Room temperature synthesis of colloidal platinum nanoparticles

Efficient preparation of stable dispersions of platinum nanoparticles from platinous chloride (K2PtCl4) was achieved by simultaneous addition of cappi ng polymer material. The size of platinum nanoparticles was controlled by c hanging the ratio of concentration of capping polymer material to the conce ntration of platinum cation used. The morphology of colloidal particles wer e studied by means of UV-visible spectrophotometry and transmission electro n microscopy (TEM). Particle size increased with low reagent concentration. The change in absorption spectra with the particle size was observed, i.e. blue shift attributed to decrease in particle size.