Template-free synthesis of zinc citrate yolk-shell microspheres and their transformation to ZnO yolk-shell nanospheres
Template-free synthesis of zinc citrate yolk-shell microspheres and their transformation to ZnO yolk-shell nanospheres
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柠檬酸锌蛋黄壳微球的无模板合成及其向氧化锌蛋黄壳纳米球的转化
DOI：
10.1039/c2jm31243c
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发表时间：
2012-01-01
影响因子：
--
通讯作者：
Shi, Rongrong
中科院分区：
文献类型：
--
作者：
Xie, Qingshui;Li, Jiangong;Shi, Rongrong
提出了一种简便、绿色、无模板法制备柠檬酸锌蛋黄壳无定形微球和晶态氧化锌蛋黄壳纳米球的新方法。在这种方法中，柠檬酸锌蛋黄壳无定形微球是在低温(90℃)下通过一次化学反应和室温老化得到的。柠檬酸锌蛋黄壳微球的平均粒径约为1.25微米，内核的平均直径为500 nm，外壳的平均厚度为150 nm。分析了时效时间对柠檬酸锌微观结构形态的影响。随着陈化时间的延长，柠檬酸锌的微观结构由实心微球、蛋黄壳微球向中空微球转变。将柠檬酸锌固体微球、蛋黄壳纳米球和空心微球完美地结合在一起，在600℃焙烧2 h即可制得氧化锌固体纳米球、蛋黄壳纳米球和中空纳米球，其中锌蛋黄壳纳米球具有最大的可见光发射和光催化活性。
A novel, facile, green and template-free approach was developed for the fabrication of amorphous zinc citrate yolk-shell microspheres and crystalline ZnO yolk-shell nanospheres. In this approach, the amorphous zinc citrate yolk-shell microspheres were prepared through a single chemical reaction at low temperature (90 degrees C) and with room temperature ageing. The zinc citrate yolk-shell microspheres have an average size of about 1.25 mu m. The average diameter of the inner cores and the average thickness of the outer shells are 500 nm and 150 nm, respectively. The effect of ageing time on the morphology of the zinc citrate microstructures was analysed. As the ageing time increases from 0 to 12 h, the zinc citrate microstructure transforms from a solid microsphere through a yolk-shell microsphere to a hollow microsphere. The ZnO solid nanospheres, yolk-shell nanospheres and hollow nanospheres can be prepared via the perfect morphology inheritance of the zinc citrate solid microspheres, yolk-shell microspheres and hollow microspheres, by calcination at 600 degrees C for 2 h. The ZnO yolk-shell nanospheres show the largest visible emission and the highest photocatalytic activity.