Mesoporous CeO2 nanowires(NWs) were synthesized through a facile hydrothermal process by using triblock copolymer F127 as the template.XRD analysis confirmed the cubic phase of the synthesized CeO2 NWs.High-yield one-...Mesoporous CeO2 nanowires(NWs) were synthesized through a facile hydrothermal process by using triblock copolymer F127 as the template.XRD analysis confirmed the cubic phase of the synthesized CeO2 NWs.High-yield one-dimensional NWs with accessible mesopores could be observed from SEM and TEM images,and the surface area of the material was confirmed to be 273 m2 g-1 with pore width distribution of 6.9-13.8 nm.The mesoporous CeO2 NWs could be used as efficient photocatalysts for organic dye degradation under UV light irradiation,which was superior compared with commercial photocatalyst P-25 and commercial CeO2 powders.The NW structure facilitates the recovery of catalyst by sedimentation,leading to the impressive reusability of these mesoporous CeO2 NWs.展开更多
ZnO/Ag nanowires （NWs） film ultraviolet （UV） detector was fabricated by a simple and low-cost solution-processed method. In order to prepare this device, Ag NWs network was first spin-coated on glass sub- strate a...ZnO/Ag nanowires （NWs） film ultraviolet （UV） detector was fabricated by a simple and low-cost solution-processed method. In order to prepare this device, Ag NWs network was first spin-coated on glass sub- strate as a transparent conducting electrode, then ZnO NWs arrays were grown vertically on the Ag NWs network based on the hydrothermal method. This UV detector exhibited an excellent detection performance with large on/off ratio and short response time. Several process and working parameters were particularly investigated to analyze the relationship between structure and performance, which include growth time of ZnO NWs array, spin speed of Ag NWs network and working temperature. This UV photoconductive detector is based on two kinds of one-dimension nanomaterials, and it was regarded as a compromise between high performance with large area, low voltage and low cost.展开更多
To further improve the performance of binders,a SiHfBCN-based high-temperature resistant adhesive was successfully synthesized by Polymer-Derived Ceramics(PDC)route using TiB2,Polysiloxane(PSO)and short SiC nanowires ...To further improve the performance of binders,a SiHfBCN-based high-temperature resistant adhesive was successfully synthesized by Polymer-Derived Ceramics(PDC)route using TiB2,Polysiloxane(PSO)and short SiC nanowires as fillers.The effect of short SiC nanowires on the adhesive strength at room temperature and high temperature,as well as the reinforcing mechanism was studied.Compared with the adhesive without SiC nanowires,after curing(at 170℃)and pyrolysis(at 1000℃)in air,the appropriate adding of SiC nanowires upgrades the room temperature and high temperature(at 1000℃ in air)adhesive strength to(12.50±0.67)MPa(up by about 32%)and(13.11±0.79)MPa(up by about 106%),respectively.Attractively,under the synergistic impact of the nanowire bridging,nanowire breaking,nanowire drawing and crack deflection,the optimized adhesive exhibits multi-stage fracture,causing the increscent fracture displacement.展开更多
Sandwich-structured flexible sensors based on graphene have high sensitivity and stability.When graphene is combined with a flexible substrate in a sandwich structure,the weak bonding between them compromises the sens...Sandwich-structured flexible sensors based on graphene have high sensitivity and stability.When graphene is combined with a flexible substrate in a sandwich structure,the weak bonding between them compromises the sensor's stability and sensitivity at low strains.This presents challenges in monitoring subtle physiological activities,such as hand bending and pulse rate.For this purpose,laser-induced graphene(LIG)is proposed to be used to prepare flexible sensors in order to improve the sensitivity and stability of the sensors at low strains.Polydimethylsiloxane(PDMS)with low modulus and polyimide(PI)with rich carbon content are selected as precursor materials for LIG,and graphene is formed through laser induction.Subsequently,silver nanowires(Ag NWs)solution is added to LIG to give the sensor low strain and high sensitivity performance.When the PI/PDMS ratio is 1:3,the Ag NWs/LIG flexible strain sensor exhibits excellent sensitivity(GF=778.468)over a small strain range(8.76%-11.25%).Meanwhile,the sensor still shows excellent stability after 2000 cycle experiments.The Ag NWs/LIG flexible strain sensor shows good performance when placed on the back of the hand,around the eyes,etc.It is demonstrated that Ag NWs/LIG flexible strain sensors have good application potential in human physiological activity monitoring,health management and medical fields,and provide a low-strain,high-sensitivity sensor design strategy for flexible wearable devices.展开更多
