Preparation of nano-TiO2 sensitized by new ruthenium complex for photocatalytic degradation of methylene blue under visible light irradiation

In this work we have synthesized cis/trans-[Cl(L)Ru(tppz)Ru(L)Cl](ClO4)2 (L = 2,2'-bipyridine-4,4′-dicarboxylic acid, tppz = tetra-2-pyridinylpyrazine) with the main objective to apply it in photocatalytic reactions. The TiO2 is sensitized with the complex to apply visible light more effectively in the photocatalytic reactions. The structure and optical properties of the photocatalyst were characterized by FT-IR, XRD, TEM, FE-SEM, EDX, DRS, BET and UV–vis spectroscopy. The FT-IR and EDX analysis confirmed the chemisorption of the ruthenium complex on the nano-TiO2 surface. According to the XRD, TEM and FE-SEM analysis it is concluded that the existence of ruthenium complex is not affected by the crystal structure and morphology of nano-TiO2. However, BET showed an increase in the surface area after dye-sensitization. The characterization results revealed that the dye-sensitized TiO2 has a wider absorption spectrum range than nano-TiO2. To evaluate the photocatalytic activity of the product, the photo degradation of the methylene blue was studied. The synthesized product could degrade 87% methylene blue in simulating waste water.