Microwave-assisted green synthesis of nanoscaled titanium oxide: photocatalyst, antibacterial and antioxidant properties

• Published in: Journal of materials science. Materials in electronics 2021-09, Vol.32 (18), p.23522-23539
• Main Authors: Muthuvel, A., Said, Nejla Mahjoub, Jothibas, M., Gurushankar, K., Mohana, V.
• Format: Article
• Language: English
• Subjects: Anatase; Antioxidants; Characterization and Evaluation of Materials; Chemistry and Materials Science; Conduction bands; Crystallites; Dyes; Electron transitions; Free radicals; High resolution electron microscopy; Industrial applications; Materials Science; Nanoparticles; Optical and Electronic Materials; Photocatalysis; Photocatalysts; Photodegradation; Scavenging; Synthesis; Titanium dioxide; Titanium oxides; Transmission electron microscopy; Valence band; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-06840-3

In the present work, microwave-assisted method is used to synthesize TiO 2 nanoparticles from Wrightia tinctoria leaf extract. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), DLS, ZE, FT-IR, Raman, PL and ultraviolet (UV)–visible studies. The XRD analysis confirmed that the catalyst is composed of anatase tetragonal TiO 2 phase with crystallite size of 9.93 nm. The HR-TEM results show that the particles are in spherical shape with particle size of ~ 22 nm (TiO 2 nanoparticles). The UV–Vis (Tauc plot) spectrum (2.52 eV) of the prepared TiO 2 nanoparticles suggest that intrinsic band gap absorption of TiO 2 and electron transition is from the valence band to conduction band. Furthermore, photocatalytic degradation of organic dyes (methyl blue and methyl orange) was studied under sunlight irradiation using synthesized nanoparticles. The synthesized nanoparticles results show 99% degradation activity as in the case of methyl orange dye compared to methyl blue dye (97%) at 90 min. TiO 2 nanoparticles synthesized using W. tinctoria leaf extract have been found to exhibit more enhanced photocatalyst degradation of organic dyes as compared to other leaf extracts. In addition, the synthesized TiO 2 nanoparticles were tested at various concentrations and these results revealed potential antibacterial activities. Antioxidant activity carried out using DPPH free radical scavenging assay revealed lower IC 50 μg/mL value 53.64 for the synthesized TiO 2 nanoparticles, respectively. The present work further suggests that it is an effort to describe an effective, eco-friendly and simple method of TiO 2 nanoparticles synthesis and to evaluate its potential for various medical and industrial applications.