Selective BTEX sensor based on a SnO2/V2O5 composite

Abstract A series of SnO 2 /V 2 O 5 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 SnO 2 and commercial V 2 O 5 as raw materials. XRD and TEM were employed to characterize these composites. The results revealed forming process of the SnO 2 /V 2 O 5 composites. Gas sensing tests of side-heating sensors showed that the SnO 2 /V 2 O 5 composites had a much better response to BTEX rather than other VOCs such as ethanol, acetone, methanal, methanol and acetic acid compared with pure SnO 2 . Among these composites, the one containing 10 wt% V 2 O 5 has the best selectivity and response ( R a / R g ) 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 V 2 O 5 on BTEX sensing of SnO 2 -based gas sensor was also discussed.