the hydrogen atom is adsorbed on boron atom at cone angle 240°.展开更多
The A1N nanostructures with a wide band-gap of 6.28 eV are considered as ideal cold cathode materials because of their low electron-affinity. Many methods have been devoted to fabricating A1N nanostructures, but high ...The A1N nanostructures with a wide band-gap of 6.28 eV are considered as ideal cold cathode materials because of their low electron-affinity. Many methods have been devoted to fabricating A1N nanostructures, but high growth temperature over 800℃ and the use of the catalysts in most methods limit their practical application and result in their poor field-emission behaviours in uniformity. This paper reports that without any catalysts, a simple chemical vapour deposition method is used to synthesize aligned A1N nanocone arrays at 550℃ on silicon substrate or indium tin oxide glass. Field emission measurements show that these nanocones prepared at low temperature have an average turn-on field of 6 V/μm and a threshold field of 11.7 V/μm as well as stable emission behaviours at high field, which suggests that they have promising applications in field emission area.展开更多
Based on the nanostructured surface model that the (platinum, Pt) nanocones grow out symmetrically from a plane substrate, the local electric field near the conical nanoparticle surface is computed and discussed. On...Based on the nanostructured surface model that the (platinum, Pt) nanocones grow out symmetrically from a plane substrate, the local electric field near the conical nanoparticle surface is computed and discussed. On the basis of these results, the adsorbed CO molecules are modelled as dipoles, and three kinds of interactions, i.e. interactions between dipoles and local electric field, between dipoles and dipoles, as well as between dipoles and nanostructured substrate, are taken into account. The spatial configuration of CO molecules adsorbed on the nanocone surface is then given by Monte-Carlo simulation. Our results show that the CO molecules adsorbed on the nanocone surface cause local agglomeration under the action of an external electric field, and this agglomeration becomes more compact with decreasing conical angle, which results in a stronger interaction among molecules. These results serve as a basis for explaining abnormal phenomena such as the abnormal infrared effect (AIRE), which was found when CO molecules were adsorbed on the nanostructured transition-metal surface.展开更多
Single crystalline boron nanocones are prepared by using a simple spin spread method in which Fe3O4 nanoparticles are pre-manipulated on Si(lll) to form catalyst patterns of different densities. The density of boron...Single crystalline boron nanocones are prepared by using a simple spin spread method in which Fe3O4 nanoparticles are pre-manipulated on Si(lll) to form catalyst patterns of different densities. The density of boron nanocones can be tuned by changing the concentration of catalyst nanoparticles. High-resolution transmission electron microscopy analysis shows that the boron nanocone has a β-tetragonal structure with good crystallization. The field emission behaviour is optimal when the spacing distance is close to the nanocone length, which indicates that this simple spin spread method has great potential applications in electron emission nanodevices.展开更多
The formation mechanism of nanocone structure on silicon(Si)surface irradiated by helium plasma has been investigated by experiments and simulations.Impurity(molybdenum)aggregated as shields on Si was found to be a ke...The formation mechanism of nanocone structure on silicon(Si)surface irradiated by helium plasma has been investigated by experiments and simulations.Impurity(molybdenum)aggregated as shields on Si was found to be a key factor to form a high density of nanocone in our previous study.Here to concrete this theory,a simulation work has been developed with SURO code based on the impurity concentration measurement of the nanocones by using electron dispersive x-ray spectroscopy.The formation process of the nanocone from a flat surface was presented.The modeling structure under an inclining ion incident direction was in good agreement with the experimental result.Moreover,the redeposition effect was proposed as another important process of nanocone formation based on results from the comparison of the cone diameter and sputtering yield between cases with and without the redeposition effect.展开更多
