The release of hazardous gas increases with the development of industry. The research of gas-sensitive materials has attracted attention. Nanoscale iron oxide (α-Fe2O3) is one of the research hotspots of gas-sensitive materials because it is a cheap, non-toxic semiconductor material. In this study, pomegranate-shaped α-Fe2O3 was synthesized using an in situ corrosion method of scorodite. Spherical-shaped α-Fe2O3 nanoparticles were included in the octahedral shells. The forming process of the structure was analyzed by a variety of measurements. The shell was formed first through the deposition of Fe(OH)3, which was produced by hydrolyzing scorodite. Then, the corrosion was continued and Fe(OH)3 precipitation was produced below the shell. The particles aggregated and formed spheres. The pomegranate-shaped α-Fe2O3 was formed when the scorodite was hydrolyzed completely. The gas-sensing properties of α-Fe2O3 were investigated. The results showed that pomegranate-shaped α-Fe2O3 was responsive to a variety of gases, especially xylene. The value of Ra/Rg was 67.29 at 340 °C when the concentration of xylene was 1000 ppm. This indicated the pomegranate-shaped α-Fe2O3 has potential application as a xylene gas sensor.
Keywords: nanomaterials; pomegranate-shaped structure; scorodite; sensor; α-Fe2O3.