Room temperature triethylamine sensing properties of polyaniline–WO3 nanocomposites with p–n heterojunctions

Abstract

Polyaniline (PANI)–tungsten oxide (WO₃) nanocomposites have been successfully synthesized using different weight percentages of tungsten oxide (10–50%) dispersed in a polyaniline matrix by a facile in situ chemical oxidation polymerization. The sensors based on PANI–WO₃ nanocomposites were fabricated on a substrate of polyethylene terephthalate (PET) films for detection of triethylamine (TEA) gas at room temperature. It was observed that the sensors of PANI–WO₃ nanocomposites show better sensitivity, selectivity, and reproducibility compared to pure PANI, particularly the sensor based on PANI–30% WO₃ operating at room temperature exhibits maximum response of 81 to 100 ppm TEA gas, that is 13 times higher than that of pure PANI. The sensing mechanism of the nanocomposites in the presence of TEA atmosphere was discussed in detail, and is attributed to the increase of percentage of doping protonic acid and the formation of p–n heterojunctions between p-type PANI and n-type WO₃.