Two-step laser synthesis of Ag@TiO ₂ nanomaterials for the photocatalytic degradation of rhodamine B

This study presents a novel, chemical-free approach for the synthesis of Ag-modified TiO 2 (Ag@TiO 2 ) nanoparticles by combining the two laser-based ablation techniques pulsed laser deposition (PLD) and pulsed laser ablation in liquids (PLAL). Initially, silver was ablated using 200 and 2000 pulses and deposited onto titanium targets via PLD. Subsequently, these modified targets were submerged in water and processed using PLAL to generate the final nanomaterials. Characterization through HRTEM, EDS, and UV–vis spectroscopy confirmed the formation of nanoparticles with a predominantly anatase TiO 2 phase. The synthesized particles exhibited spherical morphology, with average diameters ranging from 97–331 nm for the 200p sample and 86–144 nm for the 2000p sample. The photocatalytic efficiency was evaluated using rhodamine B (RhB) under UV irradiation; while RhB showed minimal self-degradation, the Ag@TiO 2 200p and 2000p NPs samples achieved degradation rates of 75.8% and 88.4%, respectively. The main novelty of this work is the combination of two laser techniques in a chemical-free process, which provides an efficient and environmentally friendly route for the fabrication of Ag@TiO 2 photocatalysts.