Green Synthesis and Characterization of TiO2 NanoparticlesUsing Aloe Vera Extract at Different pH Value
Magda S. Hanafy
Abstract
The use of plant extracts for metal oxide nanoparticles synthesis has been extensively studied as a safer alternative to ordinary methods. The present work focused on the synthesis and characterization of Titanium dioxide nanoparticles (TiO 2 NPs) by eco-friendly green synthesis method. The green synthesis was conducted at room temperature at different pH values (acidic, neutral, and basic) using Titanium tetrachloride (TiCl 4 ) as a precursor and Aloe Vera leaves extract as a reducing agent to avoid the use of hazardous chemicals. The characterization of TiO 2 NPs was carried out by UV-visible spectrophotometry, Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD) and high-resolution transmission electron microscope (HRTEM). The influence of pH on the crystalline phase and size of the TiO 2 NPs was also studied. The results revealed that, the maximum absorption of acidic, neutral, and basic TiO 2 NPs were in the UV region at 318, 326 and 320 nm respectively. The synthesized nanoparticles were spherical in shape and highly pure. Formation of TiO 2 NPs was further confirmed by FTIR spectrum showed characteristic peaks of Ti-O and Ti-O-Ti vibrations at 555 cm -1 and 1383 cm -1 , respectively. The average particle size of the acidic, neutral and basic TiO 2 NPs was 22.860.85, 15.830.902 and 13.30.68 nm, respectively. Basic TiO 2 NPs were composed of only one crystalline phase (anatase), neutral TiO 2 NPs composed of a mixture of anatase and rutile phases while acidic TiO 2 NPs composed of a mixture of anatase, rutile, and brookite phases. Basic TiO 2 NPs exhibited the smallest particle size with the purest crystalline phase, therefore, they are favored for further biomedical applications.