Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power densi...Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power density.However,issues,such as the corrosion and dissolution of the Zn anode,limited wet-tability,and lack of sufficient nucleation sites for Zn plating,have limited their practical application.The introduction of a protective layer comprising of tellurium(Te)nanobelts onto the surface of Zn anode has emerged as a promising approach to overcome these limitations and improve the electrochemical behav-ior by enhancing the safety and wettability of ZIBs,as well as providing numerous nucleation sites for Zn plating.In the presence of a Te-based protective layer,the energy power density of the surface-engineered Zn anode improved significantly(ranging from 310 to 144 W h kg^(-1),over a power density range of 270 to 1,800 W kg^(-1)),and the lifespan capability was extended.These results demonstrate that the proposed strategy of employing Te nanobelts as a protective layer holds great promise for enhancing the energy storage performance of zIBs,making them even more attractive as a viable energy storage solution forthefuture.展开更多
Rechargeable Li-S batteries(LSBs)are emerging as an important alternative to lithium-ion batteries(LIBs),owing to their high energy densities and low cost;yet sluggish redox kinetics of LiPSs results in inferior cycle...Rechargeable Li-S batteries(LSBs)are emerging as an important alternative to lithium-ion batteries(LIBs),owing to their high energy densities and low cost;yet sluggish redox kinetics of LiPSs results in inferior cycle life.Herein,we prepared multifunctional self-supporting hyphae carbon nanobelt(HCNB)as hosts by carbonization of hyphae balls of Rhizopus,which could increase the S loading of the cathode without sacrificing reaction kinetics.Trace platinum(Pt)nanoparticles were introduced into HCNBs(PtHCNBs)by ion-beam sputtering deposition.Based on the X-ray photoelectron spectroscopy analyses,the introduced trace Pt regulated the local electronic states of heteroatoms in HCNBs.Electrochemical kinetics investigation combined with operando Raman measurements revealed the accelerated reaction mechanics of sulfur species.Benefiting from the synergistic catalytic effect and the unique structures,the as-prepared PtHCNB/MWNCT/S cathodes delivered a stable capacity retention of 77%for 400 cycles at 0.5 C with a sulfur loading of 4.6 mg cm^(-2).More importantly,remarkable cycling performance was achieved with an high areal S loading of 7.6 mg cm^(-2).This finding offers a new strategy to prolong the cycle life of LSBs.展开更多
High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm...High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.展开更多
Mn doped SnO2 nanobelts (Mn:SnO2 NBs) and pure SnO2 nanobelts (SnO2 NBs) were synthesized by thermal evaporation technique at 1355°C with Ar carrier gas (25 sccm, 150 Torr). The SEM, EDS, XRD, TEM, HRTEM, SAED, X...Mn doped SnO2 nanobelts (Mn:SnO2 NBs) and pure SnO2 nanobelts (SnO2 NBs) were synthesized by thermal evaporation technique at 1355°C with Ar carrier gas (25 sccm, 150 Torr). The SEM, EDS, XRD, TEM, HRTEM, SAED, XPS, UV-Vis techniques were used to characterize the attained samples. The band gap of Mn doped SnO2 NBs by UV-Vis was measured to be 3.43 eV at room temperature, lower than that of the pure counterpart with ~3.66 eV. Mn:SnO2 NB and pure SnO2 NB sensors were developed. It is found that Mn:SnO2 NB device exhibits a higher sensitivity with 62.12% to 100 ppm of ethanol at 210°C, which is the highest sensitivity among the three tested VOC gases (ethanol, ethanediol, and acetone). The theoretical detection limit for ethanol of the sensor is 1.1 ppm. The higher response is related to the selective catalysis of the doped Mn ions.展开更多
t Molecular dynamics （MD） simulations are carried out to characterize the mechanical and thermal responses of [011^-1]-oriented ZnO nanobelts with lateral dimensions of 21.22A × 18.95 A, 31.02A× 29.42 A, a...t Molecular dynamics （MD） simulations are carried out to characterize the mechanical and thermal responses of [011^-1]-oriented ZnO nanobelts with lateral dimensions of 21.22A × 18.95 A, 31.02A× 29.42 A, and40.81A ×39.89A over the temperature range of 300-1000 K. The Young＇s modulus and thermal conductivity of the nanobelts are evaluated. Significant surface effects on properties due to the highsurface-to-volume ratios of the nanobelts are observed. For the mechanical response, surface-stress-induced internal stress plays an important role. For the thermal response, surface scattering of phonons dominates. Calculations show that the Young＇s modulus is higher than the corresponding value for bulk ZnO and decreases by -33% as the lateral dimensions increase from 21.22 A × 18.95A to 40.81 A × 39.89A. The thermal conductivity is one order of magnitude lower than the corresponding value for bulk ZnO single crystal and decreases with wire size. Specifically, the conductivity of the 21.22 A × 18.95 A belt is approximately （31-18）% lower than that of the 40.81 A × 39.89 A belt over the temperature range analyzed. A significant dependence of properties on temperature is also observed, with the Young＇s modulus decreasing on average by 12% and the conductivity decreasing by 50% as temperature increases from 300 K to 1000 K.展开更多
