High sensitive and low concentration detection of methanol by a gas sensor based on one-step synthesis α-Fe2O3 hollow spheres

Hematite (α-Fe2O3) hollow spheres were prepared by a one-step hydrothermal reaction without template and used to fabricate the gas sensors. Structure and morphology of the product were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results indicated that the α-Fe2O3 hollow spheres were composed of nanoparticles with the diameter of 50-70 nm, and the average diameter of α-Fe2O3 hollow spheres was 250 nm. The sensor based on α-Fe2O3 hollow spheres exhibited excellent sensing performance to methanol at 280 °C, and the response can be reached at 25 when the concentration as low as 10 ppm. In addition, sensing mechanism of the sensor towards α-Fe2O3 hollow spheres was investigated.