现代无机合成课程论文

上海大学2015～2016学年秋季学期研究生课程论文课程名称：现代无机合成课程编号：01SAJ9017

论文题目:Hydrothermal-Electrochemical Synthesis of ZnO Nanorods

作者姓名:刘志学号:15723697成绩:

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水热电化学合成ZnO纳米棒

刘志

上海市大场镇上大路99号上海大学理学院摘要

ZnO纳米棒具有本体ZnO材料的性质以及其纳米结构带来的一些特性使得它在传感和光发射等领域有很大潜在应用价值。本文采用SSP(soft solution proeessing)方法中的重要工艺方法—水热电化学法一步制备出ZnO纳米棒,达到了降低材料制造成本、减少环境污染、降低晶体缺陷密度的目的。

本研究首次对水热电化学法制备ZnO纳米棒的反应过程进行了热力学计算。热力学计算得到水热电化学法制备ZnO纳米棒的反应历程为:

Zn(NO3)2Zn2++2NO3-(1)

NO3-+H2O+2e-NO2-+2OH-(2)

Zn2++2OH-Zn(OH)2(3)

Zn(OH)2ZnO+H2O

水热电化学法制备的纳米棒的长度大约为4.3um，直径分布在90-150nm。对于是否添加NaOH添加剂以及120-180℃之间不同条件的各组实验样品的形貌、结构以及光致发光性质都进行了表征。在180℃合成的ZnO纳米棒显现出很强的UV 辐射和较弱的缺陷相关可见辐射，紫外-可见辐射之比约为230。这种高质量光学性质主要归功于高温生长导致较高的纳米棒生长速率（4.3um/h）。在热力学上分

相不如ZnO相稳定。因为生长温度在聚合物材料析是因为高温下缺陷相关Zn(OH)

2

承受范围之内，我们的方法提供了一种十分有前景的在灵活的聚合物基体上合成高光电性质的设备的方法。

关键词:水热电化学合成；ZnO；纳米棒；光致发光；PET，三电极体系

Hydrothermal-Electrochemical Synthesis of ZnO

Nanorods

Liuzhi

Department of Science,Shanghai University,99

Shangda Road,Dachang District,Shanghai Abstract:

Properties of zno nanorods with ontology zinc oxide(ZnO)materials and some of the features of the nano structure make it in the fields such as sensor and optical emission have great potential application value.This paper adopts an important process of the SSP(soft solution proeessing)method-hydrothermal-electrochemical method to synthesis ZnO nanorods in one step,reducing material cost and environmental pollution and cutting down the density of crystal defects.

This study synthesis ZnO nanorods by hydrothermal-electrochemical method for the first time in the word meanwhile calculate the reaction process in thermodynamic. At least,we also reaserched the reaction mechanism of this process as follows: Zn(NO3)2Zn2++2NO3-(1)

NO3-+H2O+2e-NO2-+2OH-(2)

Zn2++2OH-Zn(OH)2(3)

Zn(OH)2ZnO+H2O(4)

The height and diameter of the ZnO nanorods were up to∼4.3u m and90-150nm, respectively.The morphological,structural,and photoluminescence properties of the ZnO nanorods were examined with respect to the growth temperature(120-180°C)and the presence of NaOH additive.The nanorods synthesized at high temperature(180°C) exhibited a strong UV emission and a weak defect-related visible emission leading to a UV-visible ratio of∼230.This high optical quality was attributed to the increased growth rate of ZnO nanorods(∼4.3um/h)which was caused by the high growth temperature(180°C).This was based on the fact that the ZnO phase is thermodynamically more favorable than the defect-related Zn(OH)2phase at higher temperature.Since the growth temperature was compatible with polymer materials,our synthetic method may provide a promising way for fabricating high performance optoelectronic devices on flexible polymer substrates.

Keywords：hydrothermal-electrochemical method；ZnO；nanorods；photoluminescence；three electrode cell