Preparation of metal oxide doped ACNFs and their adsorption performance for low concentration SO₂

Metal oxide (TiO₂ or Co₃O₄) doped activated carbon nanofibers (ACNFs) were prepared by electrospinning. These nanofibers were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunner-Emmett-Teller method (BET). The results show that the average diameters of ACNFs were within the range of 200–500 nm, and the lengths were several tens of micrometers. The specific surface areas were 1146.7 m²/g for TiO₂-doped ACNFs and 1238.5 m²/g for Co₃O₄-doped ACNFs, respectively. The electrospun nanofibers were used for adsorption of low concentration sulfur dioxide (SO₂). The results showed that the adsorption rates of these ACNFs increased with an increase in SO₂ concentration. When the SO₂ concentration was 1.0 μg/mL, the adsorption rates of TiO₂-doped ACNFs and Co₃O₄-doped ACNFs were 66.2% and 67.1%, respectively. The adsorption rate also increased as the adsorption time increased. When the adsorption time was 40 min, the adsorption rates were 67.6% and 69.0% for TiO₂-doped ACNFs and Co₃O₄-doped ACNFs, respectively. The adsorption rate decreased as the adsorption temperature increased below 60℃, while it increased as the adsorption temperature increased to more than 60℃.