Aqueous zinc-ion batteries(ZIBs) have been considered as one of the most promising electrochemical devices for large-scale energy storage system owing to their low cost and high safety. Herein, Na2V6O16·2.14H2O n...Aqueous zinc-ion batteries(ZIBs) have been considered as one of the most promising electrochemical devices for large-scale energy storage system owing to their low cost and high safety. Herein, Na2V6O16·2.14H2O nanobelts are synthesized and applied as cathode material for ZIBs. The sample displays a high capacity of 466 m Ahg^-1 at 100 mAg^-1 and stable cycling performance with a capacity retention of 90% over 20 0 0 cycles at the 20 Ag^-1. Moreover, Na2V6O16·2.14H2O presents a capable rate ability and a high energy density of 312 Wh kg^-1 at a specific power of 70 Wkg^-1. The superior electrochemical performance is attributed to the large interlayer spacing and outstanding structure stability, which promise the highly reversible intercalation and extraction of zinc ion. The electrochemical kinetics and zinc ion storage mechanism are also investigated. This work demonstrates that nanoscale electrode materials with large interlayer spacing can effectively enhance the electrochemical performance of aqueous ZIBs, which can be extended to other metal ion batteries, such as magnesium ion batteries and aluminum ion batteries.展开更多
The restacking hindrance of MXene films restricts their development for high volumetric energy density of flexible supercapacitors toward applications in miniature,portable,wearable or implantable electronic devices.A...The restacking hindrance of MXene films restricts their development for high volumetric energy density of flexible supercapacitors toward applications in miniature,portable,wearable or implantable electronic devices.A valid solution is construction of rational heterojunction to achieve a synergistic property enhancement.The introduction of spacers such as graphene,CNTs,cellulose and the like demonstrates limited enhancement in rate capability.The combination of currently reported pseudocapacitive materials and MXene tends to express the potential capacitance of pseudocapacitive materials rather than MXene,leading to low volumetric capacitance.Therefore,it is necessary to exploit more ideal candidate materials to couple with MXene for fully expressing both potentials.Herein,for the first time,high electrochemically active materials of ultrathin MoO3 nanobelts are intercalated into MXene films.In the composites,MoO3 nanobelts not only act as pillaring components to prevent restacking of MXene nanosheets for fully expressing the MXene pseudocapacitance in acidic environment but also provide considerable pseudocapacitive contribution.As a result,the optimal M/MoO3 electrode not only achieves a breakthrough in volumetric capacitance(1817 F cm-3 and 545 F g-1),but also maintains good rate capability and excellent flexibility.Moreover,the corresponding symmetric supercapacitor likewise shows a remarkable energy density of 44.6 Wh L-1(13.4 Wh kg-1),rendering the flexible electrode a promising candidate for application in high-energy-density energy storage devices.展开更多
Ultralong beltlike nanostructures was successfully synthesized for V6O13 crystal by ahydrothermal route. The products are characterized by means of X-ray powder diffraction,transmission electron microscopy and high-re...Ultralong beltlike nanostructures was successfully synthesized for V6O13 crystal by ahydrothermal route. The products are characterized by means of X-ray powder diffraction,transmission electron microscopy and high-resolution transmission electron microscopy. Theexperimental results give the evidence that the V6O13 nanobelts are pure, structurally uniform andsingle crystalline, with typical widths of 50 to 300 nm and lengths of up to a few millimeters.展开更多
Lead halide perovskites have received increasing attention recently as a candidate material in various optoelectronic areas because of their high performance as light absorbers.Herein,we report the growth of CsPbI_(3)...Lead halide perovskites have received increasing attention recently as a candidate material in various optoelectronic areas because of their high performance as light absorbers.Herein,we report the growth of CsPbI_(3) nanobelts via a solution process.A single-crystalline CsPbI_(3) nanobelt with uniform morphology can be achieved by controlling the amount of PbI_(2).A single-crystalline CsPbI_(3) nanobelt possesses a mean width,length,and thickness of 100 nm,5μm,and 20 nm,respectively.In this work,photodetectors(PDs)based on individual CsPbI_(3) nanobelts are constructed and found to perform well with an external quantum efficiency and responsivity of 2.39×10^(5)% and 770 A/W,respectively.The PDs also show a high detectivity of up to 3.12×10^(12) Jones,which is at par with that of Si PDs.The PDs developed in this work exhibit great promise in various optoelectronic nanodevices.展开更多
Aqueous zinc-ion batteries(ZIBs)are deemed as the idea option for large-scale energy storage systems owing to many alluring merits including low manufacture cost,environmental friendliness,and high operations safety.H...Aqueous zinc-ion batteries(ZIBs)are deemed as the idea option for large-scale energy storage systems owing to many alluring merits including low manufacture cost,environmental friendliness,and high operations safety.However,to develop high-performance cathode is still significant for practical application of ZIBs.Herein,Ba_(0.23)V_(2)O_(5)·1.1H_(2)O(BaVO)nanobelts were fabricated as cathode materials of ZIBs by a typical hydrothermal synthesis method.Benefiting from the increased interlayer distance of 1.31 nm by Ba2+ and H2O pre-intercalated,the obtained BaVO nanobelts showed an excellent initial discharge capacity of 378 mAh·g^(-1) at 0.1 A·g^(-1),a great rate performance(e.g.,172 mAh·g^(-1) at 5 A·g^(-1)),and a superior capacity retention(93% after 2000 cycles at 5 A·g^(-1)).展开更多
