Identification and detection of toxic/explosive environmental gases are of paramount importance to various sectors such as oil/gas industries, defense, industrial processing, and civilian security. Surface acoustic wave (SAW)-based gas sensors have recently gained significant attention, owing to their desirable sensitivity, fast response/recovery time, wireless capabilities, and reliability. For detecting various types of targeted gases, SAW sensors with different device structures and sensitive materials have been developed with diversified working mechanisms. This paper is focused on overviewing recent advances in working mechanisms and theories of dominant sensitive materials and key mechanisms/principles for targeting various gases in the realm of SAW gas sensors. The basic sensing theories and parameters of SAW gas sensors are briefly discussed, and then the major influencing factors are systematically reviewed, including the effects of various sensitive layer materials, temperature/humidity, and UV illumination on the overall performance of SAW gas sensors. We further highlight the relationships and adsorption/desorption principles between sensing materials and key targeted gases, including NH3, NO2, H2S, explosive gases of H2, and 2,4,6-trinitrotoluene, and organic gases of isopropanol, ethanol, and acetone, as well as others gases of CO, SO2, and HCl. Finally, we discuss key challenges and future outlooks in designing methodologies of sensing materials and enhancing the performance of SAW gas sensors, offering fundamental guidance for developing SAW gas sensors with good sensing performance.

中文翻译：

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基于表面声波技术的有毒气体检测机理全面概述


有毒/爆炸性环境气体的识别和检测对于石油/天然气工业、国防、工业加工和民用安全等各个部门都至关重要。基于表面声波 （SAW） 的气体传感器因其理想的灵敏度、快速响应/恢复时间、无线功能和可靠性而最近受到广泛关注。为了检测各种类型的目标气体，开发了具有不同设备结构和敏感材料的 SAW 传感器，具有多样化的工作机制。本文重点介绍了 SAW 气体传感器领域中主要敏感材料的工作机制和理论的最新进展，以及针对各种气体的关键机制/原理。简要讨论了声表面波气体传感器的基本传感理论和参数，然后系统综述了主要影响因素，包括各种敏感层材料、温度/湿度和紫外线照射对声波气体传感器整体性能的影响。我们进一步强调了传感材料与关键目标气体之间的关系和吸附/解吸原理，包括 NH3、NO2、H2S、H2 和 2,4,6-三硝基甲苯的爆炸性气体，异丙醇、乙醇和丙酮的有机气体，以及 CO、SO2 和 HCl 的其他气体。最后，我们讨论了在设计传感材料方法和提高声表面声波气体传感器性能方面面临的主要挑战和未来展望，为开发具有良好传感性能的声表面声波气体传感器提供了基本指导。