Ultrasmall gold nanoparticles with the size controlled by the pores of carbide-derived carbon

Abstract

Gold nanoparticles (Au-NPs) with a narrow size distribution and average sizes ranging from a few Ångströms to several nanometers were selectively adsorbed on porous carbide-derived carbons (CDCs). CDC powders were synthesized by chlorinating several carbide precursors (TiC, Mo2C, B4C, and SiC) at different temperatures (800 C for TiC-CDC, 1100 C for B4C-CDC, 600 and 1200 C for Mo2C-CDC, and 1000 C for SiC-CDC). The size and distribution of the Au-NPs largely reflects the pore size and pore size distribution of the CDC. Catalytic activity of carbon-supported gold was a size-dependent parameter and the highest CO oxidation was identified for the smallest particles. Since the pore size of CDC can be varied from about sub-nanometer to several nanometers with a narrow distribution and the surface chemistry of CDC can be easily modified, the proposed method can be used for selective trapping of a variety of metal and nonmetal nanoparticles for catalytic and other applications. © 2011 by American Scientific Publishers All rights reserved.