EDTA-directed synthesis of highly active porous titania with bicrystalline framework

Porous titania with bicrystalline (anatase and rutile) framework was successfully synthesized by a facile hydrothermal process using inexpensive and nontoxic organic molecules, EDTA (ethylenediamine-tetra-acetic acid) or its sodium salts as a template, which could be removed from porous titania by the extraction with sodium hydroxide aqueous solution and then easily recovered by acidification. XRD investigation suggested that the ratio of anatase to rutile could be readily tuned by employing different sodium salts of EDTA. All of as-prepared porous titania showed higher activities than the commercial photocatalyst P25 for the degradation of methyl orange (MO), because of the high surface area, bicrystalline phase composition and bimodal porous structures.