The highly ordered CuO nanowire arrays of composite-oxides were synthesized within a porous anodic aluminum oxide(AAO) template by a citrate-based sol-gel route. A vacuum system was applied to draw the gel into the te...The highly ordered CuO nanowire arrays of composite-oxides were synthesized within a porous anodic aluminum oxide(AAO) template by a citrate-based sol-gel route. A vacuum system was applied to draw the gel into the template pores, which conquers the only driving force of this technique—capillary action, then the gel was thermally treated to prepare desired CuO nanowires. The results of scanning electron microscopy(SEM) indicate that the CuO nanowires are very uniformly assembled and parallel to each other in the pores of the anodic aluminum oxide(AAO) template membranes. The results of X-ray diffraction(XRD) and the selected-area electron diffraction(SAED) indicate that the CuO nanowires are monoclinic-type crystalline structure. Furthermore, X-ray photoelectron spectroscopy (XPS) demonstrates that the stoichiometric CuO is formed.展开更多
A new kind of self-standing CuO@TiO2 nanowires (NWs) film with hierarchical feature was prepared by a three-step protocol consisting of hydrothermal reaction, electroless plating, and branched growth processes. This h...A new kind of self-standing CuO@TiO2 nanowires (NWs) film with hierarchical feature was prepared by a three-step protocol consisting of hydrothermal reaction, electroless plating, and branched growth processes. This heterostructured CuO@TiO2 NWs film demonstrates the favorable physical properties in the photoelectrochemical cell (PEC) water splitting, such as the hierarchical surface, the extended optical absorption range, and the rapid interface charge transfer kinetics. Under the illumination of the simulated solar light, the pristine TiO2 NWs film only attains a photocurrent density of 0.12 mA/cm2 at 1.0 V versus reversible hydrogen electrode (RHE). Significantly, the CuO@TiO2 NWs film can yield a dramatically increased photocurrent density of 0.56 mA/cm2 at the same applied voltage. Furthermore, amperometric I?t tests of the CuO@TiO2 NWs film reveal satisfactory stability. All the above characteristics of this heterostructured CuO@TiO2 NWs film indicate its great potential in the water splitting applications with solar visible light.展开更多
We report a systematic study on wrinkling and CuO nanowires （NWs） growth in the thermal oxidation of copper foil. Copper foils with thickness of 0.5 mm were thermally oxidized in air at 500℃ for 0.5-10 h. It is fou...We report a systematic study on wrinkling and CuO nanowires （NWs） growth in the thermal oxidation of copper foil. Copper foils with thickness of 0.5 mm were thermally oxidized in air at 500℃ for 0.5-10 h. It is found that all the samples have wrinkles and the size of the wrinkles increases with the oxidation time increasing. CuO NWs can grow on both the sidehill and hilltop of wrinkle. The CuO NWs on sidehill are longer and denser than those on hilltop. The growth direction of the CuO NWs on sidehill is not vertical to the substrate but vertical to their growth surfaces. The process of wrinkling and CuO NWs growth can be divided into three stages： undulating, voiding, and cracking. The CuO NWs on both sidehill and hilltop grow at the undulating stage. However, only the CuO NWs on sidehill grow and those on hilltop stop growing at the voiding and cracking stages because of the void in hilltop. The local electric field in a wrinkle at undulating stage was calculated, and it is found that the difference of local electric field strengths between hilltop and sidehill is small, which indicates that the predominant driving force for the diffusion of Cu ion during CuO NWs growth is internal stress.展开更多
We report the preparation of porous CuO nanowires that are composed of nanoparticles （-50 nm） via a simple decomposition of a Cu（OH）2 precursor and their application as the anode materials of rechargeable Na-ion b...We report the preparation of porous CuO nanowires that are composed of nanoparticles （-50 nm） via a simple decomposition of a Cu（OH）2 precursor and their application as the anode materials of rechargeable Na-ion batteries. The as-prepared porous CuO nanowires exhibit a Brunauer-Emmett-Teller （BET） surface area of 13.05 m^2.g^-1, which is six times larger than that of bulk CuO （2.16 m^2.g^-1）. The anode of porous CuO nanowires showed discharge capacities of 640 mA.h.g^-1 in the first cycle and 303 mA.h.g^-1 after 50 cycles at 50 mA.g^-1 The high capacity is attributed to porous nanostructure which facilitates fast Na-intercalation kinetics. The mechanism of electrochemical Na-storage based on conversion reactions has been studied through cyclic voltammetry, X-ray diffraction （XRD）, Raman spectroscopy, and high resolution transmission electron microscopy （HRTEM）. It is demonstrated that in the discharge process, Na＋ions first insert into CuO to form a CuⅡ1-x CuⅠ x O1-x/2solid and a Na2O matrix then CuⅡ1-xCu Ⅰ xO1-x/2 reacts with Na＋ to produce Cu2O, and finally Cu2O decompose into Cu nanoparticles enclosed in a Na2O matrix. During the charge process, Cu nanopartides are first oxidized to generate Cu2O and then converted back to CuO. This result contributes to the design and mechanistic analysis of high-performance anodes for rechargeable Na-ion batteries.展开更多
