Environmental photochemistry with Sn/F simultaneously doped TiO2 nanoparticles: UV and visible light induced degradation of thiazine dye

Abstract

Environmental route such as degradation of toxic dyes can be improved through photochemical activity such as light driven photocatalytic degradation. Herein, fluorine and tin simultaneously doped TiO₂ nanoparticles were synthesized and characterized. The formation of anatase phase in synthesized samples and the reduction in the crystallite size of doped TiO₂ was confirmed from XRD results. The existence of O-Ti-O stretching vibration in pure and co-doped TiO₂ confirmed from FTIR results. Optical studies reveal that the band gap of co-doped TiO₂ is increased and hence it was concluded that the particle size of co-doped TiO₂ is reduced compared with as-synthesized TiO₂. The morphologies of TiO₂ changed significantly with doping of fluorine and tin. It reveals majority of the particles are hexagons, pentagons and ellipse shaped and some of them are spheres with a mean particle size of 31.17 nm. PL studies showed the reduction in intensity for Sn-F/TiO₂ accredited to the lesser recombination rate of electron-hole pair under UV light irradiation. Thus tin and fluorine doped TiO₂ could be considered as a good candidate for photocatalytic activity. The photocatalytic activity of TiO₂ and Sn-F/TiO₂ nanoparticles was analyzed separately through the degradation of methylene blue (MB) under visible and UV light irradiation. The use of Sn and F ions in the synthesis of TiO₂ are revealed not only create small sized nanoparticles but these water soluble nanoparticles have very good antibacterial and antifungal action by inhibiting the growth of bacteria and fungus.

Keywords: Antibacterial; Antifungal; Co-doping; Methylene blue; Photocatalysts; TiO(2) nanoparticles.