ZnS nanobelts with large aspect ratio are successfully synthesized on a large scale through thermally evaporating of ZnS powder with a trace of SnO_2 powder using gold coated Si wafer as the substrate at 1100°C.T...ZnS nanobelts with large aspect ratio are successfully synthesized on a large scale through thermally evaporating of ZnS powder with a trace of SnO_2 powder using gold coated Si wafer as the substrate at 1100°C.The results indicate that the as-obtained ZnS nanobelts are about 10 nm in thickness and hundreds of micrometers in length,and the aspect ratio reaches more than 104.Substrate dependent experiments are conducted to better study the growth mechanism of the ZnS nanobelts.Subsequently,optical properties of the as-synthesized ZnS nanobelts are also investigated by using a cathodoluminescence(CL) system,which shows the existence of a strong ultraviolet emission at 342 nm and two poor emission peaks at 522 nm and 683 nm at room temperature,respectively.展开更多
Carbon modified TiO_2 nanobelts(TiO_2-C) were synthesized using a hydrothermal growth method,as a support material for palladium(Pd) nanoparticles(Pd/TiO_2-C) to improve the electrocatalytic performance for methanol e...Carbon modified TiO_2 nanobelts(TiO_2-C) were synthesized using a hydrothermal growth method,as a support material for palladium(Pd) nanoparticles(Pd/TiO_2-C) to improve the electrocatalytic performance for methanol electrooxidation by comparison to Pd nanoparticles on bare TiO_2 nanobelts(Pd/TiO_2)and activated carbon(Pd/AC). Cyclic voltammetry characterization was conducted with respect to saturated calomel electrode(SCE) in an alkaline methanol solution, and the results indicate that the specific activity of Pd/TiO_2-C is 2.2 times that of Pd/AC and 1.5 times that of Pd/TiO_2. Chronoamperometry results revealed that the TiO_2-C support was comparable in stability to activated carbon, but possesses an enhanced current density for methanol oxidation at a potential of -0.2 V vs. SCE. The current study demonstrates the potential of Pd nanoparticle loaded on hierarchical TiO_2-C nanobelts for electrocatalytic applications such as fuel cells and batteries.展开更多
High-performance materials are the key to developing new alternative energy-storage systems[1-4].Sodium ion batteries(SIBs)are regarded as the promising large-scale electric energy storage owing to the high abundance ...High-performance materials are the key to developing new alternative energy-storage systems[1-4].Sodium ion batteries(SIBs)are regarded as the promising large-scale electric energy storage owing to the high abundance and low cost of sodium resources[1,5-9].However,the sluggish kinetics of Na^(+)caused by the large-sized Na^(+)(1.02A)result in the lower energy density and unsatisfactory electrochemical properties[10-14].展开更多
Monoclinic gallium oxide （βGa2O3） nanobelts are synthesized from gallium and oxygen by thermal evaporation in an axgon atmosphere and their NO2 sensing properties are studied at room temperature. Electron microscop...Monoclinic gallium oxide （βGa2O3） nanobelts are synthesized from gallium and oxygen by thermal evaporation in an axgon atmosphere and their NO2 sensing properties are studied at room temperature. Electron microscopy studies show that the nanobelts have breadths ranging from 30 to 50 nm and lengths up to tens of micrometers. Both the x-ray diffraction （XRD） and the selected are electron diffraction （SAED） examinations indicate that β-Ga203 nanobelts have grown into single crystals. Room temperature NO2 sensing tests show that the current of individual β-Ga2O3 nanobelt decreases quickly, and then gently when the NO2 concentration increases from low to high. It is caused by the NO2 molecule chemisorption and desorption processes in the surface of β-Ga2O3 nanobelt.展开更多
α-MoO3 nanobelts/carbon nanotubes（CNTs） composites were synthesized by simple hydrothermal method followed by CNTs incorporating, and characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM...α-MoO3 nanobelts/carbon nanotubes（CNTs） composites were synthesized by simple hydrothermal method followed by CNTs incorporating, and characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. Cyclic voltammogram（CV）, electrochemical impedance spectroscopy（EIS）, and galvanostatic charge/discharge testing techniques were employed to evaluate the electrochemical behaviors of α-MoO3 nanobelts/CNTs composites. The results exhibited that compared to bare α-MoO3 nanobelts, the α-MoO3 nanobelts/CNTs composites have better electrochemical performances as cathode materials for lithium ion battery, maintaining a reversible specific capacity of 222.2 mAh/g at 0.3 C after 50 cycles, and 74.1% retention of the first reversible capacity. In addition, the Rct value of the α-MoO3 nanobelts/CNTs is 13 Ω, much lower than 66 Ω of the bare α-MoO3 nanobelts. The better electrochemical performances of the α-MoO3 nanobelts/CNTs composites can be attributed to the effects of the high conductive CNTs network.展开更多
Oriented nanobelts of manganese oxide have been firstly and successfully prepared by a microemulsion technique under controlled circumstances. The samples were characterized by X-ray diffraction (XRD), transmission el...Oriented nanobelts of manganese oxide have been firstly and successfully prepared by a microemulsion technique under controlled circumstances. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM). Influences of sodium chloride and annealed temperature on the synthesis of Mn3O4 nanobelts were investigated. It was found that NaCI is the key factor to synthesize oriented Mn3O4 nanobelts and 827 K is optimum temperature to produce fine nanobelts. Oriented growth mechanism of Mn3O4 nanobelts was discussed.展开更多
