氧化锌纳米棒的生长过程研究

The Study on the Growth Process of ZnO Nanorods

利用高分子聚乙烯吡咯烷酮 (PVP)和乙酸锌的配合物作为前驱体 ,在 30 0℃温度下煅烧 ,并制备了氧化锌纳米棒。生成的产物用XRD ,TEM ,SAED等测试方法进行了表征。为了研究氧化锌纳米棒的生长过程 ,我们通过控制制备前驱体所需原料的比例不变 ,改变在 30 0℃温度下煅烧的时间 ,分别为 0 5 ,3,12和2 4h ,来观察生成产物的形貌特征。实验发现在 110℃温度下干燥的前驱体中已经有氧化锌微晶生成 ;在30 0℃温度下煅烧 0 5h后就出现了明显的由几个纳米大小的微晶所组成的氧化锌纳米棒 ;煅烧 3h后的产物是结构非常完整的径直单晶ZnO纳米棒 ;12和 2 4h煅烧前驱体生成的ZnO纳米棒长度有所增加 ,ZnO的量基本保持不变。实验发现氧化锌的生长是沿着c轴方向 ,但是在横向也有生长方向。

The authors synthesized ZnO nanorods by calcining the precursor composed of PVP and Zn(CH3COO)(2) center dot 2H(2)O at 300 degrees C. In order to investigate the growth process of ZnO nanorods, the precursor was calcined for different time (0.5, 3, 12, 24 h) and the corresponding products were measured by TEM, HR-TEM (high-resolution transmission electron microscopic), SAED (selected-area electron diffraction pattern) and XRD. The result showed that there were ZnO crystallites in the precursor of PVP and Zn(CH3COO)(2) center dot 2H(2)O, which was dried at 110 degrees C - When the precursor was calcined at 300 degrees C for 0.5 h, ZnO nanorods; could be observed with diameter of 50 nm and the nanorods consisted of two parts. One was compact nanorod with diameter of about 30 nm and the other part was ZnO crystallites attaching around the nanorod. This phenomenon indicated that there might be a transverse growth direction of ZnO nanorods at early time of crystal growth. When the precursor was calcined for 3 h, the products were direct and smooth single crystal ZnO nanorods. Further increasing the calcining time at 300 degrees C could improve the length of the ZnO nanorods; in a certain extent while. the diameter changed a little. The HR-TEM results showed that the growth direction of ZnO nanorods was along c axis.