Heterostructures of Ce-Ti/layered double hydroxides and the derived MMOs for photoenergy applications

Herein we report Ce-Ti/layered double hydroxides (LDHs) heterostructures and their transformation into the mixed oxides (MMOs) by using the reconstruction of ZnAlLDH and MgAlLDH in an aqueous solution containing TiO2 nanoparticles and Ce(SO4)2·4H2O, followed by their calcination. The novel heterostructures were investigated by powder X-ray diffraction (XRD), UV–Vis, FTIR and Raman spectroscopies, scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDXS). Furthermore, electrochemical characteristics of Ce-Ti/LDHs was studied by linear sweep voltammetry (LSV), Mott-Schottky (M-S) analysis and photo-electrochemical impedance spectroscopy (PEIS) measurements which were conducted in dark or under illumination. Photocatalytic properties of Ce-Ti/LDHs have been studied using phenol photodegradation under UV/solar light as a test reaction while the electrochemical suitability of Ce-Ti/LDHs for photocatalytic water splitting reaction is discussed. Results point out that the photocatalysts efficiency is enhanced due to the increase of the light absorption in Vis but is also a consequence of the effective interfacial electron transfer between the components of TiO2-CeO2/LDHs. This points out that a rigorous control of the composition of the heterostructures based on the LDH can be tailored as good candidates for the advanced oxidation reaction (AOR) processes that allow a more facile electron-hole separation and more efficient energy transfer can be developed.