Based on the nanostructured surface model,where conical nanoparticle arrays grow out symmetrically from a plane metal substrate,a theoretical model of the local electric potential near nanocones is built when a unifor...Based on the nanostructured surface model,where conical nanoparticle arrays grow out symmetrically from a plane metal substrate,a theoretical model of the local electric potential near nanocones is built when a uniform external electric field is applied.In terms of this model,the electric potential distribution near the nanocone arrays is obtained and given by a curved surface using a numerical computation method.The computational results show that the electric potential distribution near the nanocone arrays exhibit an obvious geometrical symmetry.These results could serve as a basis for explaining many abnormal phenomena,such as the abnormal infrared effects(AIREs) which are found on nanostructured metal surfaces,as well as a reference for investigating the applications of nanomaterials,such as nanoelectrodes and nanosensors.展开更多
The low-energy electronic states and energy gaps of carbon nanocones in an electric field are studied using a single-?-band tight-binding model. The analysis considers five perfect carbon nanocones with disclination a...The low-energy electronic states and energy gaps of carbon nanocones in an electric field are studied using a single-?-band tight-binding model. The analysis considers five perfect carbon nanocones with disclination angles of 60°, 120°, 180°, 240° and 300°, respectively. The numerical results reveal that the low-energy electronic states and energy gaps of a carbon nanocones are highly sensitive to its geometric shape(i.e. the disclination angle and height), and to the direction and magnitude of an electric field. The electric field causes a strong modulation of the state energies and energy gaps of the nanocones, changes their Fermi levels, and induces zero-gap transitions. The energy-gap modulation effect becomes particularly pronounced at higher strength of the applied electric field, and is strongly related to the geometric structure of the nanocone.展开更多
In this work,a simple and economic route was presented to fabricate an anti-icing superhydrophobic surface with nanocone structures,which were constructed only by one-step facile method of hydrothermal treatment with ...In this work,a simple and economic route was presented to fabricate an anti-icing superhydrophobic surface with nanocone structures,which were constructed only by one-step facile method of hydrothermal treatment with zinc acetate on the aluminum substrate.After modifying with fluoroalkylsilane (FAS-17),the nanocone structures with the appropriate size could induce the high superhydrophobicity with the water contact angle reaching 160.2° ± 0.4° and the sliding angle only being 1 ° ± 0.5°.Under the dynamic environments,the impact droplets could rapidly bounced off the surface with the shorter contact time of^1 0.6 ms,and it was mainly attributing to lower capillary adhesive force (water adhesion force of 4.1 μN) induced by the open system of nanocone structures.Furthermore,the superhydrophobic nanocone surfaces were verified to be a promising anti-icing/icephobic materials,on which the water droplets needed to spend the time of ~517 s to complete the entire freezing process at-10 ℃,displaying the increased ~50 times of icing-delay performance comparing with untreated substrate.Even if ice finally was formed on the superhydrophobic nanocone surfaces,it could be easily removed away with lower ice adhesion of^45 kPa.The repeatable measurement of ice adhesion strength on the same place of the superhydrophobic surface is still far less than the surface ice adhesion of smooth substrate,exhibiting better stability.展开更多
Large-scale oriented ZnO nanocone arrays were directly grown on zinc substrate through a hydro-thermal reaction of Zn foil with aqueous butylamine solution(3 mol/L) at 100-180 ℃ for 12 h.The syn-thesized products wer...Large-scale oriented ZnO nanocone arrays were directly grown on zinc substrate through a hydro-thermal reaction of Zn foil with aqueous butylamine solution(3 mol/L) at 100-180 ℃ for 12 h.The syn-thesized products were characterized with X-ray diffraction,Raman spectrum,scanning electron mi-croscopy and transmission electron microscopy.The results showed that the ZnO nanocones were single crystalline with the wurtzite structure and grown along the [0001] direction.The diameter of nanocones is decreased with increasing the reaction temperature.A possible growth mechanism was also proposed to account for the formation of the ZnO nanocone arrays.The photoluminescence spectra of the ZnO nanocone arrays were studied at room temperature,two UV emission bands at 377 and 396 nm assigned to free exciton emission and exciton-exciton collision,respectively,and phonon replicas associated with 2-E2 phonon were observed in the PL spectra.展开更多
