Synthesis, characterization and photocatalytic properties of V-doped Mn 3 O 4 nanoparticles as a visible light-activated photocatalyst

Abstract

Abstract In this study, undoped and V-doped Mn3O4 nano particles were successfully synthesized through a facile and green sol-gel method. Synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). XRD analysis confirmed that the samples were crystallized in tetragonal Mn3O4 phase. Photocatalytic activity of undoped and V-doped Mn3O4 (2, 4, and 10% V-doped Mn3O4) was investigated by photocatalytic decolorization of methylene blue (MB) under visible light irradiation. Among all the samples, 4% V-doped Mn3O4 exhibited the best photocatalytic activity for the degradation of MB under the visible light irradiation. Moreover, the impact of initial molar concentrations of H2O2 (0.00, 0.68, 1.36, 2.04 M), catalyst loading (0.002, 0.005, 0.01 g/50 ml), initial pH of the solution (2, 6, 8, 10, 12), and temperature (25, 35, 45, 55, 65 °C) on the rate of MB degradation process was studied. Results show that the optimized parameters are temperature 55 °C, initial pH = 10, 1.36 M initial concentration of H2O2 and 0.005 g/50 ml catalyst loading. In addition, the photocatalytic degradation process can be explained in terms of pseudo-first-order kinetic model.