Synthesis of Small Platinum Cube with Less Than 3 nm by the Control of Growth Kinetics

The preparation of small shape-controlled Pt nanocrystals, which should be an important material such for as catalytic application, is a hot research target pursued by many active groups. We first succeeded in synthesizing a monodispersed Pt cube of 2.8 nm in size with high shape selectivity. Such simultaneous control of both size and shape of a nanocrystal has been successfully achieved by tuning of multiple conditions for the growth kinetics of Pt nuclei during hydrogen reduction of PtCl42- in aqueous N-,N-dimethylformamide (DMF) solution. The key strategy is to produce small Pt nuclei by the consumption of most precursor ions to avoid the excessive growth of Pt nuclei, in conjunction with promoting adsorption of anionic protective and shape-forming agents by the skillful control of the solvent system. We believe that the proposed facile synthetic approach is applicable to prepare various nanocrystals with both controlled size and shape.