水热法制备氧化锌纳米棒阵列的生长动力学研究

Kinetic study on the growth of ZnO nanorod array films prepared by hydrothermal method

采用低温水热方法,在经预先修饰的基底上制备出取向高度一致的ZnO纳米棒阵列.用SEM和XRD等手段对制备的纳米棒阵列进行了表征.ZnO纳米棒阵列水热生长动力学表明:当生长时间在8h内时,纳米棒的生长速度较快,之后纳米棒的生长近乎停止,棒的长度和直径基本不再改变.在生长速度较快的8h内时,纳米棒的径向生长由两个明显的动力学过程组成,即由生长时间在1.5h内的快速生长步骤和随后的慢速生长步骤组成;纳米棒的长度以约5.5nm.min-1的生长速度增加至2.4μm.

By using a low temperature hydrothermal approach, well-aligned ZnO nanorod arrays were pre-pared on substrates, which were pre-treated with colloid pre-treating method in different growth periods of time. Scanning electron microscopy and X-ray diffraction spectroscopy were employed to study the morphology of ZnO nanorod arrays. Kinetic studies show that the first 8 h is the most important growth period, beyond which the nanorods nearly stop growing. During the first 8 h, the growth of width of ZnO nanorods contains two distinct steps： a fast step within the first 1.5 h, in which the nanorods tend to be short and wide, followed by a slow step, in which long rods with high aspect ratio are obtained. The length of ZnO nanorod arrays, which essentially represents the thickness of a homogeneous monolayer of the thin film, may be experimentally tailored to any required dimension of up to 2.4 μm at a growth rate of approximately 5.5 nm·min^-1.