Effect of Ablation Time on the Optical Properties and Functional Groups of Tantalum Oxide Nanoparticles Synthesized in Polyethylene Glycol Medium via Pulsed Laser Ablation

Abstract

Tantalum oxide nanoparticles (Ta₂O₅ NPs) were synthesized in polyethylene glycol (PEG 4000) liquid medium using pulsed laser ablation (PLAL) technique to study the effect of ablation time on their physicochemical properties. The synthesis process was carried out by ablation of pure tantalum metal using Nd:YAG laser (1064 nm, 78 mJ, 7 ns, 10 Hz) for 30 and 60 min. Characterization tests were carried out using UV–Vis and FTIR spectroscopy. The results showed that increasing the ablation time caused the colloidal suspension to become more turbid, indicating a higher concentration of nanoparticles. UV–Vis spectroscopy showed a characteristic absorption peak in the range of 285–290 nm, with the absorption intensity increasing from approximately 0.20 a.u. at 30 min to 0.40 a.u. at 60 min, without significant peak shift. FTIR analysis confirmed the formation of Ta₂O₅ through the Ta–O–Ta vibration band and demonstrated the interaction between the nanoparticle surface and PEG functional groups, including ether (C–O–C) and hydroxyl (–OH) groups, indicating effective steric stabilization. Overall, longer ablation time enhanced the formation of the oxide network and the stability of the Ta₂O₅–PEG colloidal system.