Plasmon induced hot electrons have attracted a great deal of interest as a novel route for photodetection and lightenergy harvesting. Herein, we report a hot electron photodetector in which a large array of nanocones ...Plasmon induced hot electrons have attracted a great deal of interest as a novel route for photodetection and lightenergy harvesting. Herein, we report a hot electron photodetector in which a large array of nanocones deposited sequentially with aluminum, titanium dioxide, and gold films can be integrated functionally with nanophotonics and microelectronics. The device exhibits a strong photoelectric response at around 620 nm with a responsivity of 180 μA/W under short-circuit conditions with a significant increase under 1 V reverse bias to 360 μA/W. The increase in responsivity and a red shift in the peak value with increasing bias voltage indicate that the bias causes an increase in the hot electron tunneling effect. Our approach will be advantageous for the implementation of the proposed architecture on a vast variety of integrated optoelectronic devices.展开更多
In this research, polypyrrole nanocone arrays doped with β-Naphthalene sulphonic acid (PPy-NSA) were built. This film was expected to control protein adsorption and bacterial adhesion by potential-induced reversibl...In this research, polypyrrole nanocone arrays doped with β-Naphthalene sulphonic acid (PPy-NSA) were built. This film was expected to control protein adsorption and bacterial adhesion by potential-induced reversibly redox. The scanning Kelvin probe microscopy (SKPM) and surface contact angles (SCA) tests suggested that the surface potential and wettability of PPy-NSA nanocone arrays could be controlled by simply controlling its redox property via applying potential. The controllable surface potential and wettability in return controlled the adsorption of protein and adhesion of bacteria. The proposed material might find application in the preparation of smart biomaterial surfaces that can regulate proteins and bacterial adhesion by a simple potential switching.展开更多
ZnO nanocone arrays(NCAs)decorated with black TiO2 nanoparticles(BTiO2 NPs)were uniformly anchored on the surface of carbon cloth(CC)directly by a simply electrochemical deposition method.Thus a novel B-TiO2 NPs/ZnO N...ZnO nanocone arrays(NCAs)decorated with black TiO2 nanoparticles(BTiO2 NPs)were uniformly anchored on the surface of carbon cloth(CC)directly by a simply electrochemical deposition method.Thus a novel B-TiO2 NPs/ZnO NCAs-CC hierarchical heterostructure was formed.It displayed superior performance and achieved a higher photocurrent over 0.4 mA·cm^-2 before the onset of the dark current,attributed to the separation of the photogenerated electron-hole pair.Based on the B-TiO2 NPs/ZnO NCAs-CC heterostructure,the catalyst was fabricated for promoting the separation of charge carriers.Moreover,the introduction of Ti^3+ and oxygen vacancies on the surface of TiO2 NPs expanded the absorption band edge and enhanced the electrical conductivity as well as the charge transportation on the catalytic surface.It indicates that the B-TiO2 NPs/ZnO NCAs-CC composite is beneficial to the improvement of the photoelectrochemical(PEC)activity.展开更多
Plasmon coupling is an essential strategy to realize strong local electromagnetic(EM)field which is crucial for high-performance plasmonic devices.In this work,multiple plasmon couplings are demonstrated in three-dime...Plasmon coupling is an essential strategy to realize strong local electromagnetic(EM)field which is crucial for high-performance plasmonic devices.In this work,multiple plasmon couplings are demonstrated in three-dimensional(3D)hybrid plasmonic systems composed of polydimethylsiloxane-supported ordered silver nanocone(AgNC)arrays decorated with high-density gold nanoparticles(AuNPs)which are fabricated by a template-assisted physical vapor deposition process.Strong interparticle coupling,particle-film coupling,inter-cone coupling,and particle-cone coupling are revealed by numerical simulations in such composite nanostructures,which produce intense and high-density EM hot spots,boosting highly sensitive and reproducible surface enhanced Raman scattering(SERS)detection with an enhancement factor of-1.74×10^(8).Furthermore,a linear correlation between logarithmic Raman intensity and logarithmic concentration of probe molecules is observed in a large concentration range.These results offer new ideas to develop novel plasmonic devices,and provide alternative strategy to realize flexible and high-performance SERS sensors for trace molecule detection and quantitative analysis.展开更多
