Application of Floating TiO₂ Photocatalyst for Methylene Blue Decomposition and <i>Salmonella typhimurium</i> Inactivation

• Main Authors: Marius Urbonavicius, Sarunas Varnagiris, Sandra Sakalauskaite, Emilija Demikyte, Simona Tuckute, Martynas Lelis
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Catalysts
• Subjects: floating photocatalyst; anatase TiO₂; thin films; magnetron sputtering; <i>Salmonella typhimurium</i>
• Online Access: https://www.mdpi.com/2073-4344/11/7/794

The growing level of wastewater as well as pollution of freshwater by various bacteria are essential worldwide issues which have to be solved. In this contribution, nanocrystalline anatase TiO₂ films deposited by magnetron sputtering on high-density polystyrene (HDPE) beads were applied as floating photocatalysts for <i>Salmonella typhimurium</i> bacterial inactivation in water for the first time. Additionally, the photocatalytic degradation of methylene blue dye in the presence of HDPE beads with TiO₂ film under UV-B irradiation was investigated. The suitability to adopt such floating photocatalyst structures for practical applications was tested in cycling experiments. The detailed surface morphology, crystal structure, elemental mapping, surface chemical composition and bond analysis of deposited TiO₂ films were investigated by scanning electron microscope, X-ray diffractometer and X-ray photoelectron spectroscope techniques. The bacterial viability as well as MB decomposition experiments showed promising results by demonstrating that 6% of bacterial colonies were formed after the first run and only about 1% after the next four runs, which is an appropriate outcome for practical applications. NPN uptake results showed that the permeability of the outer membrane was significantly increased as well.