Facile green synthesis of CaTiO₃, Ag@CaTiO₃ and Sm@Ag@CaTiO₃ NPs using soursop leaf extract and its enhanced catalytic properties

In this work, we used an eco-friendly method to prepare nanosized CaTiO₃, Ag@CaTiO₃, and Sm@Ag@CaTiO₃ NPs and studied how Ag and Sm influence their photocatalytic behavior. XRD analysis confirmed that all samples formed an orthorhombic perovskite structure, while microscopic observation showed that the particles were mostly spherical. UV–vis studies revealed that adding Ag and Sm improved the light-absorption ability of CaTiO₃ by slightly narrowing its band gap, with Eg values of 3.37, 3.34, and 3.32 eV for CaTiO₃, Ag@CaTiO₃, and Sm@Ag@CaTiO₃ respectively. Photocatalytic tests showed a clear enhancement in dye degradation after doping, and the Sm@Ag@CaTiO₃ sample delivered the best performance, reaching about 73–76 % degradation compared to 66.56 % for pure CaTiO₃. The enhancement observed can be attributed primarily to improved charge separation, a decrease in grain size, and increased surface activity resulting from the synergistic influence of Ag and Sm. The findings indicate that Sm@Ag@CaTiO₃ presents a viable and economical option as a photocatalyst for the treatment of dye-contaminated wastewater.