Progress toward a novel methane gas sensor based on SnO2 nanorods-nanoporous graphene hybrid

In this study, SnO2 nanorods (SnO2 NRs) and SnO2 nanorods-nanoporous graphene hybrids, SnO2 NRs-NPG, with two different weight ratios (0.05 and 0.1) of nanoporous graphene to tin salt have been prepared as sensing materials. These materials were synthesized via a facile hydrothermal method and print screened on alumina substrates for low-temperature methane (CH4) gas sensors. The structure and morphology of the fabricated sensing materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) method, transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM). The results showed that in the case of SnO2 NRs-NPG hybrids, the porous graphene sheets are decorated with SnO2 nanorods. The gas response of the prepared hybrid samples to 1000 ppm methane gas was investigated at 100-200 degrees C. The nanohybrid with 0.05 wt ratios of nanoporous graphene to tin salt showed significant sensor response of 24.9-51% to 1000-10000 ppm methane at a relatively low operating temperature of 150 degrees C which is about 600% higher than that of pure SnO2 nanorods. The substantial enhancement in the gas detection of SnO2 NRs-NPG nanohybrid, compared to the pristine SnO2, can be attributed to its larger specific surface area, the presence of nanoporous graphene as a good conductor and interactions between nanoporous graphene and SnO2 nanorods.