Fabrication and characterization of a sensitive, room temperature methane sensor based on SnO2@reduced graphene oxide-polyaniline ternary nanohybrid

Using in situ chemical polymerization, the hybridized pre-synthesized SnO2@rGO with polyaniline (SnO2@rGO-PANI) was synthetized and applied as the methane sensor at room temperature. The enhanced response of SnO2@rGO-PANI toward 100–10,000 ppm Methane at room temperature, i.e. from 26.1% to 92.3%, illustrated its excellent potential of functional properties. As a hybrid sensor, SnO2@rGO-PANI exhibited better response to Methane gas (initial concentration: 1000 ppm) than those of the bare SnO2@rGO (7.6 times) and PANI nanofiber (3 times) sensors. Compared to these sensors, SnO2@rGO-PANI showed a response of 26.1% to 100 ppm of methane, which was not detectable for pure SnO2@rGO and PANI. The enhanced methane sensitivity of SnO2@rGO-PANI is attributed to more hetero sites of p-n junctions between n-SnO2@rGO and p-PANI as well as the π-π conjugation system of PANI and rGO in the as-prepared nanohybrid. The analysis of X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, Field emission scanning electron microscopy and Transmission electron microscopy methods were applied to characterize the nanohybrid sensor