Polyol-Assisted Synthesis of Ni/Cu/Ag Trimetallic Nanoparticles for Nonlinear Optical Applications

Trimetallic nanoparticles (TMNPs) have opened a broad spectrum of applications with a new class of materialistic combinations in several fields from electronics to medicinal and environmental applications. In this work, we report the synthesis and characterization of Ni/Cu/Ag TMNPs using the polyol method and their nonlinear optical (NLO) studies. A broad surface plasmon resonance (SPR) peak at 443 nm evidences the formation of the Ni/Cu/Ag TMNPs with a peak shift compared to their mono- or bimetallic counterparts. The NLO studies showed promising results, indicating that Ni/Cu/Ag TMNPs have potential applications in optoelectronics. The calculated nonlinear absorption coefficient (β) confirmed thermally induced excited-state absorption by the prepared TMNPs. Closed-aperture z-scan analysis demonstrated a self-focusing effect, indicating a nonlinear refractive index (n₂). Further, the suitability of Ni/Cu/Ag TMNPs for optical limiting application is assessed.