Cobalt oxide nanorods with special pore structure for enhanced ethanol sensing performance.

Cobalt oxide (Co3O4) nanorods with special pore structure were successfully synthesized by a facile hydrothermal method with proper temperature calcination. The relationship between morphologies, structures and gas sensing properties under different calcination temperature were investigated by using XRD, SEM, TEM and XPS method. The Co3O4 sample calcinated at 300 °C displayed the highest response of 143 and fast response/recovery time to 100 ppm ethanol at relatively low operating temperature of 185 °C. The mechanism for enhanced gas sensing performances of Co3O4 nanorods to ethanol could be attributed to the large specific surface area and abundant pore structure through the unique Co3O4 nanorods. The particular surface components under the proper calcination temperature are also the possible reasons for such excellent sensing performances.