UV Treated Sol-gel Synthesized SnO2-Polypyrrole Sensor for Ultra-low Ammonia Detection at RT

The effect of UV illumination (254 nm) has significantly improved the sensing parameters viz. response/recovery times and % response, of SnO
2
-polypyrrole (PPy) composite based ammonia sensor. A facile and cost-effective sol-gel spin coating technique followed by vapor phase polymerization is applied for developing the sensor for ultra-low ammonia concentration detection at room temperature (RT). Electrical characterization, topography, elemental analysis and surface morphology have been examined through current-voltage (I-V) measurement, atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), respectively. The ammonia sensing characteristics of the post-UV treated sensor evidenced no recovery issue that existed in pre-UV treated sensor. Enhanced % response is also observed with rapid response and recovery times after UV treatment.