By pre-treating substrate with different methods and patterning the catalyst, selective and patterned growth of diamond and graphitic nano-structured carbon films have been realized through DC Plasma-Enhanced Hot Fila...By pre-treating substrate with different methods and patterning the catalyst, selective and patterned growth of diamond and graphitic nano-structured carbon films have been realized through DC Plasma-Enhanced Hot Filament Chemical Vapor Deposition (PE-HFCVD). Through two-step processing in an HFCVD reactor, novel nano-structured composite diamond films containing a nanocrystalline diamond layer on the top of a nanocone diamond layer have been synthesized. Well-aligned carbon nanotubes, diamond and graphitic carbon nanocones with controllable alignment orientations have been synthesized by using PE-HFCVD. The orientation of the nanostructures can be controlled by adjusting the working pressure. In a Microwave Plasma Enhanced Chemical Vapor Deposition (MW-PECVD) reactor, high-quality diamond films have been synthesized at low temperatures (310℃-550℃) without adding oxygen or halogen gas in a newly developed processing technique. In this process, carbon source originates from graphite etching, instead of hydrocarbon. The lowest growth temperature for the growth of nanocrystalline diamond films with a reasonable growth rate without addition of oxygen or halogen is 260℃.展开更多
The preparation and electrical properties of diamond nanocones are reviewed, including a maskless etching pro- cess and mechanism of large-area diamond conical nanostructure arrays using a hot filament chemical vapor ...The preparation and electrical properties of diamond nanocones are reviewed, including a maskless etching pro- cess and mechanism of large-area diamond conical nanostructure arrays using a hot filament chemical vapor deposition (HFCVD) system with negatively biased substrates, and the field electron emission, gas sensing, and quantum transport properties of a diamond nanocone array or an individual diamond nanocone. Optimal cone aspect ratio and array density are investigated, along with the relationships between the cone morphologies and experimental parameters, such as the CH4/H2 ratio of the etching gas, the bias current, and the gas pressure. The reviewed experiments demonstrate the possi- bility of using nanostructured diamond cones as a display device element, a point electron emission source, a gas sensor or a quantum device.展开更多
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.61176108 and 61774060)the Science and Technology Commission of Shanghai Municipality(Grant No.18DZ2270800)+1 种基金the City University of Hong Kong Strategic Research Grant(SRG)(Grant No.7005505)the support of the Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry(Grant No.[2015]-1098)。
文摘Flexible quasi-solid zinc-ion batteries(ZIBs)have large potential in power applications due to the low price,wearable nature,safety,and high capacity.However,the use of transition metal sulfide cathodes in ZIBs has not been studied extensively and the underlying mechanism and theoretical basis of this type of batteries are not well understood.Herein,a highly active cobalt-doped Ni_(3)S_(2) porous nanocone framework(C12NS)is designed and demonstrated as a zinc-ion battery electrode.First-principles calculation and experiments reveal that the cobalt dopant improves the battery properties greatly.The assembled flexible zinc-ion battery exhibits a high specific capacity of 453.3 mAh g^(−1)at a current density of 0.4 A g^(−1)in as well as excellent cycling stability as manifested by a capacity retention ratio of 89.5%at a current density of 4 A g^(−1)after 5000 cycles.The peak energy density of 553.9 Wh kg^(−1)is also superior to those of most recently reported NiCo-based zinc-ion batteries.More importantly,the flexible battery can be operated under severe mechanical bending and even continues to work after physical puncturing without showing leakage.These exciting results not only reveal a novel design of cathode materials for zinc-based batteries,but also suggest their immense commercial potential in portable and wearable electronics.
基金Project supported in part by the National 863 (Grant No 2007AA03Z305)973 (Grant No 2007CB935503) Projects+1 种基金the National Science Foundation of China (Grant Nos U0734003 and 60571045)China Postdoctoral Science Foundation
文摘This paper reports that a simple chemical vapour deposition method has been adopted to fabricate large scale, high density boron nanocones with thermal evaporation of B/B2O3 powders precursors in an Ar/H2 gas mixture at the synthesis temperature of 1000-1200℃. The lengths of boron nanocones are several micrometres, and the diameters of nanocone tops are in a range of 50-100 nm. transmission electron microscopy and selected area electron diffraction indicate that the nanocones are single crystalline α-tetragonal boron. The vapour liquid solid mechanism is the main formation mechanism of boron nanocones. One broad photolumineseence emission peak at the central wavelength of about 650 nm is observed under the 532 nm light excitation. Boron nanocones with good photoluminescence properties are promising candidates for applications in optical emitting devices.
