用于火电厂NO_(x)检测的Pt-In_(2)O_(3)传感器吸附及传感机理研究  

Adsorption and sensing mechanism of Pt-In_(2)O_(3) sensor for NOx detection in thermal power plants

作　　者：杨家隆 吴宝良 卢德滔 马世龙 周渠[2] YANG Jiaong;WU Baoiang;LU Detao;MA Shiong;ZHOU Qu(Jiangjin Power Supply Branch,State Grid Chongqing Electric Power Company,Chongqing402260;College of Engineering and Technology,Southwest University,Chongqing400715)

机构地区：[1]国网重庆市电力公司江津供电分公司,重庆402260 [2]西南大学工程技术学院,重庆400715

出　　处：《电子元件与材料》2024年第4期387-394,共8页Electronic Components And Materials

基　　金：国家自然科学基金(51507144)。

摘　　要：火力发电产生的NO_(x)会对生态环境和公众健康造成严重危害。目前,我国对火电厂NO_(x)检测主要采用非分散红外技术和化学发光技术,需要对烟道的样气进行人工采样,步骤繁琐且无法实现对NO_(x)准确检测,半导气体传感器具有体积小、响应快速和成本低等优点,而广泛应用于气体污染物的检测。本文采用水热法制备了本征In_(2)O_(3)和Pt-In_(2)O_(3)气敏材料。基于搭建的微量气体气敏测试平台,测试了In_(2)O_(3)基传感器对NO和NO_(2)的浓度响应和响应恢复时间。研究表明,Pt-In_(2)O_(3)传感器对30ppm NO_(2)和NO的响应值分别为7.7和10.3,响应恢复时间分别为23 s/41 s和18 s/46 s,能够满足对火电厂NO_(x)检测的要求。另外,基于密度泛函理论计算了各吸附模型的吸附能和态密度以揭示其气敏机理。分析结果表明,Pt-In_(2)O_(3)对NO(-1.55 eV)和NO_(2)(-0.92 eV)表现出强烈的化学吸附,与宏观实验测试结果一致。因此,Pt-In_(2)O_(3)传感器可实现火电厂NO_(x)气体检测。Thermal power generation produces NOx,which can cause serious harm to the ecological environment and public health.At present,the NOx detection of the thermal power plants in China mainly uses non-dispersive infrared technology and chemiluminescence technology,which need to manually collect the sample gas of the flue,which is a cumbersome step and cannot realize the accurate detection of NOx.The semi-conducting gas sensors have the advantages of small size,fast response and low cost,which are widely used for the detection of the gaseous pollutants.In this paper,the intrinsic In_(2)O_(3) and Pt-In_(2)O_(3) gas-sensitive materials were prepared by hydrothermal method.Based on the constructed trace gas-sensitive gas test platform,the concentration response and response-recovery time of In_(2) O_(3)-based sensors for NO and NO_(2) were tested.The results show that the response values of the Pt-In_(2)O_(3) sensor to 30 ppm NO_(2) and NO are 7.7 and 10.3,respectively,and the response recovery times are 23 s/41 s and 18 s/46 s,respectively,which are able to meet the requirements for NOx detection in the thermal power plants.In addition,the adsorption energy and density of states of each adsorption model were calculated based on the density functional theory to reveal its gas-sensing mechanism.The analytical results show that Pt-In_(2)O_(3) exhibits strong chemisorption of NO(-1.55 eV)and NO_(2)(-0.92 eV),which is consistent with the macroscopic experiment results.Therefore,the Pt-In_(2)O_(3) sensor can realize NOx gas detection in the thermal power plants.

关 键 词：火电厂 NO_(x)气体 水热法 Pt-In_(2)O_(3) 气敏机理 

分 类 号：TM855[电气工程—高电压与绝缘技术]