Unconventional Route to Hairy Plasmonic/Semiconductor Core/Shell Nanoparticles with Precisely Controlled Dimensions and Their Use in Solar Energy Conversion

Atom transfer radical polymerization (ATRP) of 4-vinylpyridine, t-butyl acrylate, and styrene in sequential order from a β-cyclodextrin core yielded an amphiphilic star-like triblock copolymer, poly(4-vinylpyridine)-block-poly(t-butyl acrylate)-block-polystyrene (P4VP-b-PtBA-b-PS). Subsequently, star-like triblock copolymer composed of inner hydrophilic P4VP blocks, central hydrophobic PtBA blocks, and outer hydrophobic PS blocks with well-defined molecular architecture and molecular weight of each block was judiciously exploited as nanoreactor for synthesis of precisely shaped hairy plasmonic/semiconductor Au/TiO2 core/shell nanoparticles. The resulting Au/TiO2 nanoparticles were intimately and permanently tethered with outer PS chains that enabled the superior solubility of nanoparticles in nonpolar solvents. The PS chains on the surface of these bifunctional nanoparticles were carbonized by annealing in an inert atmosphere (i.e., yielding carbon-coated Au/TiO2 nanoparticles). In comparison to a widely ...