Polyaniline-based room temperature ammonia gas sensor employing hybrid organic-inorganic substrate

Air pollution poses a serious threat to public health, and gas sensors for detection of the pollution has gained great attention over the past decades. In this work, a novel idea based on the substrate material integrated by structure and function was built to prepare NH 3 sensor with an improving sensing properties. Hybrid organic–inorganic sol gel with methacryloxy and epoxy groups was first synthesized. A hybrid organic–inorganic substrate was then prepared based on continuous condensation , radical polymerization and anionic polymerization . The thermal stability and microstructural of the hybrid substrate were studied and the results indicated that the hybrid has excellent thermal and structural stability . Then, polyaniline (PANI) was directly loaded on the hybrid substrate due to hydrogen bonding though a facile in-situ polymerization method to fabricate a PANI/hybrid nanocomposite for NH 3 sensing. The hydroxyl groups generated from the epoxide ring-open reaction and silane hydrolysis condensation contribute to improve the sensing properties. This sensor showed superior selectivity and reproducibility to 50 ppm NH 3 at room temperature. The low detection limit towards NH 3 at room temperature can reach 1 ppm. This strategy may provide a promising and straightforward method in gas sensing electronics at room temperature.