基金supported by the National Natural Science Foundation of China (11072157 and 10932006)the Program for Changjiang Scholars and Innovative Research Team in University(IRT0971)
文摘Carbon nanocones have quite fascinating elec- tronic and structural properties, whose axial vibration is sel- dom investigated in previous studies. In this paper, based on a nonlocal elasticity theory, a nonuniform rod model is ap- plied to investigate the small-scale effect and the nonuniform effect on axial vibration of nanocones. Using the modified Wentzel-Brillouin-Kramers (WBK) method, an asymptotic solution is obtained for the axial vibration of general nonuni- form nanorods. Then, using similar procedure, the axial vi- bration of nanocones is analyzed for nonuniform parameters, mode number and nonlocal parameters. Explicit expressions are derived for mode frequencies of clamped-clamped and clamped-free boundary conditions. It is found that axial vi- bration frequencies are highly overestimated by the classical rod model because of ignorance of the effect of small length scale.
文摘A systematic computational study of surface reactivity for pure and mono-hydrogenated carbon nanocoes (CNCs) formed from graphene sheets as functions of disclination angle, cone size and hydrogenation sites has been investigated through density functional (DFT) calculations and at the B3LYP/3-21G level of theory. Five disclination angles (60°, 120°, 180°, 240° and 300°) are applied and at any disclination angle four structures with different sizes are studied. For comparison, pure and mono-hydrogenated boron nitride nanocones (BNNCs) with disclination angles 60°, 120°, 180°, 240° and 300° are also investigated. The hydrogenation is done on three different sites, HS1 (above the first neighbor atom of the apex atoms), HS2 (above one atom of the apex atoms) and HS3 (above one atom far from the apex atoms). Our calculations show that the highest surface reactivity for pure CNCs and BNNCs at disclination angles 60°, 180° and 300° is 23.50 Debye for B41N49H10 cone and at disclination angles 120° and 240° is 15.30 Debye for C94H14 cone. For mono-hydrogenated CNCs, the highest surface reactivity is 22.17 Debye for C90H10-HS3 cone at angle 300° and for mono-hydrogenated BNNCs the highest surface reactivity is 28.97 Debye for B41N49H10-HS1 cone when the hydrogen atom is adsorbed on boron atom at cone angle 240°.
基金Project supported by the National Basic Research Program of China (973 Program, Grant No. 2007CB935500)863 Program (Grant No. 2007AA03Z305)+4 种基金Science Foundation for Young Scholars (Grant No. 50802117)the National Joint Science Fund with Guangdong Province (Grant Nos. U0634002 and U0734003)the Doctoral Foundation of Educational Ministry of China (Grant Nos. 20070558063 and 09lgpy28)the Science and Technology Foundation of the Educational Department of Guangdong Provincethe Science and Technology Department of Guangzhou City
文摘The A1N nanostructures with a wide band-gap of 6.28 eV are considered as ideal cold cathode materials because of their low electron-affinity. Many methods have been devoted to fabricating A1N nanostructures, but high growth temperature over 800℃ and the use of the catalysts in most methods limit their practical application and result in their poor field-emission behaviours in uniformity. This paper reports that without any catalysts, a simple chemical vapour deposition method is used to synthesize aligned A1N nanocone arrays at 550℃ on silicon substrate or indium tin oxide glass. Field emission measurements show that these nanocones prepared at low temperature have an average turn-on field of 6 V/μm and a threshold field of 11.7 V/μm as well as stable emission behaviours at high field, which suggests that they have promising applications in field emission area.
基金supported by the Natural Science Foundation of Fujian Province of China (Grant Nos C0710036 and T0750008)
文摘Based on the nanostructured surface model that the (platinum, Pt) nanocones grow out symmetrically from a plane substrate, the local electric field near the conical nanoparticle surface is computed and discussed. On the basis of these results, the adsorbed CO molecules are modelled as dipoles, and three kinds of interactions, i.e. interactions between dipoles and local electric field, between dipoles and dipoles, as well as between dipoles and nanostructured substrate, are taken into account. The spatial configuration of CO molecules adsorbed on the nanocone surface is then given by Monte-Carlo simulation. Our results show that the CO molecules adsorbed on the nanocone surface cause local agglomeration under the action of an external electric field, and this agglomeration becomes more compact with decreasing conical angle, which results in a stronger interaction among molecules. These results serve as a basis for explaining abnormal phenomena such as the abnormal infrared effect (AIRE), which was found when CO molecules were adsorbed on the nanostructured transition-metal surface.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50872147 and U0734003)the National High Technology Research and Development Program (Grant No. 2007AA03Z305)the National Basic Research Program of China(Grant No. 2007CB935503)
文摘Single crystalline boron nanocones are prepared by using a simple spin spread method in which Fe3O4 nanoparticles are pre-manipulated on Si(lll) to form catalyst patterns of different densities. The density of boron nanocones can be tuned by changing the concentration of catalyst nanoparticles. High-resolution transmission electron microscopy analysis shows that the boron nanocone has a β-tetragonal structure with good crystallization. The field emission behaviour is optimal when the spacing distance is close to the nanocone length, which indicates that this simple spin spread method has great potential applications in electron emission nanodevices.
