Enhancing the photocatalytic activity of the perovskite-based intergrowth oxide Sr3.2La0.8Fe1.5Co1.5O10-δ with Ca substitution

In this work, the photocatalytic properties of the perovskite-based intergrowth oxides (three-layer Ruddlesden-Popper phase) Sr3.2-xCaxLa0.8Fe1.5Co1.5O10-delta (SCLFCO) with x = 0, 0.2, 0.4, and 0.8 were studied by monitoring the degradation of methylene blue (MB) dye in water solution under solar irradiation. The SCLFCO samples were synthesized by a conventional solid-state reaction. XRD patterns showed the formation of a tetragonal phase for undoped and Ca doped SCLFCO samples. Scanning electron microscopy (SEM) image of the SCLFCO samples showed a mixture of small and large irregular grains and the grain size decreased with an increase in calcium content. Furthermore, an enhancement in the absorption band in the UV-VIS-NIR range occurred as the amount of calcium dopant increased, which was beneficial for the photocatalytic process because the degradation of MB dye was possible under solar irradiation. The SCLFCO sample with x = 0.8 produced a total degradation of MB (100%) after 150 min at a pH = 6.0, whereas the undoped sample with x = 0 showed only a maximum degradation of 27% after 300 min. Therefore, our results suggest that a Ca doping with x = 0.8 in the SCLFCO sample could be useful for the degradation of dyes under solar exposure in water treatment plants.