Large and uniform tetrapod-like ZnO whiskers （T-ZnO） were prepared from waste hot dipping zinc by vapor oxidation and examined by means of X-ray diffraction and ICP-AES analysis and scanning electron microscope. The...Large and uniform tetrapod-like ZnO whiskers （T-ZnO） were prepared from waste hot dipping zinc by vapor oxidation and examined by means of X-ray diffraction and ICP-AES analysis and scanning electron microscope. The products are pure hexagonal wurtzite crystals with tetrapod shape and edge size of center body 56 μm and needle length of 100130 μm. The size and shape of ZnO particles are fully controlled by the growth conditions and T-ZnO can be obtained only at 8501 000 ℃ and total gas flow rate ranging from 40 to 250 L·h-1 in which the size of the T-ZnO particles varies slightly with temperature. The process of the formation of T-ZnO is that T-ZnO may nucleate at the initial stage with a complete tetrapod shape and develop to the large size, but not the process of （preferential） growth of octahedral nuclei and subsequent growth of the needles. The experiment presents a new method to prepare T-ZnO economically by using the waste hot dipping zinc.展开更多
Some types of ZnO nanostructures with various shape and size, includingtetrapod-like ZnO (T-ZnO) nanorods, nanowires and nanoribbons, have been obtained by controlledgrowth process. The nanostructures of ZnO have been...Some types of ZnO nanostructures with various shape and size, includingtetrapod-like ZnO (T-ZnO) nanorods, nanowires and nanoribbons, have been obtained by controlledgrowth process. The nanostructures of ZnO have been investigated by means of field-emission scanningelectron microscope, transmission electron microscopy and high-resolution transmission electronmicroscopy. The growth mechanisms of various ZnO nanostructures were proposed and discussed.展开更多
ZnO tetrapod-like whiskers were prepared through a hydrothermal process using zinc powder as raw material.Its microstructure and morphology were characterized by X-ray diffraction (XRD) and transmission electron micro...ZnO tetrapod-like whiskers were prepared through a hydrothermal process using zinc powder as raw material.Its microstructure and morphology were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD results showed that the crystal structure of as-obtained sample can be indexed to hexagonal wurtzite ZnO.TEM results revealed that the ZnO sample took on tetrapod-like whisker shape.The gas sensors were prepared with the traditional sintering process and their gas sensitivities were detected.The test results of gas sensitivity showed that the sensors based on ZnO tetrapod-like whiskers are very sensitive to dilute ethanol vapor and H_2S.The relatively high sensitivity and selectivity of these sensors made from ZnO tetrapod-like whiskers demonstrated the potential for developing a new class of selective ethanol sensors.展开更多
Some types of ZnO nanostructures with various shape and size, including tetrapod-like ZnO (T-ZnO) nanorods, nanowires and nanonbbons, have been obtained by controlled growth process. The nanostructures of ZnO have bee...Some types of ZnO nanostructures with various shape and size, including tetrapod-like ZnO (T-ZnO) nanorods, nanowires and nanonbbons, have been obtained by controlled growth process. The nanostructures of ZnO have been investigated by means of field-emission scanning electron microscope, transmission electron microscopy and high-resolution transmission electron microscopy. The growth mechanisms of various ZnO nanostructures were proposed and discussed.展开更多
ZnO whiskers with a length of 30-40μm and a diameter of about 1μm were synthesized by co-precipitation of ZnSO 4 and Na2CO3 solution at room temperature followed by hydrothermal treatment of the as-prepared Zn5(CO3)...ZnO whiskers with a length of 30-40μm and a diameter of about 1μm were synthesized by co-precipitation of ZnSO 4 and Na2CO3 solution at room temperature followed by hydrothermal treatment of the as-prepared Zn5(CO3)2(OH)6 precursor at 160 ℃for 6 h.The increase of the initial solution pH promotes the hydrothermal conversion of the particulate Zn5(CO3)2(OH)6 to ZnO whiskers.The presence of minor amount of EDTA in the hydrothermal solution promotes the one dimensional growth of ZnO whiskers,leading to the formation of ZnO whiskers with a length of 50-60μm and a diameter of 1-2μm.展开更多
文摘Large and uniform tetrapod-like ZnO whiskers （T-ZnO） were prepared from waste hot dipping zinc by vapor oxidation and examined by means of X-ray diffraction and ICP-AES analysis and scanning electron microscope. The products are pure hexagonal wurtzite crystals with tetrapod shape and edge size of center body 56 μm and needle length of 100130 μm. The size and shape of ZnO particles are fully controlled by the growth conditions and T-ZnO can be obtained only at 8501 000 ℃ and total gas flow rate ranging from 40 to 250 L·h-1 in which the size of the T-ZnO particles varies slightly with temperature. The process of the formation of T-ZnO is that T-ZnO may nucleate at the initial stage with a complete tetrapod shape and develop to the large size, but not the process of （preferential） growth of octahedral nuclei and subsequent growth of the needles. The experiment presents a new method to prepare T-ZnO economically by using the waste hot dipping zinc.
基金The work was financially supported by the National Science Fund for Distinguished Young Scholars and the National Natural Science Foundation of China (No.50172006, 50232030) the Fund for Returned Overseas Scholar of Ministry of Education of China, and
文摘Some types of ZnO nanostructures with various shape and size, includingtetrapod-like ZnO (T-ZnO) nanorods, nanowires and nanoribbons, have been obtained by controlledgrowth process. The nanostructures of ZnO have been investigated by means of field-emission scanningelectron microscope, transmission electron microscopy and high-resolution transmission electronmicroscopy. The growth mechanisms of various ZnO nanostructures were proposed and discussed.
文摘ZnO tetrapod-like whiskers were prepared through a hydrothermal process using zinc powder as raw material.Its microstructure and morphology were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD results showed that the crystal structure of as-obtained sample can be indexed to hexagonal wurtzite ZnO.TEM results revealed that the ZnO sample took on tetrapod-like whisker shape.The gas sensors were prepared with the traditional sintering process and their gas sensitivities were detected.The test results of gas sensitivity showed that the sensors based on ZnO tetrapod-like whiskers are very sensitive to dilute ethanol vapor and H_2S.The relatively high sensitivity and selectivity of these sensors made from ZnO tetrapod-like whiskers demonstrated the potential for developing a new class of selective ethanol sensors.
文摘Some types of ZnO nanostructures with various shape and size, including tetrapod-like ZnO (T-ZnO) nanorods, nanowires and nanonbbons, have been obtained by controlled growth process. The nanostructures of ZnO have been investigated by means of field-emission scanning electron microscope, transmission electron microscopy and high-resolution transmission electron microscopy. The growth mechanisms of various ZnO nanostructures were proposed and discussed.
基金Project(50874066) supported by the National Natural Science Foundation of China
文摘ZnO whiskers with a length of 30-40μm and a diameter of about 1μm were synthesized by co-precipitation of ZnSO 4 and Na2CO3 solution at room temperature followed by hydrothermal treatment of the as-prepared Zn5(CO3)2(OH)6 precursor at 160 ℃for 6 h.The increase of the initial solution pH promotes the hydrothermal conversion of the particulate Zn5(CO3)2(OH)6 to ZnO whiskers.The presence of minor amount of EDTA in the hydrothermal solution promotes the one dimensional growth of ZnO whiskers,leading to the formation of ZnO whiskers with a length of 50-60μm and a diameter of 1-2μm.
