Visible light induced photocatalytic activity of rare earth titania nanocomposites

Rare earth metal oxides doped TiO2 were prepared by an incipient wetness impregnation method by varying different mol% of La, Nd and Pr and characterized by various advanced techniques such as powder X-ray diffraction (PXRD), BET-surface area, N2 adsorption–desorption measurements, UV–vis DRS, FTIR and scanning electron microscope (SEM). Analytical results demonstrated that the TiO2 nanoparticles are mesoporous in nature and doping of lanthanides could inhibit the phase transformation, increases the surface area and decreases the crystallite size of mesoporous structures of TiO2. We investigated the visible light induced photocatalytic activities of these materials towards reduction of hexavalent chromium and degradation of methylene blue for the first time. La3+-TiO2 containing 0.4 mol% lanthanum, activated at 673 K showed highest surface area (124.8 m2/g), lowest crystallite size (8 nm) and exhibits highest photocatalytic activity. The reduction of hexavalent chromium and methylene blue degradation rate followed first-order kinetics.

Graphical abstractDoping of Ln3+ on TiO2 increases the photocatalytic reaction; 80% of methylene blue (MB) degradation and 86.5% of Cr (VI) reduction were found in case of 0.4 mol% La3+ doped TiO2 against 30% of MB degradation and 45% of Cr (VI) reduction incase of neat TiO2.Figure optionsDownload full-size imageDownload as PowerPoint slide