Monoclinic Cu3V2O7（OH）2·2H2O（copper polyvanadate） hollow spheres were prepared with Na2V6O16·3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characteri...Monoclinic Cu3V2O7（OH）2·2H2O（copper polyvanadate） hollow spheres were prepared with Na2V6O16·3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characterized by X-ray powder diffraction（XRD）, Fourier transform infrared（FTIR） spectroscopy, Raman spectroscopy, thermogravimetric analysis（TGA） and X-ray photoelecton spectroscopy（XPS）. The morphology and size were observed by scanning electron microscopy（SEM）. We found that the Kagomé staircase-structural copper polyvanadate hollow spheres with an average diameter of 7 μm could be easily synthesized via the reaction of Na2V6O16·3H2O nanobelts with sufficient copper sulfate. The dielectric property of the copper polyvanadate demonstrates that dielectric loss hardly changes when the frequency of applied electric field is higher than 100 kHz. The formation process of the hollow spheres is discussed in detail by the observation of a series of products prepared for different reaction time.展开更多
This paper reports that the large-scale single crystalline boron carbide nanobelts have been fabricated through a simple carbothermal reduction method with B/B2O3/C/Fe powder as precursors at 1100℃. Transmission elec...This paper reports that the large-scale single crystalline boron carbide nanobelts have been fabricated through a simple carbothermal reduction method with B/B2O3/C/Fe powder as precursors at 1100℃. Transmission electron microscopy and selected area electron diffraction characterizations show that the boron carbide nanobelt has a B4C rhomb-centred hexagonal structure with good crystallization. Electron energy loss spectroscopy analysis indicates that the nanobelt contains only B and C, and the atomic ratio of B to C is close to 4：1. High resolution transmission electron microscopy results show that the preferential growth direction of the nanobelt is [101]. A possible growth mechanism is also discussed.展开更多
Ultrathin VO_2 nanobelts with rough alignment features are prepared on the induction layer-coated substrates by an ethylenediaminetetraacetic acid（EDTA）-mediated hydrothermal process. EDTA acts as a chelating reagen...Ultrathin VO_2 nanobelts with rough alignment features are prepared on the induction layer-coated substrates by an ethylenediaminetetraacetic acid（EDTA）-mediated hydrothermal process. EDTA acts as a chelating reagent and capping agent to facilitate the one-dimensional（1D） preferential growth of ultrathin VO_2 nanobelts with high crystallinities and good uniformities. The annealed induction layer and concentration of EDTA are found to play crucial roles in the formation of aligned and ultrathin nanobelts. Variation in EDTA concentration can change the VO_2 morphology of ultrathin nanobelts into that of thick nanoplates. Mild annealing of ultrathin VO_2 nanobelts at 350℃ in air results in the formation of V_2O_5 nanobelts with a nearly unchanged ultrathin structure. The nucleation and growth mechanism involved in the formations of nanobelts and nanoplates are proposed. The ethanol gas sensing properties of the V_2O_5 nanobelt networks-based sensor are investigated in a temperature range from 100℃ to 300℃ over ethanol concentrations ranging from 3 ppm to 500 ppm.The results indicate that the V_2O_5 nanobelt network sensor exhibits high sensitivity, good reversibility, and fast responserecovery characteristics with an optimal working temperature of 250℃.展开更多
A facile preparation of nitrogen-doped β-TiO2（N-doped β-TiO2） nanobelts and their visible-light photocatalytic activity were reported.The preparation of N-doped β-TiO2 nanobelts consisted of cation-exchange betwe...A facile preparation of nitrogen-doped β-TiO2（N-doped β-TiO2） nanobelts and their visible-light photocatalytic activity were reported.The preparation of N-doped β-TiO2 nanobelts consisted of cation-exchange between layered sodium titanate nanobelts and NH 4 ＋ in aqueous solution at room temperature and subsequent calcination in air.Such a calcination treatment is beneficial to the formation of monoclinic N-doped β-TiO2 nanobelts.Various measurement results indicate that not only were the nitrogen atoms doped into the lattice of β-TiO2 nanobelts resulting in a strong visible-light absorption,but also a large number of defects were caused by them in the lattice,increasing the stability of β-TiO2.The photocatalysis enhancement of N-doped β-TiO2 nanobelts for the photodegradation of Rhodamine B was demonstrated.展开更多
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korea government(MOTIE)(RS-2023-00303581,Multiscale Simulation-Driven Development of Cost-Effective and Stable Aqueous Zn Ion Battery with Energy Density of 110 Wh/L for Energy Storage Systems:A Korea-USA Collaboration)。
文摘Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power density.However,issues,such as the corrosion and dissolution of the Zn anode,limited wet-tability,and lack of sufficient nucleation sites for Zn plating,have limited their practical application.The introduction of a protective layer comprising of tellurium(Te)nanobelts onto the surface of Zn anode has emerged as a promising approach to overcome these limitations and improve the electrochemical behav-ior by enhancing the safety and wettability of ZIBs,as well as providing numerous nucleation sites for Zn plating.In the presence of a Te-based protective layer,the energy power density of the surface-engineered Zn anode improved significantly(ranging from 310 to 144 W h kg^(-1),over a power density range of 270 to 1,800 W kg^(-1)),and the lifespan capability was extended.These results demonstrate that the proposed strategy of employing Te nanobelts as a protective layer holds great promise for enhancing the energy storage performance of zIBs,making them even more attractive as a viable energy storage solution forthefuture.
