Preparation of porous flower-like graded structure Co 3 O 4 /g-C 3 N 4 and its ethanol gas-sensitive properties

Abstract

The porous flower-like structure of Co₃O₄ and Co₃O₄/g-C₃N₄ composites derived from the cobalt-based metal organic framework (MOF) were prepared by one-step hydrothermal method and high temperature calcination, and the gas sensitivity of the synthesized samples to ethanol gas was tested. The structure and morphology of the synthesized samples were characterized via X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and N₂ adsorption-desorption. The gas-sensitive properties of the synthesized samples for ethanol gas were tested. It was demonstrated that the response of Co₃O₄/g-C₃N₄ to 100 ppm ethanol at 220°C was 36.33, which was 1.5 times higher than that of pure Co₃O₄. In addition, this gas sensor exhibited excellent selectivity, good repeatability, and long-term stability for ethanol. The gas-sensitive properties of the Co₃O₄/g-C₃N₄ graded structure towards ethanol were attributed to the unique porous graded structure of the material, the large specific surface area and the p-n heterojunction. This method provided a new idea for the porous flower-like hierarchical structure of metal oxide semiconductors (MOS) derived from MOFs.