Using laser ablation at different laser energies for synthesis and characterization of TiO₂ thin films nanoparticles

Abstract

Titania (TiO₂) is one of the most studied nano-materials due to its unique properties and applications across diverse areas, including photocatalysis, hydrogen production, energy conservation, self-cleaning coatings, and solar cells. This study uses a novel, environmentally friendly approach to generate TiO₂ thin-film nanoparticles in 5 min via one-step laser ablation of titanium powder into nanometer-scale structures in deionized water. This top-down approach allows it to improve nanoparticle properties by adjusting laser parameters, especially laser energy, which is very important for determining the size distribution, crystalline structure, and optical band-gap behavior of the particles. The X-ray diffraction patterns of TiO₂ thin film nanoparticles indicate the formation of the rutile phase. Increasing laser energy sharpens the diffraction peaks and reduces the full width at half maximum, indicating improved crystallinity and increased crystallite size. The FESEM image confirms that all the samples have spherical to quasi-spherical nanoparticles with noticeable agglomeration. The nanoparticles exhibit consistent morphology, and the majority of nanoparticles fall within the 20–70 nm range. The UV-Vis absorption spectra of the samples are measured at different laser energies. It exhibits absorption bands at 295, 298, 297, and 296 nm for 50, 100, 150, and 250 mJ, respectively. From these bands of absorption, the absorption increased with increasing laser energy. Results indicate that as the laser energy increases, the nanoparticles' size increases significantly. The particle size and shape are influenced by laser energy.