Removing Polyvinylpyrrolidone from Catalytic Pt Nanoparticles without Modification of Superficial Order

Herein, we report a simple methodology for cleaning Pt nanoparticles, prepared by a colloidal synthesis and coated with polyvinylpyrrolidone, without loss of crystalline surface structure. To prove the removal of the polyvinylpirrolidone from a Pt surface without disturbing the superficial order, a cleaning method using a solution of H2O2/H2SO4 was tested successfully for a Pt(111) single-crystal electrode. The decontamination method was then tested for two different types of nanoparticles by mixing the suspension of nanoparticles with H2O2/H2SO4 and subsequent centrifugation. The resulting voltammetric profiles of platinum particles synthesized by the colloidal method employing PVP show a marked presence of the adsorption-state characteristic of (111) ordered surface domains. The presence of the well-ordered domains present on the surface of the nanoparticles was confirmed by using the irreversible adsorption of bismuth, tellurium and germanium.