Facile preparation of Pt hydrosols by dispersing bulk Pt with potential perturbations

Pt hydrosols have been synthesized by dispersing a pure Pt wire in a NaOH solution with square wave potential (SWP) or alternating voltage (AV). The rearrangements of superfacial Pt atoms by repeated and fast electro-redox under the potential perturbations (PPs), coupling with the impetus of concurrent hydrogen gas, account for this novel dispersion of bulk Pt. Using this strategy we are able to realize the green and facile synthesis of clean Pt nanoparticles (NPs) requiring no any precursor ions and reducers in aqueous solution under mild conditions. Moreover, the dispersion of bulk Pt has also been carried out by paired electrolysis with two Pt wires. The as-prepared Pt NPs were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). The Pt NPs exhibit high electrocatalytic activity toward the ethanol electrooxidation and weak surface-enhanced Raman scattering (SERS) signals for adsorbed pyridine.