Synthesis and characterization of Fe-doped β-Bi_2O_3 porous microspheres with enhanced visible light photocatalytic activity

摘要

Fe-doped β-Bi_2O_3 porous microspheres (Fe-Bi_2O_3) were fabricated by a facile hydrothermal method. The structures, morphology and optical properties of Fe-Bi_2O_3 samples were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy. The results from XRD analysis confirmed that a completed thermal conversion of the precursors to Fe doped β-Bi_2O_3 at the temperature of 375 ℃. The iron ions is substitution for Bi~(3+) in the Bi_2O_3 lattice structure with the presence of Fe~(3+), which proved by the XPS. The SEM observations exhibited that the morphology of the as-prepared photocatalysts was porous microspheres. According to the results of UV-vis spectra, the Fe-doped 3-Bi_2O_3 microspheres demonstrated a strong visible-light absorbance in the wavelength range of 420-600 ran. Under visible light irradiation (λ ＞ 420 nm), Fe-doped β-Bi_2O_3 photocatalysts with the content of 4 mol% displayed highest photocatalytic activity for the Methyl Orange (MO) photodegradation. The mechanism for the enhanced photocatalytic activity of Fe-doped β-Bi_2O_3 photocatalysts was also proposed.