Co3O4 hexagonal nanodisks: Synthesis and efficient ethanol gas sensing application

Abstract

Morphology, crystallinity, surface-to-volume ratio, and catalytic properties of metal oxide-based nanostructures are crucial factors that govern their gas-sensing performance. Herein, cobalt oxide (Co3O4) hexagonal nanodisks-like morphology was synthesized using a one-step, and chemical facile route. The crystallinity, structural, composition, and morphological properties of the Co3O4 hexagonal nanodisks were evaluated by employing X-ray diffraction, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The obtained results confirmed the successful synthesis of Co3O4 hexagonal nanodisks-like nanostructures in large quantities with an average size of ∼ 80 -100 nm. The synthesized Co3O4 hexagonal nanodisks-like nanostructures were utilized as sensing material to fabricate ethanol gas sensors. The ethanol sensing performance of the Co3O4 sensor was evaluated. The sensor exhibited excellent sensing properties towards 10 – 100 ppm ethanol. The highest ethanol sensing response (94%) was obtained at the operating temperature of 175 °C toward 100 ppm ethanol gas. The sensor showed a limit of detection of 10 ppm (response 12%). Also, the selectivity and stability tests of ethanol gas sensors were evaluated. The efficient ethanol sensing performance using Co3O4 hexagonal nanodisks nanostructure-based gas sensor can be attributed to the hexagonal nanodisks, which provided two-dimensional morphology and a large surface-to-volume ratio. These thin Co3O4 hexagonal nanodisks with promising ethanol gas sensing can be the potential candidate for advanced sensor technology.