基金partially supported by grants from the National Natural Science Foundation of China(52072099)Team program of the Natural Science Foundation of Heilongjiang Province,China(No.TD2021E005)
文摘Rechargeable Li-S batteries(LSBs)are emerging as an important alternative to lithium-ion batteries(LIBs),owing to their high energy densities and low cost;yet sluggish redox kinetics of LiPSs results in inferior cycle life.Herein,we prepared multifunctional self-supporting hyphae carbon nanobelt(HCNB)as hosts by carbonization of hyphae balls of Rhizopus,which could increase the S loading of the cathode without sacrificing reaction kinetics.Trace platinum(Pt)nanoparticles were introduced into HCNBs(PtHCNBs)by ion-beam sputtering deposition.Based on the X-ray photoelectron spectroscopy analyses,the introduced trace Pt regulated the local electronic states of heteroatoms in HCNBs.Electrochemical kinetics investigation combined with operando Raman measurements revealed the accelerated reaction mechanics of sulfur species.Benefiting from the synergistic catalytic effect and the unique structures,the as-prepared PtHCNB/MWNCT/S cathodes delivered a stable capacity retention of 77%for 400 cycles at 0.5 C with a sulfur loading of 4.6 mg cm^(-2).More importantly,remarkable cycling performance was achieved with an high areal S loading of 7.6 mg cm^(-2).This finding offers a new strategy to prolong the cycle life of LSBs.
基金supported by Natural Science Basic Research Program in Shaanxi Province of China(No.2023-JCYB-574)National Natural Science Foundation of China(No.62204203).
文摘High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.
文摘Mn doped SnO2 nanobelts (Mn:SnO2 NBs) and pure SnO2 nanobelts (SnO2 NBs) were synthesized by thermal evaporation technique at 1355°C with Ar carrier gas (25 sccm, 150 Torr). The SEM, EDS, XRD, TEM, HRTEM, SAED, XPS, UV-Vis techniques were used to characterize the attained samples. The band gap of Mn doped SnO2 NBs by UV-Vis was measured to be 3.43 eV at room temperature, lower than that of the pure counterpart with ~3.66 eV. Mn:SnO2 NB and pure SnO2 NB sensors were developed. It is found that Mn:SnO2 NB device exhibits a higher sensitivity with 62.12% to 100 ppm of ethanol at 210°C, which is the highest sensitivity among the three tested VOC gases (ethanol, ethanediol, and acetone). The theoretical detection limit for ethanol of the sensor is 1.1 ppm. The higher response is related to the selective catalysis of the doped Mn ions.
基金The project supported by the US National Science Foundation through CAREER grant no. CMS9984298the National Natural Science Foundation of China (10528205)
文摘t Molecular dynamics （MD） simulations are carried out to characterize the mechanical and thermal responses of [011^-1]-oriented ZnO nanobelts with lateral dimensions of 21.22A × 18.95 A, 31.02A× 29.42 A, and40.81A ×39.89A over the temperature range of 300-1000 K. The Young＇s modulus and thermal conductivity of the nanobelts are evaluated. Significant surface effects on properties due to the highsurface-to-volume ratios of the nanobelts are observed. For the mechanical response, surface-stress-induced internal stress plays an important role. For the thermal response, surface scattering of phonons dominates. Calculations show that the Young＇s modulus is higher than the corresponding value for bulk ZnO and decreases by -33% as the lateral dimensions increase from 21.22 A × 18.95A to 40.81 A × 39.89A. The thermal conductivity is one order of magnitude lower than the corresponding value for bulk ZnO single crystal and decreases with wire size. Specifically, the conductivity of the 21.22 A × 18.95 A belt is approximately （31-18）% lower than that of the 40.81 A × 39.89 A belt over the temperature range analyzed. A significant dependence of properties on temperature is also observed, with the Young＇s modulus decreasing on average by 12% and the conductivity decreasing by 50% as temperature increases from 300 K to 1000 K.
