High-surface-area ZnO nanosheets are prepared using a template-assisted hydrothermal method.A saturation moment as high as 0.02 emu/g is obtained for the ZnO nanosheets.Both photoluminescence spectroscopy and x-ray ph...High-surface-area ZnO nanosheets are prepared using a template-assisted hydrothermal method.A saturation moment as high as 0.02 emu/g is obtained for the ZnO nanosheets.Both photoluminescence spectroscopy and x-ray photoelectron spectroscopy demonstrate the existence of abundant oxygen vacancies on the surfaces of the nanosheets.In addition,the oxygen vacancy concentration increases with an increasing nanosheet surface area.The results show that the origin of the room-temperature ferromagnetism is closely related with a large surface area and oxygen vacancies of the nanosheets.This finding suggests that the high-surface-area ZnO nanosheets are promising to be applied to spintronic devices.展开更多
Nanocrystalline Mn-Zn ferrites （Mno.GZno.4Fe204） with particle size of 12 nm were synthesized hydrotherreally using spent alkaline Zn-Mn batteries, and accompanied by a study of the influencing factors. The nanocrys...Nanocrystalline Mn-Zn ferrites （Mno.GZno.4Fe204） with particle size of 12 nm were synthesized hydrotherreally using spent alkaline Zn-Mn batteries, and accompanied by a study of the influencing factors. The nanocrystals were examined by powder X-ray diffraction （XRD） for crystalline phase identification, and scanning electron microscopy （SEM） for grain morphology. The relationship between concentration of Fe（II）, Mn（II）, and Zn（II） and pH value was obtained through thermodynamic analysis of the Fe（II）-Mn（II）-Zn（II）-NaOH-H2O system. The results showed that all ions were precipitated completely at a pH value of 10-11. The optimal preparation conditions are： co-precipitation pH of 10.5, temperature of 200 ℃ and time of 9 h.展开更多
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0201001the National Natural Science Foundation of China under Grant No 11574071+1 种基金the Natural Science Foundation for Outstanding Young Researcher in Hebei Province under Grant No E2016210093the Natural Science Foundation of Hebei Province under Grant No A2018210123
文摘High-surface-area ZnO nanosheets are prepared using a template-assisted hydrothermal method.A saturation moment as high as 0.02 emu/g is obtained for the ZnO nanosheets.Both photoluminescence spectroscopy and x-ray photoelectron spectroscopy demonstrate the existence of abundant oxygen vacancies on the surfaces of the nanosheets.In addition,the oxygen vacancy concentration increases with an increasing nanosheet surface area.The results show that the origin of the room-temperature ferromagnetism is closely related with a large surface area and oxygen vacancies of the nanosheets.This finding suggests that the high-surface-area ZnO nanosheets are promising to be applied to spintronic devices.
文摘Nanocrystalline Mn-Zn ferrites （Mno.GZno.4Fe204） with particle size of 12 nm were synthesized hydrotherreally using spent alkaline Zn-Mn batteries, and accompanied by a study of the influencing factors. The nanocrystals were examined by powder X-ray diffraction （XRD） for crystalline phase identification, and scanning electron microscopy （SEM） for grain morphology. The relationship between concentration of Fe（II）, Mn（II）, and Zn（II） and pH value was obtained through thermodynamic analysis of the Fe（II）-Mn（II）-Zn（II）-NaOH-H2O system. The results showed that all ions were precipitated completely at a pH value of 10-11. The optimal preparation conditions are： co-precipitation pH of 10.5, temperature of 200 ℃ and time of 9 h.
