快速吸附与脱附的声表面波H2S传感器

本文主要研究了基于SnO₂/CuO薄膜的声表面波（SAW）传感器（室温下,工作频率约为147.8 MHz）检测H₂S气体的特性。以36°YXLiTaO₃为基片制作声表面波器件,通过采用射频磁控溅射法在其表面淀积SnO₂/CuO的复合薄膜制作出H₂S气体传感器。由场发射电子扫描电镜观察薄膜,薄膜连续均匀且表面分布大量微气孔,因而具有良好的吸附性。然后本文在85℃～205℃范围内对传感器的吸附和脱附速率、灵敏度及选择性等进行了实验研究。实验结果表明,所制备的传感器在较低温度下同时具备快速吸附和脱附特性,工作在190℃时气体吸附和脱附速率最快,检测20ppm H₂S的响应和恢复时间分别为30s、15s;工作在160℃时,传感器检测20ppmH₂S的灵敏度最高,工作频率变化约230 kHz,且对于低浓度2 ppm H₂S,频率变化可达45 kHz。同时,传感器也表现出良好的重复性和选择性。

Fast absorption and desorption H2S sensors based on surface acoustic waves

A surface acoustic wave（SAW）sensor（operating at about 147.8 MHz at room temperature）based on SnO₂/CuO composite thin films has been investigated for detecting H₂S gas in this paper.The films were deposited onto a 36°YXLiTaO₃ SAW device by a RF magnetron sputtering technique.From field emission electron scanning electron microscope image,it can be concluded that the films were continuous,uniform,and porous,exhibiting high absorbability.Then at different operating temperatures varying from 85℃to 205℃,the speed of adsorption and desorption,sensitivity,selectivity and other properties of sensing H₂S gas were studied by experiments.Our experimental results showed that the prepared sensor possessed fast adsorption and desorption characteristics,operating at relatively low temperature. For detecting 20ppm H₂S,the shortest response and recovery time of 30 s and 15 s respectively were obtained at 190℃,and the highest sensitivity of about 230kHz frequency shift was observed at 160℃.Moreover,45 kHz response can be seen for detecting low concentration of 2 ppm H₂S.Satisfied repeatability and selectivity were also demonstrated by our experiments.