Synthesis of modificated lanthanide nanoperovskites for photocatalytic removal of azo dyes under visible light irradiation

The LaNiO3, LaMnO3, and LaCoO3 nanoperovskites and also modificated LaCoO3 (LaCo0.8Ni0.2O3 and LaCoO2.9N0.1) were synthesised by a sol–gel method. The as-prepared samples were systematically characterised by scanning electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller and UV–vis diffuse spectroscopy. The XRD spectra confirmed the information of perovskite-type structure for all the prepared samples and according to SEM images; the perovskites have spherical shape with particles size less than 50 nm. The photocatalytic activity of the nanoperovskites was evaluated for removal of congo red and direct red 23 under the irradiation of visible light. The doping Ni and N in the LaCoO3 had a great effect upon its photocatalytic activity and the LaCo0.8Ni0.2O3 and LaCoO2.9N0.1 were exhibited higher photocatalytic efficiency than parent LaCoO3 due to narrower band gap, oxygen vacancies, and less agglomeration. The nanoperovskites also were stable during the photocatalytic and recycling processes.