Selective BTEX sensor based on a SnO2/V2O5 composite

A series of SnO2/V2O5 composites were designed and developed for selectively sensing BTEX (benzene, toluene, ethylbenzene, and xylol) based on a catalytic oxidation reaction. These composites were prepared with a facile solid phase reaction using sol–gel synthesized SnO2 and commercial V2O5 as raw materials. XRD and TEM were employed to characterize these composites. The results revealed forming process of the SnO2/V2O5 composites. Gas sensing tests of side-heating sensors showed that the SnO2/V2O5 composites had a much better response to BTEX rather than other VOCs such as ethanol, acetone, methanal, methanol and acetic acid compared with pure SnO2. Among these composites, the one containing 10 wt% V2O5 has the best selectivity and response (Ra/Rg) toward BTEX. At 270 °C, an optimal working temperature, the values of gas response to 50 ppm (parts per million) BTEX are more than 5 times, meanwhile the limit of detection is as low as 0.5 ppm. The influence of V2O5 on BTEX sensing of SnO2-based gas sensor was also discussed.