W18O49/CeO2 heterojunction for enhanced n-Butanol gas sensor operating at room temperature

The present work focuses on developing a high-performance n-butanol detection system through heterojunction engineering of W 18 O 49 /CeO 2 nanocomposites, aiming to achieve superior sensitivity and selectivity in volatile organic compound monitoring. The solvothermal-mediated fabrication of CeO 2 nanocrystals served as the foundation for hierarchical assembly of the W 18 O 49 /CeO 2 heterostructured sensing layer. A comprehensive investigation was organized, encompassing discriminative selectivity analysis, durability testing, response profiling, response/recovery characterization under prolonged operational conditions. Experiment confirmed that the W 18 O 49 /CeO 2 heterojunction sensor achieved peak analytical performance at room temperature, exhibiting a response of 12.2 when exposed with 100 ppm n-butanol. In contrast, the pristine W 18 O 49 had a response of 2.6, and pristine CeO 2 showed negligible response. DFT results showed that the adsorption energy of n-butanol on the W 18 O 49 /CeO 2 composite was −1.092 eV, which was much stronger than that on pristine W 18 O 49 (−0.305 eV), indicating a more favorable adsorption process. Notably, the sensor achieved a detection threshold of 1 ppm n-butanol with a response magnitude reaching 23.5 %, indicating its capability for ultra-trace gas analysis. Collectively, these findings substantiate the W 18 O 49 /CeO 2 heterojunction architecture as a highly effective sensing platform for volatile organic compound (VOC) detection, with particular applicability to n-butanol gas monitoring in smart manufacturing environments. The superior sensing efficacy stems from the synergistic charge transfer mechanism at the heterointerface, validated by both experimental characterization and theoretical modeling.