Characterization of anatase TiO ₂ nanoparticle: Comparative synthesis via microwave combustion and sol-gel techniques

Abstract

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 TiO 2 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 TiCl 3 and PAA (1:1, 1:2, and 1:3) at 300 °C. After calcination at various temperatures (400, 450, 500, and 550 °C), the TiO 2 nanoparticles prepared by the two different methods were characterized by XRD. Infrared (FTIR) spectroscopy was used to determine the chemical structures of the TiO 2 and polymer. The morphology and particle size of TiO 2 at the ideal temperature were evaluated by transmission electron microscopy (TEM). UV-VIS spectroscopy was used to characterize the optical properties of the TiO 2 samples. X-ray diffraction (XRD) analysis determined that a 1:2 ratio of TiCl 3 to PAA (MW2 and SG2) is optimal for producing well-crystallized TiO 2 in the anatase form through a microwave-based method. Calcination at 550 °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 °C, with higher calcination temperatures leading to the formation of both anatase and rutile phases. The size of the TiO 2 nanoparticles created by the microwave approach was determined to be 3–9 nm, whereas that of the TiO 2 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 TiO 2 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.