不同纳米形貌NiO敏感电极对锆基HCs传感器的性能影响研究
发布时间：2018-10-12 09:52
【摘要】：汽车作为现代化的交通工具,给人们的生产与生活带了极大方便,但同时有研究表明,汽车排放的氮氧化合物(NOx)、CO和碳水化合物(HCs)等污染物严重超标,其中产生的HCs是导致光化学烟雾的主要来源,极大危害人类健康。因此,控制汽车排放污染,加强汽车尾气污染防治技术研究,成为城市环境保护迫在眉睫的工作。基于钇稳定性氧化锆(Yttria-stablilzed zirconia,YSZ)固体电解质气敏传感器由于能对汽车尾气中HCs含量简便快速的实时监测,因而受到了广泛的关注。由于敏感电极的形貌对YSZ基碳氢化合物(HCs)传感器的响应性能影响较为明显,本实验合成了数种不同纳米形貌的NiO电极并对基于该类电极的HCs传感器的敏感性能做了一定的研究。实验以锆基HCs传感器为研究对象,利用水热合成方法制备了七种不同形貌的NiO敏感电极材料,以Pt作为传感器的参比电极材料,采用厚膜丝网印刷技术制备了YSZ基混合电位型HCs气敏传感器,对传感器进行了理化测试以及气敏特性、响应特性、稳定性、气相催化、选择性、阻抗谱以及极化曲线测试。结果显示:不同形貌NiO敏感电极传感器在600℃取得最好的响应性能,且各传感器的响应特性差别极大。在600℃、5 vol.%O2、100ppmC3H6下线性结构NiO的气相催化效率最低,进而使得更多的待测气体进入其三相界面。线状NiO敏感电极传感器阻抗谱有最小的半圆弧,其低频收缩度最大,反应活化阻抗最小,进而表现出最好的传感器响应性能。极化曲线测试得到的理论平衡电势值和传感器的实际测试值基本一致。在此基础上,尝试不同比例的YSZ掺杂商用颗粒状形貌NiO作为混合电位型传感器的敏感电极,并研究了掺杂对传感器的性能影响机理。结果显示:在600℃下,20%YSZ掺杂的NiO敏感电极传感器具有最大的输出电势。鉴于锰系电极在600℃以下有很好的气体惰性和稳定性,实验制备了以Mn2O3为参比电极,以性能优异的三种NiO材料作为敏感电极,制备了混合电位型传感器,并研究了其敏感性能。测试结果显示在550℃、5 vol.%O2、20-500 ppmC3H6条件下,三种类型传感器的阶梯响应性能和重复性良好,且三种传感器在同种测试条件下响应值差别显著,其中线性NiO在550℃、100ppm C3H6下响应值达到170mV。此外基于三种性能优异的NiO敏感电极材料制备了YSZ基电流型HCs传感器,并对传感器的敏感性能、稳定性以及选择性进行了测试。结果显示在550℃下传感器电流响应值与待测气体浓度呈现很好的线性关系,但是传感器的长期稳定性有待进一步提高。
[Abstract]:As a modern vehicle, automobile has brought great convenience to people's production and life. But at the same time, some studies have shown that the nitrogen oxide (NOx), CO) and carbohydrate (HCs) pollutants emitted by automobiles are seriously exceeding the standards. Among them, HCs is the main source of photochemical smog, which is harmful to human health. Therefore, it is an urgent task to control the automobile emission pollution and strengthen the prevention and control technology of automobile exhaust pollution. Based on yttrium stabilized zirconia (Yttria-stablilzed zirconia,YSZ) solid electrolyte gas sensor has attracted wide attention because of its simple and rapid real-time monitoring of HCs content in automobile exhaust. Because the morphology of the sensitive electrode has an obvious effect on the response performance of the YSZ based (HCs) sensor, several kinds of NiO electrodes with different nano-morphologies have been synthesized and the sensitivity of the HCs sensor based on this kind of electrode has been studied. Using zirconium based HCs sensor as the research object, seven kinds of NiO sensitive electrode materials with different morphologies were prepared by hydrothermal synthesis method. Pt was used as reference electrode material of the sensor. The YSZ based mixed potential HCs gas sensor was fabricated by thick film screen printing technique. The physical and chemical properties of the sensor, the gas sensing characteristics, the response characteristics, the stability, the gas phase catalysis, the selectivity, the impedance spectrum and the polarization curve were measured. The results show that the NiO sensor with different morphologies has the best response performance at 600 鈩，
本文编号：2265682
[Abstract]:As a modern vehicle, automobile has brought great convenience to people's production and life. But at the same time, some studies have shown that the nitrogen oxide (NOx), CO) and carbohydrate (HCs) pollutants emitted by automobiles are seriously exceeding the standards. Among them, HCs is the main source of photochemical smog, which is harmful to human health. Therefore, it is an urgent task to control the automobile emission pollution and strengthen the prevention and control technology of automobile exhaust pollution. Based on yttrium stabilized zirconia (Yttria-stablilzed zirconia,YSZ) solid electrolyte gas sensor has attracted wide attention because of its simple and rapid real-time monitoring of HCs content in automobile exhaust. Because the morphology of the sensitive electrode has an obvious effect on the response performance of the YSZ based (HCs) sensor, several kinds of NiO electrodes with different nano-morphologies have been synthesized and the sensitivity of the HCs sensor based on this kind of electrode has been studied. Using zirconium based HCs sensor as the research object, seven kinds of NiO sensitive electrode materials with different morphologies were prepared by hydrothermal synthesis method. Pt was used as reference electrode material of the sensor. The YSZ based mixed potential HCs gas sensor was fabricated by thick film screen printing technique. The physical and chemical properties of the sensor, the gas sensing characteristics, the response characteristics, the stability, the gas phase catalysis, the selectivity, the impedance spectrum and the polarization curve were measured. The results show that the NiO sensor with different morphologies has the best response performance at 600 鈩，
本文编号：2265682
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