Fabrication of methane gas sensor by layer-by-layer self-assembly of polyaniline/PdO ultra thin films on quartz crystal microbalance

The polyaniline/PdO composite was synthesized by chemical oxidative polymerization of aniline with PdO nanoparticles. A methane gas sensor was made by deposition polyaniline/PdO thin films on a mass-type quartz crystal microbalance (QCM) device through layer-by-layer (LbL) self-assembly method. Scanning electron microscopy inspection shows that the polyaniline/PdO multilayers are formed with a dense network of nanofibers. The frequency responses of the polyaniline/PdO based QCM sensor to methane gas were measured at room temperature and 50 °C. It exhibited that the polyaniline/PdO based QCM gas sensor has a better response at room temperature than that at 50 °C. Meanwhile, the humidity effect is also discussed.