Filipescu Mihaela, Dobrescu Stefan, Bercea Adrian Ionut, Bonciu Anca Florina, Marascu Valentina, Brajnicov Simona, Palla-Papavlu Alexandra
National Institute for Laser, Plasma and Radiation Physics, RO-077125 Magurele, Romania.
Polymers (Basel). 2023 Dec 26;16(1):79. doi: 10.3390/polym16010079.
A highly sensitive ammonia-gas sensor based on a tungsten trioxide and polypyrrole (WO/PPy) nanocomposite synthesized using pulsed-laser deposition (PLD) and matrix-assisted pulsed-laser evaporation (MAPLE) is presented in this study. The WO/PPy nanocomposite is prepared through a layer-by-layer alternate deposition of the PPy thin layer on the WO mesoporous layer. Extensive characterization using X-ray diffraction, FTIR and Raman spectroscopy, scanning electron microscopy, atomic force microscopy, and water contact angle are carried out on the as-prepared layers. The gas-sensing properties of the WO/PPy nanocomposite layers are systematically investigated upon exposure to ammonia gas. The results demonstrate that the WO/PPy nanocomposite sensor exhibits a lower detection limit, higher response, faster response/recovery time, and exceptional repeatability compared to the pure PPy and WO counterparts. The significant improvement in gas-sensing properties observed in the WO/PPy nanocomposite layer can be attributed to the distinctive interactions occurring at the p-n heterojunction established between the n-type WO and p-type PPy. Additionally, the enhanced surface area of the WO/PPy nanocomposite, achieved through the PLD and MAPLE synthesis techniques, contributes to its exceptional gas-sensing performance.
本研究展示了一种基于三氧化钨和聚吡咯（WO/PPy）纳米复合材料的高灵敏度氨气传感器，该复合材料采用脉冲激光沉积（PLD）和基质辅助脉冲激光蒸发（MAPLE）合成。WO/PPy纳米复合材料是通过在WO介孔层上逐层交替沉积PPy薄层制备的。对制备好的层进行了广泛的表征，包括X射线衍射、傅里叶变换红外光谱和拉曼光谱、扫描电子显微镜、原子力显微镜以及水接触角测量。系统研究了WO/PPy纳米复合材料层在暴露于氨气时的气敏特性。结果表明，与纯PPy和WO对应物相比，WO/PPy纳米复合材料传感器具有更低的检测限、更高的响应、更快的响应/恢复时间以及出色的重复性。在WO/PPy纳米复合材料层中观察到的气敏特性的显著改善可归因于在n型WO和p型PPy之间建立的p-n异质结处发生的独特相互作用。此外，通过PLD和MAPLE合成技术实现的WO/PPy纳米复合材料表面积的增加，有助于其出色的气敏性能。
