Synthesis and characterization of high photocatalytic activity and stable Ag_3PO_4/TiO_2 fibers for photocatalytic degradation of black liquor

摘要

The TiO_2 fiber was prepared by using cotton fiber as a template, and then Ag_3PO_4/TiO_2 fibers were synthesized via in situ Ag_3PO_4 particles onto the surface of TiO_2 fiber. Their structure and physical properties were characterized by means of scanning electron microscopy (SEM), specific surface analyzer, X-ray diffraction (XRD), UV-vis absorption spectra and photoluminescence spectra (PL). SEM analysis indicated that the well-defined surface morphology of natural cotton fiber was mostly preserved in TiO_2 and Ag_3PO_4/TiO_2 fibers. Compared with TiO_2 fiber, the absorbance wavelengths of Ag_3PO_4/TiO_2 fibers were apparently red shifted and the PL intensities revealed a significant decrease. By using the photocatalytic degradation of black liquor as a model reaction, the visible light and ultraviolet light catalytic efficiencies of TiO_2, Ag_3PO_4 and Ag_3PO_4/TiO_2 fibers were evaluated. The reaction results showed that Ag_3PO_4/TiO_2 fibers had stronger photocatalytic activity and excellent chemical stability in repeated and long-term applications. Therefore, the prepared Ag_3PO_4/TiO_2 fibers could act as an efficient catalyst for the photocatalytic degradation of black liquor, which suggested their promising applications. It was proposed that the ·OH radicals played the leading role in the photocatalytic degradation of the black liquor by Ag_3PO_4/TiO_2 fibers system.