A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexa...A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexapods, were formed in high morphological yields （90%） by reducing cupric acetate with o-anisidine or o-phenetidine in the presence of carboxylic acids. The architectures of these Cu2O nanowire polyhedra were examined by electron microscopy, which revealed ordered, highly aligned CU2O nanowires within the polyhedral outlines. The growth of the Cu2O nanowire polyhedra is controlled by the orientation and growth rates of the nanowire branches which are adjusted by addition of carboxylic acids. Compared to the Cu2O samples reported in the recent literature, the Cu2O nanowire octahedra exhibit notably enhanced photocatalytic activities for dye degradation in the presence of H202 under visible light, probably due to the high-density charge carriers photoexcited from the branched nanowires with their special structures. Additionally, the discussion in the recent literature of the photocatalytic activity of Cu2O in the absence of H2O2 for direct photodegradation of dyes seems questionable.展开更多
A Cu nanowire （NW）/cuprous oxide （Cu2O）-based semiconductor-liquid junction solar cell with a greatly enhanced efficiency and reduced cost was assembled. The Cu NWs function as a transparent electrode as well as p...A Cu nanowire （NW）/cuprous oxide （Cu2O）-based semiconductor-liquid junction solar cell with a greatly enhanced efficiency and reduced cost was assembled. The Cu NWs function as a transparent electrode as well as part of the Cu NWs/ Cu2O coaxial structures, which remarkably benefit the charge separation. The best solar cell reached a conversion efficiency as high as 1.92% under a simulated AM1.5G illumination, which is 106 times higher than that of cells based on fluorine-doped tin oxide and Cu2O.展开更多
To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating el...To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating electrical potential distribution on the micro-electrode chip is performed by COMSOL software, and the simulation result shows that the coupled electrical poten- tial on the floating drain electrodes is very close to the original electrical potential applied on the gate electrode, whicb means that the method can provide di-electrophoresis （DEP） force for all the electrode pairs at one time, thus realizing large-scale as- sembly at one time. With Cu/CuO nanowires well dispersed and micro-electrode chip fabrication, nanowires assembly experiments are performed and the experimental results show that Cu/CuO nanowires are assembled at hundreds of micro-electrodes pairs at one time, and the success rate of nanowires assembly also reaches 90%.展开更多
Copper oxide nanowires and nanoparticles were fabricated through electrospinning followed by calcinations in different heating conditions.It was found that the solution viscosity and environment humidity had great imp...Copper oxide nanowires and nanoparticles were fabricated through electrospinning followed by calcinations in different heating conditions.It was found that the solution viscosity and environment humidity had great impact on the morphologies of precursor nanowires,and the parameters of heat treatment,including final temperature and heating rate,significantly affected the product morphologies.展开更多
Li-ion batteries are a key technology for multiple clean energy applications.In this study,Cu2O nanowires were obtained by the reduction of cupric acetate with pyrrole.The resulting Cu2O nanowires exhibited excellent ...Li-ion batteries are a key technology for multiple clean energy applications.In this study,Cu2O nanowires were obtained by the reduction of cupric acetate with pyrrole.The resulting Cu2O nanowires exhibited excellent reversible capacities of 470mAh g-1 at rate of 1 C after 100 cycles.The results show that the Cu2O nanowires had more capacity than materials previously reported.No fading was observed over 100 cycles of charging and discharging.The compound metal Cu and incorporation of the conducting polymer polypyrrole(PPy)improved the conductivity of Cu2O and enhanced the stability of the electrode during cycling.The results from this study imply that Cu2O nanowires with high capacity and good cycle retention could be excellent candidates as anode materials for Li-ion rechargeable batteries.展开更多
基金Project(200623) supported by the Science Foundation of Shenzhen University, China
文摘The highly ordered CuO nanowire arrays of composite-oxides were synthesized within a porous anodic aluminum oxide(AAO) template by a citrate-based sol-gel route. A vacuum system was applied to draw the gel into the template pores, which conquers the only driving force of this technique—capillary action, then the gel was thermally treated to prepare desired CuO nanowires. The results of scanning electron microscopy(SEM) indicate that the CuO nanowires are very uniformly assembled and parallel to each other in the pores of the anodic aluminum oxide(AAO) template membranes. The results of X-ray diffraction(XRD) and the selected-area electron diffraction(SAED) indicate that the CuO nanowires are monoclinic-type crystalline structure. Furthermore, X-ray photoelectron spectroscopy (XPS) demonstrates that the stoichiometric CuO is formed.