The quantum confinement effect is important in nanoelectronics and optoelectronics applications; however, there is a discrepancy between the theory of quantum confinement, which indicates that band-gap widening occurs...The quantum confinement effect is important in nanoelectronics and optoelectronics applications; however, there is a discrepancy between the theory of quantum confinement, which indicates that band-gap widening occurs only at small sizes, and experimental observations of band-gap widening in large-diameter nanowires （NWs）. This paper reports an obvious blue shift of the absorption edge in the UV-visible absorption spectra of SiC NWs with diameters of 50-300 nm. On the basis of quantum confinement theory and high-resolution transmission electron microscopy images of SiC NWs, band-gap widening in SiC NWs with diameters of up to hundreds of nanometers is fully explained; the results could help to explain similar band-gap widening in other NWs with large diameters.展开更多
We describes a controllable synthesis procedure for growing a-Ee2O3 and Ee3O4 nanowires. High magnetic hematite a-Fe2O3 nanowires are successfully grown on Fe0.5Ni0.5 alloy substrates via an oxide assisted vapor-solid...We describes a controllable synthesis procedure for growing a-Ee2O3 and Ee3O4 nanowires. High magnetic hematite a-Fe2O3 nanowires are successfully grown on Fe0.5Ni0.5 alloy substrates via an oxide assisted vapor-solid process. Experimental results also indicate that previous immersion of the substrates in a solution of oxalic acid causes the grown nanowires to convert gradually into magnetite （Fe3O4） nanowires. Additionally, the saturated state of Fe3O4 nanowires is achieved as the oxalic acid concentration reaches 0.75 mol/L. The average diameter and length of nanowires expands with an increasing operation temperature and the growth density of nanowires accumulates with an increasing gas flux in the vapor-solid process. The growth mechanism of a-Fe2O3 and Fe3O4 nanowires is also discussed. The results demonstrate that the entire synthesis of nanowires can be completed within 2 h.展开更多
The structures and electronic properties of ZnO nanowires（NWs） of different diameters are investigated by employing the first-principles density functional theory. The results indicate that the oxygen vacancy（VO） ...The structures and electronic properties of ZnO nanowires（NWs） of different diameters are investigated by employing the first-principles density functional theory. The results indicate that the oxygen vacancy（VO） exerts a more evident influence on the band gap of the ZnO NWs. However, the effect will be weakened with the increase of the diameter. In addition, the energy band shifts downward due to the existence of VOand the offset decreases with the reduction of the VOconcentration. As the concentration of surface Zn atoms decreases, the conduction band shifts downward, while 2p electrons are lost in the oxygen vacancy, resulting in the split of valence band and the formation of an impurity level. Our findings agree well with the previous observations and will be of great importance for theoretical research based on ZnO NWs.展开更多
Crystal-phase low-dimensional structures offer great potential for the implementation of photonic devices of interest for quantum information processing.In this context,unveiling the fundamental parameters of the crys...Crystal-phase low-dimensional structures offer great potential for the implementation of photonic devices of interest for quantum information processing.In this context,unveiling the fundamental parameters of the crystal phase structure is of much relevance for several applications.Here,we report on the anisotropy of the g-factor tensor and diamagnetic coefficient in wurtzite/zincblende(WZ/ZB)crystal-phase quantum dots(QDs)realized in single InP nanowires.The WZ and ZB alternating axial sections in the NWs are identified by high-angle annular dark-field scanning transmission electron microscopy.The electron(hole)g-factor tensor and the exciton diamagnetic coefficients in WZ/ZB crystal-phase QDs are determined through micro-photoluminescence measurements at low temperature(4.2 K)with different magnetic field configurations,and rationalized by invoking the spin-correlated orbital current model.Our work provides key parameters for band gap engineering and spin states control in crystal-phase low-dimensional structures in nanowires.展开更多
