Synthesis and characterization of brookite-based materials: study of phase transformations by thermal treatment

Abstract

Single phase brookite, anatase and mixed brookite/anatase samples were obtained by alkaline hydrothermal synthesis. The presence of sodium ions was found to be necessary far the development of brookite phase . The nature of sodium source used in the synthesis and the duration of the hydrotherrnal treatrnent deterrnined the crystalline phase composition and morphology of the resulting materials. The influence of brookite/anatase content and morphology on phase transformation behavior by thermal treatment and surface hydroxylation of the samples was investigated by means of X­ Ray Diffraction, Fourier Transform Jnfrared Spectroscopy and Scanning Electron Microscopy .