Biosynthesis of titanium dioxide nanoparticles for the photodegradation of dyes and removal of bacteria

• Published in: Optik (Stuttgart) 2020-12, Vol.224, p.165728, Article 165728
• Main Authors: Ngoepe, Nkgaetsi Marius, Mathipa, Morongwa Mary, Hintsho-Mbita, Nomso Charmaine
• Format: Article
• Language: English
• Subjects: Antibacterial; Green synthesis; Photocatalysis; TiO2
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2020.165728

•Biosynthesis of spherical TiO2 nanoparticles with small particle sizes.•Environmentally Safe Route.•85 % degradation of MB.•Selective towards gram negative bacterial strains.•Active against real water samples as well. Water pollution associated with dyes and bacteria has become a concern to researchers due to an increase in human activity particularly in the textile industry, hospitals and households. In this study, TiO2 was synthesized using the green route and characterized via UV–vis, FTIR, TEM, SAED, SEM, EDS and XRD. It was then tested for its antibacterial and photocatalytic potential. LCMS, FTIR and EDS provided evidence of the compounds, functional groups and elements that contributed to the mechanism of metal oxide formation. UV–vis gave information on the optical properties where an absorbance peak at 327 nm was exhibited and had a bandgap of 3.53 eV. FTIR, further confirmed the formation of TiO2 with a vibration band at 497 cm−1. SEM showed a spherical shape of TiO2 and XRD demonstrated that these were of anatase structure. Thereafter, photocatalytic degradation using Methylene blue (MB) as a model pollutant was conducted, where 85.5 % of the pollutant was degraded. Furthermore, upon testing the antibacterial activity of TiO2, the material was found to be selectively active against Eschericia coli. In real water samples this material demonstrated exceptional activity. This study has shown that a potent environmentally safe material can be synthesised which has the ability to degrade and remove pollutants from various sources.