Organometallic halide perovskite materials have triggered global attention in recent years due to their exciting and optimistic high performance energy conversion properties(high luminescence efficiency and tremendous...Organometallic halide perovskite materials have triggered global attention in recent years due to their exciting and optimistic high performance energy conversion properties(high luminescence efficiency and tremendous optical absorption ability[1,2]).These interesting photovoltaic properties together make them a promising candidate for high performance optoelectronic展开更多
Photoelectrochemical(PEC)water splitting is regarded as the most promising method to generate“green hydrogen”,and zinc oxide(ZnO)has been identified as one of the promising candidates for PEC water splitting owing t...Photoelectrochemical(PEC)water splitting is regarded as the most promising method to generate“green hydrogen”,and zinc oxide(ZnO)has been identified as one of the promising candidates for PEC water splitting owing to its straddling band alignment with the water redox level.However,its PEC performance is limited due to its wide bandgap and anticipated by photocorrosion in an aqueous medium.In this work,we present strategic improvements in the PEC water splitting performance of ZnO nanowires(NWs)by nitrogen(N)-doping along with photostability by the core–shell deposition of a NiOOH cocatalyst.Highly crystalline hierarchical ZnO NWs were fabricated on Si NWs(ZnO-Si HNWs)using a metal organic chemical vapor deposition approach.The NWs were then N-doped by annealing in an NH_(3) atmosphere.The N-doped ZnO-Si HNWs(N:ZnO-Si HNWs)showed enhanced visible light absorption,and suppressed recombination of the photogenerated carriers.As compared to ZnO-Si HNWs(0.045 m A cm^(-2) at 1.23 V vs RHE),the N:ZnO-Si HNWs(0.34 m A cm^(-2) at 1.23 V vs RHE)annealed in NH^(3) ambient for 3 h at 600℃showed 7.5-fold enhancement in the photocurrent density.NiOOH-deposited N:ZnO-Si HNW photoanodes with a photostability of 82.21%over 20000 s showed 10.69-fold higher photocurrent density(0.48 m A cm^(-2) at 1.23 V vs RHE)than ZnO-Si HNWs.展开更多
基金supported by the Engineering and Technology Research Center of Food Preservation,Processing and Safety Control of Liaoning Province,Food Safety Key Lab of Liaoning Province (LNSAKF2011027)Key Laboratory Project of Department of Education of LiaoningProvince (2009s004)
文摘Mesoporous CeO2 nanowires(NWs) were synthesized through a facile hydrothermal process by using triblock copolymer F127 as the template.XRD analysis confirmed the cubic phase of the synthesized CeO2 NWs.High-yield one-dimensional NWs with accessible mesopores could be observed from SEM and TEM images,and the surface area of the material was confirmed to be 273 m2 g-1 with pore width distribution of 6.9-13.8 nm.The mesoporous CeO2 NWs could be used as efficient photocatalysts for organic dye degradation under UV light irradiation,which was superior compared with commercial photocatalyst P-25 and commercial CeO2 powders.The NW structure facilitates the recovery of catalyst by sedimentation,leading to the impressive reusability of these mesoporous CeO2 NWs.
基金supported by the National Natural Science Foundation of China(Nos.61176056,91323303,91123019)the 111 Program(No.B14040)the Open Projects from the Institute of Photonics and Photo-Technology,Provincial Key Laboratory of Photoelectronic Technology,Northwest University,China
文摘ZnO/Ag nanowires （NWs） film ultraviolet （UV） detector was fabricated by a simple and low-cost solution-processed method. In order to prepare this device, Ag NWs network was first spin-coated on glass sub- strate as a transparent conducting electrode, then ZnO NWs arrays were grown vertically on the Ag NWs network based on the hydrothermal method. This UV detector exhibited an excellent detection performance with large on/off ratio and short response time. Several process and working parameters were particularly investigated to analyze the relationship between structure and performance, which include growth time of ZnO NWs array, spin speed of Ag NWs network and working temperature. This UV photoconductive detector is based on two kinds of one-dimension nanomaterials, and it was regarded as a compromise between high performance with large area, low voltage and low cost.
