Hydrothermal synthesis of FeP4 and Fe2P-loaded α-Fe2O3 hollow spheres and applications in gas sensors

FeP4 and Fe2P-loaded hematite (α-Fe2O3) (FFH) hollow spheres with a diameter of 130–410 nm were synthesized by a hydrothermal method. The structure and morphology of the FFH hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), field-emission scanning electron microscope (FESEM), and X-ray photoelectron spectroscopy (XPS). Nitrogen adsorption–desorption isothermal measurements revealed that the FFH hollow spheres have larger BET surface area and mesopores. The gas-sensing performance of the FFH hollow spheres was investigated towards a series of typical organic solvents and fuels. The FFH hollow spheres exhibited a superior sensitivity towards flammable and irritant gases. The possible sensing mechanism of the FFH hollow spheres sensor is also proposed.