Preparation of Gold Nanorods@C Hollow Capsules and Applications in Catalysis

Abstract

Hollow capsules with gold nanorods(GNRs) embedding in the carbon shell were prepared by polypyrrole(PPy) as carbon precursor.The carboxylic-capped polystyrene(PS) nanoparticles were firstly synthesized,then the hexadecyl trimethyl ammonium bromide-stabilized GNRs were self-assembled onto their surface through the electrostatic interaction,and formed PS@ GNRs composites.Next,PPy was coated on the surface of PS@ GNRs composites;meanwhile,GNRs were embedded in the PPy shell.After calcination in nitrogen atmosphere,the PPy shell was carbonized to the carbon shell and the PS nanoparticles decomposed at the same time.During heat-treatment process,GNRs preserved rod-like morphology without aggregations due to the protection of carbon shell.Upon varying the concentration of pyrrole monomer,both PPy and carbon shell thicknesses could be readily turned.The GNRs@ C hollow capsules showed excellent catalytic performance in the reduction of methylene blue with sodium borohydride as reducing agent.