Microwave-assisted synthesis of hierarchically porous CoO/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 CoO/rGO nanocomposite synthesized by a microwave-assisted method, by which CoO nanoparticles are rapidly and uniformly anchored on rGO nanosheets. The phase composition, surface morphology of the CoO/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 (CoO/rGO-1) achieves the highest stability and response to acetone (0.5 ~ 200 ppm) at a relatively low temperature (~160 °C). Also, the CoO/rGO-1 exhibits a high acetone-sensing selectivity against the gases (or vapors) of HS, H, CH, HCHO, CHOH, CHO and CHOH. The enhanced acetone-sensing performance of the CoO/rGO composite can be attributed to the CoO/rGO p-p heterojunction and the Co-C coupling effect between CoO 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.