Porous α-Fe₂O₃ microflowers: Synthesis, structure, and enhanced acetone sensing performances

Porous α-Fe₂O₃ microflowers, which were composed of many nanospindles assembled by large numbers of nanoparticles, were successfully synthesized by calcining the FeSO₄(OH) precursor prepared through a simple ethanol-mediated method. Various techniques were employed to obtain the crystalline and morphological properties of the as-prepared products. The formation process of such microstructure was proposed according to the morphology and component of the products obtained at different reaction time. Moreover, the obtained α-Fe₂O₃ was utilized as sensing materials upon exposure to various test gases. As expected, in virtue of the less-agglomerated configuration and unique porous structure, the hierarchical α-Fe₂O₃ microflowers exhibited higher response as well as faster response/recovery time to acetone when compared with α-Fe₂O₃ nanoparticles. Significantly, the response time was measured to be 1s at the low operating temperature of 210°C.