Hydrothermal synthesis, growth mechanism and gas sensing properties of Zn-doped α-Fe2O3 microcubes

Monodisperse Zn-doped α-Fe2O3 microcubes were prepared via a facile hydrothermal method with zinc ions as the structure-directing agents. The observations of FE-SEM and TEM showed that the obtained sample has a quasi-cubic shape with an edge length of about 250 nm. It can be found that the dosage of Zn2+ in the solution had a remarkable effect on the morphology of as synthesized samples. The element analyses of the fabricated microcubes were carried out by XPS and EDS. The investigation on the evolution formation revealed that Zinc ions were critical for controlling the assembly of microcubes. Moreover, the gas sensors based on Zn-doped α-Fe2O3 microcubes were fabricated and the gas sensing performances were investigated. It was found that the gas sensor exhibited high response, good selectivity, fast response and recovery time to acetone at the working temperature of 240 °C.