Stability of uncapped gold nanoparticles produced via laser reduction in liquid

Nanoparticles are excellent catalysts due to their high surface area volume ratio that results in an increased number of catalytically active sites per unit mass. This plethora highly reactive is often contrast with the catalyst stability. Capping agents used maintain stability against aggregation; they can however have adverse effects on catalytic activity nanoparticles by obstructing reactant access sites. A unique set synthesis methods leverage lasers, such as Laser Reduction Liquid (LRL), capable producing remain stable despite lack capping agent. The mode stabilization for uncapped laser must arise from electrostatic repulsion. There three main hypotheses seek describe source this repulsion: oxidized species at particle surface, adsorbed anions or trapped electrons within particle. Two types LRL particles were analyzed: produced using a pulse duration order ns, and fs. primary difference between these two conditions arose presence (fs) absence (ns) electron rich plasma during nanoparticle synthesis. was investigated zeta potential measurements. It found ns significantly less than fs counterparts. Aggregation kinetics time resolved dynamic light scattering (TR-DLS). Using aggregation measurements, determined DLVO theory. allowed us calculate theoretical density function focus. densities similar which synthesized. These support hypothesis being key nanoparticles.