ABSTRACT
124In this chapter, tin oxide/polyaniline (SnO2/PANI) composites and aluminum (Al)-doped SnO2/PANI composites nanofiber-based gas sensors for hydrogen-gas-sensing application are presented. PANI in powder form was prepared by chemical oxidative polymerization of aniline using ammonium persulfate in acidic medium at 0-5°C. SnO2/ PANI and Al-doped SnO2/PANI composites nanofibers were synthesized by electrospinning technique and subsequent calcinations. These composite nanofibers have been characterized by X-ray diffraction, ultraviolet-visible spectroscopy and scanning electron microscopy. The response of these sensors for hydrogen gas was evaluated by monitoring the change in electrical resistance at room temperature. It was observed that Al-doped SnO2/PANI composite nanofiber-based sensors show a higher response as compared to SnO2/PANI composite nanofibers sensor. On exposure to hydrogen gas, it was also observed that composite nanofibers showed high sensitivity in temperature range of 45-50°C with relatively faster response/recovery behavior compared to pure SnO2 and Al-doped SnO2 nanofibers reported earlier.
