Pulsed Laser Ablation at Gas/Liquid/Solid Interfaces Controlled via Rotation of a Partially Submerged Disc

Abstract

The increasing interest in various nanoparticles (NPs) with well-defined properties requires their convenient and efficient production. Here, we exploit a new proposed scheme for pulsed laser ablation in liquid (PLAL), where nanosecond laser pulses process a 45° tilted, rotating copper (Cu) disc, partially submerged into ethanol. This disc rotation spreads a thin ethanol layer on its surface. The generated plasma, formed following the laser impact, led to film splashing and caused NP accumulation in the ethanol pool. Analysis of fast camera frames and measured acoustic-wave (AW) amplitudes suggest mechanistic insight and allow optimizing the parameters. The laser fluence, ablation time, and particularly the rotating target speed, controlling the layer thickness, are varied to determine their effect on the ablation products. The observed dependence of the measured AW amplitudes, surface plasmon resonance intensities, and power-specific productivities on laser fluence match the calculation results, accounting for the effective laser energies generating the plasma. This promising technique enables the continuous synthesis of crystalline Cu NPs with high efficiency and concentration, providing a basis for further optimization of solid target ablation toward the achievement of specific particles for various applications.