Fe3O4/rGO nanocomposite: synthesis and enhanced NOx gas-sensing properties at room temperature

We demonstrate a facile fabrication of Fe3O4 nanoparticle (NP)-decorated reduced graphene oxide (Fe3O4/rGO) nanocomposites and their application for the fast and selective detection of NOx at room temperature. The as-synthesized nanocomposites have layered structures and the Fe3O4 NPs with diameters ranging from 30 to 50 nm were evenly loaded on the rGO surface. Furthermore, the Fe3O4/rGO nanocomposite based gas sensor exhibits excellent sensitivity and fast response to NOx gas at room temperature. Moreover, for a NOx concentration of 97.0 ppm, the observed value of sensitivity was about 35.6%, while the response time was 29.3 s. We found that the loading density of the Fe3O4 NPs greatly affects the sensing performance of the Fe3O4/rGO nanocomposites and a suitable NP loading leads to the highest sensitivity. The synthesis method to produce rGO-based nanocomposites as novel gas sensor materials has great potential to push low cost and gas sensing nanotechnology.