Efficient Photocatalytic Degradation of Methyl Orange and Methylene Blue under Visible Light Irradiation and Sunlight by TiO2 Nanoparticles Using Novel Tridentate N2O Schiff Base Complexes

Abstract

Two novel heterocyclic Schiff base complexes ([VOL1(DMF)] [H2L1 = (E)-1-((2-amino-5-nitrophenyl)imino-methyl) naphthalen-2-ol] and [VO2L2] [H2L2 = [(E)-1-((2-aminoethyl) imino-methyl)naphthalen-2-ol]) were synthesized and FT-IR, elemental analysis and UV-Vis spectroscopy were used to fully characterize them. Single-crystal X-ray diffraction was used to determine the structure of the [VO2L2] complex, in which the coordination around the vanadium ion is best described as distorted square pyramidal. The basal plane is formed by the donor atoms (NNO) of the Schiff base ligand and one of the oxo groups while the apical position is occupied by the other oxo group in the structure. The Schiff base complexes were loaded over TiO2 photocatalyst and calcined at 450°C. The MOX/TiO2 structure and morphology were characterized by FT-IR, scanning electron microscopy (SEM), X-ray diffraction (XRD), EDX and solid state UV-Vis absorption. Photocatalytic oxidation of methyl orange (MO) and methylene blue (MB) dyes in aqueous media by solar and visible lights was used to evaluate the photocatalytic efficiency of MOX/TiO2 semi-conducting nanoparticles. The incorporation of these complexes enhanced TiO2 activation with visible light compared with naked TiO2, according to the results.