基金Projects(21107032,21473079)supported by the National Natural Science Foundation of ChinaProjects(Y201330088,Y20133003)supported by the Department of Education of Zhejiang Province,China
文摘A new kind of self-standing CuO@TiO2 nanowires (NWs) film with hierarchical feature was prepared by a three-step protocol consisting of hydrothermal reaction, electroless plating, and branched growth processes. This heterostructured CuO@TiO2 NWs film demonstrates the favorable physical properties in the photoelectrochemical cell (PEC) water splitting, such as the hierarchical surface, the extended optical absorption range, and the rapid interface charge transfer kinetics. Under the illumination of the simulated solar light, the pristine TiO2 NWs film only attains a photocurrent density of 0.12 mA/cm2 at 1.0 V versus reversible hydrogen electrode (RHE). Significantly, the CuO@TiO2 NWs film can yield a dramatically increased photocurrent density of 0.56 mA/cm2 at the same applied voltage. Furthermore, amperometric I?t tests of the CuO@TiO2 NWs film reveal satisfactory stability. All the above characteristics of this heterostructured CuO@TiO2 NWs film indicate its great potential in the water splitting applications with solar visible light.
文摘We report a systematic study on wrinkling and CuO nanowires （NWs） growth in the thermal oxidation of copper foil. Copper foils with thickness of 0.5 mm were thermally oxidized in air at 500℃ for 0.5-10 h. It is found that all the samples have wrinkles and the size of the wrinkles increases with the oxidation time increasing. CuO NWs can grow on both the sidehill and hilltop of wrinkle. The CuO NWs on sidehill are longer and denser than those on hilltop. The growth direction of the CuO NWs on sidehill is not vertical to the substrate but vertical to their growth surfaces. The process of wrinkling and CuO NWs growth can be divided into three stages： undulating, voiding, and cracking. The CuO NWs on both sidehill and hilltop grow at the undulating stage. However, only the CuO NWs on sidehill grow and those on hilltop stop growing at the voiding and cracking stages because of the void in hilltop. The local electric field in a wrinkle at undulating stage was calculated, and it is found that the difference of local electric field strengths between hilltop and sidehill is small, which indicates that the predominant driving force for the diffusion of Cu ion during CuO NWs growth is internal stress.
基金This work was supported by the National Basic Rese- arch Program of China （973 Program） （2011CB935900）, the National Natural Science Foundation of China （NSFC） （51231003 and 21322101）, the National ＂111＂ Project of China＇s Higher Education （B12015）, and the Tianjin High-Tech Project （12ZCZDJC35300）.
文摘We report the preparation of porous CuO nanowires that are composed of nanoparticles （-50 nm） via a simple decomposition of a Cu（OH）2 precursor and their application as the anode materials of rechargeable Na-ion batteries. The as-prepared porous CuO nanowires exhibit a Brunauer-Emmett-Teller （BET） surface area of 13.05 m^2.g^-1, which is six times larger than that of bulk CuO （2.16 m^2.g^-1）. The anode of porous CuO nanowires showed discharge capacities of 640 mA.h.g^-1 in the first cycle and 303 mA.h.g^-1 after 50 cycles at 50 mA.g^-1 The high capacity is attributed to porous nanostructure which facilitates fast Na-intercalation kinetics. The mechanism of electrochemical Na-storage based on conversion reactions has been studied through cyclic voltammetry, X-ray diffraction （XRD）, Raman spectroscopy, and high resolution transmission electron microscopy （HRTEM）. It is demonstrated that in the discharge process, Na＋ions first insert into CuO to form a CuⅡ1-x CuⅠ x O1-x/2solid and a Na2O matrix then CuⅡ1-xCu Ⅰ xO1-x/2 reacts with Na＋ to produce Cu2O, and finally Cu2O decompose into Cu nanoparticles enclosed in a Na2O matrix. During the charge process, Cu nanopartides are first oxidized to generate Cu2O and then converted back to CuO. This result contributes to the design and mechanistic analysis of high-performance anodes for rechargeable Na-ion batteries.