基金co-supported by the National Natural Science Foundation of China (No. 52061135102)the Innovation Training Foundation for College Students of Northwestern Polytechnical University, China (No. 202310699180)the Creative Research Foundation of the Science and Technology on Thermostructural Composite Materials Laboratory
文摘To further improve the performance of binders,a SiHfBCN-based high-temperature resistant adhesive was successfully synthesized by Polymer-Derived Ceramics(PDC)route using TiB2,Polysiloxane(PSO)and short SiC nanowires as fillers.The effect of short SiC nanowires on the adhesive strength at room temperature and high temperature,as well as the reinforcing mechanism was studied.Compared with the adhesive without SiC nanowires,after curing(at 170℃)and pyrolysis(at 1000℃)in air,the appropriate adding of SiC nanowires upgrades the room temperature and high temperature(at 1000℃ in air)adhesive strength to(12.50±0.67)MPa(up by about 32%)and(13.11±0.79)MPa(up by about 106%),respectively.Attractively,under the synergistic impact of the nanowire bridging,nanowire breaking,nanowire drawing and crack deflection,the optimized adhesive exhibits multi-stage fracture,causing the increscent fracture displacement.
基金supported by the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZDK202300606)Chongqing Municipal Natural Science Foundation(Grant No.CSTB2022NSCQ-MSX0380)+1 种基金National High-end Foreign Experts Introduction Plan(Grant No.G2022035005L)Chongqing Talent Plan of Overall Rationing System Project(Grant No.CQYC202203091156)。
文摘Sandwich-structured flexible sensors based on graphene have high sensitivity and stability.When graphene is combined with a flexible substrate in a sandwich structure,the weak bonding between them compromises the sensor's stability and sensitivity at low strains.This presents challenges in monitoring subtle physiological activities,such as hand bending and pulse rate.For this purpose,laser-induced graphene(LIG)is proposed to be used to prepare flexible sensors in order to improve the sensitivity and stability of the sensors at low strains.Polydimethylsiloxane(PDMS)with low modulus and polyimide(PI)with rich carbon content are selected as precursor materials for LIG,and graphene is formed through laser induction.Subsequently,silver nanowires(Ag NWs)solution is added to LIG to give the sensor low strain and high sensitivity performance.When the PI/PDMS ratio is 1:3,the Ag NWs/LIG flexible strain sensor exhibits excellent sensitivity(GF=778.468)over a small strain range(8.76%-11.25%).Meanwhile,the sensor still shows excellent stability after 2000 cycle experiments.The Ag NWs/LIG flexible strain sensor shows good performance when placed on the back of the hand,around the eyes,etc.It is demonstrated that Ag NWs/LIG flexible strain sensors have good application potential in human physiological activity monitoring,health management and medical fields,and provide a low-strain,high-sensitivity sensor design strategy for flexible wearable devices.
基金This work was supported by the NationalNatural Science Foundation of China （Grant No. 61675234） and the Advanced Research Foundation of the National University of Defense Technology （Grant No. zk16-03-40）.
文摘The quantum confinement effect is important in nanoelectronics and optoelectronics applications; however, there is a discrepancy between the theory of quantum confinement, which indicates that band-gap widening occurs only at small sizes, and experimental observations of band-gap widening in large-diameter nanowires （NWs）. This paper reports an obvious blue shift of the absorption edge in the UV-visible absorption spectra of SiC NWs with diameters of 50-300 nm. On the basis of quantum confinement theory and high-resolution transmission electron microscopy images of SiC NWs, band-gap widening in SiC NWs with diameters of up to hundreds of nanometers is fully explained; the results could help to explain similar band-gap widening in other NWs with large diameters.
文摘We describes a controllable synthesis procedure for growing a-Ee2O3 and Ee3O4 nanowires. High magnetic hematite a-Fe2O3 nanowires are successfully grown on Fe0.5Ni0.5 alloy substrates via an oxide assisted vapor-solid process. Experimental results also indicate that previous immersion of the substrates in a solution of oxalic acid causes the grown nanowires to convert gradually into magnetite （Fe3O4） nanowires. Additionally, the saturated state of Fe3O4 nanowires is achieved as the oxalic acid concentration reaches 0.75 mol/L. The average diameter and length of nanowires expands with an increasing operation temperature and the growth density of nanowires accumulates with an increasing gas flux in the vapor-solid process. The growth mechanism of a-Fe2O3 and Fe3O4 nanowires is also discussed. The results demonstrate that the entire synthesis of nanowires can be completed within 2 h.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51132002 and 11574261)the Natural Science Foundation of Hebei ProvinceChina(Grant No.A2015203261)
文摘The structures and electronic properties of ZnO nanowires（NWs） of different diameters are investigated by employing the first-principles density functional theory. The results indicate that the oxygen vacancy（VO） exerts a more evident influence on the band gap of the ZnO NWs. However, the effect will be weakened with the increase of the diameter. In addition, the energy band shifts downward due to the existence of VOand the offset decreases with the reduction of the VOconcentration. As the concentration of surface Zn atoms decreases, the conduction band shifts downward, while 2p electrons are lost in the oxygen vacancy, resulting in the split of valence band and the formation of an impurity level. Our findings agree well with the previous observations and will be of great importance for theoretical research based on ZnO NWs.
