Preparation of Poly(Cyclodextrin)-Protected Platinum Colloids and Application as Catalysts for Visible-Light-Induced Hydrogen Generation

Abstract

Metal colloids are attracting significant attention because of their uniform size, shape, size distribution in nanometers, and easy preparation process; their impact is evident in the recent developments in nanoscience and nanotechnology. Although protective colloids are often em- ployed to prevent the aggregation of metal colloids, they also promote some of the special properties of metal colloids. Cyclodextrin (CyD) is known to form inclusion complexes with organic compounds in solution. However, platinum colloids are properly stabilized by poly(cyclo- dextrin) (PCyD) not CyD. Platinum colloids protected by PCyD were prepared by the photoreduction of hexachloroplatinic(IV ) acid in the presence of PCyD. The PCyD-protected platinum colloids exhibited higher catalytic activities than the dextran-protected platinum colloids for visible-light-induced hydrogen generation.