Research progress of H2S sensors based on metal oxide semiconductor nanomaterials with one-dimensional structures

Abstract

The phenomenon that CuO resistors encounter gas changes opens the prelude to metal oxide semiconductors (MOSs) as gas sensing. From 1953 to 1968, the research and production of MOS gas sensors were unified, but the gas-sensitive materials used at that time were mostly bulk. Owing to the continuous exploration of material science and technology, nanomaterials began to flourish at the end of the 20th century. The emergence of nanomaterials promoted the development of gas sensors to a certain extent because the properties of MOSs are material dependent. Over the past few decades, nanomaterial applications in the field of gas sensing have led to the preparation of MOS-based gas sensors that can identify harmful gases in different environments with excellent characteristics, such as high sensitivity, selectivity, and stability, along with fast response/recovery. However, with the improving precision of gas detection, single-metal MOS materials have faced difficulty in meeting gas-sensing requirements. Therefore, preparing MOS materials into various nanostructures is desirable to improve the detection limit and sensitivity of gas sensors. When compared to nanomaterials with multiple-dimensional structures, one-dimensional counterparts exhibit improved gas-sensitive performance for H2S due to their larger specific surface area, good crystallinity, unique electron transport characteristics, and controllable grain size. Therefore, in this study, H2S gas is mainly focused, and the characteristics of nanomaterials with different one-dimensional structures based on MOSs are reviewed along with the research progress of H2S gas sensors based on nanomaterials with one-dimensional structures. Herein, regarding gas sensing, various properties of common one-dimensional nanostructures, such as nanowires, nanorods, nanofibers, and nanotubes, are thoroughly analyzed and summarized. The importance of H2S gas detection in military, medical, industrial, and everyday applications is briefly discussed, along with the common preparation methods for nanomaterials with one-dimensional structures. In addition, the working mechanism of p-type and n-type MOS as gas sensors is discussed. Furthermore, the influence of MOS-based nanomaterials with one-dimensional structures on H2S gas–sensitivity properties and mechanisms was investigated. Simultaneously, based on the gas-sensitive properties of nanomaterials with one-dimensional structures, the practical application characteristics of various nanomaterials with one-dimensional structures are highlighted. Finally, the performance improvement and future application prospects of MOS-based nanomaterials with one-dimensional structures for H2S gas sensors are discussed.

Keywords

• hydrogen sulfide gas
• one-dimensional nanostructures
• metal oxide semiconductor
• gas sensing mechanism
• the sensing performance