One step synthesis of stable nanofluids of Cu, Ag, Au, Ni, Pd, and Pt in PEG using laser ablation in liquids method and study of their capability in solar-thermal conversion

Abstract

Synthesis of pure and stable metallic nanoparticles with a fast, green, and cost-effective method is a challenging topic. Herein, stable nanofluids by the laser ablation in liquids (LAL) are prepared. The prepared nanofluids include Cu, Ag, Au, Ni, Pd, and Pt nanoparticles (having localized surface plasmon resonance (LSPR) property) dispersed in polyethylene glycol (PEG). The average particle and hydrodynamic diameters of ∼ 4.5 nm and ∼ 106 nm for Ag nanoparticles reveal the capping of nanoparticles by PEG which leads to the high stability of the nanofluids. The photo-thermal conversion capability of all the samples is studied. The Ag, Au, and Pd nanofluids show the highest capability in the photo-thermal conversion. For Ag nanofluid, the surface temperature reaches ≅ 52 °C (ΔT ≅ 24 °C) during 60 min sunlight radiation. Moreover, the eligibility of the Ag nanofluid in converting light to heat is examined in different light intensities and various nanoparticle concentrations. For all the synthesized nanofluids, the thermal properties including, stored energy ratio, total stored energy, photo-thermal conversion efficiency, and heat dissipation are calculated and compared. Based on all results, the prepared nanofluids show noticeable eligibilities: simplicity, environmental-friendly, and fast preparation method, no need for stabilizers or hazardous chemicals, thermal durability and stability, and good performance in photo-thermal conversion.