TiO Nanosphere/MoSe Nanosheet-Based Heterojunction Gas Sensor for High-Sensitivity Sulfur Dioxide Detection.

With the growing severity of air pollution, monitoring harmful gases that pose risks to both human health and the ecological environment has become a focal point of research. Titanium dioxide (TiO) demonstrates significant potential for application in SO gas detection. However, the performance of pure TiO is limited. In this study, TiO nanospheres and MoSe nanosheets were synthesized using a hydrothermal method, and the gas-sensing properties of TiO/MoSe nanostructures for SO detection were investigated. The TiO/MoSe composites (with a TiO-to-MoSe volume ratio of 2:1) were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The TiO/MoSe sensor exhibited high sensitivity to SO; the response to 100 ppm of SO reached as high as 59.3, with a significantly shorter response and recovery time (15 s/13 s), as well as excellent repeatability, selectivity, and long-term stability. The experimental results suggest that the enhanced SO adsorption capacity of the TiO/MoSe composite can be attributed to the formation of an n-n heterojunction and the unique microstructural features of TiO/MoSe. Therefore, the TiO/MoSe sensor represents a promising candidate for rapid SO detection, providing a theoretical foundation for the development and application of high-performance SO sensors.