以La_2O_3和Ta_2O_5为原材料,采用固相反应法制备了La_2La Ta O_7粉体。用X射线衍射技术、扫描电子显微镜、EDS电子能谱分析了粉体的相结构,显微形貌和元素组成。用激光颗粒度仪和比表面积分析仪分析了粉体的颗粒度及表面积,用可见光照...以La_2O_3和Ta_2O_5为原材料,采用固相反应法制备了La_2La Ta O_7粉体。用X射线衍射技术、扫描电子显微镜、EDS电子能谱分析了粉体的相结构,显微形貌和元素组成。用激光颗粒度仪和比表面积分析仪分析了粉体的颗粒度及表面积,用可见光照射下亚甲基蓝的降解率分析了该粉体的光催化活性。结果表明,本文成功合成了纯净具有单一氟铝镁钠石结构的La_2La Ta O_7粉体,粉体具有明显的团聚现象,其平均颗粒度约为24μm,比表面积仅为0.463 m^2/g。经过150 min照射后,该粉体对亚甲基蓝的降解率达到68%,其较低的降解率可能与其较低的比表面积有关。展开更多
Long lasting blue-green-emitting Sr4Al14O25:Eu2+ phosphors were synthesized by solid-state reactions.The phosphors were investigated by X-ray diffraction(XRD) and fluorescence spectrophotometer.A pure phase of Sr4Al14...Long lasting blue-green-emitting Sr4Al14O25:Eu2+ phosphors were synthesized by solid-state reactions.The phosphors were investigated by X-ray diffraction(XRD) and fluorescence spectrophotometer.A pure phase of Sr4Al14O25:Eu2+ phosphor was obtained at 1250 °C.There are two different types of Eu emission centers in Sr4Al14O25:Eu2+ phosphor.The effects of the Eu2+ concentration and the reducing temperature on the distribution of Eu2+ among different sites were investigated.The energy transfer mechanism between...展开更多
文摘以La_2O_3和Ta_2O_5为原材料,采用固相反应法制备了La_2La Ta O_7粉体。用X射线衍射技术、扫描电子显微镜、EDS电子能谱分析了粉体的相结构,显微形貌和元素组成。用激光颗粒度仪和比表面积分析仪分析了粉体的颗粒度及表面积,用可见光照射下亚甲基蓝的降解率分析了该粉体的光催化活性。结果表明,本文成功合成了纯净具有单一氟铝镁钠石结构的La_2La Ta O_7粉体,粉体具有明显的团聚现象,其平均颗粒度约为24μm,比表面积仅为0.463 m^2/g。经过150 min照射后,该粉体对亚甲基蓝的降解率达到68%,其较低的降解率可能与其较低的比表面积有关。
基金supported by the National Natural Science Foundation of China (60477034)
文摘Long lasting blue-green-emitting Sr4Al14O25:Eu2+ phosphors were synthesized by solid-state reactions.The phosphors were investigated by X-ray diffraction(XRD) and fluorescence spectrophotometer.A pure phase of Sr4Al14O25:Eu2+ phosphor was obtained at 1250 °C.There are two different types of Eu emission centers in Sr4Al14O25:Eu2+ phosphor.The effects of the Eu2+ concentration and the reducing temperature on the distribution of Eu2+ among different sites were investigated.The energy transfer mechanism between...
