Synthesis and characterization of size-controllable titanium dioxide nanocolloids via pulsed laser ablation in distilled water

Titanium dioxide (TiO2) nanocolloids were synthesized using pulsed laser ablation in liquid (PLAL) by ablating a titanium target in distilled water with a 532 nm Q-switched nanosecond Nd: YAG laser. The effects of laser fluence (1.3–3.25 J/cm2) and irradiation time (5–20 min) on the morphology, size, and optical properties of TiO2 nanoparticles were investigated. The colloidal nanoparticles were characterized using transmission electron microscopy (TEM), UV–vis spectroscopy, X-ray analysis (EDXA), and inductively coupled plasma (ICP) analysis. TEM images revealed that the TiO2 nanoparticles were pri- marily spherical, with sizes ranging approximately from 4.5 ± 1.5 to 10.6 ± 4.5 nm, depend- ing on the applied laser fluence and irradiation time. The UV–vis spectra showed distinct UV absorption peaks at approximately 225.3 ± 0.3 nm, while the estimated bandgap values ranged from 3.67±0.01 to 4.0±0.02 eV under different laser ablation conditions. Overall, these findings demonstrate that PLAL is a reliable and efficient method for synthesizing TiO2 nanocolloids with high purity and controllable sizes.