Morphological change and photocatalytic activity of titanium phosphates

Abstract

Titanium phosphates with wide range of phosphate content (phosphate/Ti = 0 similar to 2) are prepared by one step hydrothermal method, and their photocatalytic property are valuated based on the rate of oxidative degradation of organic pollutants (4-chlorophenol, trichlorophenol and bisphenol A). The crystal phase, optical property, and morphology of samples are investigated by XRD, diffuse reflectance Uv-vis spectroscopy and SEM/TEM. We find that TiO2 Exhibits 100 similar to 500 nm elliptical spherical structure which is composed of individual anatase phase of TiO2. As the content of phosphate increases, rice grain shaped TiO2 with anatase phase is change into jagged intertwined crystals with layered structure, followed by fibrous structure (TiO2). The Uv-vis absorbance spectra of TiPs shift to shorter wavelength as the phosphate content increases. Therefore, the photocatalytic activity of TiPs has tendency to decrease, as the phosphate content increases. However, TiO2 exhibits better photocatalytic property than, pure TiO2 for the photo-degradation of organic pollutants. We attribute this enhanced photocatalytic property of TiO2 to the larger surface area and smaller crystallite of TiO2 which originates from the incorporation of phosphate in TiO2 acting as a crystal growth inhibitor. (C) 2017 Elsevier B.V. All rights reserved.