氧化铟微结构的制备、改性及其气敏特性研究

发布时间：2018-04-29 05:04

  本文选题：氧化铟 + 水热法　； 参考：《太原理工大学》2017年硕士论文

【摘要】：氧化铟(In_2O_3)作为一种禁带宽度为3.55-3.75 eV的n型半导体金属氧化物材料,由于其具有较好的催化活性、较高的电导率和较宽的禁带宽度,作为气敏材料被广泛应用于气体传感器领域。近年来,研究发现通过掺杂改性可有效提高In_2O_3气体传感器的气敏性能。本文采用水热法制备了In_2O_3微结构,通过掺杂贵金属、金属氧化物来研究In_2O_3气体传感器的气敏性能。利用XRD、SEM、EDS、TEM和XPS对合成的样品的晶体结构、微观形貌、元素组成及价态进行表征分析。同时,对制备的In_2O_3气体传感器进行了气敏特性测试,实验结果表明:(1)采用水热法合成In_2O_3空心微球结构,表征结果表明制备的In_2O_3为立方体型结构。气敏特性实验结果表明:在最佳工作温度(300℃)下,传感器对100 ppm异丙醇的气敏响应达到10.3,响应恢复分别时间为2 s/7 s,最低检测极限仅为500 ppb;(2)制备出了不同浓度(0 mol%,1 mol%,3 mol%和5 mol%)Au掺杂花状In_2O_3微结构,分析结果证明Au掺杂的引入对In_2O_3微结构的形貌没有影响。气敏特性实验结果显示,Au掺杂In_2O_3不但降低了传感器的最佳工作温度(250℃),而且提高了传感器的响应。尤其,3 mol%Au掺杂In_2O_3气体传感器对100 ppm丙酮的最大气敏响应可达23.1;(3)合成了纯的和不同浓度(1 mol%,3 mol%和5 mol%)Mo掺杂花状In_2O_3结构;研究了传感器对乙醇的气敏特性。气敏实验表明,在最佳工作温度(185℃)下,3 mol%Mo掺杂In_2O_3传感器(Mo3In)对100 ppm乙醇的响应可达7,是纯In_2O_3气体传感器(Mo0In)响应的1.8倍。同时,Mo掺杂的引入也有效的改善了传感器的响应恢复时间、选择性、稳定性等性能。同时,本文对传感器的气敏机理也进行了讨论于分析,贵金属(Au)掺杂不但可以增大材料的电导率,而且又能起到催化作用,改善传感器的气敏性能;普通金属氧化物的引入,可形成异质结结构,拓宽耗尽层的宽度,有效的提高元件的气敏特性。
[Abstract]:As an n-type semiconductor metal oxide material with a band gap of 3.55-3.75eV, Inn _ 2O _ 3) has been widely used in gas sensors because of its good catalytic activity, high conductivity and wide band gap. In recent years, it has been found that doping modification can effectively improve the gas sensitivity of In_2O_3 gas sensors. In this paper, In_2O_3 microstructures were prepared by hydrothermal method. The gas-sensing properties of In_2O_3 gas sensors were studied by doping precious metals and metal oxides. The crystal structure, microstructure, elemental composition and valence state of the synthesized samples were characterized by TEM and XPS. At the same time, the gas sensing characteristics of the prepared In_2O_3 gas sensor were tested. The experimental results show that the In_2O_3 hollow microspheres were synthesized by hydrothermal method. The characterization results show that the prepared In_2O_3 is cubic. The experimental results of gas sensitivity show that the optimum operating temperature is 300 鈩，

本文编号：1818492