A Comparison of Eu-Doped α-Fe2O3 Nanotubes and Nanowires for Acetone Sensing

Abstract

Pure and Eu-doped (1.0, 3.0, 5.0[Formula: see text]wt.%) [Formula: see text]-Fe2O3 (PFO and EFO) nanotubes and nanowires have been successfully synthesized through the combination of electrospinning and calcination techniques. The structures, morphologies and chemical compositions of the as-obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric and differential scanning calorimetry (TG-DSC) and energy dispersive spectrum (EDS), respectively. To demonstrate the superior gas sensing performance of the doped nanotubes, a contrastive gas sensing study between PFO (EFO) nanotubes and nanowires was performed. It turned out that Eu doping could magnify the impact of morphology on gas sensitivity. Specifically, at the optimum operating temperature of 240[Formula: see text]C, the response value of PFO nanotubes to 100[Formula: see text]ppm acetone is slightly higher than that of nanowires (3.59/2.20). EFO (3.0[Formula: see text]wt.%) nanotubes have a response of 84.05, which is almost 2.7 times as high as that of nanowires (31.54). Moreover, they possess more rapid response/recovery time (11[Formula: see text]s and 36[Formula: see text]s, respectively) than nanowires (17[Formula: see text]s and 40[Formula: see text]s, respectively). The lowest detection limit for acetone is 0.1[Formula: see text]ppm and its response is 2.15. In addition, both of EFO nanotubes and nanowires sensors have a good linearity (0.1–500[Formula: see text]ppm) and favorable selectivity in acetone detection.