Characterization of anatase TiO2 nanoparticle: Comparative synthesis via microwave combustion and sol-gel techniques

Using polyacrylic acid (PAA) as the template polymer and titanium tri-chloride as the titanium source, two distinct methods were employed in this study to prepare TiO2 nanoparticles: a sol-gel method and a microwave combustion method. The methods described above were used to determine the ideal polymer ratio to create three distinct molar proportions of TiCl3 and PAA (1:1, 1:2, and 1:3) at 300 degrees C. After calcination at various temperatures (400, 450, 500, and 550 degrees C), the TiO2 nanoparticles prepared by the two different methods were characterized by XRD. Infrared (FTIR) spectroscopy was used to determine the chemical structures of the TiO2 and polymer. The morphology and particle size of TiO2 at the ideal temperature were evaluated by transmission electron microscopy (TEM). UV-VIS spectroscopy was used to characterize the optical properties of the TiO2 samples. X-ray diffraction (XRD) analysis determined that a 1:2 ratio of TiCl3 to PAA (MW2 and SG2) is optimal for producing well-crystallized TiO2 in the anatase form through a microwave-based method. Calcination at 550 degrees C further enhanced the crystallization of anatase nanoparticles, mainly when the microwave method was applied. In contrast, the sol-gel method indicated that the powder remained amorphous at 300 degrees C, with higher calcination temperatures leading to the formation of both anatase and rutile phases. The size of the TiO2 nanoparticles created by the microwave approach was determined to be 3-9 nm, whereas that of the TiO2 particles prepared by the sol-gel method was 8-20 nm. MW2 and SG2 had band gaps of 3.17 eV and 3.15 eV. In this study, we successfully synthesized nano-anatase TiO2 using an efficient and time-saving approach (microwave combustion method) in conjunction with heat treatment. The resulting material has potential applications in various fields, including energy storage, supercapacitor electrodes, photoelectric conversion, optical coatings, beam splitters, and anti-reflection coatings.