Fabrication and design of a toxic gas sensor based on polyaniline/titanium dioxide nanocomposite film by layer-by-layer self-assembly

摘要: A sensitive polyaniline (PANI)/titanium dioxide (TiO2) based toxic gas sensor deposited on a quartz crystal microbalance (QCM) chip was fabricated and developed through electrostatic layer-by-layer (LbL) self-assembly (SA) with titanium sol as original materials. The synthesis process the obtained nanocomposite were confirmed home-made measurement set-up, field-emission scanning electron microscopy (FE-SEM), transmission (TEM), Fourier transform infrared spectroscopic (FTIR) X-ray diffraction (XRD), which demonstrates that thin PANI/TiO2 sensing film successfully achieved by LbL self-assembly. response found to be greatly influenced number of layers. resulting exhibited good sensitivity smooth shift in terms responses frequency data compared resistance data. It high toward 10 ppm three different gases (ammonia, hydrogen sulfide trimethylamine) an evident fast recovery time. showed excellent reversibility long-term stability well selectivity towards NH3. In real-time application, performance accurate evaluation typical foodstuffs. coated QCM substrate via provides promising efficient detect relatively low concentrations.