SnO_2 whiskers were prepared from the decomposition of whisker-like SnC_2O_4,which was precipitated by a reaction between an aqueous SnCl_2 and oxalic acid solution at high solution temperatures (80℃).After the decom...SnO_2 whiskers were prepared from the decomposition of whisker-like SnC_2O_4,which was precipitated by a reaction between an aqueous SnCl_2 and oxalic acid solution at high solution temperatures (80℃).After the decomposition of SnC_2O_4 at 450℃,SnO_2 whiskers containing both of rutile and metastable orthorhombic phases were obtained with the content of the orthorhombic phase decreasing with increasing heat-treatment temperature and time.The effect of orthorhombic phase upon CO gas sensitivity was investigated by measuring the evolution of the primary particle size and the CO sensitivity with repeating heat treatment at 450℃.The 50μg/g CO sensitivity increased with decreasing concentration of the orthorhombic phase despite particle coarsening,which suggests that the orthorhombic phase is detrimental to the CO gas sensitivity.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
文摘SnO_2 whiskers were prepared from the decomposition of whisker-like SnC_2O_4,which was precipitated by a reaction between an aqueous SnCl_2 and oxalic acid solution at high solution temperatures (80℃).After the decomposition of SnC_2O_4 at 450℃,SnO_2 whiskers containing both of rutile and metastable orthorhombic phases were obtained with the content of the orthorhombic phase decreasing with increasing heat-treatment temperature and time.The effect of orthorhombic phase upon CO gas sensitivity was investigated by measuring the evolution of the primary particle size and the CO sensitivity with repeating heat treatment at 450℃.The 50μg/g CO sensitivity increased with decreasing concentration of the orthorhombic phase despite particle coarsening,which suggests that the orthorhombic phase is detrimental to the CO gas sensitivity.
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.
