Halogen-driven adjustment of the colloidal stability of gold nanoparticles produced by laser ablation in liquids

In this study, we explore the influence of bromide anions concentration on the surface chemistry of colloidal gold nanoparticles synthesized via Pulsed Laser Ablation in Liquids (PLAL). Using X-ray photoelectron spectroscopy (XPS) in a controlled environment, by probing a beam of free-standing gold nanoparticles, we quantitatively characterize the surface composition of the nanoparticles, revealing that bromide adsorption significantly contributes to surface oxidation independently of counterion type and pH for alkaline solution. Additionally, our findings demonstrate the adjustability of halogen coverage post-synthesis, offering a versatile method for controlling nanoparticle properties.