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
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
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
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
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
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
Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrat...Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrate based on nanocone forests.The substrates are prepared by using plasma treatment technique,which is a simple,fast and high-throughput approach.The SERS substrate based on nanocone forests exhibits high sensitivity.In the experiment,miRNA with a concentration as low as 10-10 M can be achieved.Meanwhile,the proposed SERS substrate shows a high uniformity over a large area.These experimental results demonstrate great potential of the 3D SERS substrate in wide applications.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
Large-scale oriented ZnO nanocone arrays were directly grown on zinc substrate through a hydrothermal reaction of Zn foil with aqueous butylamine solution (3 mol/L) at 100–180 °C for 12 h. The synthesized produc...Large-scale oriented ZnO nanocone arrays were directly grown on zinc substrate through a hydrothermal reaction of Zn foil with aqueous butylamine solution (3 mol/L) at 100–180 °C for 12 h. The synthesized products were characterized with X-ray diffraction, Raman spectrum, scanning electron microscopy 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
Nanostructured surface is a promising photon management strategy to tune spectrum in design of the selective solar absorber.In this paper,we propose a nanocone structured surface as a perfect solar absorber in applica...Nanostructured surface is a promising photon management strategy to tune spectrum in design of the selective solar absorber.In this paper,we propose a nanocone structured surface as a perfect solar absorber in application of the solar thermoelectric generators(STEGs).The trade-off between the solar absorption and the mid-infrared emission is obtained to maximize the STEG efficiency.The effects of the geometric parameters,thermal concentration,incident angle and polarized state as well as the lattice arrangement are systematically investigated.The results show that the STEGs equipped with our proposed selective solar absorber can achieve a peak efficiency of 6.53%under AM1.5G condition(no optical concentration).Furthermore,the selective solar absorber exhibits insensitive behavior to the incident angle and polarization angle as well.This means that the proposed selective solar absorber can utilize solar energy as much as possible and be generally suitable in equipping the STEGs without optical concentration.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
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
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
The uneven deposition of lithium(Li) on current collectors causes serious dendrite growth and volume expansion. Commercial foamed copper(Cu) current collectors are unsuitable for Li anodes because of their large volum...The uneven deposition of lithium(Li) on current collectors causes serious dendrite growth and volume expansion. Commercial foamed copper(Cu) current collectors are unsuitable for Li anodes because of their large volume and mass and lithiophobic nature. Herein, a three-dimensional(3 D) copper@tin(Cu@Sn) nanocone current collector with small volume, light weight, and lithiophilic nature was prepared by a simple electrodeposition method. The synergy of the nanoconical structure and lithiophilic Sn promotes the even deposition of Li and effectively inhibits the formation of Li dendrites. The resultant half batteries exhibit high Coulombic efficiency of 97.6% after 100 cycles at 1 mA cm^(-2), and the symmetrical Li battery demonstrates a prolonged lifespan of over 600 h at 1 mA cm^(-2). The full battery based on organic liquid electrolyte with LiFePO_(4) also exhibits a long lifespan of 550 cycles with high capacity retention of 95.1% at 1 C.Moreover, 3 D Cu@Sn nanocone-based solid-state batteries exhibit excellent electrochemical performance and show no decay after 500 cycles at 1 C. Our work provides a strategy for fabricating 3 D current collectors for high-energy-density Li metal batteries.展开更多
Periodic metal nanoarrays serving as cavities can support directional-tunable amplified spontaneous emission that goes beyond the diffraction limit due to the hybrid states of surface plasmons and Bloch surface waves....Periodic metal nanoarrays serving as cavities can support directional-tunable amplified spontaneous emission that goes beyond the diffraction limit due to the hybrid states of surface plasmons and Bloch surface waves.Most of these modes'interactions remain within the weak coupling regime,yet strong coupling is also anticipated to occur.In this work,we present an intriguing case of amplified spontaneous emission(ASE),amplified by the splitting upper polariton mode within a strong coupling system,stemming from a square lattice of plasmonic cone lattices(PCLs).The PCLs are fabricated using an anodized aluminum oxide membrane(AAO),which facilitates strong coupling between surface plasmons and Bloch surface wave modes,with the maximum Rabi splitting observed at 0.258 eV for the sample with an aspect ratio of 0.33.A 13.5-fold increase in amplified spontaneous emission is recorded when the emission from Nile Red coincides with this flat energy branch of upper polariton,which exhibits a high photon density of states.Reduced group velocity can prolong photon lifetime and boost the probability of light-matter interaction.The observed ASE phenomenon in this strong coupling plasmonic system widens the scope for applications in nanolasing and polariton lasing.展开更多
The utilization of nanostructures with diverse geometric shapes is essential for manipulating the energy of electromagnetic(EM) fields and achieving various applications in optics, such as nanofocusing. The plasmonic ...The utilization of nanostructures with diverse geometric shapes is essential for manipulating the energy of electromagnetic(EM) fields and achieving various applications in optics, such as nanofocusing. The plasmonic cone structure is highly representative in the field of nanofocusing applications, effectively guiding EM field energy to the tip of the cone and resulting in high local electric field and temperature effects. In certain chemical catalytic applications, an elevated temperature and a larger surface area may be required to enhance catalysis reactions. Here, we propose a hollow gold nanocone structure that can achieve higher temperature both at the tip and within its hollow region under the excitation of an EM field.Through rigorous finite element method(FEM) simulations, we investigated the EM field and temperature distribution of the hollow cone at various cone angles and identified those angles that yield higher local temperatures. Additionally, the analysis of the scattering cross section of hollow cones reveals that the presence of electric dipole component of the EM field corresponds to Fabry–Perot-like(FP-like) resonance in short wavelengths(600 nm–1200 nm), which predominantly contributes to the temperature localization. These findings provide novel insights into utilizing conical nanostructures for applications such as catalysis.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 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 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.
