Facile synthesis and photocatalytic property of bicrystalline TiO_2/rectorite composites

摘要

The TiO_2/rectorite composites with a bicrystalline (anatase and rutile) framework were synthesized by a facile sol-gel method using titanium tetraisopropoxide as a TiO_2 precursor at different temperatures. The as-obtained composites were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectrum, and Brunauer-Emmett-Teller (BET). XRD and HRTEM analyses confirm that the layered structure of rectorite in the TiO_2/rectorite composites was destroyed to some extent. The TiO_2/rectorite composites prepared at low temperature (80°C) without calcination exhibited strong adsorbility for acid red G (ARG), and showed a high photocatalytic activity for the decomposition of ARG and the persistent organic pollutant 4-nitrophenol (4-NP) under UV irradiation. The excellent photocatalytic activity of the as-obtained composites can be attributed to the synergetic effect of the anatase-rutile mixed phase and bimodal pore structure in the composites. A possible mechanism of the photocatalysis over the TiO_2/rectorite composites was proposed.