Effect of Mg²⁺ doping and Mn²⁺ Co-doping on the structural, optical, and photocatalytic properties of CaTiO₃ nanopowders prepared by the sol–gel method

This study focused on the synthesis and characterization of CaTiO₃ powders doped with Mg²⁺ (10 mol%) and co-doped with various ratios of Mn²⁺ (0, 2, 4, 6, 8, and 10 mol%), which were prepared via a low-cost sol–gel method and calcined at 900 °C for 3 h. These nanopowders were investigated for their potential as improved photocatalysts. The powders were comprehensively analyzed using X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, photoelectron spectrometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, Brunauer–Emmett–Teller analysis, UV–visible spectroscopy and differential scanning calorimetry. The experimental results indicated that all diffraction peaks correspond to the orthorhombic phase of CaTiO₃ with no impurity phases detected. These was corroborated by FTIR, Raman spectroscopy, and XPS analysis. The crystallite size, influenced by the doping levels, was estimated to range from 25 to 34 nm. Increasing the doping concentration reduces the band gap energy of the doped samples, introducing new energy levels within the band structure. Furthermore, the photocatalytic activity result shows that the CaTiO₃ doped with Mg²⁺ (10 mol%) and co-doped with Mn²⁺ (10 mol%) is an effective photocatalyst for the degradation of crystal violet dye under UV light irradiation.