Controllable synthesis of TiO2 nanoparticles and their photocatalytic activity in dye degradation

Titanium dioxide nanoparticles were synthesized by hydrolyzing titanium tetrachloride (TiCl4) in a controlled manner using a homemade glass apparatus. The structural properties and chemical composition were studied using X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller surface area analysis, selected area electron diffraction, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. The X-ray diffraction pattern and the high-resolution transmission electron microscope analyses confirmed that the TiO2 nanoparticles are composed of photo-active anatase and brookite phases. The photocatalytic activity of the TiO2 nanoparticles was demonstrated by photo-degradation of methylene blue and congo red under UV-Vis light illumination. Studying how pH affects the degradation of methylene blue revealed that its photocatalytic degradation on TiO2 nanoparticles is more efficient under alkaline conditions, whereas the congo red degradation is more efficient under acidic conditions.