基金This work was financially supported by the National Natural Science Foundation of China （No. 21071079）, the Research Fund of the State Key Laboratory of Materials-Oriented Chemical Engineering （2009）, and the Young Teachers Fund of Nanjing University of Technology.
文摘A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexapods, were formed in high morphological yields （90%） by reducing cupric acetate with o-anisidine or o-phenetidine in the presence of carboxylic acids. The architectures of these Cu2O nanowire polyhedra were examined by electron microscopy, which revealed ordered, highly aligned CU2O nanowires within the polyhedral outlines. The growth of the Cu2O nanowire polyhedra is controlled by the orientation and growth rates of the nanowire branches which are adjusted by addition of carboxylic acids. Compared to the Cu2O samples reported in the recent literature, the Cu2O nanowire octahedra exhibit notably enhanced photocatalytic activities for dye degradation in the presence of H202 under visible light, probably due to the high-density charge carriers photoexcited from the branched nanowires with their special structures. Additionally, the discussion in the recent literature of the photocatalytic activity of Cu2O in the absence of H2O2 for direct photodegradation of dyes seems questionable.
基金Acknowledgements This work was financially supported by the National Basic Research Program of China （No. 2012CB932303）, the National Natural Science Foundation of China （No. 61301036）, Shanghai Municipal Natural Science Foundation （Nos. 13ZR1463600 and 13XD1403900） and the Innovation Project of Shanghai Institute of Ceramics.
文摘A Cu nanowire （NW）/cuprous oxide （Cu2O）-based semiconductor-liquid junction solar cell with a greatly enhanced efficiency and reduced cost was assembled. The Cu NWs function as a transparent electrode as well as part of the Cu NWs/ Cu2O coaxial structures, which remarkably benefit the charge separation. The best solar cell reached a conversion efficiency as high as 1.92% under a simulated AM1.5G illumination, which is 106 times higher than that of cells based on fluorine-doped tin oxide and Cu2O.
基金supported by the National Natural Science Foundation of China(Grant No.51005230)China Postdoctoral Science Foundation(Grant No.2012M520654)the Education Department of Liaoning Province Science and Ttechnology Research Projects(Grant No.L2012213)
文摘To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating electrical potential distribution on the micro-electrode chip is performed by COMSOL software, and the simulation result shows that the coupled electrical poten- tial on the floating drain electrodes is very close to the original electrical potential applied on the gate electrode, whicb means that the method can provide di-electrophoresis （DEP） force for all the electrode pairs at one time, thus realizing large-scale as- sembly at one time. With Cu/CuO nanowires well dispersed and micro-electrode chip fabrication, nanowires assembly experiments are performed and the experimental results show that Cu/CuO nanowires are assembled at hundreds of micro-electrodes pairs at one time, and the success rate of nanowires assembly also reaches 90%.
基金The National Natural Science Foundation of China(Grant No.51171006)The Key Research Project in Science and Technology of Leshan(Grant No.12GZD066)
文摘Copper oxide nanowires and nanoparticles were fabricated through electrospinning followed by calcinations in different heating conditions.It was found that the solution viscosity and environment humidity had great impact on the morphologies of precursor nanowires,and the parameters of heat treatment,including final temperature and heating rate,significantly affected the product morphologies.
基金supported by the National Natural Science Foundation of China (Grant No. 81270209)Shanghai Pujiang Program (Grant No. 11PJD011)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning and Medical-Engineering (Science) Cross-Research Fund of Shanghai Jiao Tong University (Grant No. YG2013MS20)
文摘Li-ion batteries are a key technology for multiple clean energy applications.In this study,Cu2O nanowires were obtained by the reduction of cupric acetate with pyrrole.The resulting Cu2O nanowires exhibited excellent reversible capacities of 470mAh g-1 at rate of 1 C after 100 cycles.The results show that the Cu2O nanowires had more capacity than materials previously reported.No fading was observed over 100 cycles of charging and discharging.The compound metal Cu and incorporation of the conducting polymer polypyrrole(PPy)improved the conductivity of Cu2O and enhanced the stability of the electrode during cycling.The results from this study imply that Cu2O nanowires with high capacity and good cycle retention could be excellent candidates as anode materials for Li-ion rechargeable batteries.
