Solvothermal Synthesis of CeO2–TiO2 Nanocomposite for Visible Light Photocatalytic Detoxification of Cyanide

Abstract

A CeO2–TiO2 nanocomposite was synthesized solvothermally using ascorbic acid (A), urea (U), or polyvinylpyrrolidone (PVP). Powder X-ray and selected area electron diffractometries and Raman spectroscopy confirm the anatase phase of TiO2 and face-centered cubic lattice of CeO2. Energy dispersive X-ray spectroscopy confirms the purity of the synthesized composites and provides their compositions. Scanning electron, field emission scanning electron, and transmission electron microscopies give the sizes and shapes of the synthesized nanoparticles. UV–visible diffuse reflectance spectroscopy shows the optical absorption edges of CeO2–TiO2 (A), CeO2–TiO2 (U), and CeO2–TiO2 (PVP) as 510, 441, and 410 nm, respectively. The blue, blue-green, and green emissions shown by the three nanocomposites indicate the existence of defects such as oxygen vacancies in the crystal lattices. All three composites differ in their electrical properties, obtained by solid-state impedance spectroscopy. Furthermore, solid-state impeda...