Yue Dan, Lu Wei, Jin Lin, Li Chunyang, Luo Wen, Wang Mengnan, Wang Zhenling, Hao Jianhua
The Key Laboratory of Rare Earth Functional Materials and Applications, Zhoukou Normal University, Zhoukou 466001, P. R. China.
Nanoscale. 2014 Nov 21;6(22):13795-802. doi: 10.1039/c4nr04359f.
Lanthanide doped ZnO mushroom-like 3D hierarchical structures have been fabricated by polyol-mediated method and characterized by various microstructural and optical techniques. The results indicate that the as-prepared ZnO:Ln(3+) (Ln = Tb, Eu) samples have a hexagonal phase structure and possess a mushroom-like 3D hierarchical morphology. The length of the whole mushroom from stipe bottom to pileus top is about 1.0 μm, and the diameters of pileus and stipe are about 0.8 μm and 0.4 μm, respectively. It is found that the flow of N2 is the key parameter for the formation of the novel ZnO structure and the addition of (NH4)2HPO4 has a prominent effect on the phase structure and the growth of mushroom-like morphology. The potential mechanism of forming this morphology is proposed. The pileus of the formed mushroom is assembled by several radial ZnO:Ln(3+) nanorods, whereas the stipe is composed of over layered ZnO:Ln(3+) nanosheets. Moreover, asymmetrical I-V characteristic curves of ZnO:Ln(3+) mushrooms indicate that the texture composition of the 3D hierarchical morphology might lead to the asymmetrical transport behavior of electrical conductivity. Lanthanide doped ZnO samples can exhibit red or green emission under the excitation of UV light.
通过多元醇介导法制备了镧系掺杂的ZnO蘑菇状三维分级结构，并采用各种微观结构和光学技术对其进行了表征。结果表明，所制备的ZnO:Ln(3+)（Ln = Tb、Eu）样品具有六方相结构，并呈现出蘑菇状三维分级形态。整个蘑菇从菌柄底部到菌盖顶部的长度约为1.0μm，菌盖和菌柄的直径分别约为0.8μm和0.4μm。研究发现，N2的流量是形成新型ZnO结构的关键参数，(NH4)2HPO4的添加对相结构和蘑菇状形态的生长有显著影响。提出了形成这种形态的潜在机制。所形成蘑菇的菌盖由几根径向排列的ZnO:Ln(3+)纳米棒组装而成，而菌柄则由多层ZnO:Ln(3+)纳米片组成。此外，ZnO:Ln(3+)蘑菇的不对称I-V特性曲线表明，三维分级形态的织构组成可能导致电导率的不对称传输行为。镧系掺杂的ZnO样品在紫外光激发下可发出红色或绿色荧光。
