Preparation of Nanoclusters Encapsulating Ultrafine Platinum Nanoparticles

摘要

Platinum colloidal solutions have showed potential applications in various fields such as environment, biomedicine, catalysis, electronics, etc. According to a charateristic of polyvinyl pyrolidone) (PVP) solution in which poly(vinyl pyrrolidone) chains are crosslinked and insoluble at higher temperatures with alkaline medium, we introduce a novel method to prepare nanoclusters like poly(vinyl pyrolidone)-based nanogels containing ultrafine platinum nanoparticles when hexachloroplatinic acid was reduced with mixture of poly(vinyl pyrolidone) and trisodium citrate at higher temperatures in alkaline medium. Formations of platinum nanoparticles and the nanoclusters were investigated under different pH and molecular weight of polyvinyl pyrolidone). The colloidal solutions were characterized by UV-visible, XRD and TEM. Our results indicated that ultrafine platinum nanoparticles arround 2 nm encapsulated in nanoclusters when the preparation was conducted in alkaline media and platinum nanoparticles were produced at smaller size when lower molecular weight of poly( vinyl pyrrolidone) was used.