SnO_(2)气体传感器敏感层厚度对乙醇气体响应性能的影响

Influence of sensitive layer thickness of SnO_(2) gas sensor on response performance of ethanol gas

为了探究二氧化锡(SnO_(2))—乙醇响应体系中的敏感层厚度对传感器响应性能的影响,通过静电纺丝法,制备了SnO_(2)中空纳米纤维。利用所制备的纳米纤维制作了不同敏感层厚度的电阻型气体传感器,并对所制备的传感器进行了乙醇气体响应性能研究。测试结果表明:敏感层厚度改变了气体传感器的响应值与乙醇气体体积分数在双对数坐标系中的斜率,并且敏感层厚度对该斜率的影响还随着温度的改变而不同;敏感层厚度改变了气体传感器的最佳响应温度。敏感层厚度越小,最佳响应温度越高。目标气体在敏感材料内部的扩散过程中,会吸附在敏感材料表面发生异相催化反应,而气体传感器敏感层的厚度会影响目标气体的扩散,从而改变敏感层内部微环境中的气体成分及其含量,并对气体传感器的响应性能产生影响。

In order to explore the influence of the thickness of the sensitive layer on the response performance of the sensor in SnO_(2)-ethanol response system,SnO_(2) hollow nanofibers are prepared by electrospinning.The prepared nanofibers are used to fabricate resistive gas sensors with different sensitive layer thicknesses.And the response performance of the prepared sensor to ethanol gas is studied.The test results show that the thickness of the sensitive layer changes the slope of the response value of gas sensor and the ethanol gas volume fraction in the double logarithmic coordinate system,and the influence of the thickness of the sensitive layer on the slope is also different with the change of temperature.The thickness of the sensitive layer changes the optimal response temperature of the gas sensor.The smaller the thickness of the sensitive layer,the higher the optimal response temperature.During the diffusion process of the target gas inside the sensitive material,it will be adsorbed on the surface of the sensitive material to cause a heterogeneous catalytic reaction,and the thickness of the sensitive layer of gas sensor will affect the diffusion of the target gas,thereby change the gas composition and content in the microenvironment inside the sensitive layer,and have an impact on the response performance of the gas sensor.