基金supported in part by a Grant-in Aid for Scientific Research (Nos.17KK0132, 19H01874) from the Japan Society for the Promotion of Science (JSPS)supported by National MCF Energy R&D Program of China (Nos.2018YFE0311100 and 2018YFE0303105)National Natural Science Foundation of China (No.12075047)
文摘The formation mechanism of nanocone structure on silicon(Si)surface irradiated by helium plasma has been investigated by experiments and simulations.Impurity(molybdenum)aggregated as shields on Si was found to be a key factor to form a high density of nanocone in our previous study.Here to concrete this theory,a simulation work has been developed with SURO code based on the impurity concentration measurement of the nanocones by using electron dispersive x-ray spectroscopy.The formation process of the nanocone from a flat surface was presented.The modeling structure under an inclining ion incident direction was in good agreement with the experimental result.Moreover,the redeposition effect was proposed as another important process of nanocone formation based on results from the comparison of the cone diameter and sputtering yield between cases with and without the redeposition effect.
基金Project supported by the Natural Science Foundation of Fujian Province,China (Grant Nos. 2010J01210,B509043A,and2011J05006)
文摘Based on the nanostructured surface model,where conical nanoparticle arrays grow out symmetrically from a plane metal substrate,a theoretical model of the local electric potential near nanocones is built when a uniform external electric field is applied.In terms of this model,the electric potential distribution near the nanocone arrays is obtained and given by a curved surface using a numerical computation method.The computational results show that the electric potential distribution near the nanocone arrays exhibit an obvious geometrical symmetry.These results could serve as a basis for explaining many abnormal phenomena,such as the abnormal infrared effects(AIREs) which are found on nanostructured metal surfaces,as well as a reference for investigating the applications of nanomaterials,such as nanoelectrodes and nanosensors.
基金supported in part by the National Science Council of Taiwan under Grant Nos.NSC 96-2221-E-492-007-MY3 and NSC 98-2221-E-006-131-MY3National Center for Theoretical Science(NCTS)in Taiwan
文摘The low-energy electronic states and energy gaps of carbon nanocones in an electric field are studied using a single-?-band tight-binding model. The analysis considers five perfect carbon nanocones with disclination angles of 60°, 120°, 180°, 240° and 300°, respectively. The numerical results reveal that the low-energy electronic states and energy gaps of a carbon nanocones are highly sensitive to its geometric shape(i.e. the disclination angle and height), and to the direction and magnitude of an electric field. The electric field causes a strong modulation of the state energies and energy gaps of the nanocones, changes their Fermi levels, and induces zero-gap transitions. The energy-gap modulation effect becomes particularly pronounced at higher strength of the applied electric field, and is strongly related to the geometric structure of the nanocone.
基金the National Natural Science Foundation of China (Nos.51671105 and 51705244)the National Postdoctoral Program for Innovative Talents (BX201600073)+4 种基金the Project Funded by China Postdoctoral Science Foundation (2017M610329)the Natural Science Foundation of Jiangsu Province (No. BK20170790)Jiangsu Planned Projects for Postdoctoral Research Funds (No.1701200B)General Project of Zhejiang Provincial Department of Education (Y201737320)the NUAA Innovation Program for Graduate Education (kfjj20170608,kfjj20180609).
