Catalytic tuning of laser-induced bimetallic core–shell nanoparticles

This study investigates silver–platinum (Ag@Pt and Pt@Ag) core–shell nanoparticles (NPs) synthesized by Q-switched Nd:YAG (1064 nm) laser ablation in deionized water for catalytic applications. Monometallic Ag and Pt NPs were synthesized by ablating the respective metal targets. Core–shell structures were fabricated via sequential ablation, forming Pt shells on Ag cores (5–10 min) and Ag shells on Pt cores. The nanostructures were characterized using UV–Vis spectroscopy, SEM/EDX, XRD, and finite-difference time-domain (FDTD) simulations. UV–Vis spectra showed dual LSPR peaks with Pt red-shift and Ag blue-shift, confirming core–shell formation. FDTD simulations revealed strong near-field enhancement at the interface, promoting charge transfer. The NPs exhibited a crystalline face-centered cubic structure, spherical morphology, and distinct core–shell contrast. Catalytic activity was evaluated via NaBH4-assisted degradation of methylene blue and methyl orange (10−5 M), achieving ≈99–100% degradation with rate constants up to ∼10.9 min−1.