Formation, gradual oxidation mechanism and tunable optical properties of Bi/Bi2O3 nanoparticles prepared by Nd:YAG laser ablation in liquid: Dissolved oxygen as genesis of tractable oxidation

• Published in: Materials research bulletin Vol. 97; pp. 421 - 427
• Main Authors: Dadashi, S., Poursalehi, R., Delavari H., H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2018
• Subjects: Bismuth oxide nanoparticle; Laser ablation; Optical properties; Oxidation mechanism; Photocatalytic activity; Bismuth oxide nanoparticle; Photocatalytic activity; Laser ablation; Optical properties; Oxidation mechanism
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2017.09.029

Laser ablation in water in comparison with other method for nanofabrication provides a flexible and fast method for the preparation of metal and metal oxide with high purity. Furthermore, outright surface oxidation of nanoparticles by synthesis in water provides a facile approach for oxidation and mechanism of metal oxide nanoparticles formation by laser ablation. [Display omitted] •Colloidal Bi/Bi2O3 nanoparticles were synthesized by pulsed Nd:YAG laser ablation in liquid.•Optical properties, formation and oxidation mechanism of Bi/Bi2O3 nanoparticles have been studied.•Two-step oxidation mechanism is proposed including the oxidation during and after ablation.•Optical absorption of Bi2O3 nanoparticles can be fine-tuned via tailoring the oxide shell thickness of nanoparticles.•Photocatalytic activity of Bi/Bi2O3 nanoparticles was investigated by degrading aqueous solution of methylene blue. Colloidal Bi/Bi2O3 nanoparticles were synthesized by pulsed Nd:YAG laser ablation of metallic bismuth target. Structural characterization and optical properties of Bi/Bi2O3 nanoparticles have been studied. Moreover mechanism of nanoparticles formation and oxidation of Bi nanoparticles were proposed, according to experimental data from UV–vis spectroscopy and calculation of optical properties. SEM and XRD analyses indicate the formation of Bi2O3 nanoparticles with mean size of 27±4nm which are mixing of four phases including rhombohedra crystal structure of Bi, Bi(OH)3, monoclinic α-Bi2O3 and tetragonal β-Bi2O3. In addition, optical extinction of Bi2O3 nanoparticles can be fine-tuned in the visible spectral region by tailoring the oxide radii in nanoparticles. Overall synthesis of Bi2O3 nanoparticles by laser ablation in deionized water with high purity and controllable oxide shell illustrating a relatively effective technique for nanoparticle synthesis. Finally, photocatalytic activity of Bi/Bi2O3 nanoparticles was investigated by degrading an aqueous solution of methylene blue under LED UV irradiation.