文摘In this work,a simple and economic route was presented to fabricate an anti-icing superhydrophobic surface with nanocone structures,which were constructed only by one-step facile method of hydrothermal treatment with zinc acetate on the aluminum substrate.After modifying with fluoroalkylsilane (FAS-17),the nanocone structures with the appropriate size could induce the high superhydrophobicity with the water contact angle reaching 160.2° ± 0.4° and the sliding angle only being 1 ° ± 0.5°.Under the dynamic environments,the impact droplets could rapidly bounced off the surface with the shorter contact time of^1 0.6 ms,and it was mainly attributing to lower capillary adhesive force (water adhesion force of 4.1 μN) induced by the open system of nanocone structures.Furthermore,the superhydrophobic nanocone surfaces were verified to be a promising anti-icing/icephobic materials,on which the water droplets needed to spend the time of ~517 s to complete the entire freezing process at-10 ℃,displaying the increased ~50 times of icing-delay performance comparing with untreated substrate.Even if ice finally was formed on the superhydrophobic nanocone surfaces,it could be easily removed away with lower ice adhesion of^45 kPa.The repeatable measurement of ice adhesion strength on the same place of the superhydrophobic surface is still far less than the surface ice adhesion of smooth substrate,exhibiting better stability.
基金Supported by the National Natural Science Foundation of China (Grant No. 20573072)Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20060718010)
文摘Large-scale oriented ZnO nanocone arrays were directly grown on zinc substrate through a hydro-thermal reaction of Zn foil with aqueous butylamine solution(3 mol/L) at 100-180 ℃ for 12 h.The syn-thesized products were characterized with X-ray diffraction,Raman spectrum,scanning electron mi-croscopy and transmission electron microscopy.The results showed that the ZnO nanocones were single crystalline with the wurtzite structure and grown along the [0001] direction.The diameter of nanocones is decreased with increasing the reaction temperature.A possible growth mechanism was also proposed to account for the formation of the ZnO nanocone arrays.The photoluminescence spectra of the ZnO nanocone arrays were studied at room temperature,two UV emission bands at 377 and 396 nm assigned to free exciton emission and exciton-exciton collision,respectively,and phonon replicas associated with 2-E2 phonon were observed in the PL spectra.
基金National Natural Science Foundation of China(NSFC)(61675171,61675169,61522507)Fundamental Research Funds for the Central Universities of China(3102017HQZZ022,3102017zy021)Shaanxi Provincical Key R&D Program(2018KW-009)
文摘Plasmon induced hot electrons have attracted a great deal of interest as a novel route for photodetection and lightenergy harvesting. Herein, we report a hot electron photodetector in which a large array of nanocones deposited sequentially with aluminum, titanium dioxide, and gold films can be integrated functionally with nanophotonics and microelectronics. The device exhibits a strong photoelectric response at around 620 nm with a responsivity of 180 μA/W under short-circuit conditions with a significant increase under 1 V reverse bias to 360 μA/W. The increase in responsivity and a red shift in the peak value with increasing bias voltage indicate that the bias causes an increase in the hot electron tunneling effect. Our approach will be advantageous for the implementation of the proposed architecture on a vast variety of integrated optoelectronic devices.
基金the financial support of the National Basic Research Program of China (Grant No. 2012CB619100)the National High Technology Research and Development Program of China (863 Program, Grant No. 2015AA033502)+2 种基金the National Natural Science Foundation of China (Grant Nos. 51372087, 51072055 and 51232002)the Science and Technology Planning Project of Guangdong Province, China (Grant No. 2014A010105048)the State Key Laboratory for Mechanical Behavior of Materials, China (Grant No. 20141607)
文摘In this research, polypyrrole nanocone arrays doped with β-Naphthalene sulphonic acid (PPy-NSA) were built. This film was expected to control protein adsorption and bacterial adhesion by potential-induced reversibly redox. The scanning Kelvin probe microscopy (SKPM) and surface contact angles (SCA) tests suggested that the surface potential and wettability of PPy-NSA nanocone arrays could be controlled by simply controlling its redox property via applying potential. The controllable surface potential and wettability in return controlled the adsorption of protein and adhesion of bacteria. The proposed material might find application in the preparation of smart biomaterial surfaces that can regulate proteins and bacterial adhesion by a simple potential switching.
