Impacts of various solvents in ultrasonic irradiation and green synthesis of platinum nanoparticle

Platinum nanoparticles (Pt NPs) with excellent physicochemical properties have been produced using various techniques, including sonochemistry method. However, the effect of solvent type on the irradiation power and structure, morphology and colloidal stability of Pt NPs synthesized via sonication has received less attention. In this work, Pt NPs were sonochemically-assisted green synthesized in various solvents (water, ethanol and methanol) using the Prosopis farcta fruits extract (PFFs) as a reducing agent. The structure, morphology and colloidal stability (surface charge) of the synthesized Pt NPs were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Zeta potential, respectively, for exploring the physicochemical properties of Pt NPs. The Pt NPs produced were a face-centred cubic structure of crystalline Pt and mainly semispherically shaped with sizes range from1.6 nm to 5 nm. It was found that the interaction of the solvent with Pt NPs in the presence of ultrasound plays an important role in modulating particle size and surface charge. TEM results demonstrated the smallest NPs size of Pt NPs was acquired in methanol. The stability of Pt NPs in water, ethanol and methanol was -31 mV, +2.14 mV and -6.76 mV, respectively. This shows that the size and surface charge (zeta potential) of Pt NPs depends on the solvent's physical properties (viscosity, boiling point, and polarity).