文摘Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrate based on nanocone forests.The substrates are prepared by using plasma treatment technique,which is a simple,fast and high-throughput approach.The SERS substrate based on nanocone forests exhibits high sensitivity.In the experiment,miRNA with a concentration as low as 10-10 M can be achieved.Meanwhile,the proposed SERS substrate shows a high uniformity over a large area.These experimental results demonstrate great potential of the 3D SERS substrate in wide applications.
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 hydrothermal reaction of Zn foil with aqueous butylamine solution (3 mol/L) at 100–180 °C for 12 h. The synthesized products were characterized with X-ray diffraction, Raman spectrum, scanning electron microscopy 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supported by the National Natural Science Foundation of China(Grant No.51336003)the 333 Scientific Research Project of Jiangsu Province(Grant No.BRA2011134)
文摘Nanostructured surface is a promising photon management strategy to tune spectrum in design of the selective solar absorber.In this paper,we propose a nanocone structured surface as a perfect solar absorber in application of the solar thermoelectric generators(STEGs).The trade-off between the solar absorption and the mid-infrared emission is obtained to maximize the STEG efficiency.The effects of the geometric parameters,thermal concentration,incident angle and polarized state as well as the lattice arrangement are systematically investigated.The results show that the STEGs equipped with our proposed selective solar absorber can achieve a peak efficiency of 6.53%under AM1.5G condition(no optical concentration).Furthermore,the selective solar absorber exhibits insensitive behavior to the incident angle and polarization angle as well.This means that the proposed selective solar absorber can utilize solar energy as much as possible and be generally suitable in equipping the STEGs without optical concentration.
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.
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 (51771094 and 21835004)the National Key R&D Program of China (2016YFB0901500)+1 种基金the Ministry of Education of China (B12015 and IRT13R30)Tianjin Natural Science Foundation (18JCZDJC31500)。
文摘The uneven deposition of lithium(Li) on current collectors causes serious dendrite growth and volume expansion. Commercial foamed copper(Cu) current collectors are unsuitable for Li anodes because of their large volume and mass and lithiophobic nature. Herein, a three-dimensional(3 D) copper@tin(Cu@Sn) nanocone current collector with small volume, light weight, and lithiophilic nature was prepared by a simple electrodeposition method. The synergy of the nanoconical structure and lithiophilic Sn promotes the even deposition of Li and effectively inhibits the formation of Li dendrites. The resultant half batteries exhibit high Coulombic efficiency of 97.6% after 100 cycles at 1 mA cm^(-2), and the symmetrical Li battery demonstrates a prolonged lifespan of over 600 h at 1 mA cm^(-2). The full battery based on organic liquid electrolyte with LiFePO_(4) also exhibits a long lifespan of 550 cycles with high capacity retention of 95.1% at 1 C.Moreover, 3 D Cu@Sn nanocone-based solid-state batteries exhibit excellent electrochemical performance and show no decay after 500 cycles at 1 C. Our work provides a strategy for fabricating 3 D current collectors for high-energy-density Li metal batteries.
基金financial supports from National Natural Science Foundation of China(No.61905051)Natural Science Foundation of Heilongjiang Province(No.LH2020F027).
文摘Periodic metal nanoarrays serving as cavities can support directional-tunable amplified spontaneous emission that goes beyond the diffraction limit due to the hybrid states of surface plasmons and Bloch surface waves.Most of these modes'interactions remain within the weak coupling regime,yet strong coupling is also anticipated to occur.In this work,we present an intriguing case of amplified spontaneous emission(ASE),amplified by the splitting upper polariton mode within a strong coupling system,stemming from a square lattice of plasmonic cone lattices(PCLs).The PCLs are fabricated using an anodized aluminum oxide membrane(AAO),which facilitates strong coupling between surface plasmons and Bloch surface wave modes,with the maximum Rabi splitting observed at 0.258 eV for the sample with an aspect ratio of 0.33.A 13.5-fold increase in amplified spontaneous emission is recorded when the emission from Nile Red coincides with this flat energy branch of upper polariton,which exhibits a high photon density of states.Reduced group velocity can prolong photon lifetime and boost the probability of light-matter interaction.The observed ASE phenomenon in this strong coupling plasmonic system widens the scope for applications in nanolasing and polariton lasing.
基金Project supported by the Science and Technology Department of Gansu Province, China (Grant No. 24RCKB011)the National Natural Science Foundation of China (Grant No. 12325511)。
文摘The utilization of nanostructures with diverse geometric shapes is essential for manipulating the energy of electromagnetic(EM) fields and achieving various applications in optics, such as nanofocusing. The plasmonic cone structure is highly representative in the field of nanofocusing applications, effectively guiding EM field energy to the tip of the cone and resulting in high local electric field and temperature effects. In certain chemical catalytic applications, an elevated temperature and a larger surface area may be required to enhance catalysis reactions. Here, we propose a hollow gold nanocone structure that can achieve higher temperature both at the tip and within its hollow region under the excitation of an EM field.Through rigorous finite element method(FEM) simulations, we investigated the EM field and temperature distribution of the hollow cone at various cone angles and identified those angles that yield higher local temperatures. Additionally, the analysis of the scattering cross section of hollow cones reveals that the presence of electric dipole component of the EM field corresponds to Fabry–Perot-like(FP-like) resonance in short wavelengths(600 nm–1200 nm), which predominantly contributes to the temperature localization. These findings provide novel insights into utilizing conical nanostructures for applications such as catalysis.
