Time-Resolved SAXS Study of Gold and Silver Bimetallic Nanoparticle Formation for Controlled Nanostar Synthesis

This study aims to investigates the nucleation and growth mechanisms of gold nanoparticles (GNPs) and gold nanostars (GNSs) using time-resolved in situ small-angle X-ray scattering (SAXS) at the ESRF beamline ID02. By employing an accelerated Turkevich method, HAuCl₄ is rapidly reduced in an acidified ascorbic acid solution, forming GNPs. The addition of AgNO₃ within the first few seconds promotes nanostar morphology through silver-gold interaction. We focus on how temperature and the precise timing of AgNO₃ addition influence particle size, shape, and concentration. This research aims to uncover key mechanisms in nanoparticle formation and improve control over GNS synthesis for catalysis, sensing, and biomedical applications.