Morphology-controlled synthesis and gas-sensing properties of Fe2(MoO4)3 microspheres

3D Fe-2(MoO4)(3) microspheres were prepared by hydrothermal method with polyethylene glycol (PEG) assisted. The structure, morphology and crystal phase of the 3D Fe-2(MoO4)(3) microspheres samples were characterized by X-ray power diffraction and scanning electron microscopy. The 3D Fe-2(MoO4)(3) microspheres were composed of nanosheets. The diameter of 3D Fe-2(MoO4)(3) microsphere and thickness of nanosheets were controlled by the molecular weight of PEG. The size of microsphere decreased with the molecular weight increase, the Fe-2(MoO4)(3) microspheres prepared with PEG-2000 showed the minimum mean diameter of 17.8 mu m and nanosheets thickness of 65 nm. The sensors based on the hierarchical 3D Fe-2(MoO4)(3) exhibited excellent gas sensing performances, which showed high response to n-butanol at low operating temperature and high response to acetone at relatively high operating temperature. The highest responses of sensor were 5.7 and 3.4 to 1 ppm n-butanol and acetone at corresponding optimum working temperature. The Fe-2(MoO4)(3) microspheres have a potential application in n-butanol and acetone detection, and it can be applied in diabetes diagnosis due to good low concentration response to acetone.