Sonochemical formation of colloidal platinum

The ultrasound irradiation of aqueous solutions of PtCl2−6 was found to produce colloidal platinum of about 3 nm in diameter. The presence of aliphatic alcohols significantly enhanced the reduction process. It is shown that the extent of reduction of PtCl2−6 in the presence of alcohol is directly related to the Gibbs surface excess of the alcohol at the air-water interface. The significance of this is discussed in relation to ultrasound induced cavitation in solution.