Unpredicted Visible Light Induced Advanced Photocatalytic Performance of Eu Doped CaTiO3 Nanoparticles Prepared by Facile Sol–Gel Technique

Here, we propose a novel photocatalyst of europium doped calcium titanate (Eu:CaTiO3) were synthesized by simple sol–gel method. The synthesized catalyst samples were further annealed at various temperatures (500, 700 and 900 °C) under air environment in order to get the high order crystalline nature. Role of annealing temperature is vital to improving the structural, optical and photocatalytic behavior of the samples. XRD, SEM and TEM results illustrate that Eu:CaTiO3 catalyst have nanocrystalline with orthorhombic structure and individual spherical shaped morphology (size of the nanoparticles of 35–50 nm). A considerable red shift in the absorption edge and significant decrease in the band gap energy was found while the annealing temperature is increased from 500 to 700 °C. Recombination of photo-generated electron–hole pair was further demonstrated by PL spectra investigation. The photo-degradation test was monitored methyl orange (MO) and rhodamine B (RhB) dye solutions under visible light irradiation. The 900 °C annealed sample showed superior photocatalytic performance such as high degradation efficiency (93%), huge first order kinetics (0.0932 min−1) and long term stability towards MO dye than RhB.