Nano-crystalline Ce-doped TiO2 powders: sol-gel synthesis and optoelectronic properties

Abstract

Nanoparticles (NPs) of pure titanium dioxide (TiO2) and impure titanium dioxide (Ce-doped TiO2) were made with impurity percentages of 1%, 2%, 3%, 4%, and 6% by the sol-gel technique, with a new precursor of tetratitaniumisopropoxide (TTIP) and cerium chloride (CeCl3), acetic acid as a catalyst, and ethylene glycol as stabilizer in an ethanol solvent. The morphological, structural, and optical properties of NPs were examined. An XRD analysis showed that the TiO2 NPs had a tetragonal structure as the sample structures did not change as a result of the insertion cerium impurity into the TiO2 lattice. The structural results have also shown that the size of NPs is reduced by an increase in Ce impurities as the pure size of 38 nm reduces to 21.4 nm because of 6% impurity. A FESEM analysis showed that an increase in the impurity percentage reduces NPs uniformity because of its reducing size. The apparent shape and mean diameter of NPs obtained by TEM analysis was 25.2 nm for with 3% impurities in a quasi-spherical form. The UV-DRS optical analysis results showed that the band gap increases due to an increase in the Ce impurity percentage from 2.75 eV for pure TiO2 NPs to 3.09 eV for NPs with 6% impurities. In addition, a photoluminescence analysis showed that the intensity increased following an increase in impurities because of a band-gap increase.