New TiO₂/MgAl-LDH Nanocomposites for the Photocatalytic Degradation of Dyes

In this study we report the synthesis of a series of composite nanostructures comprising LDH and TiO₂ phases. The materials characterization showed that the LDH crystallites are encapsulated inside the TiO₂ matrix after the anatase seeds are deposited on Mg_x Al-LDHs. The structure in which LDH phase is embedded into anatase matrix is unique bringing important advantages to the photocatalytic performances of the nanocomposites. The photocatalytic activity of the prepared nanocomposites was tested on the degradation of the methylene blue (MB) in aqueous solution. The photocatalytic activities of the nanocomposites were compared with commercial TiO₂ nanoparticles Degussa P25. The nanocomposites exhibited superior photocatalytic activity in basic environment because the negatively charged surface of TiO₂ nanoparticles at high pH attracts the positively charged methylene blue species.