纳米Zn-Al-O类材料制备及其气敏特性研究

发布时间：2018-01-06 02:09

本文关键词：纳米Zn-Al-O类材料制备及其气敏特性研究　出处：《西北大学》2017年硕士论文　论文类型：学位论文

【摘要】：在大气环境问题日益严重的今天,气体传感器的研究和制备成为研究的热点,纳米半导体金属氧化物传感器是其中重要的一类,具有制备简单、体积小、低成本等优点。但是单一金属氧化物传感器的灵敏度、选择性仍具有一定的局限性;虽金属掺杂会改善其气敏性能,但大多数都是贵重金属且成本高;发现复合氧化物气体传感器可以通过形成异质结或者协同效应来提高气敏特性。因此,寻找一种形貌可控、高灵敏度、高选择性、稳定性良好的复合气敏材料具有重要的实用价值。本文采用低温水浴法,在多孔阳极氧化铝(AAO,Anodic Aluminum Oxide)基底上制备出了均匀性较好的 Zn-Al LDH/ZnO 复合物(Zn-Al LDH,Zn-Al Layered Double Hydroxide)前驱体,然后通过退火处理获得了 ZnAl_2O_4/ZnO复合氧化物,并研究了退火温度对ZnAl_2O_4/ZnO气敏性能的影响,本文的主要研究成果如下:1.以高纯铝片为原料,利用二次阳极氧化法在草酸溶液中,在氧化时间为2h、氧化电压为40V、除膜时间2h、扩孔时间为lh条件下制备出有序性和一致性较好的AAO基底。2.制备乙酸锌和六次甲基四胺的水溶液,采用低温水浴法在AAO基底上制备Zn-Al LDH/ZnO 复合物薄膜,研究了溶液浓度、反应物浓度比、反应温度和时间对薄膜结构和形貌的影响。结果表明,在60℃、5h、乙酸锌浓度为0.005mol/L、乙酸锌与六次甲基四胺浓度比为1:10时制备出大面积连续性较好的纳米片花球状Zn-Al LDH/ZnO复合物。3.将制备的Zn-Al LDH/ZnO复合物作为前驱体,通过退火处理,研究了前驱体反应物浓度比、退火温度的影响,发现在600℃下、浓度比1:10退火后制备出了结晶性能较好的ZnAl_2O_4/ZnO复合氧化物。4.测试并分析了 ZnAl_2O_4/ZnO复合氧化物对甲醇、乙醇、丙酮的气敏特性。研究发现,随着退火温度的升高复合氧化物对甲醇、乙醇、丙酮的灵敏度越高,这是因为600℃退火比500,400℃退火所制备的复合氧化物中ZnO晶粒密度高。
[Abstract]:In the atmosphere of increasingly serious environmental problems today, research and preparation of gas sensors has become a hot research, nano metal oxide semiconductor sensor is one of the important category, has the advantages of simple preparation, small volume, low cost and other advantages. But the single metal oxide sensor sensitivity and selectivity still has some limitations though; metal doping will improve its gas sensitive properties, but most of them are precious metals and high cost; composite oxide gas sensor can be found by forming a heterojunction or synergistic effect to improve the gas sensing properties. Therefore, looking for a kind of controllable morphology, high sensitivity, high selectivity, good stability of the composite gas sensing material has important practical value. This paper uses the low temperature water bath method, porous anodic alumina (AAO Anodic, Aluminum Oxide) fabricated Zn-Al LDH/ZnO composite with better homogeneity (Zn -Al LDH, Zn-Al Layered Double Hydroxide) precursor, and then obtained the ZnAl_2O_4/ZnO composite oxide by annealing, and the effects of annealing temperature on gas sensing properties of ZnAl_2O_4/ZnO, the main research results are as follows: 1. with high purity aluminum in oxalic acid solution as raw material, using two anodic oxidation on the oxidation time for 2h, the oxidation voltage is 40V, in addition to membrane 2h, reaming time LH prepared under the water solution of order and the consistency of the AAO substrate.2. preparation of zinc acetate and six methyl four amine, preparation of Zn-Al LDH/ZnO composite films on AAO substrate by low temperature water bath method, study the concentration of the solution, concentration of reactant ratio, reaction temperature and time on the structure and morphology of the films. The results show that in the 60 DEG C, 5h, zinc acetate concentration is 0.005mol/L, zinc acetate and six methyl four amine concentration large surface preparation ratio of 1: 10 system Product of good continuity of nano spherical Zn-Al LDH/ZnO composite.3. film were Zn-Al LDH/ZnO complexes were used as precursors by annealing, the precursor concentration of reactant ratio, the effect of annealing temperature, found at 600 DEG C, concentration ratio of 1:10 after annealing prepared the ZnAl_2O_4/ZnO composite oxide.4. test well the crystallization properties and analysis of ZnAl_2O_4/ZnO composite oxides on ethanol, methanol, acetone gas sensing properties. The study found that with the increase of annealing temperature of composite oxide for methanol, ethanol, acetone, the sensitivity is high, this is because the composite oxide annealed at 600 C to 500400 C prepared by annealing the ZnO grain density is high.

【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212;TB33

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