Synthesis of TiO₂ Nanoparticles by Precipitation Method and Its Photocatalytic Activity: Experimental Design by Taguchi Method

Titanium dioxide (TiO 2 ) nanoparticles were synthesized via a chemical precipitation method. The study employed the Taguchi statistical approach to optimize synthesis parameters for enhanced photocatalytic activity. Results identified the solvent and reflux time as the most influential factors affecting both particle size and photocatalytic performance. Characterization by X‐ray diffraction (XRD) confirmed that most samples exhibited the anatase phase, while scanning electronic microscopy (SEM) analysis revealed agglomerates of spherical and oval nanoparticles with sizes ranging from 35 to 77 nm. The bandgap was calculated using diffuse reflectance spectroscopy, and all samples exhibited a consistent value of 3.35 eV. No significant variations in bandgap were observed among the samples. Photocatalytic activity was evaluated through photodegradation of aqueous aniline solutions under UV irradiation, achieving degradation efficiencies between 82% and 95.5%. Optimization via the Taguchi method led to a maximum aniline removal efficiency of over 98%, confirming the effectiveness of the approach. SEM images of the optimal sample displayed a porous surface morphology with an average particle size of 40 nm, which could be verified by transmission electron microscopy (TEM) micrographs. The results showed the effectiveness of the Taguchi statistical approach in the optimization of synthesis conditions to enhance photocatalytic performance.