Synthesis of nearly monodisperse Co3O4 nanocubes via a microwave-assisted solvothermal process and their gas sensing properties

Nearly monodisperse Co3O4 nanocubes have been prepared by a microwave-assisted solvothermal (MS) method at 180 °C for 20 min. The samples are characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD pattern and TEM images of the products illustrated that Co3O4 nanocubes had a cubic phase with a lateral size of ∼20 nm. The gas response of the Co3O4 nanocubes was studied to several typical organic gases. The Co3O4 nanocubes showed good gas sensing performance towards xylene and ethanol vapors with rapid and high responses at a low-operating temperature. The results showed that the Co3O4 nanocubes can be used to fabricate high performance gas sensors.

► Nearly dispersed Co3O4 nanocubes were synthesized with a microwave-assisted two-phase method.
► These nanocubes were used as gas sensing materials and had good responses to xylene and ethanol.
► The responses of the gas sensors fabricated by Co3O4 nanocubes to arenes increased with the number of the methyl group in the benzene ring.