Sol–gel derived (Sr,Ni)Al2O4 composites for benzene and toluene sensors

Strontium(II) added NiAl2O4 composites prepared by sol–gel technique was utilized for the detection of benzene and toluene vapors. XRD, SEM and BET measurements were employed to identify the structural phases, surface morphology and surface area. The (Sr,Ni)Al2O4 composites sintered at 900 °C were subjected to dc resistance measurements in the temperature range of 30–200 °C to study the benzene and toluene vapor detection characteristics. The maximum sensitivity of the composites was obtained at 150 °C. An increase in the sensitivity was observed with increase in benzene and toluene concentration from 100 to 5000 ppm at 150 °C. Among the different compositions, the (Sr,Ni)Al2O4 composites with higher strontium content (NiSA5) showed the best sensitivity towards benzene and toluene vapor detection.