The vitaminC@P25TiO2NPs, on the other hand, were obtained through an optimized method based on Mallakpour et al. [27]. Initially, 0.02 g of P25TiO2NPs were dispersed in 1 mL of ultrapure water and stirred in a Vortex. Next, 100 μL of HCl (0.01 M) were added (pH 2) to 100 uL of P25TiO2NPs to avoid gel formation. Then, 100 μL of vitamin C dissolved in ultra-pure water (5.0 × 10−3 M) solution were added to the mixture and was ultrasonicated for 30 min. Finally, vitamin C was added in excess to gain a beige-orange color suspension, and the ultrasonication continued for another 30 min. The pellet obtained after centrifuging the suspension for 10 min at 4500 rpm was resuspended in ultrapure water, centrifuged again, and then lyophilized.
sufiicient sulphuric acid to extract up to 95 per cent or more, of the titanium oxide prescut. This extraction is carried on so that the resulting product, after the addition of the required amount of sulphuric acid, is in the form of a dry powdered .mass, in which approximately 95 per cent of the titanium is in a soluble form. Th dry powdered mass is thenextractedin suitable leaching tanks with water, whereby a solution of approximately 70 grams of sulphuric acid and 100 grams of titanium oxide to the liter, is obtained.