This study examines the influence of annealing temperature on titanium dioxide (TiO₂) nanoparticles. We synthesized the TiO₂ nanoparticles using the Sol-Gel process and annealed them at various temperatures. The structural investigation demonstrated excellent crystallinity and morphology. Particle size increases with annealing temperature. Annealing at higher temperatures boosted photoluminescence intensity and green colour purity.

Abstract

Titanium dioxide (TiO₂) nanoparticles (NPs) were synthesized using the sol–gel method. The samples obtained were subsequently annealed at different temperatures, ranging from 450°C to 1200^○C. The structural, morphology, and photoluminescence properties of TiO₂ were investigated. The x-ray diffraction (XRD) results of the TiO₂ (as-prepared) revealed an amorphous structure. The annealed samples revealed a mixed phase of anatase and rutile, with rutile becoming more prominent as the temperature increased. The crystallite size increased from 3.183 nm to 35.328 nm. The macrostrain decreased from 2.5 to 0.21. The Fourier transform infrared (FTIR) spectroscopy also revealed the formation of titanium dioxide, as indicated by the presence of the Ti─O functional group. The field emission gun scanning electron microscopy (FEG–SEM) showed a spherical shape of TiO₂ NPs. The elemental composition of titanium (Ti) and oxygen (O) was revealed by energy-dispersive x-ray spectroscopy (EDX). Transmission electron microscopy (TEM) revealed an irregular morphology at higher annealing temperatures (AT). Photoluminescence (PL) spectra were used to analyze the optical properties of TiO₂. TiO₂ annealed at 600°C showed low PL intensity, whereas TiO₂ annealed at 1200°C had the highest PL intensity. The Commission Internationale de I'Eclairage (CIE) analysis revealed that AT has tuned the emission color from blue–green to more green.