基金the National Natural Science Foundation of China(Grant Nos.51662036 and 61704114)the Open Foundation of Engineering Research Center of Materials-Oriented Chemical Engineering of Xinjiang Bintuan(2016BTRC005)the Graduate Student Scientific Research Innovation Projects in Xinjiang Autonomous Region,China(XJGRI2017046).
文摘ZnO nanocone arrays(NCAs)decorated with black TiO2 nanoparticles(BTiO2 NPs)were uniformly anchored on the surface of carbon cloth(CC)directly by a simply electrochemical deposition method.Thus a novel B-TiO2 NPs/ZnO NCAs-CC hierarchical heterostructure was formed.It displayed superior performance and achieved a higher photocurrent over 0.4 mA·cm^-2 before the onset of the dark current,attributed to the separation of the photogenerated electron-hole pair.Based on the B-TiO2 NPs/ZnO NCAs-CC heterostructure,the catalyst was fabricated for promoting the separation of charge carriers.Moreover,the introduction of Ti^3+ and oxygen vacancies on the surface of TiO2 NPs expanded the absorption band edge and enhanced the electrical conductivity as well as the charge transportation on the catalytic surface.It indicates that the B-TiO2 NPs/ZnO NCAs-CC composite is beneficial to the improvement of the photoelectrochemical(PEC)activity.
基金supported by the National Natural Science Foundation of China(No.51871003).
文摘Plasmon coupling is an essential strategy to realize strong local electromagnetic(EM)field which is crucial for high-performance plasmonic devices.In this work,multiple plasmon couplings are demonstrated in three-dimensional(3D)hybrid plasmonic systems composed of polydimethylsiloxane-supported ordered silver nanocone(AgNC)arrays decorated with high-density gold nanoparticles(AuNPs)which are fabricated by a template-assisted physical vapor deposition process.Strong interparticle coupling,particle-film coupling,inter-cone coupling,and particle-cone coupling are revealed by numerical simulations in such composite nanostructures,which produce intense and high-density EM hot spots,boosting highly sensitive and reproducible surface enhanced Raman scattering(SERS)detection with an enhancement factor of-1.74×10^(8).Furthermore,a linear correlation between logarithmic Raman intensity and logarithmic concentration of probe molecules is observed in a large concentration range.These results offer new ideas to develop novel plasmonic devices,and provide alternative strategy to realize flexible and high-performance SERS sensors for trace molecule detection and quantitative analysis.
文摘By pre-treating substrate with different methods and patterning the catalyst, selective and patterned growth of diamond and graphitic nano-structured carbon films have been realized through DC Plasma-Enhanced Hot Filament Chemical Vapor Deposition (PE-HFCVD). Through two-step processing in an HFCVD reactor, novel nano-structured composite diamond films containing a nanocrystalline diamond layer on the top of a nanocone diamond layer have been synthesized. Well-aligned carbon nanotubes, diamond and graphitic carbon nanocones with controllable alignment orientations have been synthesized by using PE-HFCVD. The orientation of the nanostructures can be controlled by adjusting the working pressure. In a Microwave Plasma Enhanced Chemical Vapor Deposition (MW-PECVD) reactor, high-quality diamond films have been synthesized at low temperatures (310℃-550℃) without adding oxygen or halogen gas in a newly developed processing technique. In this process, carbon source originates from graphite etching, instead of hydrocarbon. The lowest growth temperature for the growth of nanocrystalline diamond films with a reasonable growth rate without addition of oxygen or halogen is 260℃.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51272278, 11174362, and 91023041)the National Basic Research Program of China (Grant No. 2009CB930502)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KJCX2-EW-W02)
文摘The preparation and electrical properties of diamond nanocones are reviewed, including a maskless etching pro- cess and mechanism of large-area diamond conical nanostructure arrays using a hot filament chemical vapor deposition (HFCVD) system with negatively biased substrates, and the field electron emission, gas sensing, and quantum transport properties of a diamond nanocone array or an individual diamond nanocone. Optimal cone aspect ratio and array density are investigated, along with the relationships between the cone morphologies and experimental parameters, such as the CH4/H2 ratio of the etching gas, the bias current, and the gas pressure. The reviewed experiments demonstrate the possi- bility of using nanostructured diamond cones as a display device element, a point electron emission source, a gas sensor or a quantum device.