基金supported by the National Natural Science Foundation of China (Nos. 51772193 , 51702063)Nature Science Fund of Liaoning Province (No. 20180550200)+1 种基金China Postdoctoral Science Foundation(2018M630340)Project of Science and Technology Plan Shenyang (No. 17-231-1-18)
文摘Aqueous zinc-ion batteries(ZIBs) have been considered as one of the most promising electrochemical devices for large-scale energy storage system owing to their low cost and high safety. Herein, Na2V6O16·2.14H2O nanobelts are synthesized and applied as cathode material for ZIBs. The sample displays a high capacity of 466 m Ahg^-1 at 100 mAg^-1 and stable cycling performance with a capacity retention of 90% over 20 0 0 cycles at the 20 Ag^-1. Moreover, Na2V6O16·2.14H2O presents a capable rate ability and a high energy density of 312 Wh kg^-1 at a specific power of 70 Wkg^-1. The superior electrochemical performance is attributed to the large interlayer spacing and outstanding structure stability, which promise the highly reversible intercalation and extraction of zinc ion. The electrochemical kinetics and zinc ion storage mechanism are also investigated. This work demonstrates that nanoscale electrode materials with large interlayer spacing can effectively enhance the electrochemical performance of aqueous ZIBs, which can be extended to other metal ion batteries, such as magnesium ion batteries and aluminum ion batteries.
基金supported by Major Science and Technology Projects of Heilongjiang Province(2019ZX09A01)National Key Technology R&D Program(Grant No.2017YFB1401805)+1 种基金the China Postdoctoral Science Foundation(2019T120285,2018M641884)Heilongjiang Province Postdoctoral Science Foundation(LBH-Z18235)。
文摘The restacking hindrance of MXene films restricts their development for high volumetric energy density of flexible supercapacitors toward applications in miniature,portable,wearable or implantable electronic devices.A valid solution is construction of rational heterojunction to achieve a synergistic property enhancement.The introduction of spacers such as graphene,CNTs,cellulose and the like demonstrates limited enhancement in rate capability.The combination of currently reported pseudocapacitive materials and MXene tends to express the potential capacitance of pseudocapacitive materials rather than MXene,leading to low volumetric capacitance.Therefore,it is necessary to exploit more ideal candidate materials to couple with MXene for fully expressing both potentials.Herein,for the first time,high electrochemically active materials of ultrathin MoO3 nanobelts are intercalated into MXene films.In the composites,MoO3 nanobelts not only act as pillaring components to prevent restacking of MXene nanosheets for fully expressing the MXene pseudocapacitance in acidic environment but also provide considerable pseudocapacitive contribution.As a result,the optimal M/MoO3 electrode not only achieves a breakthrough in volumetric capacitance(1817 F cm-3 and 545 F g-1),but also maintains good rate capability and excellent flexibility.Moreover,the corresponding symmetric supercapacitor likewise shows a remarkable energy density of 44.6 Wh L-1(13.4 Wh kg-1),rendering the flexible electrode a promising candidate for application in high-energy-density energy storage devices.
基金This work was supported by the National Natural Science Foundation of China(No 50072028).
文摘Ultralong beltlike nanostructures was successfully synthesized for V6O13 crystal by ahydrothermal route. The products are characterized by means of X-ray powder diffraction,transmission electron microscopy and high-resolution transmission electron microscopy. Theexperimental results give the evidence that the V6O13 nanobelts are pure, structurally uniform andsingle crystalline, with typical widths of 50 to 300 nm and lengths of up to a few millimeters.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51974021 and 51902020)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-18-045A1 and FRF-TP-19-004B2Z)+1 种基金the National Postdoctoral Program for Innovative Talents(BX20180034)the China Postdoctoral Science Foundation(Grant No.2018M641192).
文摘Lead halide perovskites have received increasing attention recently as a candidate material in various optoelectronic areas because of their high performance as light absorbers.Herein,we report the growth of CsPbI_(3) nanobelts via a solution process.A single-crystalline CsPbI_(3) nanobelt with uniform morphology can be achieved by controlling the amount of PbI_(2).A single-crystalline CsPbI_(3) nanobelt possesses a mean width,length,and thickness of 100 nm,5μm,and 20 nm,respectively.In this work,photodetectors(PDs)based on individual CsPbI_(3) nanobelts are constructed and found to perform well with an external quantum efficiency and responsivity of 2.39×10^(5)% and 770 A/W,respectively.The PDs also show a high detectivity of up to 3.12×10^(12) Jones,which is at par with that of Si PDs.The PDs developed in this work exhibit great promise in various optoelectronic nanodevices.
基金supported by the National Natural Science Foundation of China(No.21905037)the Doctoral research startup fund of Liaoning Province,China(No.2020-BS-066)+2 种基金the China Postdoctoral Science Foundation(No.2020M670719)the Fundamental Research Funds for the Central Universities(No.3132019328)the financial support from China Scholarship Council(CSC).
