Synthesis of pure and La-doped anatase nanopowders by sol–gel and hydrothermal methods and their efficiency in photocatalytic degradation of alprazolam

Abstract

Pure and La3+ doped titanium dioxide (TiO2) nanopowders were obtained by sol–gel and hydrothermal methods. A precursor was titanium tetrachloride and concentrations of dopants were 0.5 and 1.0mol%. Procedures of both methods were the same, up to the last part of synthesis (the transformation from the mother liquor to oxide nanopowders), in order to find the influence of applied methods on the properties of nanopowders. XRD results have shown that all synthesized nanopowders were in the anatase phase. It was seen from DSC measurements that anatase to rutile phase transition took place at a higher temperature with a higher concentration of dopant (La3+). The samples obtained by the sol–gel method had a higher temperature of phase transition than related samples obtained by the hydrothermal method. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the pharmaceutical alprazolam.