Microwave-assisted synthesis of hierarchically porous Co3O4/rGO nanocomposite for low-temperature acetone detection.

Acetone sensors with high response and excellent selectivity are of enormous demand for monitoring the diabetes. This paper has reported a novel porous 3D hierarchical Co3O4/rGO nanocomposite synthesized by a microwave-assisted method, by which Co3O4 nanoparticles are rapidly and uniformly anchored on rGO nanosheets. The phase composition, surface morphology of the Co3O4/rGO composites and the effect of rGO on their acetone-sensing performance were systematically investigated. The results show that the sample with an optimized content of rGO (Co3O4/rGO-1) achieves the highest stability and response to acetone (0.5 ~ 200 ppm) at a relatively low temperature (~160 °C). Also, the Co3O4/rGO-1 exhibits a high acetone-sensing selectivity against the gases (or vapors) of H2S, H2, CH4, HCHO, CH3OH, C3H8O and C2H5OH. The enhanced acetone-sensing performance of the Co3O4/rGO composite can be attributed to the Co3O4/rGO p-p heterojunction and the Co3+-C coupling effect between Co3O4 and rGO, improving transport of carriers. In addition, the unique 3D hierarchically porous structure and large surface areas are favorable to adsorption and desorption of gas molecules. This facile microwave-assisted method provides a charming strategy to develop smart rGO-based nanomaterials for real-time detection of harmful gases and rapid medical diagnosis.