Unlocking the role of byproducts in reactive laser ablation in liquids: A pathway to dual-function Au-Ti nanostructures

In this study, we explore the dual functionality of reactive laser ablation in liquids (RLAL) for fabricating nonequilibrium Au-Ti nanoparticles (NPs) and laser-induced periodic surface structures (LIPSS) on Ti solid targets. By irradiating Ti solid targets in an aqueous KAuCl₄ solution, we synthesize Au-Ti NPs with distinct optoelectronic properties, including enhanced light absorption into the visible spectrum and plasmonic effects that promote efficient charge separation. Concurrently, LIPSS formed on the Ti surface act as heterogeneous nucleation sites, facilitating controlled nanostructure growth and significantly enhancing the solid target's photocatalytic performance. Both the NPs and treated Ti solid target exhibit promising electrochemical activity, with the presence of Au-boosting light-driven processes under UV and visible light. The synergy between the NPs’ optoelectronic behavior and the potential catalytic properties of the modified Ti surfaces creates a versatile platform for applications in photocatalysis, energy conversion, and sensors after further developments. Our findings underscore RLAL as a sustainable, efficient method for creating multielement nanostructures and modifying solid surfaces, advancing their utility in green chemistry and light-driven technologies.