文摘Aqueous zinc-ion batteries(ZIBs)are deemed as the idea option for large-scale energy storage systems owing to many alluring merits including low manufacture cost,environmental friendliness,and high operations safety.However,to develop high-performance cathode is still significant for practical application of ZIBs.Herein,Ba_(0.23)V_(2)O_(5)·1.1H_(2)O(BaVO)nanobelts were fabricated as cathode materials of ZIBs by a typical hydrothermal synthesis method.Benefiting from the increased interlayer distance of 1.31 nm by Ba2+ and H2O pre-intercalated,the obtained BaVO nanobelts showed an excellent initial discharge capacity of 378 mAh·g^(-1) at 0.1 A·g^(-1),a great rate performance(e.g.,172 mAh·g^(-1) at 5 A·g^(-1)),and a superior capacity retention(93% after 2000 cycles at 5 A·g^(-1)).
基金sponsored by the Scientific Research Fund of Heilongjiang Provincial Education Department(11551117)China Postdoctoral Foundation(20090460875)+1 种基金Pre-research Fund(2009KYG-01)Youth Skeleton Teacher Fund(10KXQ-07)of Harbin Normal University
文摘ZnS nanobelts with large aspect ratio are successfully synthesized on a large scale through thermally evaporating of ZnS powder with a trace of SnO_2 powder using gold coated Si wafer as the substrate at 1100°C.The results indicate that the as-obtained ZnS nanobelts are about 10 nm in thickness and hundreds of micrometers in length,and the aspect ratio reaches more than 104.Substrate dependent experiments are conducted to better study the growth mechanism of the ZnS nanobelts.Subsequently,optical properties of the as-synthesized ZnS nanobelts are also investigated by using a cathodoluminescence(CL) system,which shows the existence of a strong ultraviolet emission at 342 nm and two poor emission peaks at 522 nm and 683 nm at room temperature,respectively.
基金supported by FedDev Ontario through the Applied Research and Commercialization (ARC) Initiative and the Natural Sciences and Engineering Research Council of Canada (NSERC) programMicrobonds, Inc. for additional financial support
文摘Carbon modified TiO_2 nanobelts(TiO_2-C) were synthesized using a hydrothermal growth method,as a support material for palladium(Pd) nanoparticles(Pd/TiO_2-C) to improve the electrocatalytic performance for methanol electrooxidation by comparison to Pd nanoparticles on bare TiO_2 nanobelts(Pd/TiO_2)and activated carbon(Pd/AC). Cyclic voltammetry characterization was conducted with respect to saturated calomel electrode(SCE) in an alkaline methanol solution, and the results indicate that the specific activity of Pd/TiO_2-C is 2.2 times that of Pd/AC and 1.5 times that of Pd/TiO_2. Chronoamperometry results revealed that the TiO_2-C support was comparable in stability to activated carbon, but possesses an enhanced current density for methanol oxidation at a potential of -0.2 V vs. SCE. The current study demonstrates the potential of Pd nanoparticle loaded on hierarchical TiO_2-C nanobelts for electrocatalytic applications such as fuel cells and batteries.
基金supported by the National Natural Science Foundation of China(Nos.21905058,21663029)Guangdong University of Technology Hundred Talents Program(No.220418136)Guangdong University of Technology Youth Hundred Talents Program(No.220413671)。
文摘High-performance materials are the key to developing new alternative energy-storage systems[1-4].Sodium ion batteries(SIBs)are regarded as the promising large-scale electric energy storage owing to the high abundance and low cost of sodium resources[1,5-9].However,the sluggish kinetics of Na^(+)caused by the large-sized Na^(+)(1.02A)result in the lower energy density and unsatisfactory electrochemical properties[10-14].
文摘Monoclinic gallium oxide （βGa2O3） nanobelts are synthesized from gallium and oxygen by thermal evaporation in an axgon atmosphere and their NO2 sensing properties are studied at room temperature. Electron microscopy studies show that the nanobelts have breadths ranging from 30 to 50 nm and lengths up to tens of micrometers. Both the x-ray diffraction （XRD） and the selected are electron diffraction （SAED） examinations indicate that β-Ga203 nanobelts have grown into single crystals. Room temperature NO2 sensing tests show that the current of individual β-Ga2O3 nanobelt decreases quickly, and then gently when the NO2 concentration increases from low to high. It is caused by the NO2 molecule chemisorption and desorption processes in the surface of β-Ga2O3 nanobelt.
基金Funded by the Fundamental Research Funds for the Central Universities(No.2014QNA08)
文摘α-MoO3 nanobelts/carbon nanotubes（CNTs） composites were synthesized by simple hydrothermal method followed by CNTs incorporating, and characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. Cyclic voltammogram（CV）, electrochemical impedance spectroscopy（EIS）, and galvanostatic charge/discharge testing techniques were employed to evaluate the electrochemical behaviors of α-MoO3 nanobelts/CNTs composites. The results exhibited that compared to bare α-MoO3 nanobelts, the α-MoO3 nanobelts/CNTs composites have better electrochemical performances as cathode materials for lithium ion battery, maintaining a reversible specific capacity of 222.2 mAh/g at 0.3 C after 50 cycles, and 74.1% retention of the first reversible capacity. In addition, the Rct value of the α-MoO3 nanobelts/CNTs is 13 Ω, much lower than 66 Ω of the bare α-MoO3 nanobelts. The better electrochemical performances of the α-MoO3 nanobelts/CNTs composites can be attributed to the effects of the high conductive CNTs network.
