空心和多孔Y_(2)O_(3):Eu^(3+)微球的超声喷雾热解法可控合成及其光致发光性能

Controllable synthesis and photoluminescence properties of Y_(2)O_(3):Eu^(3+)hollow microspheres and porous microspheres via ultrasonic spray pyrolysis

以蔗糖或柠檬酸为辅助剂,通过改变超声喷雾热解期间雾滴中溶剂的蒸发方式和溶质聚集状态,进行空心和多孔Y_(2)O_(3):Eu^(3+)微球的可控合成。探究了辅助剂的种类和比例对微球形貌的影响,提出了空心和多孔Y_(2)O_(3):Eu^(3+)微球形成机制,并分析了空心和多孔Y_(2)O_(3):Eu^(3+)微球的晶体结构及光致发光性能。结果表明:Y_(2)O_(3):Eu^(3+)微球组分均匀,仍保留立方Y2O3结构;添加蔗糖后可获得中空结构,添加柠檬酸则为多孔结构,这归因于添加的蔗糖在雾滴干燥时络合成膜,水分透过膜蒸发,溶质沉积在膜内壁形成空心球壳,而添加的柠檬酸则与溶质形成均匀的螯合物,在高热解温时产生大量原位介孔;空心和多孔Y_(2)O_(3):Eu^(3+)微球均在611 nm处表现出典型的红光发射,且空心微球的发光强度可达不添加辅助剂合成的实心微球的96.6%。该研究可为大规模产业化合成形貌可控的空心和多孔Y_(2)O_(3):Eu^(3+)微球提供参考。

In this paper,with sucrose and citric acid as auxiliary agents,the controllable synthesis of Y_(2)O_(3):Eu^(3+)hollow microspheres and porous microspheres was realized by changing the solvent evaporation mode and solute agglomeration state of mist droplets during ultrasonic spray pyrolysis.Herein,the effects of the types and proportions of auxiliary agents on the morphology of microspheres were systematically explored,and the formation mechanism of Y_(2)O_(3):Eu^(3+)hollow microspheres and porous microspheres was proposed.Furthermore,the crystal structure and photoluminescence properties of Y_(2)O_(3):Eu^(3+)hollow microspheres and porous microspheres were also analyzed.Our results show that the Y_(2)O_(3):Eu^(3+)microspheres obtained have uniform composition and still retain the cubic Y2O3structure.The hollow structure can be obtained after adding sucrose,while the porous structure can be obtained with the addition of citric acid.The hollow structure was formed as sucrose could bond into a film on the mist droplets′surface as fog drop dry,promoting the deposition of solutes in the inner film wall with the moisture evaporating.However,the citric acid added could form uniform chelates with solute,and decomposition of chelates resulted in a mass of in situ mesopores at high temperature.Photoluminescence spectrum indicated that hollow and porous microspheres both exhibited typical red emission at 611 nm,and the hollow microspheres′luminous intensity was 96.6%of that of solid microspheres prepared without adjuvants.Overall,our results are believed to provide a novel guideline for industrialized preparation of hollow/porous Y_(2)O_(3):Eu^(3+)microspheres with controllable morphology.