基金This work was supported by the National Natural Science Foundation of China(Nos.11934019,61675228,11721404,51761145104,and 11874419)the Strategic Priority Research Program,the Instrument Developing Project and the Interdisciplinary Innovation Team of the Chinese Academy of Sciences(Nos.XDB28000000 and YJKYYQ20180036)+2 种基金the Key RD Program of Guangdong Province(No.2018B030329001)the Key Laboratory Fund(No.614280303051701)We acknowledge financial support from the SUPERTOP project,QUANTERA ERA-NET Cofund in Quantum Technologies.
文摘Crystal-phase low-dimensional structures offer great potential for the implementation of photonic devices of interest for quantum information processing.In this context,unveiling the fundamental parameters of the crystal phase structure is of much relevance for several applications.Here,we report on the anisotropy of the g-factor tensor and diamagnetic coefficient in wurtzite/zincblende(WZ/ZB)crystal-phase quantum dots(QDs)realized in single InP nanowires.The WZ and ZB alternating axial sections in the NWs are identified by high-angle annular dark-field scanning transmission electron microscopy.The electron(hole)g-factor tensor and the exciton diamagnetic coefficients in WZ/ZB crystal-phase QDs are determined through micro-photoluminescence measurements at low temperature(4.2 K)with different magnetic field configurations,and rationalized by invoking the spin-correlated orbital current model.Our work provides key parameters for band gap engineering and spin states control in crystal-phase low-dimensional structures in nanowires.
文摘Organometallic halide perovskite materials have triggered global attention in recent years due to their exciting and optimistic high performance energy conversion properties(high luminescence efficiency and tremendous optical absorption ability[1,2]).These interesting photovoltaic properties together make them a promising candidate for high performance optoelectronic
基金supported by the National Research Foundation of Korea(NRF),funded by the Ministry of Education,Science,and Technology(2018R1A6A1A03024334,NRF-2019R1A2C1006360)supported by Basic Science Research Capacity Enhancement Project through Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(2019R1A6C1010024)。
文摘Photoelectrochemical(PEC)water splitting is regarded as the most promising method to generate“green hydrogen”,and zinc oxide(ZnO)has been identified as one of the promising candidates for PEC water splitting owing to its straddling band alignment with the water redox level.However,its PEC performance is limited due to its wide bandgap and anticipated by photocorrosion in an aqueous medium.In this work,we present strategic improvements in the PEC water splitting performance of ZnO nanowires(NWs)by nitrogen(N)-doping along with photostability by the core–shell deposition of a NiOOH cocatalyst.Highly crystalline hierarchical ZnO NWs were fabricated on Si NWs(ZnO-Si HNWs)using a metal organic chemical vapor deposition approach.The NWs were then N-doped by annealing in an NH_(3) atmosphere.The N-doped ZnO-Si HNWs(N:ZnO-Si HNWs)showed enhanced visible light absorption,and suppressed recombination of the photogenerated carriers.As compared to ZnO-Si HNWs(0.045 m A cm^(-2) at 1.23 V vs RHE),the N:ZnO-Si HNWs(0.34 m A cm^(-2) at 1.23 V vs RHE)annealed in NH^(3) ambient for 3 h at 600℃showed 7.5-fold enhancement in the photocurrent density.NiOOH-deposited N:ZnO-Si HNW photoanodes with a photostability of 82.21%over 20000 s showed 10.69-fold higher photocurrent density(0.48 m A cm^(-2) at 1.23 V vs RHE)than ZnO-Si HNWs.
