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

Abstract

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.

Graphical Abstract

Keywords:

• Nano-TiO₂
• photocatalytic
• methylene blue
• visible light
• dye-sensitized

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Ferdowsi University of Mashhad (3/46325).