Biosynthesis of TiO₂ nanoparticles using Commelina benghanlensis for the photodegradation of methylene blue dye and antibiotics: Effect of plant concentration

We report on the degradation of MB dye and the antibiotic, sulfisoxazole using various TiO₂ nanoparticles (TiO₂-NPs) prepared via C. benghalensis plant extract. The structure of the TiO₂-NPs transformed from a combination of rutile and anatase phase to only the anatase phase at higher C. benghalensis plant concentration. Whereas, the surface morphology disclosed nanoparticles, which were reduced in size with plant extract concentration. The 30 g TiO₂-NPs demonstrated a photocatalytic degradation of 65 % MB dye, with OH radicals being the species responsible. Moreover, a remarkable degradation of 82.4 % for the antibiotic sulfisoxazole at pH 12 was noted for the 30 g TiO₂-NPs. Such improvement could be justified by superior surface area, higher relative concentration of oxygen vacancies observed for the 30 g TiO₂-NPs. The magnetic study showed that the samples possess a near-zero coercivity, making it probable to be magnetically detached from the solution. Therefore, these results point out that the characteristics of the TiO₂ can be altered by changing the C. benghalensis plant concentrations. Finally, the multifunctional features of these materials to degrade a variety of pollutants in water streams makes them very competitive for practical applications.