Fabrication of a novel visible-light-driven photocatalyst Ag-AgI-TiO2 nanoparticles supported on carbon nanofibers

Novel visible-light-driven photocatalysts Ag-AgI-TiO2 nanoparticles embedded onto carbon nanofibers were successfully prepared. Electrospinning technology followed by high-temperature calcination was adopted for the fabrication of carbon nanofibers (CNFs) acting as a supporter. Ag-TiO2/CNFs nanocomposites were prepared by combining in situ reduction with physical adsorption process. Ag-AgI-TiO2/CNFs were synthesized by oxidizing some silver nanoparticles (Ag NPs) contained in Ag-TiO2/CNFs to silver iodine (AgI) via chemical oxidation method using iodine (I-2) as oxidation agents. The as-prepared nanocomposites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (DRS), and Fourier transform infrared spectroscopy (FTIR). The as-fabricated Ag-AgI-TiO2/CNFs showed high efficient adsorption and photocatalytic activity for decomposition of methyl orange (MO), acid red 18 (AR18), methylene blue (MB), and fluorescence sodium under visible light irradiation, which were attributed to the synergistic effects between the high adsorption capacity, good conductivity of carbon nanofibers, and the extraordinary plasma effect of Ag-AgI nanoparticles. In addition, the as-prepared composites could be easily separated from the solution phase due to the large length-diameter ratio of CNFs. The mechanism for the enhanced photocatalytic activity concerned with Ag-AgI-TiO2/CNF was proposed. (C) 2015 Elsevier B.V. All rights reserved.