Formation of bismuth oxide nanostructures via laser ablation in water

Bismuth oxide nanomaterials are increasingly recognized for their promising electronic and optical properties, especially in electrochemical and biomedical applications. In this study, we demonstrate that a variety of bismuth oxide nanostructures can be synthesized through pulsed laser ablation in liquids (PLAL) by adjusting the concentration of dissolved gases from ambient conditions. Structural and compositional analysis was performed using x-ray diffraction, Raman spectroscopy, and FTIR spectroscopy. Morphological studies were conducted using atomic force microscopy and transmission electron microscopy. Our findings reveal that factors such as pressure, dissolved gases, and laser fluence play critical roles in determining the final structure and composition of the resulting nanomaterial. The various phases observed ranged from spherical metallic bismuth nanoparticles to monoclinic bismuth oxide nanowire bundles, and orthorhombic bismuth carbonate oxide nanosheets. This research highlights the importance of free radicals produced during the ablation event, alongside longer-term oxidation processes, in influencing the overall composition and morphology.