Gas sensitivity of polyaniline/SnO2 hybrids to volatile organic compounds

Polyaniline (PAn) was prepared by chemical oxidation polymerization and characterized by FT-IR. PAn/SnO2 materials with different mass fractions of PAn were prepared by mechanical mixing. Compared with single PAn and SnO2, the gas sensitivity of PAn/SnO2 materials to volatile organic compounds (VOCs, methanol, ethanol and acetone) was studied. The possible response mechanism of PAn/SnO2 materials to VOCs was also discussed. It is found that PAn/SnO2 materials have gas sensitivity to VOCs at 90 °C among the four operating temperatures (room temperature, 30, 60 and 90 °C), but PAn and SnO2 have no gas sensitivity at the above temperatures. The sensitivity of PAn/SnO2 materials shows linear increase with the increase of methanol concentration, but saturation with the increase of ethanol and acetone concentrations. PAn/SnO2 materials have high selectivity, fast response-recovery time and low operation temperature to VOCs, but pure PAn and SnO2 do not have.