基金support from the National Natural Science Foundation of China under grant No.550071028Program of Science and Technology Bureau of Qingdao under grant No.03-2-IR-18
文摘Oriented nanobelts of manganese oxide have been firstly and successfully prepared by a microemulsion technique under controlled circumstances. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM). Influences of sodium chloride and annealed temperature on the synthesis of Mn3O4 nanobelts were investigated. It was found that NaCI is the key factor to synthesize oriented Mn3O4 nanobelts and 827 K is optimum temperature to produce fine nanobelts. Oriented growth mechanism of Mn3O4 nanobelts was discussed.
基金Supported by the "973" Basic Research Foundation of China(No.2006CB932605)the National Natural Science Founda-tion of China(No.20876002).
文摘Monoclinic Cu3V2O7（OH）2·2H2O（copper polyvanadate） hollow spheres were prepared with Na2V6O16·3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characterized by X-ray powder diffraction（XRD）, Fourier transform infrared（FTIR） spectroscopy, Raman spectroscopy, thermogravimetric analysis（TGA） and X-ray photoelecton spectroscopy（XPS）. The morphology and size were observed by scanning electron microscopy（SEM）. We found that the Kagomé staircase-structural copper polyvanadate hollow spheres with an average diameter of 7 μm could be easily synthesized via the reaction of Na2V6O16·3H2O nanobelts with sufficient copper sulfate. The dielectric property of the copper polyvanadate demonstrates that dielectric loss hardly changes when the frequency of applied electric field is higher than 100 kHz. The formation process of the hollow spheres is discussed in detail by the observation of a series of products prepared for different reaction time.
基金Project supported by the National 863 (Grant No 2007AA03Z305)973 (Grant No 2007CB935503) programthe National Science Foundation of China (Grant Nos 60571045, 60620120443, Guo-JI He-Zuo)
文摘This paper reports that the large-scale single crystalline boron carbide nanobelts have been fabricated through a simple carbothermal reduction method with B/B2O3/C/Fe powder as precursors at 1100℃. Transmission electron microscopy and selected area electron diffraction characterizations show that the boron carbide nanobelt has a B4C rhomb-centred hexagonal structure with good crystallization. Electron energy loss spectroscopy analysis indicates that the nanobelt contains only B and C, and the atomic ratio of B to C is close to 4：1. High resolution transmission electron microscopy results show that the preferential growth direction of the nanobelt is [101]. A possible growth mechanism is also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61274074,61271070,and 61574100)
文摘Ultrathin VO_2 nanobelts with rough alignment features are prepared on the induction layer-coated substrates by an ethylenediaminetetraacetic acid（EDTA）-mediated hydrothermal process. EDTA acts as a chelating reagent and capping agent to facilitate the one-dimensional（1D） preferential growth of ultrathin VO_2 nanobelts with high crystallinities and good uniformities. The annealed induction layer and concentration of EDTA are found to play crucial roles in the formation of aligned and ultrathin nanobelts. Variation in EDTA concentration can change the VO_2 morphology of ultrathin nanobelts into that of thick nanoplates. Mild annealing of ultrathin VO_2 nanobelts at 350℃ in air results in the formation of V_2O_5 nanobelts with a nearly unchanged ultrathin structure. The nucleation and growth mechanism involved in the formations of nanobelts and nanoplates are proposed. The ethanol gas sensing properties of the V_2O_5 nanobelt networks-based sensor are investigated in a temperature range from 100℃ to 300℃ over ethanol concentrations ranging from 3 ppm to 500 ppm.The results indicate that the V_2O_5 nanobelt network sensor exhibits high sensitivity, good reversibility, and fast responserecovery characteristics with an optimal working temperature of 250℃.
基金Supported by the National Basic Research Program of China(No.2006CB932605)the National Natural Science Foundation of China(No.20876002)the Fund of Beijing Technology and Business University for the Talent,China
文摘A facile preparation of nitrogen-doped β-TiO2（N-doped β-TiO2） nanobelts and their visible-light photocatalytic activity were reported.The preparation of N-doped β-TiO2 nanobelts consisted of cation-exchange between layered sodium titanate nanobelts and NH 4 ＋ in aqueous solution at room temperature and subsequent calcination in air.Such a calcination treatment is beneficial to the formation of monoclinic N-doped β-TiO2 nanobelts.Various measurement results indicate that not only were the nitrogen atoms doped into the lattice of β-TiO2 nanobelts resulting in a strong visible-light absorption,but also a large number of defects were caused by them in the lattice,increasing the stability of β-TiO2.The photocatalysis enhancement of N-doped β-TiO2 nanobelts for the photodegradation of Rhodamine B was demonstrated.
