Abstract:
The aim of this work is to study the effect of lanthanum doping on the phase formation
processes in ceramics based on CaTiO3
, as well as to evaluate the effectiveness of the ceramics as
photocatalysts for the decomposition of the organic dye Rhodamine B. The methods used were
scanning electron microscopy to evaluate the morphological features of the synthesized ceramics,
X-ray diffraction to determine the phase composition and structural parameters, and UV-Vis spectroscopy to determine the optical properties of the ceramics. During the experiments it was found
that an increase in the lanthanum dopant concentration from 0.05 to 0.25 mol leads to the formation
of the orthorhombic phase La0.3Ca0.7TiO3 and the displacement from the ceramic structure of the
impurity phase TiO2, which presence is typical for the synthesized ceramics by solid-phase synthesis. On the basis of the data of the X-ray phase analysis the dynamics of phase transformations
depending on concentration of lanthanum was established: CaTiO3/TiO2 → CaTiO3/La2TiO5 →
CaTiO3/La0.3Ca0.7TiO3 → La0.3Ca0.7TiO3
. During the determination of photocatalytic activity it was
found that the formation of La0.3Ca0.7TiO3 phase leads to an increase in the decomposition rate as
well as the degree of mineralization.
