Gao Xiangdong, Li Xiaomin, Yu Weidong
State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics of Chinese Academy of Sciences, Shanghai, 200050, People's Republic of China.
J Phys Chem B. 2005 Jan 27;109(3):1155-61. doi: 10.1021/jp046267s.
Flowerlike ZnO nanostructures (FZNs) have been deposited on Si substrate from aqueous solution by the hexamethylenetetramine (HMT)-assisted thermolysis of zinc-ethylenediamine (en) complex at low temperature (95 degrees C) and in a short time (60 min). Obtained FZNs exhibit well-defined flowerlike morphology, hexagonal wurtzite structure, and strong UV photoluminescence. The flower petals constructed by many well-aligned nanorods possess the typical tapering feature with tip sizes of 30-50 nm. Effects of en, zinc-en molar ratio, HMT, and reaction time were investigated. Results show that en is determinative to the formation of FZNs, and the partial capping of NH(3).(CH(2))(2).NH(3) molecules on the side surface of the ZnO crystal is responsible for the tapering feature of petals. HMT can step into the nucleation process of ZnO and inhibit the formation of nanorods on the substrate by preventing heterogeneous precipitation. Moreover, the formation of twin crystal ZnO nuclei at low precursor concentrations and their further evolution into spindle crystals with clear middle interfaces are also vitally important for the development of FZNs.
通过六亚甲基四胺（HMT）辅助的乙二胺锌（en）配合物在低温（95℃）和短时间（60分钟）下的热分解，从水溶液中在硅衬底上沉积了花状氧化锌纳米结构（FZNs）。所获得的FZNs呈现出明确的花状形态、六方纤锌矿结构和强烈的紫外光致发光。由许多排列良好的纳米棒构成的花瓣具有典型的逐渐变细特征，尖端尺寸为30 - 50纳米。研究了乙二胺、锌 - 乙二胺摩尔比、六亚甲基四胺和反应时间的影响。结果表明，乙二胺对FZNs的形成起决定性作用，并且NH(3).(CH(2))(2).NH(3)分子在ZnO晶体侧面的部分封端作用导致了花瓣的逐渐变细特征。六亚甲基四胺可以进入ZnO的成核过程，并通过防止异质沉淀来抑制衬底上纳米棒的形成。此外，在前体浓度较低时形成孪晶ZnO核以及它们进一步演变成具有清晰中间界面的纺锤体晶体对于FZNs的形成也至关重要。
