Meso- and macroporous coral-like Co3O4 for VOCs gas sensor

Meso- and macroporous coral-like Co3O4 was synthesized via a facile self-sustained decomposition using the complexes of metallic salts and organics (metal-organic complexes). Porous Co3O4 material was characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectrum (XPS) to examine the morphology and microstructure to find out the cause. Co3O4 with the meso- and macroporous structure consisting of nanoparticles has a coral-like shape with a size of tens of micrometers and exhibits the hierarchically porous morphology, in which the walls of the macropores contain smaller mesopores. The gas-sensing characteristics of the porous Co3O4 for volatile organic compounds (VOCs) were investigated. The gas response to 1000 ppm n-butanol reaches a maximum of 27.7 at an operating temperature of 120 °C, and about five times of the Co3O4 particles. The porous Co3O4 also exhibits certain selectivity and response/recovery time.