【Device Papers】Study on unusual response behavior of NO₂ sensor based on UV enhanced Pd-functionalized Ga₂O₃ microrods

      Researchers from the Nanjing University have published a dissertation titled "Study on unusual response behavior of NO₂ sensor based on UV enhanced Pd-functionalized Ga₂O₃ microrods" in Sensors and Actuators B: Chemical.

Abstract

      In this study, we synthesized Pd/Ga₂O₃ composite materials and evaluated their gas sensitivity to NO₂ at room temperature (RT). The Pd/Ga₂O₃ composite demonstrated superior gas sensing performance compared to Ga₂O₃, with a detailed analysis of its unusual response mechanism. Under UV irradiation, the performance of the Pd/Ga₂O₃ sensor (UV Pd/Ga₂O₃) was significantly enhanced. The response to 100 ppm NO₂ for the UV Pd/Ga₂O₃ sensor was 146.56%, surpassing both the Pd/Ga₂O₃ and Ga₂O₃ sensors. Specifically, the UV Pd/Ga₂O₃ sensor showed a 1.5-fold increase in response over the Pd/Ga₂O₃ sensor and a 2.17-fold increase over the Ga₂O₃ sensor. Furthermore, the response and recovery times for the UV Pd/Ga₂O₃ sensor were 12 s and 23 s, respectively, which are significantly faster than the Ga₂O₃ sensor's 20 s and 82 s. The detection limit for NO₂ was improved to 51 ppb, which is a substantial advancement over previous room-temperature Ga₂O₃-based sensors. The UV Pd/Ga₂O₃ sensor also displayed excellent selectivity, repeatability, resistance to humidity, and long-term stability.

DOI：

https://doi.org/10.1016/j.snb.2025.137266