Novel CuO/CeF3/CeO2 porous nanosheet for high sensitivity isobutanol gas sensor

Despite being classified as a low-toxicity chemical, isobutanol poses non-negligible hazards to human health and the environment. This study reports, for the first time, the successful synthesis of porous CuO/CeF 3 /CeO 2 nanocomposites via a two-step hydrothermal method and demonstrates their application in isobutanol gas detection. The composition and morphological characteristics of the sensing material were determined through XRD, SEM, TEM, EDX, FT-IR, Raman, UV-vis, and XPS, and its gas-sensing properties were systematically investigated. The CuO/CeF 3 /CeO 2 -3 sensor exhibits a high response of 24.5 towards 100 ppm isobutanol at 180 °C, which is nearly eight times that of pristine CuO (3.1). Additionally, it demonstrates rapid response and recovery time of 13 s and 9 s, respectively, and still achieves a considerable response of 3.6 even at a low concentration of 5 ppm. Furthermore, the short-term repeatability, gas selectivity, response under various relative humidity levels, and long-term stability (over 28 days) of the sensor were evaluated. Finally, the mechanism behind the enhanced gas-sensing performance of the CuO/CeF 3 /CeO 2 sensor was thoroughly investigated, which is primarily attributed to four aspects: the synergistic modulation effect of the p-n heterojunction and the insulating layer, the formation of the porous structure, the significantly increased proportion of chemisorbed oxygen (O C ), and the dual catalytic effect exerted by both CeF 3 and CeO 2 .