Indium doped SnO2/polyaniline nanocomposites as a DMMP gas sensor at room temperature

Initially, indium doped SnO2 (In-SnO2) nanoparticles were synthesised, using co-precipitation technique which then utilised to produce Indium doped SnO2/Polyaniline (In-SnO2/PANi) nanocomposites using in-situ polymerisation. The as-synthesised nanocomposites were found to be selective towards sensing of dimethyl methyl phosphonate (DMMP) gas. The influence of doping on structural, optical, thermal stability, morphology and shape were investigated using XRD, FT-IR, FE-SEM, XPS and EDS. The concentration of doping was optimised for maximum gas response. Furthermore, the gas sensing experiment was executed at various humidity levels. 9@ISP nanocomposites show maximal response (85.1%) as compared to pure PANi, pure SnO2, 0@ISP, 3@ISP, 6@ISP, 12@ISP and 15@ISP nanocomposites. For 10 ppm of DMMA gas, response and recovery times were 33.5 and 27.1 s, respectively. As the DMMP gas concentration rises from 1 to 25 ppm, reaction to gas sensors was found to be increased. DMMP gas shows enhanced selectivity towards 9@ISP nanocomposite as compared to the other gases (xylene, toluene, benzene, and acetonitrile gas). The reproducibility study of 9@ISP nanocomposite was performed for 30 days and found to be impressive. [GRAPHICS] .