Hydrothermal synthesis, characterization and catalytic performance of La3+ and Sm3+ - doped Bi2Mn2O7 nanocatalysts for Biginelli reactions

La3+ and Sm3+ - doped Bi2Mn2O7 nanocatalysts were synthesized in 1 M NaOH aqueous solution, via a stoichiometric 1:1 Bi:Mn molar ratio hydrothermal method at 180 °C for 48 h. Bi(NO3)3, MnO2, La(NO3)3 and Sm2O3 were used as raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique. Both of the La3+ and Sm3+ - doped Bi2Mn2O7 nanomaterials were crystallized in a cubic crystal structure with space group Fd3 ̄m. The morphologies of the synthesized materials were studied by field emission scanning electron microscope (FESEM). The optical properties of the as-synthesized nanomaterials were studied by ultraviolet visible (UV-Vis) diffuse reflectance spectra (DRS). It was found that the optical band gaps were increased with dopoing La3+ and Sm3+ into Bi2Mn2O7. Catalytic performance of the synthesized nanomaterials were investigated in Biginelli reactions which showed excellent efficiency. Correlation between the catalytic performance with the band gap and hard/soft proportion of the metal ions was shown.