Room-temperature ammonia sensor based on MoS2/polyaniline

Ammonia (NH3) pollution poses a serious threat to human health and environmental safety. To achieve low-cost, rapid detection of ammonia, this paper proposes a sensor based on a molybdenum disulfide (MoS₂)/polyaniline (PANI) composite material for quick ammonia detection. The powdery MoS₂/PANI composite was synthesized using hydrothermal reaction and in-situ polymerization methods. The resulting materials were characterized using X-ray diffraction and other techniques to determine their composition and unique morphology. A sensor was fabricated by wrapping gold electrodes around an alumina ceramic tube. The sensor exhibits excellent gas-sensitive performance, providing precise responses to ammonia concentrations ranging from 3 to 250 ppm at room temperature. A segmented fitting method (3-20 ppm and 20-250 ppm) yielded good linear relationships with R² values of 0.997 and 0.998, respectively. It features rapid response, high sensitivity, and good selectivity, achieving a response to 200 ppm ammonia in 15 seconds and a maximum sensitivity of approximately 45% at 20 ppm. This method is characterized by simple manufacturing, low cost, and good reproducibility, showing promising applications in industrial production, healthcare, and environmental monitoring.